samples/event/event.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        event.cpp
   3 // Purpose:     wxWidgets sample demonstrating different event usage
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     31.01.01
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2001-2009 Vadim Zeitlin
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx/wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 // for all others, include the necessary headers (this file is usually all you
  28 // need because it includes almost all "standard" wxWidgets headers)
  29 #ifndef WX_PRECOMP
  30     #include "wx/wx.h"
  31 #endif
  32
  33 #ifndef __WXMSW__
  34     #include "../sample.xpm"
  35 #endif
  36
  37 #include <wx/statline.h>
  38 #include <wx/log.h>
  39
  40 // ----------------------------------------------------------------------------
  41 // event constants
  42 // ----------------------------------------------------------------------------
  43
  44 // define a custom event type (we don't need a separate declaration here but
  45 // usually you would use a matching wxDECLARE_EVENT in a header)
  46 wxDEFINE_EVENT(wxEVT_MY_CUSTOM_COMMAND, wxCommandEvent);
  47
  48 // it may also be convenient to define an event table macro for this event type
  49 #define EVT_MY_CUSTOM_COMMAND(id, fn) \
  50     DECLARE_EVENT_TABLE_ENTRY( \
  51         wxEVT_MY_CUSTOM_COMMAND, id, wxID_ANY, \
  52         wxCommandEventHandler(fn), \
  53         (wxObject *) NULL \
  54     ),
  55
  56 // ----------------------------------------------------------------------------
  57 // private classes
  58 // ----------------------------------------------------------------------------
  59
  60 // Define a new application type, each program should derive a class from wxApp
  61 class MyApp : public wxApp
  62 {
  63 public:
  64     // override base class virtuals
  65     // ----------------------------
  66
  67     // this one is called on application startup and is a good place for the app
  68     // initialization (doing it here and not in the ctor allows to have an error
  69     // return: if OnInit() returns false, the application terminates)
  70     virtual bool OnInit();
  71
  72     // these are regular event handlers used to highlight the events handling
  73     // order
  74     void OnClickDynamicHandlerApp(wxCommandEvent& event);
  75     void OnClickStaticHandlerApp(wxCommandEvent& event);
  76
  77     // we override wxConsoleApp::FilterEvent used to highlight the events
  78     // handling order
  79     virtual int FilterEvent(wxEvent& event);
  80
  81 private:
  82     DECLARE_EVENT_TABLE()
  83 };
  84
  85 // Define a custom button used to highlight the events handling order
  86 class MyEvtTestButton : public wxButton
  87 {
  88 public:
  89     static long BUTTON_ID;
  90
  91     MyEvtTestButton(wxWindow *parent, const wxString& label)
  92         : wxButton(parent, BUTTON_ID, label)
  93     {
  94         // Add a dynamic handler for this button event to button itself
  95         Connect(wxEVT_COMMAND_BUTTON_CLICKED,
  96                 wxCommandEventHandler(MyEvtTestButton::OnClickDynamicHandler));
  97     }
  98
  99 private:
 100     void OnClickDynamicHandler(wxCommandEvent& event)
 101     {
 102         wxLogMessage("Step 3 in \"How Events are Processed\":\n"
 103                      "Button::ownDynamicHandler");
 104
 105         event.Skip();
 106     }
 107
 108     void OnClickStaticHandler(wxCommandEvent& event)
 109     {
 110         wxLogMessage("Step 4 in \"How Events are Processed\":\n"
 111                      "Button::ownStaticHandler");
 112
 113         event.Skip();
 114     }
 115
 116     DECLARE_EVENT_TABLE()
 117 };
 118
 119 long MyEvtTestButton::BUTTON_ID = wxNewId();
 120
 121 // Define a new frame type: this is going to be our main frame
 122 class MyFrame : public wxFrame
 123 {
 124 public:
 125     // ctor(s)
 126     MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
 127     virtual ~MyFrame();
 128
 129     void OnQuit(wxCommandEvent& event);
 130     void OnAbout(wxCommandEvent& event);
 131 #ifdef wxHAS_EVENT_BIND
 132     void OnBind(wxCommandEvent& event);
 133 #endif // wxHAS_EVENT_BIND
 134     void OnConnect(wxCommandEvent& event);
 135     void OnDynamic(wxCommandEvent& event);
 136     void OnPushEventHandler(wxCommandEvent& event);
 137     void OnPopEventHandler(wxCommandEvent& event);
 138     void OnTest(wxCommandEvent& event);
 139
 140     void OnFireCustom(wxCommandEvent& event);
 141     void OnProcessCustom(wxCommandEvent& event);
 142
 143     void OnUpdateUIPop(wxUpdateUIEvent& event);
 144
 145     // regular event handlers used to highlight the events handling order
 146     void OnClickDynamicHandlerFrame(wxCommandEvent& event);
 147     void OnClickDynamicHandlerButton(wxCommandEvent& event);
 148     void OnClickStaticHandlerFrame(wxCommandEvent& event);
 149
 150 private:
 151     // symbolic names for the status bar fields
 152     enum
 153     {
 154         Status_Main = 0,
 155         Status_Dynamic,
 156         Status_Push
 157     };
 158
 159     void UpdateDynamicStatus(bool on)
 160     {
 161 #if wxUSE_STATUSBAR
 162         if ( on )
 163         {
 164             SetStatusText("You can now use \"Dynamic\" item in the menu");
 165             SetStatusText("Dynamic: on", Status_Dynamic);
 166         }
 167         else
 168         {
 169             SetStatusText("You can no more use \"Dynamic\" item in the menu");
 170             SetStatusText("Dynamic: off", Status_Dynamic);
 171         }
 172 #endif // wxUSE_STATUSBAR
 173     }
 174
 175     // number of pushed event handlers
 176     unsigned m_nPush;
 177
 178     // the button to whose event we connect dynamically
 179     wxButton *m_btnDynamic;
 180
 181     // the button used to highlight the event handlers execution order
 182     MyEvtTestButton *m_testBtn;
 183
 184
 185     // any class wishing to process wxWidgets events must use this macro
 186     DECLARE_EVENT_TABLE()
 187 };
 188
 189 // Define a custom event handler
 190 class MyEvtHandler : public wxEvtHandler
 191 {
 192 public:
 193     MyEvtHandler(size_t level) { m_level = level; }
 194
 195     void OnTest(wxCommandEvent& event)
 196     {
 197         wxLogMessage(wxT("This is the pushed test event handler #%u"), m_level);
 198
 199         // if we don't skip the event, the other event handlers won't get it:
 200         // try commenting out this line and see what changes
 201         event.Skip();
 202     }
 203
 204 private:
 205     unsigned m_level;
 206
 207     DECLARE_EVENT_TABLE()
 208 };
 209
 210 // ----------------------------------------------------------------------------
 211 // constants
 212 // ----------------------------------------------------------------------------
 213
 214 // IDs for the controls and the menu commands
 215 enum
 216 {
 217     // menu items
 218     Event_Quit = 1,
 219     Event_About,
 220     Event_Bind,
 221     Event_Connect,
 222     Event_Dynamic,
 223     Event_Push,
 224     Event_Pop,
 225     Event_Custom,
 226     Event_Test
 227 };
 228
 229 // ----------------------------------------------------------------------------
 230 // event tables and other macros for wxWidgets
 231 // ----------------------------------------------------------------------------
 232
 233 // The event tables connect the wxWidgets events with the functions (event
 234 // handlers) which process them.
 235 BEGIN_EVENT_TABLE(MyApp, wxApp)
 236     // Add a static handler for button Click event in the app
 237     EVT_BUTTON(MyEvtTestButton::BUTTON_ID, MyApp::OnClickStaticHandlerApp)
 238 END_EVENT_TABLE()
 239
 240 BEGIN_EVENT_TABLE(MyEvtTestButton, wxButton)
 241     // Add a static handler to this button itself for its own event
 242     EVT_BUTTON(BUTTON_ID, MyEvtTestButton::OnClickStaticHandler)
 243 END_EVENT_TABLE()
 244
 245 // This can be also done at run-time, but for the
 246 // simple menu events like this the static method is much simpler.
 247 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 248     EVT_MENU(Event_Quit,  MyFrame::OnQuit)
 249     EVT_MENU(Event_About, MyFrame::OnAbout)
 250
 251 #ifdef wxHAS_EVENT_BIND
 252     EVT_MENU(Event_Bind, MyFrame::OnBind)
 253 #endif // wxHAS_EVENT_BIND
 254     EVT_MENU(Event_Connect, MyFrame::OnConnect)
 255
 256     EVT_MENU(Event_Custom, MyFrame::OnFireCustom)
 257     EVT_MENU(Event_Test, MyFrame::OnTest)
 258     EVT_MENU(Event_Push, MyFrame::OnPushEventHandler)
 259     EVT_MENU(Event_Pop, MyFrame::OnPopEventHandler)
 260
 261     EVT_UPDATE_UI(Event_Pop, MyFrame::OnUpdateUIPop)
 262
 263     EVT_MY_CUSTOM_COMMAND(wxID_ANY, MyFrame::OnProcessCustom)
 264
 265     // the line below would also work if OnProcessCustom() were defined as
 266     // taking a wxEvent (as required by EVT_CUSTOM) and not wxCommandEvent
 267     //EVT_CUSTOM(wxEVT_MY_CUSTOM_COMMAND, wxID_ANY, MyFrame::OnProcessCustom)
 268
 269     // Add a static handler in the parent frame for button event
 270     EVT_BUTTON(MyEvtTestButton::BUTTON_ID, MyFrame::OnClickStaticHandlerFrame)
 271 END_EVENT_TABLE()
 272
 273 BEGIN_EVENT_TABLE(MyEvtHandler, wxEvtHandler)
 274     EVT_MENU(Event_Test, MyEvtHandler::OnTest)
 275 END_EVENT_TABLE()
 276
 277 // Create a new application object: this macro will allow wxWidgets to create
 278 // the application object during program execution (it's better than using a
 279 // static object for many reasons) and also declares the accessor function
 280 // wxGetApp() which will return the reference of the right type (i.e. MyApp and
 281 // not wxApp)
 282 IMPLEMENT_APP(MyApp)
 283
 284 // ============================================================================
 285 // implementation
 286 // ============================================================================
 287
 288 // ----------------------------------------------------------------------------
 289 // the application class
 290 // ----------------------------------------------------------------------------
 291
 292 // 'Main program' equivalent: the program execution "starts" here
 293 bool MyApp::OnInit()
 294 {
 295     if ( !wxApp::OnInit() )
 296         return false;
 297
 298     // create the main application window
 299     MyFrame *frame = new MyFrame(wxT("Event wxWidgets Sample"),
 300                                  wxPoint(50, 50), wxSize(600, 340));
 301
 302     // and show it (the frames, unlike simple controls, are not shown when
 303     // created initially)
 304     frame->Show(true);
 305
 306     // Add a dynamic handler at the application level for the test button
 307     Connect(MyEvtTestButton::BUTTON_ID, wxEVT_COMMAND_BUTTON_CLICKED,
 308             wxCommandEventHandler(MyApp::OnClickDynamicHandlerApp));
 309
 310     // success: wxApp::OnRun() will be called which will enter the main message
 311     // loop and the application will run. If we returned false here, the
 312     // application would exit immediately.
 313     return true;
 314 }
 315
 316 // This is always the first to handle an event !
 317 int MyApp::FilterEvent(wxEvent& event)
 318 {
 319     if ( event.GetEventType() == wxEVT_COMMAND_BUTTON_CLICKED &&
 320             event.GetId() == MyEvtTestButton::BUTTON_ID )
 321     {
 322         wxLogMessage("Step 0 in \"How Events are Processed\":\n"
 323                      "App::FilterEvent");
 324     }
 325
 326     return wxApp::FilterEvent(event);
 327 }
 328
 329 void MyApp::OnClickDynamicHandlerApp(wxCommandEvent& event)
 330 {
 331     wxLogMessage("Step 7, 3 in \"How Events are Processed\":\n"
 332                  "App::DynamicHandler_InAppTable");
 333
 334     event.Skip();
 335 }
 336
 337 void MyApp::OnClickStaticHandlerApp(wxCommandEvent& event)
 338 {
 339     wxLogMessage("Step 7, 4 in \"How Events are Processed\":\n"
 340                  "App::StaticHandler_InAppTable");
 341
 342     wxLogMessage("Button click processed, there should be no more messages "
 343                  "about handling events from the button.\n\n"
 344                  "The log below shows the order in which the handlers "
 345                  "were executed.");
 346     wxLog::FlushActive();
 347
 348     event.Skip();
 349 }
 350
 351 // ----------------------------------------------------------------------------
 352 // main frame
 353 // ----------------------------------------------------------------------------
 354
 355 // frame constructor
 356 MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
 357        : wxFrame(NULL, wxID_ANY, title, pos, size)
 358 {
 359     SetIcon(wxICON(sample));
 360
 361     // init members
 362     m_nPush = 0;
 363     m_btnDynamic = NULL;
 364
 365     // create a menu bar
 366     wxMenu *menuFile = new wxMenu;
 367
 368     menuFile->Append(Event_About, wxT("&About\tCtrl-A"), wxT("Show about dialog"));
 369     menuFile->AppendSeparator();
 370     menuFile->Append(Event_Quit, wxT("E&xit\tAlt-X"), wxT("Quit this program"));
 371
 372     wxMenu *menuEvent = new wxMenu;
 373 #ifdef wxHAS_EVENT_BIND
 374     menuEvent->AppendCheckItem(Event_Bind, "&Bind\tCtrl-B",
 375                                "Bind or unbind a dynamic event handler");
 376 #endif // wxHAS_EVENT_BIND
 377     menuEvent->AppendCheckItem(Event_Connect, wxT("&Connect\tCtrl-C"),
 378                      wxT("Connect or disconnect the dynamic event handler"));
 379     menuEvent->Append(Event_Dynamic, wxT("&Dynamic event\tCtrl-D"),
 380                       wxT("Dynamic event sample - only works after Connect"));
 381     menuEvent->AppendSeparator();
 382     menuEvent->Append(Event_Push, wxT("&Push event handler\tCtrl-P"),
 383                       wxT("Push event handler for test event"));
 384     menuEvent->Append(Event_Pop, wxT("P&op event handler\tCtrl-O"),
 385                       wxT("Pop event handler for test event"));
 386     menuEvent->Append(Event_Test, wxT("Test event\tCtrl-T"),
 387                       wxT("Test event processed by pushed event handler"));
 388     menuEvent->AppendSeparator();
 389     menuEvent->Append(Event_Custom, wxT("Fire c&ustom event\tCtrl-U"),
 390                       wxT("Generate a custom event"));
 391
 392     // now append the freshly created menu to the menu bar...
 393     wxMenuBar *menuBar = new wxMenuBar();
 394     menuBar->Append(menuFile, wxT("&File"));
 395     menuBar->Append(menuEvent, wxT("&Event"));
 396
 397     // ... and attach this menu bar to the frame
 398     SetMenuBar(menuBar);
 399
 400 #if wxUSE_STATUSBAR
 401     CreateStatusBar(3);
 402     SetStatusText(wxT("Welcome to wxWidgets event sample"));
 403     SetStatusText(wxT("Dynamic: off"), Status_Dynamic);
 404     SetStatusText(wxT("Push count: 0"), Status_Push);
 405 #endif // wxUSE_STATUSBAR
 406
 407     wxPanel * const panel = new wxPanel(this);
 408     wxSizer * const mainSizer = new wxBoxSizer(wxVERTICAL);
 409     wxSizer * const sizer = new wxBoxSizer(wxHORIZONTAL);
 410     const wxSizerFlags centreY(wxSizerFlags().Centre().Border());
 411     sizer->Add(new wxStaticText(panel, wxID_ANY,
 412         "This button will only work if its handler is dynamically connected"),
 413         centreY);
 414     m_btnDynamic = new wxButton(panel, Event_Dynamic, "&Dynamic button");
 415     sizer->Add(m_btnDynamic, centreY);
 416
 417     mainSizer->Add(sizer, 1, wxEXPAND);
 418     mainSizer->Add(new wxStaticLine(panel), 0, wxEXPAND);
 419     mainSizer->Add(new wxStaticLine(panel), 0, wxEXPAND);
 420
 421     m_testBtn = new MyEvtTestButton(panel, "Test Event Handlers Execution Order");
 422
 423     // After being created, an instance of MyEvtTestButton already has its own
 424     // event handlers (see class definition);
 425
 426     // Add a dynamic handler for this button event in the parent frame
 427     Connect(m_testBtn->GetId(), wxEVT_COMMAND_BUTTON_CLICKED,
 428             wxCommandEventHandler(MyFrame::OnClickDynamicHandlerFrame));
 429
 430     // Bind a method of this frame (notice "this" argument!) to the button
 431     // itself
 432     m_testBtn->Connect(wxEVT_COMMAND_BUTTON_CLICKED,
 433                        wxCommandEventHandler(MyFrame::OnClickDynamicHandlerButton),
 434                        NULL,
 435                        this);
 436
 437     mainSizer->Add(m_testBtn);
 438     panel->SetSizer(mainSizer);
 439 }
 440
 441 MyFrame::~MyFrame()
 442 {
 443     // we must pop any remaining event handlers to avoid memory leaks and
 444     // crashes!
 445     while ( m_nPush-- != 0 )
 446     {
 447         PopEventHandler(true /* delete handler */);
 448     }
 449 }
 450
 451 // ----------------------------------------------------------------------------
 452 // standard event handlers
 453 // ----------------------------------------------------------------------------
 454
 455 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 456 {
 457     // true is to force the frame to close
 458     Close(true);
 459 }
 460
 461 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 462 {
 463     wxMessageBox("Event sample shows different ways of using events\n"
 464                  "(c) 2001-2009 Vadim Zeitlin",
 465                  "About wxWidgets Event Sample",
 466                  wxOK | wxICON_INFORMATION, this);
 467 }
 468
 469 void MyFrame::OnClickStaticHandlerFrame(wxCommandEvent& event)
 470 {
 471     wxLogMessage("Step 6, 4 in \"How Events are Processed\":\n"
 472                  "parentWin::StaticHandler_InFrameTable");
 473
 474     event.Skip();
 475 }
 476
 477 // ----------------------------------------------------------------------------
 478 // dynamic event handling stuff
 479 // ----------------------------------------------------------------------------
 480
 481 void MyFrame::OnClickDynamicHandlerFrame(wxCommandEvent& event)
 482 {
 483     wxLogMessage("Step 6, 3 in \"How Events are Processed\":\n"
 484                  "parentWin::DynamicHandler_InFrameTable");
 485
 486     event.Skip();
 487 }
 488
 489 void MyFrame::OnClickDynamicHandlerButton(wxCommandEvent& event)
 490 {
 491     wxLogMessage("Step 3 in \"How Events are Processed\":\n"
 492                  "parentWin::DynamicHandler_InButtonTable");
 493
 494     event.Skip();
 495 }
 496
 497 void MyFrame::OnDynamic(wxCommandEvent& event)
 498 {
 499     wxString origin;
 500     if ( event.GetEventObject() == this )
 501         origin = "menu item";
 502     else if ( event.GetEventObject() == m_btnDynamic )
 503         origin = "button";
 504     else
 505         origin = "unknown event source";
 506
 507     wxMessageBox
 508     (
 509         "This message box is shown from the dynamically connected "
 510         "event handler in response to event generated by " + origin,
 511         "wxWidgets Event Sample", wxOK | wxICON_INFORMATION, this
 512     );
 513 }
 514
 515 #ifdef wxHAS_EVENT_BIND
 516
 517 void MyFrame::OnBind(wxCommandEvent& event)
 518 {
 519     if ( event.IsChecked() )
 520     {
 521         // as we bind directly to the button, there is no need to use an id
 522         // here: the button will only ever get its own events
 523         m_btnDynamic->Bind(wxEVT_COMMAND_BUTTON_CLICKED, &MyFrame::OnDynamic,
 524                            this);
 525
 526         // but we do need the id for the menu command as the frame gets all of
 527         // them
 528         Bind(wxEVT_COMMAND_MENU_SELECTED, &MyFrame::OnDynamic, this,
 529              Event_Dynamic);
 530     }
 531     else // disconnect
 532     {
 533         m_btnDynamic->Unbind(wxEVT_COMMAND_BUTTON_CLICKED,
 534                              &MyFrame::OnDynamic, this);
 535         Unbind(wxEVT_COMMAND_MENU_SELECTED, &MyFrame::OnDynamic, this,
 536                Event_Dynamic);
 537     }
 538
 539     UpdateDynamicStatus(event.IsChecked());
 540 }
 541
 542 #endif // wxHAS_EVENT_BIND
 543
 544 void MyFrame::OnConnect(wxCommandEvent& event)
 545 {
 546     if ( event.IsChecked() )
 547     {
 548         m_btnDynamic->Connect(wxID_ANY, wxEVT_COMMAND_BUTTON_CLICKED,
 549                               wxCommandEventHandler(MyFrame::OnDynamic),
 550                               NULL, this);
 551         Connect(Event_Dynamic, wxEVT_COMMAND_MENU_SELECTED,
 552                 wxCommandEventHandler(MyFrame::OnDynamic));
 553     }
 554     else // disconnect
 555     {
 556         m_btnDynamic->Disconnect(wxID_ANY, wxEVT_COMMAND_BUTTON_CLICKED,
 557                                  wxCommandEventHandler(MyFrame::OnDynamic),
 558                                  NULL, this);
 559         Disconnect(Event_Dynamic, wxEVT_COMMAND_MENU_SELECTED,
 560                    wxCommandEventHandler(MyFrame::OnDynamic));
 561     }
 562
 563     UpdateDynamicStatus(event.IsChecked());
 564 }
 565
 566 // ----------------------------------------------------------------------------
 567 // push/pop event handlers support
 568 // ----------------------------------------------------------------------------
 569
 570 void MyFrame::OnPushEventHandler(wxCommandEvent& WXUNUSED(event))
 571 {
 572     PushEventHandler(new MyEvtHandler(++m_nPush));
 573
 574 #if wxUSE_STATUSBAR
 575     SetStatusText(wxString::Format(wxT("Push count: %u"), m_nPush), Status_Push);
 576 #endif // wxUSE_STATUSBAR
 577 }
 578
 579 void MyFrame::OnPopEventHandler(wxCommandEvent& WXUNUSED(event))
 580 {
 581     wxCHECK_RET( m_nPush, wxT("this command should be disabled!") );
 582
 583     PopEventHandler(true /* delete handler */);
 584     m_nPush--;
 585
 586 #if wxUSE_STATUSBAR
 587     SetStatusText(wxString::Format(wxT("Push count: %u"), m_nPush), Status_Push);
 588 #endif // wxUSE_STATUSBAR
 589 }
 590
 591 void MyFrame::OnTest(wxCommandEvent& WXUNUSED(event))
 592 {
 593     wxLogMessage(wxT("This is the test event handler in the main frame"));
 594 }
 595
 596 void MyFrame::OnUpdateUIPop(wxUpdateUIEvent& event)
 597 {
 598     event.Enable( m_nPush > 0 );
 599 }
 600
 601 // ----------------------------------------------------------------------------
 602 // custom event methods
 603 // ----------------------------------------------------------------------------
 604
 605 void MyFrame::OnFireCustom(wxCommandEvent& WXUNUSED(event))
 606 {
 607     wxCommandEvent eventCustom(wxEVT_MY_CUSTOM_COMMAND);
 608
 609     wxPostEvent(this, eventCustom);
 610 }
 611
 612 void MyFrame::OnProcessCustom(wxCommandEvent& WXUNUSED(event))
 613 {
 614     wxLogMessage(wxT("Got a custom event!"));
 615 }
 616