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
  22     #pragma interface
  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     void EraseBg(bool eraseBg) { m_eraseBg = eraseBg; Refresh(); }
  64
  65 private:
  66     void OnPaint( wxPaintEvent &event );
  67     void OnChar( wxKeyEvent &event );
  68     void OnEraseBackground( wxEraseEvent &event );
  69
  70     void DoPaint(wxDC& dc);
  71
  72
  73     wxBitmap    m_bitmap;
  74     wxString    m_text;
  75
  76     // use wxMemoryDC in OnPaint()?
  77     bool m_useBuffer;
  78
  79     // paint custom background in OnEraseBackground()?
  80     bool m_eraseBg;
  81
  82
  83     DECLARE_EVENT_TABLE()
  84 };
  85
  86 class MyFrame : public wxFrame
  87 {
  88 public:
  89     MyFrame();
  90
  91     void OnUseBuffer(wxCommandEvent& event);
  92     void OnEraseBg(wxCommandEvent& event);
  93     void OnQuit(wxCommandEvent& event);
  94     void OnAbout(wxCommandEvent& event);
  95
  96 private:
  97     MyCanvas *m_canvas;
  98
  99     DECLARE_EVENT_TABLE()
 100 };
 101
 102
 103 // ----------------------------------------------------------------------------
 104 // constants
 105 // ----------------------------------------------------------------------------
 106
 107 enum
 108 {
 109     // menu items
 110     Erase_Menu_UseBuffer = 100,
 111     Erase_Menu_EraseBg,
 112     Erase_Menu_Exit = wxID_EXIT,
 113     Erase_Menu_About = wxID_ABOUT
 114 };
 115
 116
 117 // ----------------------------------------------------------------------------
 118 // the application class
 119 // ----------------------------------------------------------------------------
 120
 121 IMPLEMENT_APP(MyApp)
 122
 123 bool MyApp::OnInit()
 124 {
 125     MyFrame *frame = new MyFrame;
 126
 127     frame->Show(true);
 128
 129     return true;
 130 }
 131
 132 // ----------------------------------------------------------------------------
 133 // main frame
 134 // ----------------------------------------------------------------------------
 135
 136 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 137     EVT_MENU(Erase_Menu_UseBuffer,  MyFrame::OnUseBuffer)
 138     EVT_MENU(Erase_Menu_EraseBg,  MyFrame::OnEraseBg)
 139     EVT_MENU(Erase_Menu_Exit,  MyFrame::OnQuit)
 140     EVT_MENU(Erase_Menu_About, MyFrame::OnAbout)
 141 END_EVENT_TABLE()
 142
 143 // frame constructor
 144 MyFrame::MyFrame()
 145        : wxFrame(NULL, wxID_ANY, _T("Erase sample"),
 146                  wxPoint(50, 50), wxSize(450, 340))
 147 {
 148     SetIcon(wxICON(mondrian));
 149
 150     wxMenu *menuFile = new wxMenu(_T(""), wxMENU_TEAROFF);
 151     menuFile->AppendCheckItem(Erase_Menu_UseBuffer, _T("&Use memory DC\tCtrl-M"));
 152     menuFile->AppendCheckItem(Erase_Menu_EraseBg, _T("Custom &background\tCtrl-B"));
 153     menuFile->AppendSeparator();
 154     menuFile->Append(Erase_Menu_Exit, _T("E&xit\tAlt-X"), _T("Quit this program"));
 155
 156
 157     wxMenu *helpMenu = new wxMenu;
 158     helpMenu->Append(Erase_Menu_About, _T("&About...\tCtrl-A"), _T("Show about dialog"));
 159
 160     wxMenuBar *menuBar = new wxMenuBar();
 161     menuBar->Append(menuFile, _T("&File"));
 162     menuBar->Append(helpMenu, _T("&Help"));
 163
 164     SetMenuBar(menuBar);
 165
 166 #if wxUSE_STATUSBAR
 167     // create a status bar just for fun (by default with 1 pane only)
 168     CreateStatusBar(2);
 169     SetStatusText(_T("Welcome to wxWidgets erase sample!"));
 170 #endif // wxUSE_STATUSBAR
 171
 172     m_canvas = new MyCanvas( this );
 173 }
 174
 175
 176 void MyFrame::OnUseBuffer(wxCommandEvent& event)
 177 {
 178     m_canvas->UseBuffer(event.IsChecked());
 179 }
 180
 181 void MyFrame::OnEraseBg(wxCommandEvent& event)
 182 {
 183     m_canvas->EraseBg(event.IsChecked());
 184 }
 185
 186 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 187 {
 188     Close(true);
 189 }
 190
 191 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 192 {
 193     wxMessageBox(_T("This sample shows how you can draw custom background."),
 194                  _T("About Erase Sample"), wxOK | wxICON_INFORMATION, this);
 195 }
 196
 197
 198 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 199     EVT_PAINT(  MyCanvas::OnPaint)
 200     EVT_CHAR(  MyCanvas::OnChar)
 201     EVT_ERASE_BACKGROUND(  MyCanvas::OnEraseBackground)
 202 END_EVENT_TABLE()
 203
 204 MyCanvas::MyCanvas( wxFrame *parent )
 205         : wxScrolledWindow( parent, wxID_ANY, wxDefaultPosition, wxDefaultSize,
 206                             wxScrolledWindowStyle | wxSUNKEN_BORDER )
 207 {
 208     m_eraseBg =
 209     m_useBuffer = false;
 210
 211     SetScrollbars( 10, 10, 40, 100, 0, 0 );
 212
 213     m_bitmap = wxBitmap( wxICON(mondrian) );
 214
 215     new wxStaticBitmap( this, wxID_ANY, m_bitmap, wxPoint(80,20) );
 216
 217     SetFocusIgnoringChildren();
 218 }
 219
 220 void MyCanvas::OnChar( wxKeyEvent &event )
 221 {
 222 #if wxUSE_UNICODE
 223     if (event.m_uniChar)
 224     {
 225         m_text += event.m_uniChar;
 226         Refresh();
 227         return;
 228     }
 229 #endif
 230
 231     // some test cases
 232     switch (event.m_keyCode)
 233     {
 234         case WXK_UP: m_text += wxT( "<UP>" ); break;
 235         case WXK_LEFT: m_text += wxT( "<LEFT>" ); break;
 236         case WXK_RIGHT: m_text += wxT( "<RIGHT>" ); break;
 237         case WXK_DOWN: m_text += wxT( "<DOWN>" ); break;
 238         case WXK_RETURN: m_text += wxT( "<ENTER>" ); break;
 239         default: m_text += (wxChar)event.m_keyCode; break;
 240     }
 241 }
 242
 243 void MyCanvas::DoPaint(wxDC& dc)
 244 {
 245     dc.SetBrush( *wxBLACK_BRUSH );
 246     dc.DrawRectangle( 10,10,200,50 );
 247
 248     dc.DrawBitmap( m_bitmap, 10, 20, true );
 249
 250     dc.SetTextForeground(*wxBLUE);
 251     dc.DrawText(_T("This text is drawn from OnPaint"), 65, 65);
 252
 253     wxString tmp;
 254     tmp.Printf( _T("Hit any key to display more text: %s"), m_text.c_str() );
 255     int w,h;
 256     dc.GetTextExtent( tmp, &w, &h );
 257     dc.SetBrush( *wxWHITE_BRUSH );
 258     dc.DrawRectangle( 65, 85, w, h );
 259     dc.DrawText( tmp, 65, 85 );
 260
 261 #if 0
 262     wxRegionIterator upd( GetUpdateRegion() );
 263     while (upd)
 264     {
 265         wxLogDebug( _T("Paint: %d %d %d %d"), upd.GetX(), upd.GetY(), upd.GetWidth(), upd.GetHeight() );
 266         upd ++;
 267     }
 268 #endif
 269
 270 #if 0
 271     wxSize size = GetSize();
 272     wxSize client_size = GetClientSize();
 273     wxLogDebug( _T("size %d %d client_size %d %d"), size.x, size.y, client_size.x, client_size.y );
 274 #endif
 275
 276 #if 0
 277     int i;
 278     dc.SetPen( *wxWHITE_PEN );
 279     for (i = 0; i < 20; i += 2)
 280        dc.DrawLine( i,i, i+100,i );
 281
 282     dc.SetPen( *wxWHITE_PEN );
 283     for (i = 200; i < 220; i += 2)
 284        dc.DrawLine( i-200,i, i-100,i );
 285
 286     wxRegion region( 110, 110, 80, 80 );
 287     wxRegion hole( 130, 130, 40, 1 );
 288     region.Intersect( hole );
 289     dc.SetClippingRegion( region );
 290
 291     dc.SetBrush( *wxRED_BRUSH );
 292     dc.DrawRectangle( 100, 100, 200, 200 );
 293
 294     dc.DestroyClippingRegion();
 295
 296     dc.SetPen( *wxTRANSPARENT_PEN );
 297
 298     wxRegion strip( 110, 200, 30, 1 );
 299     wxRegionIterator it( strip );
 300     while (it)
 301     {
 302         dc.DrawRectangle( it.GetX(), it.GetY(), it.GetWidth(), it.GetHeight() );
 303         it ++;
 304     }
 305 #endif // 0
 306 }
 307
 308 void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
 309 {
 310     wxPaintDC dcWin(this);
 311     PrepareDC( dcWin );
 312
 313     if ( m_useBuffer )
 314     {
 315         const wxSize size = GetClientSize();
 316         wxMemoryDC dc;
 317         wxBitmap bmp(size.x, size.y);
 318         dc.SelectObject(bmp);
 319         dc.Blit(0, 0, size.x, size.y, &dcWin, 0, 0);
 320         dc.DrawText(_T("(copy of background)"), 5, 120 );
 321
 322         DoPaint(dc);
 323
 324         dcWin.Blit(0, 0, size.x, size.y, &dc, 0, 0);
 325     }
 326     else
 327     {
 328         DoPaint(dcWin);
 329     }
 330 }
 331
 332 void MyCanvas::OnEraseBackground( wxEraseEvent& event )
 333 {
 334     if ( !m_eraseBg )
 335     {
 336         event.Skip();
 337         return;
 338     }
 339
 340     wxDC& dc = *event.GetDC();
 341     dc.SetPen(*wxGREEN_PEN);
 342
 343     PrepareDC( dc );
 344
 345     // clear any junk currently displayed
 346     dc.Clear();
 347
 348     const wxSize size = GetClientSize();
 349     for ( int x = 0; x < size.x; x += 15 )
 350     {
 351         dc.DrawLine(x, 0, x, size.y);
 352     }
 353
 354     for ( int y = 0; y < size.y; y += 15 )
 355     {
 356         dc.DrawLine(0, y, size.x, y);
 357     }
 358
 359     dc.SetTextForeground(*wxRED);
 360     dc.DrawText(_T("This text is drawn from OnEraseBackground"), 60, 160);
 361 }
 362