samples/erase/erase.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        erase.cpp
   3 // Purpose:     Erase wxWidgets sample
   4 // Author:      Robert Roebling
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Robert Roebling
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #if defined(__GNUG__) && !defined(__APPLE__)
  21     #pragma implementation "erase.cpp"
  22     #pragma interface "erase.cpp"
  23 #endif
  24
  25 // For compilers that support precompilation, includes "wx/wx.h".
  26 #include "wx/wxprec.h"
  27
  28 #ifdef __BORLANDC__
  29     #pragma hdrstop
  30 #endif
  31
  32 // for all others, include the necessary headers (this file is usually all you
  33 // need because it includes almost all "standard" wxWidgets headers)
  34 #ifndef WX_PRECOMP
  35     #include "wx/wx.h"
  36 #endif
  37
  38 // ----------------------------------------------------------------------------
  39 // resources
  40 // ----------------------------------------------------------------------------
  41 // the application icon
  42 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__) || defined(__WXX11__)
  43     #include "mondrian.xpm"
  44 #endif
  45
  46 // ----------------------------------------------------------------------------
  47 // private classes
  48 // ----------------------------------------------------------------------------
  49
  50 class MyApp : public wxApp
  51 {
  52 public:
  53     virtual bool OnInit();
  54 };
  55
  56
  57 class MyCanvas : public wxScrolledWindow
  58 {
  59 public:
  60     MyCanvas( wxFrame *parent );
  61
  62     void UseBuffer(bool useBuffer) { m_useBuffer = useBuffer; Refresh(); }
  63
  64 private:
  65     void OnPaint( wxPaintEvent &event );
  66     void OnChar( wxKeyEvent &event );
  67     void OnEraseBackground( wxEraseEvent &event );
  68
  69     void DoPaint(wxDC& dc);
  70
  71
  72     wxBitmap    m_bitmap;
  73     wxString    m_text;
  74
  75     // use wxMemoryDC in OnPaint()?
  76     bool m_useBuffer;
  77
  78     DECLARE_EVENT_TABLE()
  79 };
  80
  81 class MyFrame : public wxFrame
  82 {
  83 public:
  84     MyFrame();
  85
  86     void OnUseBuffer(wxCommandEvent& event);
  87     void OnQuit(wxCommandEvent& event);
  88     void OnAbout(wxCommandEvent& event);
  89
  90 private:
  91     MyCanvas *m_canvas;
  92
  93     DECLARE_EVENT_TABLE()
  94 };
  95
  96
  97 // ----------------------------------------------------------------------------
  98 // constants
  99 // ----------------------------------------------------------------------------
 100
 101 enum
 102 {
 103     // menu items
 104     Erase_Menu_UseBuffer = 100,
 105     Erase_Menu_Exit = wxID_EXIT,
 106     Erase_Menu_About = wxID_ABOUT
 107 };
 108
 109
 110 // ----------------------------------------------------------------------------
 111 // the application class
 112 // ----------------------------------------------------------------------------
 113
 114 IMPLEMENT_APP(MyApp)
 115
 116 bool MyApp::OnInit()
 117 {
 118     MyFrame *frame = new MyFrame;
 119
 120     frame->Show(true);
 121
 122     return true;
 123 }
 124
 125 // ----------------------------------------------------------------------------
 126 // main frame
 127 // ----------------------------------------------------------------------------
 128
 129 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 130     EVT_MENU(Erase_Menu_UseBuffer,  MyFrame::OnUseBuffer)
 131     EVT_MENU(Erase_Menu_Exit,  MyFrame::OnQuit)
 132     EVT_MENU(Erase_Menu_About, MyFrame::OnAbout)
 133 END_EVENT_TABLE()
 134
 135 // frame constructor
 136 MyFrame::MyFrame()
 137        : wxFrame(NULL, wxID_ANY, _T("Erase sample"),
 138                  wxPoint(50, 50), wxSize(450, 340))
 139 {
 140     SetIcon(wxICON(mondrian));
 141
 142     wxMenu *menuFile = new wxMenu(_T(""), wxMENU_TEAROFF);
 143     menuFile->AppendCheckItem(Erase_Menu_UseBuffer, _T("&Use memory DC\tCtrl-M"));
 144     menuFile->AppendSeparator();
 145     menuFile->Append(Erase_Menu_Exit, _T("E&xit\tAlt-X"), _T("Quit this program"));
 146
 147
 148     wxMenu *helpMenu = new wxMenu;
 149     helpMenu->Append(Erase_Menu_About, _T("&About...\tCtrl-A"), _T("Show about dialog"));
 150
 151     wxMenuBar *menuBar = new wxMenuBar();
 152     menuBar->Append(menuFile, _T("&File"));
 153     menuBar->Append(helpMenu, _T("&Help"));
 154
 155     SetMenuBar(menuBar);
 156
 157 #if wxUSE_STATUSBAR
 158     // create a status bar just for fun (by default with 1 pane only)
 159     CreateStatusBar(2);
 160     SetStatusText(_T("Welcome to wxWidgets erase sample!"));
 161 #endif // wxUSE_STATUSBAR
 162
 163     m_canvas = new MyCanvas( this );
 164 }
 165
 166
 167 void MyFrame::OnUseBuffer(wxCommandEvent& event)
 168 {
 169     m_canvas->UseBuffer(event.IsChecked());
 170 }
 171
 172 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 173 {
 174     Close(true);
 175 }
 176
 177 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 178 {
 179     wxMessageBox(_T("This sample shows how you can draw custom background."),
 180                  _T("About Erase Sample"), wxOK | wxICON_INFORMATION, this);
 181 }
 182
 183
 184 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 185     EVT_PAINT(  MyCanvas::OnPaint)
 186     EVT_CHAR(  MyCanvas::OnChar)
 187     EVT_ERASE_BACKGROUND(  MyCanvas::OnEraseBackground)
 188 END_EVENT_TABLE()
 189
 190 MyCanvas::MyCanvas( wxFrame *parent )
 191         : wxScrolledWindow( parent, wxID_ANY, wxDefaultPosition, wxDefaultSize,
 192                             wxScrolledWindowStyle | wxSUNKEN_BORDER )
 193 {
 194     m_useBuffer = false;
 195
 196     SetScrollbars( 10, 10, 40, 100, 0, 0 );
 197
 198     m_bitmap = wxBitmap( wxICON(mondrian) );
 199
 200     new wxStaticBitmap( this, wxID_ANY, m_bitmap, wxPoint(80,20) );
 201 }
 202
 203 void MyCanvas::OnChar( wxKeyEvent &event )
 204 {
 205 #if wxUSE_UNICODE
 206     if (event.m_uniChar)
 207     {
 208         m_text += event.m_uniChar;
 209         Refresh();
 210         return;
 211     }
 212 #endif
 213
 214     // some test cases
 215     switch (event.m_keyCode)
 216     {
 217         case WXK_UP: m_text += wxT( "<UP>" ); break;
 218         case WXK_LEFT: m_text += wxT( "<LEFT>" ); break;
 219         case WXK_RIGHT: m_text += wxT( "<RIGHT>" ); break;
 220         case WXK_DOWN: m_text += wxT( "<DOWN>" ); break;
 221         case WXK_RETURN: m_text += wxT( "<ENTER>" ); break;
 222         default: m_text += (wxChar)event.m_keyCode; break;
 223     }
 224 }
 225
 226 void MyCanvas::DoPaint(wxDC& dc)
 227 {
 228     dc.SetBrush( *wxBLACK_BRUSH );
 229     dc.DrawRectangle( 0,0,200,50 );
 230
 231     dc.DrawBitmap( m_bitmap, 10, 20, true );
 232
 233     dc.SetTextForeground(*wxBLUE);
 234     dc.DrawText(_T("This text is drawn from OnPaint"), 65, 65);
 235
 236     wxString tmp;
 237     tmp.Printf( _T("Hit any key to display more text: %s"), m_text.c_str() );
 238     int w,h;
 239     dc.GetTextExtent( tmp, &w, &h );
 240     dc.SetBrush( *wxWHITE_BRUSH );
 241     dc.DrawRectangle( 65, 85, w, h );
 242     dc.DrawText( tmp, 65, 85 );
 243
 244 #if 0
 245     wxRegionIterator upd( GetUpdateRegion() );
 246     while (upd)
 247     {
 248         wxLogDebug( _T("Paint: %d %d %d %d"), upd.GetX(), upd.GetY(), upd.GetWidth(), upd.GetHeight() );
 249         upd ++;
 250     }
 251 #endif
 252
 253 #if 0
 254     wxSize size = GetSize();
 255     wxSize client_size = GetClientSize();
 256     wxLogDebug( _T("size %d %d client_size %d %d"), size.x, size.y, client_size.x, client_size.y );
 257 #endif
 258
 259 #if 0
 260     int i;
 261     dc.SetPen( *wxWHITE_PEN );
 262     for (i = 0; i < 20; i += 2)
 263        dc.DrawLine( i,i, i+100,i );
 264
 265     dc.SetPen( *wxWHITE_PEN );
 266     for (i = 200; i < 220; i += 2)
 267        dc.DrawLine( i-200,i, i-100,i );
 268
 269     wxRegion region( 110, 110, 80, 80 );
 270     wxRegion hole( 130, 130, 40, 1 );
 271     region.Intersect( hole );
 272     dc.SetClippingRegion( region );
 273
 274     dc.SetBrush( *wxRED_BRUSH );
 275     dc.DrawRectangle( 100, 100, 200, 200 );
 276
 277     dc.DestroyClippingRegion();
 278
 279     dc.SetPen( *wxTRANSPARENT_PEN );
 280
 281     wxRegion strip( 110, 200, 30, 1 );
 282     wxRegionIterator it( strip );
 283     while (it)
 284     {
 285         dc.DrawRectangle( it.GetX(), it.GetY(), it.GetWidth(), it.GetHeight() );
 286         it ++;
 287     }
 288 #endif // 0
 289 }
 290
 291 void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
 292 {
 293     wxPaintDC dcWin(this);
 294     PrepareDC( dcWin );
 295
 296     if ( m_useBuffer )
 297     {
 298         const wxSize size = GetClientSize();
 299         wxMemoryDC dc;
 300         wxBitmap bmp(size.x, size.y);
 301         dc.SelectObject(bmp);
 302         dc.Blit(0, 0, size.x, size.y, &dcWin, 0, 0);
 303         dc.DrawText(_T("(copy of background)"), 5, 120 );
 304
 305         DoPaint(dc);
 306
 307         dcWin.Blit(0, 0, size.x, size.y, &dc, 0, 0);
 308     }
 309     else
 310     {
 311         DoPaint(dcWin);
 312     }
 313 }
 314
 315 void MyCanvas::OnEraseBackground( wxEraseEvent& event )
 316 {
 317     wxDC& dc = *event.GetDC();
 318     dc.SetPen(*wxGREEN_PEN);
 319
 320     // clear any junk currently displayed
 321     dc.Clear();
 322
 323     const wxSize size = GetClientSize();
 324     for ( int x = 0; x < size.x; x += 10 )
 325     {
 326         dc.DrawLine(x, 0, x, size.y);
 327     }
 328
 329     for ( int y = 0; y < size.y; y += 10 )
 330     {
 331         dc.DrawLine(0, y, size.x, y);
 332     }
 333
 334     dc.SetTextForeground(*wxRED);
 335     dc.DrawText(_T("This text is drawn from OnEraseBackground"), 60, 60);
 336 }
 337