d9ced90bcf
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58676 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
115 lines
5.6 KiB
C
115 lines
5.6 KiB
C
/////////////////////////////////////////////////////////////////////////////
|
|
// Name: windowsizing.h
|
|
// Purpose: topic overview
|
|
// Author: wxWidgets team
|
|
// RCS-ID: $Id$
|
|
// Licence: wxWindows license
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
/**
|
|
|
|
@page overview_windowsizing Window Sizing Overview
|
|
|
|
It can sometimes be confusing to keep track of the various size-related
|
|
attributes of a wxWindow, how they relate to each other, and how they interact
|
|
with sizers. This document will attempt to clear the fog a little, and give
|
|
some simple explanations of things.
|
|
|
|
@li @ref overview_windowsizing_glossary
|
|
@li @ref overview_windowsizing_func
|
|
|
|
|
|
<hr>
|
|
|
|
|
|
@section overview_windowsizing_glossary Glossary
|
|
|
|
@li @b "Best Size": the best size of a widget depends on what kind of widget it is,
|
|
and usually also on the contents of the widget. For example a wxListBox's best
|
|
size will be calculated based on how many items it has, up to a certain limit,
|
|
or a wxButton's best size will be calculated based on its label size, but
|
|
normally won't be smaller than the platform default button size (unless a style
|
|
flag overrides that).
|
|
There is a special virtual method in the C++ window classes called
|
|
wxWindow::DoGetBestSize() that a class needs to override if it wants to calculate
|
|
its own best size based on its content.
|
|
|
|
@li @b "Minimal Size": the minimal size of a widget is a size that is normally explicitly
|
|
set by the programmer either with the wxWindow::SetMinSize() method or with the
|
|
wxWindow::SetSizeHints() method.
|
|
Most controls will also set the minimal size to the size given in the control's
|
|
constructor if a non-default value is passed.
|
|
Top-level windows such as wxFrame will not allow the user to resize the frame below
|
|
the minimal size.
|
|
|
|
@li @b "Maximum Size": just like for the minimal size, the maximum size is normally
|
|
explicitely set by the programmer with the wxWindow::SetMaxSize() method or
|
|
with wxWindow::SetSizeHints().
|
|
Top-level windows such as wxFrame will not allow the user to resize the frame above
|
|
the maximum size.
|
|
|
|
@li @b "Size": the size of a widget can be explicitly set or fetched with the
|
|
wxWindow::SetSize() or wxWindow::GetSize() methods.
|
|
This size value is the size that the widget is currently using on screen and is
|
|
the way to change the size of something that is not being managed by a sizer.
|
|
|
|
@li @b "Client Size": the client size represents the widget's area inside of any
|
|
borders belonging to the widget and is the area that can be drawn upon in a
|
|
@c EVT_PAINT event. If a widget doesn't have a border then its client size is
|
|
the same as its size.
|
|
|
|
@li @b "Initial Size": the initial size of a widget is the size given to the
|
|
constructor of the widget, if any.
|
|
As mentioned above most controls will also set this size value as the control's
|
|
minimal size. If the size passed to the constructor is the default ::wxDefaultSize,
|
|
or if the size is not fully specified (such as wxSize(150,-1)) then most controls
|
|
will fill in the missing size components using the best size and will set the
|
|
initial size of the control to the resulting size.
|
|
|
|
@li @b "Virtual Size": the virtual size is the size of the potentially viewable
|
|
area of the widget.
|
|
The virtual size of a widget may be larger than its actual size and in this
|
|
case scrollbars will appear to the let the user 'explore' the full contents
|
|
of the widget.
|
|
See wxScrolled for more info.
|
|
|
|
|
|
@section overview_windowsizing_func Functions related to sizing
|
|
|
|
@li wxWindow::GetEffectiveMinSize(): returns a blending of the widget's minimal size
|
|
and best size, giving precedence to the minimal size.
|
|
For example, if a widget's min size is set to (150, -1) and the best size is
|
|
(80, 22) then the best fitting size is (150, 22). If the min size is (50, 20)
|
|
then the best fitting size is (50, 20). This method is what is called by the
|
|
sizers when determining what the requirements of each item in the sizer is,
|
|
and is used for calculating the overall minimum needs of the sizer.
|
|
|
|
@li wxWindow::SetInitialSize(): this is a little different than the typical size
|
|
setters. Rather than just setting an "initial size" attribute it actually sets
|
|
the minimal size to the value passed in, blends that value with the best size,
|
|
and then sets the size of the widget to be the result.
|
|
So you can consider this method to be a "Smart SetSize". This method is what is
|
|
called by the constructor of most controls to set the minimal size and the initial
|
|
size of the control.
|
|
|
|
@li wxWindow::Fit(): this method sets the size of a window to fit around its children.
|
|
If it has no children then nothing is done, if it does have children then the size
|
|
of the window is set to the window's best size.
|
|
|
|
@li wxSizer::Fit(): this sets the size of the window to be large enough to
|
|
accommodate the minimum size needed by the sizer, (along with a few other
|
|
constraints...). If the sizer is the one that is assigned to the window then
|
|
this should be equivalent to wxWindow::Fit().
|
|
|
|
@li wxSizer::Layout(): recalculates the minimum space needed by each item in the
|
|
sizer, and then lays out the items within the space currently allotted to the sizer.
|
|
|
|
@li wxWindow::Layout(): if the window has a sizer then it sets the space given to
|
|
the sizer to the current size of the window, which results in a call to
|
|
wxSizer::Layout(). If the window has layout constraints instead of a sizer then
|
|
the constraints algorithm is run. The @c Layout() method is what is called by
|
|
the default @c EVT_SIZE handler for container windows.
|
|
|
|
*/
|
|
|