wxWidgets/samples/event/event.cpp
2001-05-27 13:21:16 +00:00

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/////////////////////////////////////////////////////////////////////////////
// Name: event.cpp
// Purpose: wxWindows sample demonstrating different event usage
// Author: Vadim Zeitlin
// Modified by:
// Created: 31.01.01
// RCS-ID: $Id$
// Copyright: (c) 2001 Vadim Zeitlin
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
// ============================================================================
// declarations
// ============================================================================
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
#ifdef __GNUG__
// DO NOT use event.cpp here, it breaks statics initialization in
// src/common/event.cpp and nothing works at all then!
#pragma implementation "eventsample.cpp"
#pragma interface "eventsample.cpp"
#endif
// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"
#ifdef __BORLANDC__
#pragma hdrstop
#endif
// for all others, include the necessary headers (this file is usually all you
// need because it includes almost all "standard" wxWindows headers)
#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif
// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------
// Define a new application type, each program should derive a class from wxApp
class MyApp : public wxApp
{
public:
// override base class virtuals
// ----------------------------
// this one is called on application startup and is a good place for the app
// initialization (doing it here and not in the ctor allows to have an error
// return: if OnInit() returns false, the application terminates)
virtual bool OnInit();
};
// Define a new frame type: this is going to be our main frame
class MyFrame : public wxFrame
{
public:
// ctor(s)
MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
virtual ~MyFrame();
void OnQuit(wxCommandEvent& event);
void OnAbout(wxCommandEvent& event);
void OnConnect(wxCommandEvent& event);
void OnDynamic(wxCommandEvent& event);
void OnPushEventHandler(wxCommandEvent& event);
void OnPopEventHandler(wxCommandEvent& event);
void OnTest(wxCommandEvent& event);
void OnUpdateUIPop(wxUpdateUIEvent& event);
protected:
// number of pushed event handlers
size_t m_nPush;
private:
// any class wishing to process wxWindows events must use this macro
DECLARE_EVENT_TABLE()
};
// Define a custom event handler
class MyEvtHandler : public wxEvtHandler
{
public:
MyEvtHandler(size_t level) { m_level = level; }
void OnTest(wxCommandEvent& event)
{
wxLogMessage(_T("This is the pushed test event handler #%u"), m_level);
// if we don't skip the event, the other event handlers won't get it:
// try commenting out this line and see what changes
event.Skip();
}
private:
size_t m_level;
DECLARE_EVENT_TABLE()
};
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
// IDs for the controls and the menu commands
enum
{
// menu items
Event_Quit = 1,
Event_About,
Event_Connect,
Event_Dynamic,
Event_Push,
Event_Pop,
Event_Test
};
// status bar fields
enum
{
Status_Main = 0,
Status_Dynamic,
Status_Push
};
// ----------------------------------------------------------------------------
// event tables and other macros for wxWindows
// ----------------------------------------------------------------------------
// the event tables connect the wxWindows events with the functions (event
// handlers) which process them. It can be also done at run-time, but for the
// simple menu events like this the static method is much simpler.
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(Event_Quit, MyFrame::OnQuit)
EVT_MENU(Event_About, MyFrame::OnAbout)
EVT_MENU(Event_Connect, MyFrame::OnConnect)
EVT_MENU(Event_Test, MyFrame::OnTest)
EVT_MENU(Event_Push, MyFrame::OnPushEventHandler)
EVT_MENU(Event_Pop, MyFrame::OnPopEventHandler)
EVT_UPDATE_UI(Event_Pop, MyFrame::OnUpdateUIPop)
END_EVENT_TABLE()
BEGIN_EVENT_TABLE(MyEvtHandler, wxEvtHandler)
EVT_MENU(Event_Test, MyEvtHandler::OnTest)
END_EVENT_TABLE()
// Create a new application object: this macro will allow wxWindows to create
// the application object during program execution (it's better than using a
// static object for many reasons) and also declares the accessor function
// wxGetApp() which will return the reference of the right type (i.e. MyApp and
// not wxApp)
IMPLEMENT_APP(MyApp)
// ============================================================================
// implementation
// ============================================================================
// ----------------------------------------------------------------------------
// the application class
// ----------------------------------------------------------------------------
// 'Main program' equivalent: the program execution "starts" here
bool MyApp::OnInit()
{
// create the main application window
MyFrame *frame = new MyFrame("Event wxWindows Sample",
wxPoint(50, 50), wxSize(450, 340));
// and show it (the frames, unlike simple controls, are not shown when
// created initially)
frame->Show(TRUE);
// success: wxApp::OnRun() will be called which will enter the main message
// loop and the application will run. If we returned FALSE here, the
// application would exit immediately.
return TRUE;
}
// ----------------------------------------------------------------------------
// main frame
// ----------------------------------------------------------------------------
// frame constructor
MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
: wxFrame((wxFrame *)NULL, -1, title, pos, size)
{
// init members
m_nPush = 0;
// create a menu bar
wxMenu *menuFile = new wxMenu;
menuFile->Append(Event_About, "&About...\tCtrl-A", "Show about dialog");
menuFile->AppendSeparator();
menuFile->Append(Event_Quit, "E&xit\tAlt-X", "Quit this program");
wxMenu *menuEvent = new wxMenu;
menuEvent->Append(Event_Connect, "&Connect\tCtrl-C",
"Connect or disconnect the dynamic event handler",
TRUE /* checkable */);
menuEvent->Append(Event_Dynamic, "&Dynamic event\tCtrl-D",
"Dynamic event sample - only works after Connect");
menuEvent->AppendSeparator();
menuEvent->Append(Event_Push, "&Push event handler\tCtrl-P",
"Push event handler for test event");
menuEvent->Append(Event_Pop, "P&op event handler\tCtrl-O",
"Pop event handler for test event");
menuEvent->Append(Event_Test, "Test event\tCtrl-T",
"Test event processed by pushed event handler");
// now append the freshly created menu to the menu bar...
wxMenuBar *menuBar = new wxMenuBar();
menuBar->Append(menuFile, "&File");
menuBar->Append(menuEvent, "&Event");
// ... and attach this menu bar to the frame
SetMenuBar(menuBar);
#if wxUSE_STATUSBAR
CreateStatusBar(3);
SetStatusText("Welcome to wxWindows event sample");
SetStatusText(_T("Dynamic: off"), Status_Dynamic);
SetStatusText(_T("Push count: 0"), Status_Push);
#endif // wxUSE_STATUSBAR
}
MyFrame::~MyFrame()
{
// we must pop any remaining event handlers to avoid memory leaks and
// crashes!
while ( m_nPush-- != 0 )
{
PopEventHandler(TRUE /* delete handler */);
}
}
// ----------------------------------------------------------------------------
// standard event handlers
// ----------------------------------------------------------------------------
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
// TRUE is to force the frame to close
Close(TRUE);
}
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
wxMessageBox(_T("Event sample shows different ways of using events\n"
"<EFBFBD> 2001 Vadim Zeitlin"),
_T("About Event Sample"), wxOK | wxICON_INFORMATION, this);
}
// ----------------------------------------------------------------------------
// dynamic event handling stuff
// ----------------------------------------------------------------------------
void MyFrame::OnDynamic(wxCommandEvent& WXUNUSED(event))
{
wxMessageBox(_T("This is a dynamic event handler which can be connected "
"and disconnected during run-time."),
_T("Dynamic Event Handler"), wxOK | wxICON_INFORMATION, this);
}
void MyFrame::OnConnect(wxCommandEvent& event)
{
if ( event.IsChecked() )
{
// disconnect
Connect(Event_Dynamic, -1, wxEVT_COMMAND_MENU_SELECTED,
(wxObjectEventFunction)
(wxEventFunction)
(wxCommandEventFunction)&MyFrame::OnDynamic);
SetStatusText(_T("You can now use \"Dynamic\" item in the menu"));
SetStatusText(_T("Dynamic: on"), Status_Dynamic);
}
else // connect
{
Disconnect(Event_Dynamic, -1, wxEVT_COMMAND_MENU_SELECTED);
SetStatusText(_T("You can no more use \"Dynamic\" item in the menu"));
SetStatusText(_T("Dynamic: off"), Status_Dynamic);
}
}
// ----------------------------------------------------------------------------
// push/pop event handlers support
// ----------------------------------------------------------------------------
void MyFrame::OnPushEventHandler(wxCommandEvent& WXUNUSED(event))
{
PushEventHandler(new MyEvtHandler(++m_nPush));
SetStatusText(wxString::Format(_T("Push count: %u"), m_nPush), Status_Push);
}
void MyFrame::OnPopEventHandler(wxCommandEvent& WXUNUSED(event))
{
wxCHECK_RET( m_nPush, _T("this command should be disabled!") );
PopEventHandler(TRUE /* delete handler */);
m_nPush--;
SetStatusText(wxString::Format(_T("Push count: %u"), m_nPush), Status_Push);
}
void MyFrame::OnTest(wxCommandEvent& event)
{
wxLogMessage(_T("This is the test event handler in the main frame"));
}
void MyFrame::OnUpdateUIPop(wxUpdateUIEvent& event)
{
event.Enable( m_nPush > 0 );
}