moved the samples in a separate page so it has a summary of all the samples descriptions and so writing references to samples is shorter (@ref page_samples_xxx instead of @ref page_utils_samples_xxx)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@52705 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
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Francesco Montorsi 2008-03-22 17:42:29 +00:00
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@li @subpage page_introduction
@li @subpage page_multiplatform
@li @subpage page_utils
@li @subpage page_samples
@li @subpage page_strategies
@li @subpage page_libs
@li @subpage page_constants

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/////////////////////////////////////////////////////////////////////////////
// Name: samples.h
// Purpose: Samples page of the Doxygen manual
// Author: wxWidgets team
// RCS-ID: $Id: utilities.h 52634 2008-03-20 13:45:17Z VS $
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
/**
@page page_samples Samples supplied with wxWidgets
Probably the best way to learn wxWidgets is by reading the source of some 70+
samples provided with it. Many aspects of wxWidgets programming can be learnt
from them, but sometimes it is not simple to just choose the right sample to
look at. This overview aims at describing what each sample does/demonstrates to
make it easier to find the relevant one if a simple grep through all sources
didn't help. They also provide some notes about using the samples and what
features of wxWidgets are they supposed to test.
There are currently more than 50 different samples as part of wxWidgets and
this list is not complete. You should start your tour of wxWidgets with the
minimal sample which is the wxWidgets version of
"Hello, world!". It shows the basic structure of wxWidgets program and is the
most commented sample of all - looking at its source code is recommended.
The next most useful samples are probably widgets
and controls which show many of wxWidgets native and
generic controls, such as buttons, listboxes, checkboxes, comboboxes etc.
Other, more complicated controls, have their own samples. In this category you
may find the following samples showing the corresponding controls:
@li wxCalendarCtrl: @ref page_samples_calendar
@li wxListCtrl: @ref page_samples_listctrl
@li wxTreeCtrl: @ref page_samples_treectrl
@li wxGrid: @ref page_samples_grid
Finally, it might be helpful to do a search in the entire sample directory if
you can't find the sample showing the control you are interested in by
name. Most classes contained in wxWidgets occur in at least one of the samples.
@beginInvisibleTable
<tr><td>
@li @ref page_samples_minimal
@li @ref page_samples_animate
@li @ref page_samples_artprovider
@li @ref page_samples_calendar
@li @ref page_samples_config
@li @ref page_samples_controls
@li @ref page_samples_debugrpt
@li @ref page_samples_dialogs
@li @ref page_samples_dialup
@li @ref page_samples_dnd
@li @ref page_samples_event
@li @ref page_samples_except
@li @ref page_samples_exec
@li @ref page_samples_font
@li @ref page_samples_grid
@li @ref page_samples_html
@li @ref page_samples_image
</td><td>
@li @ref page_samples_internat
@li @ref page_samples_layout
@li @ref page_samples_listctrl
@li @ref page_samples_mediaplayer
@li @ref page_samples_notebook
@li @ref page_samples_render
@li @ref page_samples_scrollsub
@li @ref page_samples_sockets
@li @ref page_samples_sound
@li @ref page_samples_statbar
@li @ref page_samples_taborder
@li @ref page_samples_text
@li @ref page_samples_thread
@li @ref page_samples_toolbar
@li @ref page_samples_treectrl
@li @ref page_samples_widgets
@li @ref page_samples_wizard
</td></tr>
@endTable
<hr>
@section page_samples_minimal Minimal sample
The minimal sample is what most people will know under the term Hello World,
i.e. a minimal program that doesn't demonstrate anything apart from what is
needed to write a program that will display a "hello" dialog. This is usually
a good starting point for learning how to use wxWidgets.
@section page_samples_animate Animate sample
The @c animate sample shows how you can use wxAnimationCtrl
control and shows concept of a platform-dependent animation encapsulated
in wxAnimation.
@section page_samples_artprovider Art provider sample
The @c artprov sample shows how you can customize the look of standard
wxWidgets dialogs by replacing default bitmaps/icons with your own versions.
It also shows how you can use wxArtProvider to
get stock bitmaps for use in your application.
@section page_samples_calendar Calendar sample
This font shows the calendar control in action. It
shows how to configure the control (see the different options in the calendar
menu) and also how to process the notifications from it.
@section page_samples_config Config sample
This sample demonstrates the wxConfig classes in a platform
independent way, i.e. it uses text based files to store a given configuration under
Unix and uses the Registry under Windows.
See @ref overview_config for the descriptions of all features of this class.
@section page_samples_controls Controls sample
The controls sample is the main test program for most simple controls used in
wxWidgets. The sample tests their basic functionality, events, placement,
modification in terms of colour and font as well as the possibility to change
the controls programmatically, such as adding an item to a list box etc. Apart
from that, the sample uses a wxNotebook and tests most
features of this special control (using bitmap in the tabs, using
wxSizer instances and wxLayoutConstraints within notebook pages, advancing pages
programmatically and vetoing a page change by intercepting the wxNotebookEvent.
The various controls tested are listed here:
@li wxButton
@li wxBitmapButton
@li wxCheckBox
@li wxChoice
@li wxComboBox
@li wxGauge
@li wxStaticBox
@li wxListBox
@li wxSpinCtrl
@li wxSpinButton
@li wxStaticText
@li wxStaticBitmap
@li wxRadioBox
@li wxRadioButton
@li wxSlider
@section page_samples_debugrpt DebugRpt sample
This sample shows how to use wxDebugReport class to
generate a debug report in case of a program crash or otherwise. On start up,
it proposes to either crash itself (by dereferencing a NULL pointer) or
generate debug report without doing it. Next it initializes the debug report
with standard information adding a custom file to it (just a timestamp) and
allows to view the information gathered using
wxDebugReportPreview.
For the report processing part of the sample to work you should make available
a Web server accepting form uploads, otherwise
wxDebugReportUpload will report an error.
@section page_samples_dialogs Dialogs sample
This sample shows how to use the common dialogs available from wxWidgets. These
dialogs are described in detail in the @ref overview_cmndlg.
@section page_samples_dialup Dialup sample
This sample shows the wxDialUpManager
class. In the status bar, it displays the information gathered through its
interface: in particular, the current connection status (online or offline) and
whether the connection is permanent (in which case a string `LAN' appears in
the third status bar field - but note that you may be on a LAN not
connected to the Internet, in which case you will not see this) or not.
Using the menu entries, you may also dial or hang up the line if you have a
modem attached and (this only makes sense for Windows) list the available
connections.
@section page_samples_dnd DnD sample
This sample shows both clipboard and drag and drop in action. It is quite non
trivial and may be safely used as a basis for implementing the clipboard and
drag and drop operations in a real-life program.
When you run the sample, its screen is split in several parts. On the top,
there are two listboxes which show the standard derivations of
wxDropTarget:
wxTextDropTarget and
wxFileDropTarget.
The middle of the sample window is taken by the log window which shows what is
going on (of course, this only works in debug builds) and may be helpful to see
the sequence of steps of data transfer.
Finally, the last part is used for dragging text from it to either one of the
listboxes (only one will accept it) or another application. The last
functionality available from the main frame is to paste a bitmap from the
clipboard (or, in the case of the Windows version, also a metafile) - it will be
shown in a new frame.
So far, everything we mentioned was implemented with minimal amount of code
using standard wxWidgets classes. The more advanced features are demonstrated
if you create a shape frame from the main frame menu. A shape is a geometric
object which has a position, size and color. It models some
application-specific data in this sample. A shape object supports its own
private wxDataFormat which means that you may cut and
paste it or drag and drop (between one and the same or different shapes) from
one sample instance to another (or the same). However, chances are that no
other program supports this format and so shapes can also be rendered as
bitmaps which allows them to be pasted/dropped in many other applications
(and, under Windows, also as metafiles which are supported by most of Windows
programs as well - try Write/Wordpad, for example).
Take a look at DnDShapeDataObject class to see how you may use
wxDataObject to achieve this.
@section page_samples_event Event sample
The event sample demonstrates various features of the wxWidgets events. It
shows using dynamic events and connecting/disconnecting the event handlers
during run time and also using
PushEventHandler() and
PopEventHandler().
@section page_samples_except Except(ions) sample
This very simple sample shows how to use C++ exceptions in wxWidgets programs,
i.e. where to catch the exception which may be thrown by the program code. It
doesn't do anything very exciting by itself, you need to study its code to
understand what goes on.
You need to build the library with @c wxUSE_EXCEPTIONS being set to @c 1
and compile your code with C++ exceptions support to be able to build this
sample.
@section page_samples_exec Exec sample
The exec sample demonstrates the wxExecute and
wxShell functions. Both of them are used to execute the
external programs and the sample shows how to do this synchronously (waiting
until the program terminates) or asynchronously (notification will come later).
It also shows how to capture the output of the child process in both
synchronous and asynchronous cases and how to kill the processes with
wxProcess::Kill and test for their existence with
wxProcess::Exists.
@section page_samples_font Font sample
The font sample demonstrates wxFont,
wxFontEnumerator and
wxFontMapper classes. It allows you to see the fonts
available (to wxWidgets) on the computer and shows all characters of the
chosen font as well.
@section page_samples_grid Grid sample
@todo WRITE THIS DESCRIPTION.
@section page_samples_html HTML samples
Eight HTML samples (you can find them in directory @c samples/html)
cover all features of the HTML sub-library.
@li @b Test demonstrates how to create wxHtmlWindow
and also shows most supported HTML tags.
@li @b Widget shows how you can embed ordinary controls or windows within an
HTML page. It also nicely explains how to write new tag handlers and extend
the library to work with unsupported tags.
@li @b About may give you an idea how to write good-looking About boxes.
@li @b Zip demonstrates use of virtual file systems in wxHTML. The zip archives
handler (ships with wxWidgets) allows you to access HTML pages stored
in a compressed archive as if they were ordinary files.
@li @b Virtual is yet another virtual file systems demo. This one generates pages at run-time.
You may find it useful if you need to display some reports in your application.
@li @b Printing explains use of wxHtmlEasyPrinting
class which serves as as-simple-as-possible interface for printing HTML
documents without much work. In fact, only few function calls are sufficient.
@li @b Help and @b Helpview are variations on displaying HTML help
(compatible with MS HTML Help Workshop). @e Help shows how to embed
wxHtmlHelpController in your application
while @e Helpview is a simple tool that only pops up the help window and
displays help books given at command line.
@section page_samples_image Image sample
The image sample demonstrates use of the wxImage class
and shows how to download images in a variety of formats, currently PNG, GIF,
TIFF, JPEG, BMP, PNM and PCX. The top of the sample shows two rectangles, one
of which is drawn directly in the window, the other one is drawn into a
wxBitmap, converted to a wxImage, saved as a PNG image
and then reloaded from the PNG file again so that conversions between wxImage
and wxBitmap as well as loading and saving PNG files are tested.
At the bottom of the main frame there is a test for using a monochrome bitmap by
drawing into a wxMemoryDC. The bitmap is then drawn
specifying the foreground and background colours with
wxDC::SetTextForeground and
wxDC::SetTextBackground (on the left). The
bitmap is then converted to a wxImage and the foreground colour (black) is
replaced with red using wxImage::Replace.
This sample also contains the code for testing the image rotation and resizing
and using raw bitmap access, see the corresponding menu commands.
@section page_samples_internat Internat(ionalization) sample
The not very clearly named internat sample demonstrates the wxWidgets
internationalization (i18n for short from now on) features. To be more
precise, it only shows localization support, i.e. support for translating the
program messages into another language while true i18n would also involve
changing the other aspects of the programs behaviour.
More information about this sample can be found in the @c readme.txt file in
its directory. Please also see the @ref overview_i18n.
@section page_samples_layout Layout sample
The layout sample demonstrates the two different layout systems offered
by wxWidgets. When starting the program, you will see a frame with some
controls and some graphics. The controls will change their size whenever
you resize the entire frame and the exact behaviour of the size changes
is determined using the wxLayoutConstraints
class. See also the overview and the
wxIndividualLayoutConstraint
class for further information.
The menu in this sample offers two more tests, one showing how to use
a wxBoxSizer in a simple dialog and the other one
showing how to use sizers in connection with a wxNotebook
class. See also wxSizer.
@section page_samples_listctrl Listctrl sample
This sample shows the wxListCtrl control. Different modes
supported by the control (list, icons, small icons, report) may be chosen from
the menu.
The sample also provides some timings for adding/deleting/sorting a lot of
(several thousands) items into the control.
@section page_samples_mediaplayer Mediaplayer sample
This sample demonstrates how to use all the features of
wxMediaCtrl and play various types of sound, video,
and other files.
It replaces the old dynamic sample.
@section page_samples_notebook Notebook sample
This samples shows wxBookCtrl family of controls.
Although initially it was written to demonstrate wxNotebook
only, it can now be also used to see wxListbook,
wxChoicebook and wxTreebook in action.
Test each of the controls, their orientation, images and pages using
commands through menu.
@section page_samples_render Render sample
This sample shows how to replace the default wxWidgets
renderer and also how to write a shared library
(DLL) implementing a renderer and load and unload it during the run-time.
@section page_samples_scrollsub Scroll subwindow sample
This sample demonstrates use of the wxScrolledWindow
class including placing subwindows into it and drawing simple graphics. It uses the
SetTargetWindow method and thus the effect
of scrolling does not show in the scrolled window itself, but in one of its subwindows.
Additionally, this samples demonstrates how to optimize drawing operations in wxWidgets,
in particular using the wxWindow::IsExposed method with
the aim to prevent unnecessary drawing in the window and thus reducing or removing
flicker on screen.
@section page_samples_sockets Sockets sample
The sockets sample demonstrates how to use the communication facilities
provided by wxSocket. There are two different
applications in this sample: a server, which is implemented using a
wxSocketServer object, and a client, which
is implemented as a wxSocketClient.
The server binds to the local address, using TCP port number 3000,
sets up an event handler to be notified of incoming connection requests
(@b wxSOCKET_CONNECTION events), and sits there, waiting for clients
(@e listening, in socket parlance). For each accepted connection,
a new wxSocketBase object is created. These
socket objects are independent from the server that created them, so
they set up their own event handler, and then request to be notified
of @b wxSOCKET_INPUT (incoming data) or @b wxSOCKET_LOST
(connection closed at the remote end) events. In the sample, the event
handler is the same for all connections; to find out which socket the
event is addressed to, the GetSocket function
is used.
Although it might take some time to get used to the event-oriented
system upon which wxSocket is built, the benefits are many. See, for
example, that the server application, while being single-threaded
(and of course without using fork() or ugly select() loops) can handle
an arbitrary number of connections.
The client starts up unconnected, so you can use the Connect... option
to specify the address of the server you are going to connect to (the
TCP port number is hard-coded as 3000). Once connected, a number of
tests are possible. Currently, three tests are implemented. They show
how to use the basic IO calls in wxSocketBase,
such as wxSocketBase::Read, wxSocketBase::Write,
wxSocketBase::ReadMsg and wxSocketBase::WriteMsg,
and how to set up the correct IO flags depending on what you are going to
do. See the comments in the code for more information. Note that because
both clients and connection objects in the server set up an event handler
to catch @b wxSOCKET_LOST events, each one is immediately notified
if the other end closes the connection.
There is also a URL test which shows how to use
the wxURL class to fetch data from a given URL.
The sockets sample is work in progress. Some things to do:
@li More tests for basic socket functionality.
@li More tests for protocol classes (wxProtocol and its descendants).
@li Tests for the recently added (and still in alpha stage) datagram sockets.
@li New samples which actually do something useful (suggestions accepted).
@section page_samples_sound Sound sample
The @c sound sample shows how to use wxSound for simple
audio output (e.g. notifications).
@section page_samples_statbar Statbar sample
This sample shows how to create and use wxStatusBar. Although most of the
samples have a statusbar, they usually only create a default one and only
do it once.
Here you can see how to recreate the statusbar (with possibly different number
of fields) and how to use it to show icons/bitmaps and/or put arbitrary
controls into it.
@section page_samples_taborder Tab order sample
This sample allows to test keyboard navigation (mostly done using the
@c TAB key, hence the sample name) between different controls.
It shows the use of wxWindow::MoveBeforeInTabOrder() and
MoveAfterInTabOrder() methods to change
the default order of the windows in the navigation chain and of
wxWindow::Navigate() for moving focus along this
chain.
@section page_samples_text Text sample
This sample demonstrates four features: firstly the use and many variants of
the wxTextCtrl class (single line, multi line, read only,
password, ignoring TAB, ignoring ENTER).
Secondly it shows how to intercept a wxKeyEvent in both
the raw form using the @c EVT_KEY_UP and @c EVT_KEY_DOWN macros and the
higher level from using the @c EVT_CHAR macro. All characters will be logged
in a log window at the bottom of the main window. By pressing some of the function
keys, you can test some actions in the text ctrl as well as get statistics on the
text ctrls, which is useful for testing if these statistics actually are correct.
Thirdly, on platforms which support it, the sample will offer to copy text to the
wxClipboard and to paste text from it. The GTK version will
use the so called PRIMARY SELECTION, which is the pseudo clipboard under X and
best known from pasting text to the XTerm program.
Last not least: some of the text controls have tooltips and the sample also shows
how tooltips can be centrally disabled and their latency controlled.
@section page_samples_thread Thread sample
This sample demonstrates use of threads in connection with GUI programs.
There are two fundamentally different ways to use threads in GUI programs and
either way has to take care of the fact that the GUI library itself usually
is not multi-threading safe, i.e. that it might crash if two threads try to
access the GUI class simultaneously. One way to prevent that is have a normal
GUI program in the main thread and some worker threads which work in the
background. In order to make communication between the main thread and the
worker threads possible, wxWidgets offers the wxPostEvent
function and this sample makes use of this function.
The other way to use a so called Mutex (such as those offered in the wxMutex
class) that prevent threads from accessing the GUI classes as long as any other
thread accesses them. For this, wxWidgets has the wxMutexGuiEnter
and wxMutexGuiLeave functions, both of which are
used and tested in the sample as well.
See also @ref overview_thread and wxThread.
@section page_samples_toolbar Toolbar sample
The toolbar sample shows the wxToolBar class in action.
The following things are demonstrated:
@li Creating the toolbar using wxToolBar::AddTool and wxToolBar::AddControl: see
MyApp::InitToolbar in the sample.
@li Using @c EVT_UPDATE_UI handler for automatically enabling/disabling
toolbar buttons without having to explicitly call EnableTool. This is done
in MyFrame::OnUpdateCopyAndCut.
@li Using wxToolBar::DeleteTool and wxToolBar::InsertTool to dynamically update the
toolbar.
Some buttons in the main toolbar are check buttons, i.e. they stay checked when
pressed. On the platforms which support it, the sample also adds a combobox
to the toolbar showing how you can use arbitrary controls and not only buttons
in it.
If you toggle another toolbar in the sample (using @c Ctrl-A) you will also
see the radio toolbar buttons in action: the first three buttons form a radio
group, i.e. checking any of them automatically unchecks the previously
checked one.
@section page_samples_treectrl Treectrl sample
This sample demonstrates using the wxTreeCtrl class. Here
you may see how to process various notification messages sent by this control
and also when they occur (by looking at the messages in the text control in
the bottom part of the frame).
Adding, inserting and deleting items and branches from the tree as well as
sorting (in default alphabetical order as well as in custom one) is
demonstrated here as well - try the corresponding menu entries.
@section page_samples_widgets Widgets sample
The widgets sample is the main presentation program for most simple and advanced
native controls and complex generic widgets provided by wxWidgets.
The sample tests their basic functionality, events, placement, modification
in terms of colour and font as well as the possibility to change
the controls programmatically, such as adding an item to a list box etc.
All widgets are categorized for easy browsing.
@section page_samples_wizard Wizard sample
This sample shows the so-called wizard dialog (implemented using
wxWizard and related classes). It shows almost all
features supported:
@li Using bitmaps with the wizard and changing them depending on the page
shown (notice that wxValidationPage in the sample has a different image from
the other ones)
@li Using TransferDataFromWindow
to verify that the data entered is correct before passing to the next page
(done in wxValidationPage which forces the user to check a checkbox before
continuing).
@li Using more elaborated techniques to allow returning to the previous
page, but not continuing to the next one or vice versa (in wxRadioboxPage)
@li This (wxRadioboxPage) page also shows how the page may process the
@e Cancel button itself instead of relying on the wizard parent to do it.
@li Normally, the order of the pages in the wizard is known at compile-time,
but sometimes it depends on the user choices: wxCheckboxPage shows how to
dynamically decide which page to display next (see also
wxWizardPage)
*/

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/**
@page page_utils Utilities and samples supplied with wxWidgets
@page page_utils Utilities supplied with wxWidgets
@li @ref page_utils_utils
@li @ref page_utils_samples
In addition to the wxWidgets libraries (see @ref page_libs), some utilities
are available to the users in the @c utils hierarchy (even if some of them are
explicitely coinceived for wxWidgets maintainance and will probably be of
little use to others).
Please note that these utilities do represent only the utilities developed
and maintained by the wxWidgets team.
There are lots of other user-contributed and user-maintained packages;
see the wxWidgets download page: http://www.wxwidgets.org/downloads
or directly http://wxcode.sourceforge.net or http://www.wxcommunity.com/ .
<hr>
@li @ref page_utils_emulator
@li @ref page_utils_helpgen
@li @ref page_utils_helpview
@li @ref page_utils_hhp2cached
@li @ref page_utils_tex2rtf
@li @ref page_utils_wxrc
@section page_utils_utils Utilities
<hr>
In addition to the @ref page_libs, some
additional utilities are supplied in the @c utils hierarchy.
For other user-contributed packages, please see the Contributions page
on the wxWidgets Web site http://www.wxwidgets.org.
@section page_utils_emulator Emulator
Xnest-based display emulator for X11-based PDA applications.
@subsection page_utils_utils_helpview Helpview
<!-- On some systems, the Xnest window does not synchronise with the
'skin' window. THIS ISN'T THE PLACE FOR THIS STATEMENT I THINK -->
Helpview is a program for displaying wxWidgets HTML
Help files. In many cases, you may wish to use the wxWidgets HTML
Help classes from within your application, but this provides a
handy stand-alone viewer. See @ref overview_html for more details.
You can find it in @c samples/html/helpview.
This program can be found in @c utils/emulator.
@subsection page_utils_utils_tex2rtf Tex2RTF
Supplied with wxWidgets is a utility called Tex2RTF for
converting @e LaTeX manuals HTML, MS HTML Help, wxHTML Help, RTF, and Windows
Help RTF formats. Tex2RTF was used for the wxWidgets manuals and can be used
independently by authors wishing to create on-line and printed manuals from the
same @e LaTeX source. Please see the separate documentation for Tex2RTF.
You can find it under @c utils/tex2rtf.
@section page_utils_helpgen Helpgen
@subsection page_utils_utils_helpgen Helpgen
Helpgen takes C++ header files and generates a Tex2RTF-compatible
documentation file for each class it finds, using comments as appropriate.
This is a good way to start a reference for a set of classes.
Helpgen takes C++ header files and generates a Tex2RTF-compatible
documentation file for each class it finds, using comments as appropriate.
This is a good way to start a reference for a set of classes.
Helpgen can be found in @c utils/HelpGen.
Helpgen can be found in @c utils/HelpGen.
@subsection page_utils_utils_emulator Emulator
Xnest-based display emulator for X11-based PDA applications.
On some systems, the Xnest window does not synchronise with the
'skin' window. This program can be found in @c utils/emulator.
@section page_utils_helpview Helpview
Helpview is a program for displaying wxWidgets HTML
Help files. In many cases, you may wish to use the wxWidgets HTML
Help classes from within your application, but this provides a
handy stand-alone viewer. See @ref overview_html for more details.
You can find Helpview in @c utils/helpview.
@section page_utils_samples Samples
@section page_utils_hhp2cached HHP2Cached
Probably the best way to learn wxWidgets is by reading the source of some 50+
samples provided with it. Many aspects of wxWidgets programming can be learnt
from them, but sometimes it is not simple to just choose the right sample to
look at. This overview aims at describing what each sample does/demonstrates to
make it easier to find the relevant one if a simple grep through all sources
didn't help. They also provide some notes about using the samples and what
features of wxWidgets are they supposed to test.
This utility creates a "cached" version of a @c .hhp file; using cached @c .hhp
files in wxHtmlHelpController can drammatically improve the performances
of the help viewer. See wxHtmlHelpController for more details.
There are currently more than 50 different samples as part of wxWidgets and
this list is not complete. You should start your tour of wxWidgets with the
minimal sample which is the wxWidgets version of
"Hello, world!". It shows the basic structure of wxWidgets program and is the
most commented sample of all - looking at its source code is recommended.
You can find HHP2Cached in @c utils/helpview.
The next most useful samples are probably widgets
and controls which show many of wxWidgets native and
generic controls, such as buttons, listboxes, checkboxes, comboboxes etc.
Other, more complicated controls, have their own samples. In this category you
may find the following samples showing the corresponding controls:
@section page_utils_tex2rtf Tex2RTF
@li wxCalendarCtrl: @ref page_utils_samples_calendar
@li wxListCtrl: @ref page_utils_samples_listctrl
@li wxTreeCtrl: @ref page_utils_samples_treectrl
@li wxGrid: @ref page_utils_samples_grid
Supplied with wxWidgets is a utility called Tex2RTF for
converting @e LaTeX manuals HTML, MS HTML Help, wxHTML Help, RTF, and Windows
Help RTF formats. Tex2RTF was used for the wxWidgets manuals and can be used
independently by authors wishing to create on-line and printed manuals from the
same @e LaTeX source. Please see the separate documentation for Tex2RTF.
Finally, it might be helpful to do a search in the entire sample directory if
you can't find the sample showing the control you are interested in by
name. Most classes contained in wxWidgets occur in at least one of the samples.
You can find it under @c utils/tex2rtf.
@subsection page_utils_samples_minimal Minimal sample
@section page_utils_wxrc WxRC
The minimal sample is what most people will know under the term Hello World,
i.e. a minimal program that doesn't demonstrate anything apart from what is
needed to write a program that will display a "hello" dialog. This is usually
a good starting point for learning how to use wxWidgets.
This utility allows the user to compile @e binary versions of their XRC files,
which are compressed and can be loaded faster than plain XRC files.
See @ref overview_xrc for more info.
You can find it under @c utils/wxrc.
@subsection page_utils_samples_animate Animate sample
The @c animate sample shows how you can use wxAnimationCtrl
control and shows concept of a platform-dependent animation encapsulated
in wxAnimation.
@subsection page_utils_samples_artprovider Art provider sample
The @c artprov sample shows how you can customize the look of standard
wxWidgets dialogs by replacing default bitmaps/icons with your own versions.
It also shows how you can use wxArtProvider to
get stock bitmaps for use in your application.
@subsection page_utils_samples_calendar Calendar sample
This font shows the calendar control in action. It
shows how to configure the control (see the different options in the calendar
menu) and also how to process the notifications from it.
@subsection page_utils_samples_config Config sample
This sample demonstrates the wxConfig classes in a platform
independent way, i.e. it uses text based files to store a given configuration under
Unix and uses the Registry under Windows.
See @ref overview_config for the descriptions of all features of this class.
@subsection page_utils_samples_controls Controls sample
The controls sample is the main test program for most simple controls used in
wxWidgets. The sample tests their basic functionality, events, placement,
modification in terms of colour and font as well as the possibility to change
the controls programmatically, such as adding an item to a list box etc. Apart
from that, the sample uses a wxNotebook and tests most
features of this special control (using bitmap in the tabs, using
wxSizer instances and wxLayoutConstraints within notebook pages, advancing pages
programmatically and vetoing a page change by intercepting the wxNotebookEvent.
The various controls tested are listed here:
@li wxButton
@li wxBitmapButton
@li wxCheckBox
@li wxChoice
@li wxComboBox
@li wxGauge
@li wxStaticBox
@li wxListBox
@li wxSpinCtrl
@li wxSpinButton
@li wxStaticText
@li wxStaticBitmap
@li wxRadioBox
@li wxRadioButton
@li wxSlider
@subsection page_utils_samples_debugrpt DebugRpt sample
This sample shows how to use wxDebugReport class to
generate a debug report in case of a program crash or otherwise. On start up,
it proposes to either crash itself (by dereferencing a NULL pointer) or
generate debug report without doing it. Next it initializes the debug report
with standard information adding a custom file to it (just a timestamp) and
allows to view the information gathered using
wxDebugReportPreview.
For the report processing part of the sample to work you should make available
a Web server accepting form uploads, otherwise
wxDebugReportUpload will report an error.
@subsection page_utils_samples_dialogs Dialogs sample
This sample shows how to use the common dialogs available from wxWidgets. These
dialogs are described in detail in the @ref overview_cmndlg.
@subsection page_utils_samples_dialup Dialup sample
This sample shows the wxDialUpManager
class. In the status bar, it displays the information gathered through its
interface: in particular, the current connection status (online or offline) and
whether the connection is permanent (in which case a string `LAN' appears in
the third status bar field - but note that you may be on a LAN not
connected to the Internet, in which case you will not see this) or not.
Using the menu entries, you may also dial or hang up the line if you have a
modem attached and (this only makes sense for Windows) list the available
connections.
@subsection page_utils_samples_dnd DnD sample
This sample shows both clipboard and drag and drop in action. It is quite non
trivial and may be safely used as a basis for implementing the clipboard and
drag and drop operations in a real-life program.
When you run the sample, its screen is split in several parts. On the top,
there are two listboxes which show the standard derivations of
wxDropTarget:
wxTextDropTarget and
wxFileDropTarget.
The middle of the sample window is taken by the log window which shows what is
going on (of course, this only works in debug builds) and may be helpful to see
the sequence of steps of data transfer.
Finally, the last part is used for dragging text from it to either one of the
listboxes (only one will accept it) or another application. The last
functionality available from the main frame is to paste a bitmap from the
clipboard (or, in the case of the Windows version, also a metafile) - it will be
shown in a new frame.
So far, everything we mentioned was implemented with minimal amount of code
using standard wxWidgets classes. The more advanced features are demonstrated
if you create a shape frame from the main frame menu. A shape is a geometric
object which has a position, size and color. It models some
application-specific data in this sample. A shape object supports its own
private wxDataFormat which means that you may cut and
paste it or drag and drop (between one and the same or different shapes) from
one sample instance to another (or the same). However, chances are that no
other program supports this format and so shapes can also be rendered as
bitmaps which allows them to be pasted/dropped in many other applications
(and, under Windows, also as metafiles which are supported by most of Windows
programs as well - try Write/Wordpad, for example).
Take a look at DnDShapeDataObject class to see how you may use
wxDataObject to achieve this.
@subsection page_utils_samples_event Event sample
The event sample demonstrates various features of the wxWidgets events. It
shows using dynamic events and connecting/disconnecting the event handlers
during run time and also using
PushEventHandler() and
PopEventHandler().
@subsection page_utils_samples_except Except(ions) sample
This very simple sample shows how to use C++ exceptions in wxWidgets programs,
i.e. where to catch the exception which may be thrown by the program code. It
doesn't do anything very exciting by itself, you need to study its code to
understand what goes on.
You need to build the library with @c wxUSE_EXCEPTIONS being set to @c 1
and compile your code with C++ exceptions support to be able to build this
sample.
@subsection page_utils_samples_exec Exec sample
The exec sample demonstrates the wxExecute and
wxShell functions. Both of them are used to execute the
external programs and the sample shows how to do this synchronously (waiting
until the program terminates) or asynchronously (notification will come later).
It also shows how to capture the output of the child process in both
synchronous and asynchronous cases and how to kill the processes with
wxProcess::Kill and test for their existence with
wxProcess::Exists.
@subsection page_utils_samples_font Font sample
The font sample demonstrates wxFont,
wxFontEnumerator and
wxFontMapper classes. It allows you to see the fonts
available (to wxWidgets) on the computer and shows all characters of the
chosen font as well.
@subsection page_utils_samples_grid Grid sample
TODO.
@subsection page_utils_samples_html HTML samples
Eight HTML samples (you can find them in directory @c samples/html)
cover all features of the HTML sub-library.
@li @b Test demonstrates how to create wxHtmlWindow
and also shows most supported HTML tags.
@li @b Widget shows how you can embed ordinary controls or windows within an
HTML page. It also nicely explains how to write new tag handlers and extend
the library to work with unsupported tags.
@li @b About may give you an idea how to write good-looking About boxes.
@li @b Zip demonstrates use of virtual file systems in wxHTML. The zip archives
handler (ships with wxWidgets) allows you to access HTML pages stored
in a compressed archive as if they were ordinary files.
@li @b Virtual is yet another virtual file systems demo. This one generates pages at run-time.
You may find it useful if you need to display some reports in your application.
@li @b Printing explains use of wxHtmlEasyPrinting
class which serves as as-simple-as-possible interface for printing HTML
documents without much work. In fact, only few function calls are sufficient.
@li @b Help and @b Helpview are variations on displaying HTML help
(compatible with MS HTML Help Workshop). @e Help shows how to embed
wxHtmlHelpController in your application
while @e Helpview is a simple tool that only pops up the help window and
displays help books given at command line.
@subsection page_utils_samples_image Image sample
The image sample demonstrates use of the wxImage class
and shows how to download images in a variety of formats, currently PNG, GIF,
TIFF, JPEG, BMP, PNM and PCX. The top of the sample shows two rectangles, one
of which is drawn directly in the window, the other one is drawn into a
wxBitmap, converted to a wxImage, saved as a PNG image
and then reloaded from the PNG file again so that conversions between wxImage
and wxBitmap as well as loading and saving PNG files are tested.
At the bottom of the main frame there is a test for using a monochrome bitmap by
drawing into a wxMemoryDC. The bitmap is then drawn
specifying the foreground and background colours with
wxDC::SetTextForeground and
wxDC::SetTextBackground (on the left). The
bitmap is then converted to a wxImage and the foreground colour (black) is
replaced with red using wxImage::Replace.
This sample also contains the code for testing the image rotation and resizing
and using raw bitmap access, see the corresponding menu commands.
@subsection page_utils_samples_internat Internat(ionalization) sample
The not very clearly named internat sample demonstrates the wxWidgets
internationalization (i18n for short from now on) features. To be more
precise, it only shows localization support, i.e. support for translating the
program messages into another language while true i18n would also involve
changing the other aspects of the programs behaviour.
More information about this sample can be found in the @c readme.txt file in
its directory. Please also see the @ref overview_i18n.
@subsection page_utils_samples_layout Layout sample
The layout sample demonstrates the two different layout systems offered
by wxWidgets. When starting the program, you will see a frame with some
controls and some graphics. The controls will change their size whenever
you resize the entire frame and the exact behaviour of the size changes
is determined using the wxLayoutConstraints
class. See also the overview and the
wxIndividualLayoutConstraint
class for further information.
The menu in this sample offers two more tests, one showing how to use
a wxBoxSizer in a simple dialog and the other one
showing how to use sizers in connection with a wxNotebook
class. See also wxSizer.
@subsection page_utils_samples_listctrl Listctrl sample
This sample shows the wxListCtrl control. Different modes
supported by the control (list, icons, small icons, report) may be chosen from
the menu.
The sample also provides some timings for adding/deleting/sorting a lot of
(several thousands) items into the control.
@subsection page_utils_samples_mediaplayer Mediaplayer sample
This sample demonstrates how to use all the features of
wxMediaCtrl and play various types of sound, video,
and other files.
It replaces the old dynamic sample.
@subsection page_utils_samples_notebook Notebook sample
This samples shows wxBookCtrl family of controls.
Although initially it was written to demonstrate wxNotebook
only, it can now be also used to see wxListbook,
wxChoicebook and wxTreebook in action.
Test each of the controls, their orientation, images and pages using
commands through menu.
@subsection page_utils_samples_render Render sample
This sample shows how to replace the default wxWidgets
renderer and also how to write a shared library
(DLL) implementing a renderer and load and unload it during the run-time.
@subsection page_utils_samples_scrollsub Scroll subwindow sample
This sample demonstrates use of the wxScrolledWindow
class including placing subwindows into it and drawing simple graphics. It uses the
SetTargetWindow method and thus the effect
of scrolling does not show in the scrolled window itself, but in one of its subwindows.
Additionally, this samples demonstrates how to optimize drawing operations in wxWidgets,
in particular using the wxWindow::IsExposed method with
the aim to prevent unnecessary drawing in the window and thus reducing or removing
flicker on screen.
@subsection page_utils_samples_sockets Sockets sample
The sockets sample demonstrates how to use the communication facilities
provided by wxSocket. There are two different
applications in this sample: a server, which is implemented using a
wxSocketServer object, and a client, which
is implemented as a wxSocketClient.
The server binds to the local address, using TCP port number 3000,
sets up an event handler to be notified of incoming connection requests
(@b wxSOCKET_CONNECTION events), and sits there, waiting for clients
(@e listening, in socket parlance). For each accepted connection,
a new wxSocketBase object is created. These
socket objects are independent from the server that created them, so
they set up their own event handler, and then request to be notified
of @b wxSOCKET_INPUT (incoming data) or @b wxSOCKET_LOST
(connection closed at the remote end) events. In the sample, the event
handler is the same for all connections; to find out which socket the
event is addressed to, the GetSocket function
is used.
Although it might take some time to get used to the event-oriented
system upon which wxSocket is built, the benefits are many. See, for
example, that the server application, while being single-threaded
(and of course without using fork() or ugly select() loops) can handle
an arbitrary number of connections.
The client starts up unconnected, so you can use the Connect... option
to specify the address of the server you are going to connect to (the
TCP port number is hard-coded as 3000). Once connected, a number of
tests are possible. Currently, three tests are implemented. They show
how to use the basic IO calls in wxSocketBase,
such as wxSocketBase::Read, wxSocketBase::Write,
wxSocketBase::ReadMsg and wxSocketBase::WriteMsg,
and how to set up the correct IO flags depending on what you are going to
do. See the comments in the code for more information. Note that because
both clients and connection objects in the server set up an event handler
to catch @b wxSOCKET_LOST events, each one is immediately notified
if the other end closes the connection.
There is also a URL test which shows how to use
the wxURL class to fetch data from a given URL.
The sockets sample is work in progress. Some things to do:
@li More tests for basic socket functionality.
@li More tests for protocol classes (wxProtocol and its descendants).
@li Tests for the recently added (and still in alpha stage) datagram sockets.
@li New samples which actually do something useful (suggestions accepted).
@subsection page_utils_samples_sound Sound sample
The @c sound sample shows how to use wxSound for simple
audio output (e.g. notifications).
@subsection page_utils_samples_statbar Statbar sample
This sample shows how to create and use wxStatusBar. Although most of the
samples have a statusbar, they usually only create a default one and only
do it once.
Here you can see how to recreate the statusbar (with possibly different number
of fields) and how to use it to show icons/bitmaps and/or put arbitrary
controls into it.
@subsection page_utils_samples_taborder Tab order sample
This sample allows to test keyboard navigation (mostly done using the
@c TAB key, hence the sample name) between different controls.
It shows the use of wxWindow::MoveBeforeInTabOrder() and
MoveAfterInTabOrder() methods to change
the default order of the windows in the navigation chain and of
wxWindow::Navigate() for moving focus along this
chain.
@subsection page_utils_samples_text Text sample
This sample demonstrates four features: firstly the use and many variants of
the wxTextCtrl class (single line, multi line, read only,
password, ignoring TAB, ignoring ENTER).
Secondly it shows how to intercept a wxKeyEvent in both
the raw form using the @c EVT_KEY_UP and @c EVT_KEY_DOWN macros and the
higher level from using the @c EVT_CHAR macro. All characters will be logged
in a log window at the bottom of the main window. By pressing some of the function
keys, you can test some actions in the text ctrl as well as get statistics on the
text ctrls, which is useful for testing if these statistics actually are correct.
Thirdly, on platforms which support it, the sample will offer to copy text to the
wxClipboard and to paste text from it. The GTK version will
use the so called PRIMARY SELECTION, which is the pseudo clipboard under X and
best known from pasting text to the XTerm program.
Last not least: some of the text controls have tooltips and the sample also shows
how tooltips can be centrally disabled and their latency controlled.
@subsection page_utils_samples_thread Thread sample
This sample demonstrates use of threads in connection with GUI programs.
There are two fundamentally different ways to use threads in GUI programs and
either way has to take care of the fact that the GUI library itself usually
is not multi-threading safe, i.e. that it might crash if two threads try to
access the GUI class simultaneously. One way to prevent that is have a normal
GUI program in the main thread and some worker threads which work in the
background. In order to make communication between the main thread and the
worker threads possible, wxWidgets offers the wxPostEvent
function and this sample makes use of this function.
The other way to use a so called Mutex (such as those offered in the wxMutex
class) that prevent threads from accessing the GUI classes as long as any other
thread accesses them. For this, wxWidgets has the wxMutexGuiEnter
and wxMutexGuiLeave functions, both of which are
used and tested in the sample as well.
See also @ref overview_thread and wxThread.
@subsection page_utils_samples_toolbar Toolbar sample
The toolbar sample shows the wxToolBar class in action.
The following things are demonstrated:
@li Creating the toolbar using wxToolBar::AddTool and wxToolBar::AddControl: see
MyApp::InitToolbar in the sample.
@li Using @c EVT_UPDATE_UI handler for automatically enabling/disabling
toolbar buttons without having to explicitly call EnableTool. This is done
in MyFrame::OnUpdateCopyAndCut.
@li Using wxToolBar::DeleteTool and wxToolBar::InsertTool to dynamically update the
toolbar.
Some buttons in the main toolbar are check buttons, i.e. they stay checked when
pressed. On the platforms which support it, the sample also adds a combobox
to the toolbar showing how you can use arbitrary controls and not only buttons
in it.
If you toggle another toolbar in the sample (using @c Ctrl-A) you will also
see the radio toolbar buttons in action: the first three buttons form a radio
group, i.e. checking any of them automatically unchecks the previously
checked one.
@subsection page_utils_samples_treectrl Treectrl sample
This sample demonstrates using the wxTreeCtrl class. Here
you may see how to process various notification messages sent by this control
and also when they occur (by looking at the messages in the text control in
the bottom part of the frame).
Adding, inserting and deleting items and branches from the tree as well as
sorting (in default alphabetical order as well as in custom one) is
demonstrated here as well - try the corresponding menu entries.
@subsection page_utils_samples_widgets Widgets sample
The widgets sample is the main presentation program for most simple and advanced
native controls and complex generic widgets provided by wxWidgets.
The sample tests their basic functionality, events, placement, modification
in terms of colour and font as well as the possibility to change
the controls programmatically, such as adding an item to a list box etc.
All widgets are categorized for easy browsing.
@subsection page_utils_samples_wizard Wizard sample
This sample shows the so-called wizard dialog (implemented using
wxWizard and related classes). It shows almost all
features supported:
@li Using bitmaps with the wizard and changing them depending on the page
shown (notice that wxValidationPage in the sample has a different image from
the other ones)
@li Using TransferDataFromWindow
to verify that the data entered is correct before passing to the next page
(done in wxValidationPage which forces the user to check a checkbox before
continuing).
@li Using more elaborated techniques to allow returning to the previous
page, but not continuing to the next one or vice versa (in wxRadioboxPage)
@li This (wxRadioboxPage) page also shows how the page may process the
@e Cancel button itself instead of relying on the wizard parent to do it.
@li Normally, the order of the pages in the wizard is known at compile-time,
but sometimes it depends on the user choices: wxCheckboxPage shows how to
dynamically decide which page to display next (see also
wxWizardPage)
*/

View File

@ -38,7 +38,7 @@ displayed one page at a time. wxWidgets has five variants of this control:
@li wxTreebook: controlled by a wxTreeCtrl
@li wxToolbook: controlled by a wxToolBar
See the @ref page_utils_samples_notebook for an example of wxBookCtrl usage.
See the @ref page_samples_notebook for an example of wxBookCtrl usage.
@section overview_bookctrl_bestbookctrl Best Book

View File

@ -8,75 +8,75 @@
/**
@page overview_dataobject wxDataObject Overview
@page overview_dataobject wxDataObject Overview
Classes: wxDataObject, wxClipboard, wxDataFormat, wxDropSource, wxDropTarget
Classes: wxDataObject, wxClipboard, wxDataFormat, wxDropSource, wxDropTarget
See also: @ref overview_dnd and @ref page_utils_samples_dnd
See also: @ref overview_dnd and @ref page_samples_dnd
This overview discusses data transfer through clipboard or drag and drop.
In wxWidgets, these two ways to transfer data (either between different
applications or inside one and the same) are very similar which allows to
implement both of them using almost the same code - or, in other
words, if you implement drag and drop support for your application, you get
clipboard support for free and vice versa.
This overview discusses data transfer through clipboard or drag and drop.
In wxWidgets, these two ways to transfer data (either between different
applications or inside one and the same) are very similar which allows to
implement both of them using almost the same code - or, in other
words, if you implement drag and drop support for your application, you get
clipboard support for free and vice versa.
At the heart of both clipboard and drag and drop operations lies the
wxDataObject class. The objects of this class (or, to
be precise, classes derived from it) represent the data which is being carried
by the mouse during drag and drop operation or copied to or pasted from the
clipboard. wxDataObject is a "smart" piece of data because it knows which
formats it supports (see GetFormatCount and GetAllFormats) and knows how to
render itself in any of them (see GetDataHere). It can also receive its value
from the outside in a format it supports if it implements the SetData method.
Please see the documentation of this class for more details.
At the heart of both clipboard and drag and drop operations lies the
wxDataObject class. The objects of this class (or, to
be precise, classes derived from it) represent the data which is being carried
by the mouse during drag and drop operation or copied to or pasted from the
clipboard. wxDataObject is a "smart" piece of data because it knows which
formats it supports (see GetFormatCount and GetAllFormats) and knows how to
render itself in any of them (see GetDataHere). It can also receive its value
from the outside in a format it supports if it implements the SetData method.
Please see the documentation of this class for more details.
Both clipboard and drag and drop operations have two sides: the source and
target, the data provider and the data receiver. These which may be in the same
application and even the same window when, for example, you drag some text from
one position to another in a word processor. Let us describe what each of them
should do.
Both clipboard and drag and drop operations have two sides: the source and
target, the data provider and the data receiver. These which may be in the same
application and even the same window when, for example, you drag some text from
one position to another in a word processor. Let us describe what each of them
should do.
@li @ref overview_dataobject_source
@li @ref overview_dataobject_target
@li @ref overview_dataobject_source
@li @ref overview_dataobject_target
<hr>
<hr>
@section overview_dataobject_source The data provider (source) duties
@section overview_dataobject_source The data provider (source) duties
The data provider is responsible for creating a wxDataObject containing the
data to be transferred. Then it should either pass it to the clipboard using
wxClipboard::SetData function or to wxDropSource and call wxDropSource::DoDragDrop
function.
The data provider is responsible for creating a wxDataObject containing the
data to be transferred. Then it should either pass it to the clipboard using
wxClipboard::SetData function or to wxDropSource and call wxDropSource::DoDragDrop
function.
The only (but important) difference is that the object for the clipboard
transfer must always be created on the heap (i.e. using @c new) and it will
be freed by the clipboard when it is no longer needed (indeed, it is not known
in advance when, if ever, the data will be pasted from the clipboard). On the
other hand, the object for drag and drop operation must only exist while
wxDropSource::DoDragDrop executes and may be safely deleted afterwards and so
can be created either on heap or on stack (i.e. as a local variable).
The only (but important) difference is that the object for the clipboard
transfer must always be created on the heap (i.e. using @c new) and it will
be freed by the clipboard when it is no longer needed (indeed, it is not known
in advance when, if ever, the data will be pasted from the clipboard). On the
other hand, the object for drag and drop operation must only exist while
wxDropSource::DoDragDrop executes and may be safely deleted afterwards and so
can be created either on heap or on stack (i.e. as a local variable).
Another small difference is that in the case of clipboard operation, the
application usually knows in advance whether it copies or cuts (i.e. copies and
deletes) data - in fact, this usually depends on which menu item the user
chose. But for drag and drop it can only know it after
wxDropSource::DoDragDrop returns (from its return value).
Another small difference is that in the case of clipboard operation, the
application usually knows in advance whether it copies or cuts (i.e. copies and
deletes) data - in fact, this usually depends on which menu item the user
chose. But for drag and drop it can only know it after
wxDropSource::DoDragDrop returns (from its return value).
@section overview_dataobject_target The data receiver (target) duties
@section overview_dataobject_target The data receiver (target) duties
To receive (paste in usual terminology) data from the clipboard, you should
create a wxDataObject derived class which supports the data formats you need
and pass it as argument to wxClipboard::GetData. If it returns @false,
no data in (any of) the supported format(s) is available. If it returns @true,
the data has been successfully transferred to wxDataObject.
To receive (paste in usual terminology) data from the clipboard, you should
create a wxDataObject derived class which supports the data formats you need
and pass it as argument to wxClipboard::GetData. If it returns @false,
no data in (any of) the supported format(s) is available. If it returns @true,
the data has been successfully transferred to wxDataObject.
For drag and drop case, the wxDropTarget::OnData virtual function will be called
when a data object is dropped, from which the data itself may be requested by calling
wxDropTarget::GetData method which fills the data object.
For drag and drop case, the wxDropTarget::OnData virtual function will be called
when a data object is dropped, from which the data itself may be requested by calling
wxDropTarget::GetData method which fills the data object.
*/

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@ -8,54 +8,54 @@
/**
@page overview_dnd Drag and Drop Overview
@page overview_dnd Drag and Drop Overview
Classes: wxDataObject, wxTextDataObject, wxDropSource, wxDropTarget,
wxTextDropTarget, wxFileDropTarget
Classes: wxDataObject, wxTextDataObject, wxDropSource, wxDropTarget,
wxTextDropTarget, wxFileDropTarget
Note that @c wxUSE_DRAG_AND_DROP must be defined in @c setup.h in order
to use drag and drop in wxWidgets.
Note that @c wxUSE_DRAG_AND_DROP must be defined in @c setup.h in order
to use drag and drop in wxWidgets.
See also: @ref overview_dataobject and @ref page_utils_samples_dnd.
See also: @ref overview_dataobject and @ref page_samples_dnd.
It may be noted that data transfer to and from the clipboard is quite
similar to data transfer with drag and drop and the code to implement
these two types is almost the same. In particular, both data transfer
mechanisms store data in some kind of wxDataObject and identify its format(s)
using the wxDataFormat class.
It may be noted that data transfer to and from the clipboard is quite
similar to data transfer with drag and drop and the code to implement
these two types is almost the same. In particular, both data transfer
mechanisms store data in some kind of wxDataObject and identify its format(s)
using the wxDataFormat class.
To be a @e drag source, i.e. to provide the data which may be dragged by
the user elsewhere, you should implement the following steps:
To be a @e drag source, i.e. to provide the data which may be dragged by
the user elsewhere, you should implement the following steps:
@li @b Preparation: First of all, a data object must be created and
initialized with the data you wish to drag. For example:
@li @b Preparation: First of all, a data object must be created and
initialized with the data you wish to drag. For example:
@code
wxTextDataObject my_data("This text will be dragged.");
@endcode
@code
wxTextDataObject my_data("This text will be dragged.");
@endcode
@li <b>Drag start</b>: To start the dragging process (typically in response to a
mouse click) you must call wxDropSource::DoDragDrop like this:
@li <b>Drag start</b>: To start the dragging process (typically in response to a
mouse click) you must call wxDropSource::DoDragDrop like this:
@code
wxDropSource dragSource( this );
dragSource.SetData( my_data );
wxDragResult result = dragSource.DoDragDrop( true );
@endcode
@code
wxDropSource dragSource( this );
dragSource.SetData( my_data );
wxDragResult result = dragSource.DoDragDrop( true );
@endcode
@li @b Dragging: The call to DoDragDrop() blocks the program until the user releases
the mouse button (unless you override the wxDropSource::GiveFeedback function to
do something special). When the mouse moves in a window of a program which understands
the same drag-and-drop protocol (any program under Windows or any program supporting
the XDnD protocol under X Windows), the corresponding wxDropTarget methods
are called - see below.
@li @b Dragging: The call to DoDragDrop() blocks the program until the user releases
the mouse button (unless you override the wxDropSource::GiveFeedback function to
do something special). When the mouse moves in a window of a program which understands
the same drag-and-drop protocol (any program under Windows or any program supporting
the XDnD protocol under X Windows), the corresponding wxDropTarget methods
are called - see below.
@li <b>Processing the result</b>: DoDragDrop() returns an @e effect code which
is one of the values of @c wxDragResult enum (explained in wxDropTarget page):
@li <b>Processing the result</b>: DoDragDrop() returns an @e effect code which
is one of the values of @c wxDragResult enum (explained in wxDropTarget page):
@code
switch (result)
{
@code
switch (result)
{
case wxDragCopy:
// copy the data
break;
@ -65,31 +65,31 @@
default:
// do nothing
break;
}
@endcode
}
@endcode
To be a @e drop target, i.e. to receive the data dropped by the user you should
follow the instructions below:
To be a @e drop target, i.e. to receive the data dropped by the user you should
follow the instructions below:
@li @b Initialization: For a window to be a drop target, it needs to have
an associated wxDropTarget object. Normally, you will call wxWindow::SetDropTarget
during window creation associating your drop target with it. You must derive a class
from wxDropTarget and override its pure virtual methods. Alternatively, you may
derive from wxTextDropTarget or wxFileDropTarget and override their OnDropText()
or OnDropFiles() method.
@li @b Initialization: For a window to be a drop target, it needs to have
an associated wxDropTarget object. Normally, you will call wxWindow::SetDropTarget
during window creation associating your drop target with it. You must derive a class
from wxDropTarget and override its pure virtual methods. Alternatively, you may
derive from wxTextDropTarget or wxFileDropTarget and override their OnDropText()
or OnDropFiles() method.
@li @b Drop: When the user releases the mouse over a window, wxWidgets
asks the associated wxDropTarget object if it accepts the data. For this,
a wxDataObject must be associated with the drop target and this data object will
be responsible for the format negotiation between the drag source and the drop target.
If all goes well, then wxDropTarget::OnData will get called and the wxDataObject belonging
to the drop target can get filled with data.
@li @b Drop: When the user releases the mouse over a window, wxWidgets
asks the associated wxDropTarget object if it accepts the data. For this,
a wxDataObject must be associated with the drop target and this data object will
be responsible for the format negotiation between the drag source and the drop target.
If all goes well, then wxDropTarget::OnData will get called and the wxDataObject belonging
to the drop target can get filled with data.
@li <b>The end</b>: After processing the data, DoDragDrop() returns either
wxDragCopy or wxDragMove depending on the state of the keys Ctrl, Shift
and Alt at the moment of the drop. There is currently no way for the drop
target to change this return code.
@li <b>The end</b>: After processing the data, DoDragDrop() returns either
wxDragCopy or wxDragMove depending on the state of the keys Ctrl, Shift
and Alt at the moment of the drop. There is currently no way for the drop
target to change this return code.
*/

View File

@ -8,484 +8,484 @@
/**
@page overview_eventhandling Event Handling
@page overview_eventhandling Event Handling
Classes: wxEvtHandler, wxWindow, wxEvent
Classes: wxEvtHandler, wxWindow, wxEvent
@li @ref overview_eventhandling_introduction
@li @ref overview_eventhandling_processing
@li @ref overview_eventhandling_prog
@li @ref overview_eventhandling_pluggable
@li @ref overview_eventhandling_winid
@li @ref overview_eventhandling_custom
@li @ref overview_eventhandling_macros
@li @ref overview_eventhandling_introduction
@li @ref overview_eventhandling_processing
@li @ref overview_eventhandling_prog
@li @ref overview_eventhandling_pluggable
@li @ref overview_eventhandling_winid
@li @ref overview_eventhandling_custom
@li @ref overview_eventhandling_macros
<hr>
<hr>
@section overview_eventhandling_introduction Introduction
@section overview_eventhandling_introduction Introduction
Before version 2.0 of wxWidgets, events were handled by the application
either by supplying callback functions, or by overriding virtual member
functions such as @b OnSize.
Before version 2.0 of wxWidgets, events were handled by the application
either by supplying callback functions, or by overriding virtual member
functions such as @b OnSize.
From wxWidgets 2.0, @e event tables are used instead, with a few exceptions.
An event table is placed in an implementation file to tell wxWidgets how to map
events to member functions. These member functions are not virtual functions, but
they are all similar in form: they take a single wxEvent-derived argument,
and have a void return type.
Here's an example of an event table.
From wxWidgets 2.0, @e event tables are used instead, with a few exceptions.
An event table is placed in an implementation file to tell wxWidgets how to map
events to member functions. These member functions are not virtual functions, but
they are all similar in form: they take a single wxEvent-derived argument,
and have a void return type.
Here's an example of an event table.
@code
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(wxID_EXIT, MyFrame::OnExit)
EVT_MENU(DO_TEST, MyFrame::DoTest)
EVT_SIZE(MyFrame::OnSize)
EVT_BUTTON(BUTTON1, MyFrame::OnButton1)
END_EVENT_TABLE()
@endcode
@code
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(wxID_EXIT, MyFrame::OnExit)
EVT_MENU(DO_TEST, MyFrame::DoTest)
EVT_SIZE(MyFrame::OnSize)
EVT_BUTTON(BUTTON1, MyFrame::OnButton1)
END_EVENT_TABLE()
@endcode
The first two entries map menu commands to two different member functions. The
EVT_SIZE macro doesn't need a window identifier, since normally you are only
interested in the current window's size events.
The first two entries map menu commands to two different member functions. The
EVT_SIZE macro doesn't need a window identifier, since normally you are only
interested in the current window's size events.
The EVT_BUTTON macro demonstrates that the originating event does not have to
come from the window class implementing the event table -- if the event source
is a button within a panel within a frame, this will still work, because event
tables are searched up through the hierarchy of windows for the command events.
In this case, the button's event table will be searched, then the parent
panel's, then the frame's.
The EVT_BUTTON macro demonstrates that the originating event does not have to
come from the window class implementing the event table -- if the event source
is a button within a panel within a frame, this will still work, because event
tables are searched up through the hierarchy of windows for the command events.
In this case, the button's event table will be searched, then the parent
panel's, then the frame's.
As mentioned before, the member functions that handle events do not have to be
virtual. Indeed, the member functions should not be virtual as the event
handler ignores that the functions are virtual, i.e. overriding a virtual
member function in a derived class will not have any effect. These member
functions take an event argument, and the class of event differs according to
the type of event and the class of the originating window. For size events,
wxSizeEvent is used. For menu commands and most control commands
(such as button presses), wxCommandEvent is used. When controls get more
complicated, then specific event classes are used, such as wxTreeEvent for
events from wxTreeCtrl windows.
As mentioned before, the member functions that handle events do not have to be
virtual. Indeed, the member functions should not be virtual as the event
handler ignores that the functions are virtual, i.e. overriding a virtual
member function in a derived class will not have any effect. These member
functions take an event argument, and the class of event differs according to
the type of event and the class of the originating window. For size events,
wxSizeEvent is used. For menu commands and most control commands
(such as button presses), wxCommandEvent is used. When controls get more
complicated, then specific event classes are used, such as wxTreeEvent for
events from wxTreeCtrl windows.
As well as the event table in the implementation file, there must also be a
DECLARE_EVENT_TABLE macro somewhere in the class declaration. For example:
As well as the event table in the implementation file, there must also be a
DECLARE_EVENT_TABLE macro somewhere in the class declaration. For example:
@code
class MyFrame : public wxFrame
{
public:
...
void OnExit(wxCommandEvent& event);
void OnSize(wxSizeEvent& event);
@code
class MyFrame : public wxFrame
{
public:
...
void OnExit(wxCommandEvent& event);
void OnSize(wxSizeEvent& event);
protected:
int m_count;
...
protected:
int m_count;
...
DECLARE_EVENT_TABLE()
};
@endcode
DECLARE_EVENT_TABLE()
};
@endcode
Note that this macro may occur in any section of the class (public, protected
or private) but that it is probably better to insert it at the end, as shown,
because this macro implicitly changes the access to protected which may be
quite unexpected if there is anything following it.
Note that this macro may occur in any section of the class (public, protected
or private) but that it is probably better to insert it at the end, as shown,
because this macro implicitly changes the access to protected which may be
quite unexpected if there is anything following it.
Finally, if you don't like using macros for static initialization of the event
tables you may also use wxEvtHandler::Connect to
connect the events to the handlers dynamically, during run-time. See the
@ref page_utils_samples_event for an example of doing it.
Finally, if you don't like using macros for static initialization of the event
tables you may also use wxEvtHandler::Connect to
connect the events to the handlers dynamically, during run-time. See the
@ref page_samples_event for an example of doing it.
@section overview_eventhandling_processing How events are processed
@section overview_eventhandling_processing How events are processed
When an event is received from the windowing system, wxWidgets calls
wxEvtHandler::ProcessEvent on the first
event handler object belonging to the window generating the event.
When an event is received from the windowing system, wxWidgets calls
wxEvtHandler::ProcessEvent on the first
event handler object belonging to the window generating the event.
It may be noted that wxWidgets' event processing system implements something
very close to virtual methods in normal C++, i.e. it is possible to alter
the behaviour of a class by overriding its event handling functions. In
many cases this works even for changing the behaviour of native controls.
It may be noted that wxWidgets' event processing system implements something
very close to virtual methods in normal C++, i.e. it is possible to alter
the behaviour of a class by overriding its event handling functions. In
many cases this works even for changing the behaviour of native controls.
For example it is possible to filter out a number of key events sent by the
system to a native text control by overriding wxTextCtrl and defining a
handler for key events using EVT_KEY_DOWN. This would indeed prevent
any key events from being sent to the native control - which might not be
what is desired. In this case the event handler function has to call Skip()
so as to indicate that the search for the event handler should continue.
For example it is possible to filter out a number of key events sent by the
system to a native text control by overriding wxTextCtrl and defining a
handler for key events using EVT_KEY_DOWN. This would indeed prevent
any key events from being sent to the native control - which might not be
what is desired. In this case the event handler function has to call Skip()
so as to indicate that the search for the event handler should continue.
To summarize, instead of explicitly calling the base class version as you
would have done with C++ virtual functions (i.e. @e wxTextCtrl::OnChar()),
you should instead call wxEvent::Skip.
To summarize, instead of explicitly calling the base class version as you
would have done with C++ virtual functions (i.e. @e wxTextCtrl::OnChar()),
you should instead call wxEvent::Skip.
In practice, this would look like this if the derived text control only
accepts 'a' to 'z' and 'A' to 'Z':
In practice, this would look like this if the derived text control only
accepts 'a' to 'z' and 'A' to 'Z':
@code
void MyTextCtrl::OnChar(wxKeyEvent& event)
{
if ( isalpha( event.KeyCode() ) )
{
@code
void MyTextCtrl::OnChar(wxKeyEvent& event)
{
if ( isalpha( event.KeyCode() ) )
{
// key code is within legal range. we call event.Skip() so the
// event can be processed either in the base wxWidgets class
// or the native control.
event.Skip();
}
else
{
}
else
{
// illegal key hit. we don't call event.Skip() so the
// event is not processed anywhere else.
wxBell();
}
}
@endcode
The normal order of event table searching by ProcessEvent is as follows:
@li If the object is disabled (via a call to wxEvtHandler::SetEvtHandlerEnabled)
the function skips to step (6).
@li If the object is a wxWindow, @b ProcessEvent is recursively called on the window's
wxValidator. If this returns @true, the function exits.
@li @b SearchEventTable is called for this event handler. If this fails, the base
class table is tried, and so on until no more tables exist or an appropriate
function was found, in which case the function exits.
@li The search is applied down the entire chain of event handlers (usually the chain has
a length of one). If this succeeds, the function exits.
@li If the object is a wxWindow and the event is set to set to propagate (in the library only
wxCommandEvent based events are set to propagate), @b ProcessEvent is recursively applied
to the parent window's event handler. If this returns @true, the function exits.
@li Finally, @b ProcessEvent is called on the wxApp object.
<b>Pay close attention to Step 5</b>. People often overlook or get
confused by this powerful feature of the wxWidgets event processing
system. To put it a different way, events set to propagate
(see wxEvent::ShouldPropagate)
(most likely derived either directly or indirectly from wxCommandEvent)
will travel up the containment hierarchy from child to parent until the
maximal propagation level is reached or an event handler is found that
doesn't call @c event.Skip().
Finally, there is another additional complication (which, in fact, simplifies
life of wxWidgets programmers significantly): when propagating the command
events upwards to the parent window, the event propagation stops when it
reaches the parent dialog, if any. This means that you don't risk to get
unexpected events from the dialog controls (which might be left unprocessed by
the dialog itself because it doesn't care about them) when a modal dialog is
popped up. The events do propagate beyond the frames, however. The rationale
for this choice is that there are only a few frames in a typical application
and their parent-child relation are well understood by the programmer while it
may be very difficult, if not impossible, to track down all the dialogs which
may be popped up in a complex program (remember that some are created
automatically by wxWidgets). If you need to specify a different behaviour for
some reason, you can use wxWindow::SetExtraStyle(wxWS_EX_BLOCK_EVENTS)
explicitly to prevent the events from being propagated beyond the given window
or unset this flag for the dialogs which have it on by default.
Typically events that deal with a window as a window (size, motion,
paint, mouse, keyboard, etc.) are sent only to the window. Events
that have a higher level of meaning and/or are generated by the window
itself, (button click, menu select, tree expand, etc.) are command
events and are sent up to the parent to see if it is interested in the event.
Note that your application may wish to override ProcessEvent to redirect processing of
events. This is done in the document/view framework, for example, to allow event handlers
to be defined in the document or view. To test for command events (which will probably
be the only events you wish to redirect), you may use wxEvent::IsCommandEvent for efficiency,
instead of using the slower run-time type system.
As mentioned above, only command events are recursively applied to the parents event
handler in the library itself. As this quite often causes confusion for users,
here is a list of system events which will NOT get sent to the parent's event handler:
@li wxEvent: The event base class
@li wxActivateEvent: A window or application activation event
@li wxCloseEvent: A close window or end session event
@li wxEraseEvent: An erase background event
@li wxFocusEvent: A window focus event
@li wxKeyEvent: A keypress event
@li wxIdleEvent: An idle event
@li wxInitDialogEvent: A dialog initialisation event
@li wxJoystickEvent: A joystick event
@li wxMenuEvent: A menu event
@li wxMouseEvent: A mouse event
@li wxMoveEvent: A move event
@li wxPaintEvent: A paint event
@li wxQueryLayoutInfoEvent: Used to query layout information
@li wxSetCursorEvent: Used for special cursor processing based on current mouse position
@li wxSizeEvent: A size event
@li wxScrollWinEvent: A scroll event sent by a scrolled window (not a scroll bar)
@li wxSysColourChangedEvent: A system colour change event
In some cases, it might be desired by the programmer to get a certain number
of system events in a parent window, for example all key events sent to, but not
used by, the native controls in a dialog. In this case, a special event handler
will have to be written that will override ProcessEvent() in order to pass
all events (or any selection of them) to the parent window.
@section overview_eventhandling_prog Events generated by the user vs programmatically generated events
While generically wxEvents can be generated both by user
actions (e.g. resize of a wxWindow) and by calls to functions
(e.g. wxWindow::SetSize), wxWidgets controls normally send wxCommandEvent-derived
events only for the user-generated events. The only @b exceptions to this rule are:
@li wxNotebook::AddPage: No event-free alternatives
@li wxNotebook::AdvanceSelection: No event-free alternatives
@li wxNotebook::DeletePage: No event-free alternatives
@li wxNotebook::SetSelection: Use wxNotebook::ChangeSelection instead, as
wxNotebook::SetSelection is deprecated
@li wxTreeCtrl::Delete: No event-free alternatives
@li wxTreeCtrl::DeleteAllItems: No event-free alternatives
@li wxTreeCtrl::EditLabel: No event-free alternatives
@li All wxTextCtrl methods
wxTextCtrl::ChangeValue can be used instead of wxTextCtrl::SetValue but the other
functions, such as wxTextCtrl::Replace or wxTextCtrl::WriteText don't have event-free
equivalents.
@section overview_eventhandling_pluggable Pluggable event handlers
In fact, you don't have to derive a new class from a window class
if you don't want to. You can derive a new class from wxEvtHandler instead,
defining the appropriate event table, and then call wxWindow::SetEventHandler
(or, preferably, wxWindow::PushEventHandler) to make this
event handler the object that responds to events. This way, you can avoid
a lot of class derivation, and use instances of the same event handler class (but different
objects as the same event handler object shouldn't be used more than once) to
handle events from instances of different widget classes.
If you ever have to call a window's event handler
manually, use the GetEventHandler function to retrieve the window's event handler and use that
to call the member function. By default, GetEventHandler returns a pointer to the window itself
unless an application has redirected event handling using SetEventHandler or PushEventHandler.
One use of PushEventHandler is to temporarily or permanently change the
behaviour of the GUI. For example, you might want to invoke a dialog editor
in your application that changes aspects of dialog boxes. You can
grab all the input for an existing dialog box, and edit it 'in situ',
before restoring its behaviour to normal. So even if the application
has derived new classes to customize behaviour, your utility can indulge
in a spot of body-snatching. It could be a useful technique for on-line
tutorials, too, where you take a user through a serious of steps and
don't want them to diverge from the lesson. Here, you can examine the events
coming from buttons and windows, and if acceptable, pass them through to
the original event handler. Use PushEventHandler/PopEventHandler
to form a chain of event handlers, where each handler processes a different
range of events independently from the other handlers.
@section overview_eventhandling_winid Window identifiers
Window identifiers are integers, and are used to
uniquely determine window identity in the event system (though you can use it
for other purposes). In fact, identifiers do not need to be unique
across your entire application just so long as they are unique within a
particular context you're interested in, such as a frame and its children. You
may use the @c wxID_OK identifier, for example, on any number of dialogs so
long as you don't have several within the same dialog.
If you pass @c wxID_ANY to a window constructor, an identifier will be
generated for you automatically by wxWidgets. This is useful when you don't
care about the exact identifier either because you're not going to process the
events from the control being created at all or because you process the events
from all controls in one place (in which case you should specify @c wxID_ANY
in the event table or wxEvtHandler::Connect call
as well. The automatically generated identifiers are always negative and so
will never conflict with the user-specified identifiers which must be always
positive.
See @ref page_stdevtid for the list of standard identifiers availabel.
You can use wxID_HIGHEST to determine the number above which it is safe to
define your own identifiers. Or, you can use identifiers below wxID_LOWEST.
Finally, you can allocate identifiers dynamically using wxNewId() function to.
If you use wxNewId() consistently in your application, you can be sure that
the your identifiers don't conflict accidentally.
@section overview_eventhandling_custom Custom event summary
@subsection overview_eventhandling_custom_general General approach
Since version 2.2.x of wxWidgets, each event type is identified by ID which
is given to the event type @e at runtime which makes it possible to add
new event types to the library or application without risking ID clashes
(two different event types mistakingly getting the same event ID). This
event type ID is stored in a struct of type @b const wxEventType.
In order to define a new event type, there are principally two choices.
One is to define a entirely new event class (typically deriving from
wxEvent or wxCommandEvent.
The other is to use the existing event classes and give them an new event
type. You'll have to define and declare a new event type using either way,
and this is done using the following macros:
@code
// in the header of the source file
BEGIN_DECLARE_EVENT_TYPES()
DECLARE_EVENT_TYPE(name, value)
END_DECLARE_EVENT_TYPES()
// in the implementation
DEFINE_EVENT_TYPE(name)
@endcode
You can ignore the @e value parameter of the DECLARE_EVENT_TYPE macro
since it is used only for backwards compatibility with wxWidgets 2.0.x based
applications where you have to give the event type ID an explicit value.
See also the @ref page_utils_samples_event for an example of code
defining and working with the custom event types.
@subsection overview_eventhandling_custom_existing Using existing event classes
If you just want to use a wxCommandEvent with
a new event type, you can then use one of the generic event table macros
listed below, without having to define a new macro yourself. This also
has the advantage that you won't have to define a new wxEvent::Clone()
method for posting events between threads etc. This could look like this
in your code:
@code
DECLARE_EVENT_TYPE(wxEVT_MY_EVENT, -1)
DEFINE_EVENT_TYPE(wxEVT_MY_EVENT)
// user code intercepting the event
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU (wxID_EXIT, MyFrame::OnExit)
// ....
EVT_COMMAND (ID_MY_WINDOW, wxEVT_MY_EVENT, MyFrame::OnMyEvent)
END_EVENT_TABLE()
void MyFrame::OnMyEvent( wxCommandEvent )
{
// do something
wxString text = event.GetText();
}
}
}
@endcode
The normal order of event table searching by ProcessEvent is as follows:
@li If the object is disabled (via a call to wxEvtHandler::SetEvtHandlerEnabled)
the function skips to step (6).
@li If the object is a wxWindow, @b ProcessEvent is recursively called on the window's
wxValidator. If this returns @true, the function exits.
@li @b SearchEventTable is called for this event handler. If this fails, the base
class table is tried, and so on until no more tables exist or an appropriate
function was found, in which case the function exits.
@li The search is applied down the entire chain of event handlers (usually the chain has
a length of one). If this succeeds, the function exits.
@li If the object is a wxWindow and the event is set to set to propagate (in the library only
wxCommandEvent based events are set to propagate), @b ProcessEvent is recursively applied
to the parent window's event handler. If this returns @true, the function exits.
@li Finally, @b ProcessEvent is called on the wxApp object.
<b>Pay close attention to Step 5</b>. People often overlook or get
confused by this powerful feature of the wxWidgets event processing
system. To put it a different way, events set to propagate
(see wxEvent::ShouldPropagate)
(most likely derived either directly or indirectly from wxCommandEvent)
will travel up the containment hierarchy from child to parent until the
maximal propagation level is reached or an event handler is found that
doesn't call @c event.Skip().
Finally, there is another additional complication (which, in fact, simplifies
life of wxWidgets programmers significantly): when propagating the command
events upwards to the parent window, the event propagation stops when it
reaches the parent dialog, if any. This means that you don't risk to get
unexpected events from the dialog controls (which might be left unprocessed by
the dialog itself because it doesn't care about them) when a modal dialog is
popped up. The events do propagate beyond the frames, however. The rationale
for this choice is that there are only a few frames in a typical application
and their parent-child relation are well understood by the programmer while it
may be very difficult, if not impossible, to track down all the dialogs which
may be popped up in a complex program (remember that some are created
automatically by wxWidgets). If you need to specify a different behaviour for
some reason, you can use wxWindow::SetExtraStyle(wxWS_EX_BLOCK_EVENTS)
explicitly to prevent the events from being propagated beyond the given window
or unset this flag for the dialogs which have it on by default.
Typically events that deal with a window as a window (size, motion,
paint, mouse, keyboard, etc.) are sent only to the window. Events
that have a higher level of meaning and/or are generated by the window
itself, (button click, menu select, tree expand, etc.) are command
events and are sent up to the parent to see if it is interested in the event.
Note that your application may wish to override ProcessEvent to redirect processing of
events. This is done in the document/view framework, for example, to allow event handlers
to be defined in the document or view. To test for command events (which will probably
be the only events you wish to redirect), you may use wxEvent::IsCommandEvent for efficiency,
instead of using the slower run-time type system.
As mentioned above, only command events are recursively applied to the parents event
handler in the library itself. As this quite often causes confusion for users,
here is a list of system events which will NOT get sent to the parent's event handler:
@li wxEvent: The event base class
@li wxActivateEvent: A window or application activation event
@li wxCloseEvent: A close window or end session event
@li wxEraseEvent: An erase background event
@li wxFocusEvent: A window focus event
@li wxKeyEvent: A keypress event
@li wxIdleEvent: An idle event
@li wxInitDialogEvent: A dialog initialisation event
@li wxJoystickEvent: A joystick event
@li wxMenuEvent: A menu event
@li wxMouseEvent: A mouse event
@li wxMoveEvent: A move event
@li wxPaintEvent: A paint event
@li wxQueryLayoutInfoEvent: Used to query layout information
@li wxSetCursorEvent: Used for special cursor processing based on current mouse position
@li wxSizeEvent: A size event
@li wxScrollWinEvent: A scroll event sent by a scrolled window (not a scroll bar)
@li wxSysColourChangedEvent: A system colour change event
In some cases, it might be desired by the programmer to get a certain number
of system events in a parent window, for example all key events sent to, but not
used by, the native controls in a dialog. In this case, a special event handler
will have to be written that will override ProcessEvent() in order to pass
all events (or any selection of them) to the parent window.
@section overview_eventhandling_prog Events generated by the user vs programmatically generated events
While generically wxEvents can be generated both by user
actions (e.g. resize of a wxWindow) and by calls to functions
(e.g. wxWindow::SetSize), wxWidgets controls normally send wxCommandEvent-derived
events only for the user-generated events. The only @b exceptions to this rule are:
@li wxNotebook::AddPage: No event-free alternatives
@li wxNotebook::AdvanceSelection: No event-free alternatives
@li wxNotebook::DeletePage: No event-free alternatives
@li wxNotebook::SetSelection: Use wxNotebook::ChangeSelection instead, as
wxNotebook::SetSelection is deprecated
@li wxTreeCtrl::Delete: No event-free alternatives
@li wxTreeCtrl::DeleteAllItems: No event-free alternatives
@li wxTreeCtrl::EditLabel: No event-free alternatives
@li All wxTextCtrl methods
wxTextCtrl::ChangeValue can be used instead of wxTextCtrl::SetValue but the other
functions, such as wxTextCtrl::Replace or wxTextCtrl::WriteText don't have event-free
equivalents.
@section overview_eventhandling_pluggable Pluggable event handlers
In fact, you don't have to derive a new class from a window class
if you don't want to. You can derive a new class from wxEvtHandler instead,
defining the appropriate event table, and then call wxWindow::SetEventHandler
(or, preferably, wxWindow::PushEventHandler) to make this
event handler the object that responds to events. This way, you can avoid
a lot of class derivation, and use instances of the same event handler class (but different
objects as the same event handler object shouldn't be used more than once) to
handle events from instances of different widget classes.
If you ever have to call a window's event handler
manually, use the GetEventHandler function to retrieve the window's event handler and use that
to call the member function. By default, GetEventHandler returns a pointer to the window itself
unless an application has redirected event handling using SetEventHandler or PushEventHandler.
One use of PushEventHandler is to temporarily or permanently change the
behaviour of the GUI. For example, you might want to invoke a dialog editor
in your application that changes aspects of dialog boxes. You can
grab all the input for an existing dialog box, and edit it 'in situ',
before restoring its behaviour to normal. So even if the application
has derived new classes to customize behaviour, your utility can indulge
in a spot of body-snatching. It could be a useful technique for on-line
tutorials, too, where you take a user through a serious of steps and
don't want them to diverge from the lesson. Here, you can examine the events
coming from buttons and windows, and if acceptable, pass them through to
the original event handler. Use PushEventHandler/PopEventHandler
to form a chain of event handlers, where each handler processes a different
range of events independently from the other handlers.
@section overview_eventhandling_winid Window identifiers
Window identifiers are integers, and are used to
uniquely determine window identity in the event system (though you can use it
for other purposes). In fact, identifiers do not need to be unique
across your entire application just so long as they are unique within a
particular context you're interested in, such as a frame and its children. You
may use the @c wxID_OK identifier, for example, on any number of dialogs so
long as you don't have several within the same dialog.
If you pass @c wxID_ANY to a window constructor, an identifier will be
generated for you automatically by wxWidgets. This is useful when you don't
care about the exact identifier either because you're not going to process the
events from the control being created at all or because you process the events
from all controls in one place (in which case you should specify @c wxID_ANY
in the event table or wxEvtHandler::Connect call
as well. The automatically generated identifiers are always negative and so
will never conflict with the user-specified identifiers which must be always
positive.
See @ref page_stdevtid for the list of standard identifiers availabel.
You can use wxID_HIGHEST to determine the number above which it is safe to
define your own identifiers. Or, you can use identifiers below wxID_LOWEST.
Finally, you can allocate identifiers dynamically using wxNewId() function to.
If you use wxNewId() consistently in your application, you can be sure that
the your identifiers don't conflict accidentally.
@section overview_eventhandling_custom Custom event summary
@subsection overview_eventhandling_custom_general General approach
Since version 2.2.x of wxWidgets, each event type is identified by ID which
is given to the event type @e at runtime which makes it possible to add
new event types to the library or application without risking ID clashes
(two different event types mistakingly getting the same event ID). This
event type ID is stored in a struct of type @b const wxEventType.
In order to define a new event type, there are principally two choices.
One is to define a entirely new event class (typically deriving from
wxEvent or wxCommandEvent.
The other is to use the existing event classes and give them an new event
type. You'll have to define and declare a new event type using either way,
and this is done using the following macros:
@code
// in the header of the source file
BEGIN_DECLARE_EVENT_TYPES()
DECLARE_EVENT_TYPE(name, value)
END_DECLARE_EVENT_TYPES()
// in the implementation
DEFINE_EVENT_TYPE(name)
@endcode
You can ignore the @e value parameter of the DECLARE_EVENT_TYPE macro
since it is used only for backwards compatibility with wxWidgets 2.0.x based
applications where you have to give the event type ID an explicit value.
See also the @ref page_samples_event for an example of code
defining and working with the custom event types.
@subsection overview_eventhandling_custom_existing Using existing event classes
If you just want to use a wxCommandEvent with
a new event type, you can then use one of the generic event table macros
listed below, without having to define a new macro yourself. This also
has the advantage that you won't have to define a new wxEvent::Clone()
method for posting events between threads etc. This could look like this
in your code:
@code
DECLARE_EVENT_TYPE(wxEVT_MY_EVENT, -1)
DEFINE_EVENT_TYPE(wxEVT_MY_EVENT)
// user code intercepting the event
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU (wxID_EXIT, MyFrame::OnExit)
// ....
EVT_COMMAND (ID_MY_WINDOW, wxEVT_MY_EVENT, MyFrame::OnMyEvent)
END_EVENT_TABLE()
void MyFrame::OnMyEvent( wxCommandEvent )
{
// do something
wxString text = event.GetText();
}
// user code sending the event
// user code sending the event
void MyWindow::SendEvent()
{
wxCommandEvent event( wxEVT_MY_EVENT, GetId() );
event.SetEventObject( this );
// Give it some contents
event.SetText( wxT("Hallo") );
// Send it
GetEventHandler()->ProcessEvent( event );
}
@endcode
void MyWindow::SendEvent()
{
wxCommandEvent event( wxEVT_MY_EVENT, GetId() );
event.SetEventObject( this );
// Give it some contents
event.SetText( wxT("Hallo") );
// Send it
GetEventHandler()->ProcessEvent( event );
}
@endcode
@subsection overview_eventhandling_custom_generic Generic event table macros
@subsection overview_eventhandling_custom_generic Generic event table macros
@beginTable
@row2col{EVT_CUSTOM(event\, id\, func),
Allows you to add a custom event table
entry by specifying the event identifier (such as wxEVT_SIZE),
the window identifier, and a member function to call.}
@row2col{EVT_CUSTOM_RANGE(event\, id1\, id2\, func),
The same as EVT_CUSTOM, but responds to a range of window identifiers.}
@row2col{EVT_COMMAND(id\, event\, func),
The same as EVT_CUSTOM, but expects a member function with a
wxCommandEvent argument.}
@row2col{EVT_COMMAND_RANGE(id1\, id2\, event\, func),
The same as EVT_CUSTOM_RANGE, but
expects a member function with a wxCommandEvent argument.}
@row2col{EVT_NOTIFY(event\, id\, func),
The same as EVT_CUSTOM, but
expects a member function with a wxNotifyEvent argument.}
@row2col{EVT_NOTIFY_RANGE(event\, id1\, id2\, func),
The same as EVT_CUSTOM_RANGE, but
expects a member function with a wxNotifyEvent argument.}
@endTable
@beginTable
@row2col{EVT_CUSTOM(event\, id\, func),
Allows you to add a custom event table
entry by specifying the event identifier (such as wxEVT_SIZE),
the window identifier, and a member function to call.}
@row2col{EVT_CUSTOM_RANGE(event\, id1\, id2\, func),
The same as EVT_CUSTOM, but responds to a range of window identifiers.}
@row2col{EVT_COMMAND(id\, event\, func),
The same as EVT_CUSTOM, but expects a member function with a
wxCommandEvent argument.}
@row2col{EVT_COMMAND_RANGE(id1\, id2\, event\, func),
The same as EVT_CUSTOM_RANGE, but
expects a member function with a wxCommandEvent argument.}
@row2col{EVT_NOTIFY(event\, id\, func),
The same as EVT_CUSTOM, but
expects a member function with a wxNotifyEvent argument.}
@row2col{EVT_NOTIFY_RANGE(event\, id1\, id2\, func),
The same as EVT_CUSTOM_RANGE, but
expects a member function with a wxNotifyEvent argument.}
@endTable
@subsection overview_eventhandling_custom_ownclass Defining your own event class
@subsection overview_eventhandling_custom_ownclass Defining your own event class
Under certain circumstances, it will be required to define your own event
class e.g. for sending more complex data from one place to another. Apart
from defining your event class, you will also need to define your own
event table macro (which is quite long). Watch out to put in enough
casts to the inherited event function. Here is an example:
Under certain circumstances, it will be required to define your own event
class e.g. for sending more complex data from one place to another. Apart
from defining your event class, you will also need to define your own
event table macro (which is quite long). Watch out to put in enough
casts to the inherited event function. Here is an example:
@code
// code defining event
@code
// code defining event
class wxPlotEvent: public wxNotifyEvent
{
public:
wxPlotEvent( wxEventType commandType = wxEVT_NULL, int id = 0 );
class wxPlotEvent: public wxNotifyEvent
{
public:
wxPlotEvent( wxEventType commandType = wxEVT_NULL, int id = 0 );
// accessors
wxPlotCurve *GetCurve()
{ return m_curve; }
// accessors
wxPlotCurve *GetCurve()
{ return m_curve; }
// required for sending with wxPostEvent()
virtual wxEvent *Clone() const;
// required for sending with wxPostEvent()
virtual wxEvent *Clone() const;
private:
wxPlotCurve *m_curve;
};
private:
wxPlotCurve *m_curve;
};
DECLARE_EVENT_TYPE( wxEVT_PLOT_ACTION, -1 )
DECLARE_EVENT_TYPE( wxEVT_PLOT_ACTION, -1 )
typedef void (wxEvtHandler::*wxPlotEventFunction)(wxPlotEvent&);
typedef void (wxEvtHandler::*wxPlotEventFunction)(wxPlotEvent&);
#define EVT_PLOT(id, fn) \
DECLARE_EVENT_TABLE_ENTRY( wxEVT_PLOT_ACTION, id, -1, \
(wxObjectEventFunction) (wxEventFunction) (wxCommandEventFunction) (wxNotifyEventFunction) \
wxStaticCastEvent( wxPlotEventFunction, &fn ), (wxObject *) NULL ),
#define EVT_PLOT(id, fn) \
DECLARE_EVENT_TABLE_ENTRY( wxEVT_PLOT_ACTION, id, -1, \
(wxObjectEventFunction) (wxEventFunction) (wxCommandEventFunction) (wxNotifyEventFunction) \
wxStaticCastEvent( wxPlotEventFunction, &fn ), (wxObject *) NULL ),
// code implementing the event type and the event class
// code implementing the event type and the event class
DEFINE_EVENT_TYPE( wxEVT_PLOT_ACTION )
DEFINE_EVENT_TYPE( wxEVT_PLOT_ACTION )
wxPlotEvent::wxPlotEvent( ...
wxPlotEvent::wxPlotEvent( ...
// user code intercepting the event
// user code intercepting the event
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_PLOT (ID_MY_WINDOW, MyFrame::OnPlot)
END_EVENT_TABLE()
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_PLOT (ID_MY_WINDOW, MyFrame::OnPlot)
END_EVENT_TABLE()
void MyFrame::OnPlot( wxPlotEvent &event )
{
wxPlotCurve *curve = event.GetCurve();
}
void MyFrame::OnPlot( wxPlotEvent &event )
{
wxPlotCurve *curve = event.GetCurve();
}
// user code sending the event
// user code sending the event
void MyWindow::SendEvent()
{
wxPlotEvent event( wxEVT_PLOT_ACTION, GetId() );
event.SetEventObject( this );
event.SetCurve( m_curve );
GetEventHandler()->ProcessEvent( event );
}
@endcode
void MyWindow::SendEvent()
{
wxPlotEvent event( wxEVT_PLOT_ACTION, GetId() );
event.SetEventObject( this );
event.SetCurve( m_curve );
GetEventHandler()->ProcessEvent( event );
}
@endcode
@section overview_eventhandling_macros Event macros summary
@section overview_eventhandling_macros Event macros summary
For the full list of event classes, please see the
@ref page_class_cat_events page.
For the full list of event classes, please see the
@ref page_class_cat_events page.
*/

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@ -8,81 +8,81 @@
/**
@page overview_fontencoding Font Encodings
@page overview_fontencoding Font Encodings
wxWidgets has support for multiple font encodings.
wxWidgets has support for multiple font encodings.
By encoding we mean here the mapping between the character codes and the
letters. Probably the most well-known encoding is (7 bit) ASCII one which is
used almost universally now to represent the letters of the English alphabet
and some other common characters. However, it is not enough to represent the
letters of foreign alphabets and here other encodings come into play. Please
note that we will only discuss 8-bit fonts here and not Unicode
(see @ref overview_unicode).
By encoding we mean here the mapping between the character codes and the
letters. Probably the most well-known encoding is (7 bit) ASCII one which is
used almost universally now to represent the letters of the English alphabet
and some other common characters. However, it is not enough to represent the
letters of foreign alphabets and here other encodings come into play. Please
note that we will only discuss 8-bit fonts here and not Unicode
(see @ref overview_unicode).
Font encoding support is ensured by several classes:
wxFont itself, but also wxFontEnumerator and wxFontMapper. wxFont encoding
support is reflected by a (new) constructor parameter @e encoding which takes
one of the following values (elements of enumeration type @c wxFontEncoding):
Font encoding support is ensured by several classes:
wxFont itself, but also wxFontEnumerator and wxFontMapper. wxFont encoding
support is reflected by a (new) constructor parameter @e encoding which takes
one of the following values (elements of enumeration type @c wxFontEncoding):
@beginDefList
@itemdef{wxFONTENCODING_SYSTEM,
The default encoding of the underlying
operating system (notice that this might be a "foreign" encoding for foreign
versions of Windows 9x/NT).}
@itemdef{wxFONTENCODING_DEFAULT,
The applications default encoding as returned by wxFont::GetDefaultEncoding.
On program startup, the applications default encoding is the same as
wxFONTENCODING_SYSTEM, but may be changed to make all the fonts created later
to use it (by default).}
@itemdef{wxFONTENCODING_ISO8859_1..15,
ISO8859 family encodings which are
usually used by all non-Microsoft operating systems.}
@itemdef{wxFONTENCODING_KOI8,
Standard Cyrillic encoding for the Internet
(but see also wxFONTENCODING_ISO8859_5 and wxFONTENCODING_CP1251).}
@itemdef{wxFONTENCODING_CP1250, Microsoft analogue of ISO8859-2}
@itemdef{wxFONTENCODING_CP1251, Microsoft analogue of ISO8859-5}
@itemdef{wxFONTENCODING_CP1252, Microsoft analogue of ISO8859-1}
@endDefList
@beginDefList
@itemdef{wxFONTENCODING_SYSTEM,
The default encoding of the underlying
operating system (notice that this might be a "foreign" encoding for foreign
versions of Windows 9x/NT).}
@itemdef{wxFONTENCODING_DEFAULT,
The applications default encoding as returned by wxFont::GetDefaultEncoding.
On program startup, the applications default encoding is the same as
wxFONTENCODING_SYSTEM, but may be changed to make all the fonts created later
to use it (by default).}
@itemdef{wxFONTENCODING_ISO8859_1..15,
ISO8859 family encodings which are
usually used by all non-Microsoft operating systems.}
@itemdef{wxFONTENCODING_KOI8,
Standard Cyrillic encoding for the Internet
(but see also wxFONTENCODING_ISO8859_5 and wxFONTENCODING_CP1251).}
@itemdef{wxFONTENCODING_CP1250, Microsoft analogue of ISO8859-2}
@itemdef{wxFONTENCODING_CP1251, Microsoft analogue of ISO8859-5}
@itemdef{wxFONTENCODING_CP1252, Microsoft analogue of ISO8859-1}
@endDefList
As you may see, Microsoft's encoding partly mirror the standard ISO8859 ones,
but there are (minor) differences even between ISO8859-1 (Latin1, ISO encoding
for Western Europe) and CP1251 (WinLatin1, standard code page for English
versions of Windows) and there are more of them for other encodings.
As you may see, Microsoft's encoding partly mirror the standard ISO8859 ones,
but there are (minor) differences even between ISO8859-1 (Latin1, ISO encoding
for Western Europe) and CP1251 (WinLatin1, standard code page for English
versions of Windows) and there are more of them for other encodings.
The situation is particularly complicated with Cyrillic encodings for which
(more than) three incompatible encodings exist: KOI8 (the old standard, widely
used on the Internet), ISO8859-5 (ISO standard for Cyrillic) and CP1251
(WinCyrillic).
The situation is particularly complicated with Cyrillic encodings for which
(more than) three incompatible encodings exist: KOI8 (the old standard, widely
used on the Internet), ISO8859-5 (ISO standard for Cyrillic) and CP1251
(WinCyrillic).
This abundance of (incompatible) encodings should make it clear that using
encodings is less easy than it might seem. The problems arise both from the
fact that the standard encodings for the given language (say Russian, which is
written in Cyrillic) are different on different platforms and because the
fonts in the given encoding might just not be installed (this is especially a
problem with Unix, or, in general, non-Win32 systems).
This abundance of (incompatible) encodings should make it clear that using
encodings is less easy than it might seem. The problems arise both from the
fact that the standard encodings for the given language (say Russian, which is
written in Cyrillic) are different on different platforms and because the
fonts in the given encoding might just not be installed (this is especially a
problem with Unix, or, in general, non-Win32 systems).
To clarify, the wxFontEnumerator
class may be used to enumerate both all available encodings and to find the
facename(s) in which the given encoding exists. If you can find the font in
the correct encoding with wxFontEnumerator then your troubles are over, but,
unfortunately, sometimes this is not enough. For example, there is no standard
way (that I know of, please tell me if you do!) to find a font on a Windows system
for KOI8 encoding (only for WinCyrillic one which is quite different), so
wxFontEnumerator will never return one, even if the user has installed a KOI8
font on his system.
To clarify, the wxFontEnumerator
class may be used to enumerate both all available encodings and to find the
facename(s) in which the given encoding exists. If you can find the font in
the correct encoding with wxFontEnumerator then your troubles are over, but,
unfortunately, sometimes this is not enough. For example, there is no standard
way (that I know of, please tell me if you do!) to find a font on a Windows system
for KOI8 encoding (only for WinCyrillic one which is quite different), so
wxFontEnumerator will never return one, even if the user has installed a KOI8
font on his system.
To solve this problem, a wxFontMapper class is provided.
To solve this problem, a wxFontMapper class is provided.
This class stores the mapping between the encodings and the font face
names which support them in wxConfig object. Of
course, it would be fairly useless if it tried to determine these mappings by
itself, so, instead, it (optionally) asks the user and remembers his answers
so that the next time the program will automatically choose the correct font.
All these topics are illustrated by the @ref page_utils_samples_font;
please refer to it and the documentation of the classes mentioned here for
further explanations.
This class stores the mapping between the encodings and the font face
names which support them in wxConfig object. Of
course, it would be fairly useless if it tried to determine these mappings by
itself, so, instead, it (optionally) asks the user and remembers his answers
so that the next time the program will automatically choose the correct font.
All these topics are illustrated by the @ref page_samples_font;
please refer to it and the documentation of the classes mentioned here for
further explanations.
*/

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@ -84,7 +84,7 @@ translated special key names such as Backspace, End, Insert, etc.
@see
@li The gettext Manual: http://www.gnu.org/software/gettext/manual/gettext.html
@li @ref overview_nonenglish - It focuses on handling charsets related problems.
@li @ref page_utils_samples_internat - Shows you how all this looks in practice.
@li @ref page_samples_internat - Shows you how all this looks in practice.
*/