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 // 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 // ----------------------------------------------------------------------------
  34 // resources
  35 // ----------------------------------------------------------------------------
  36 // the application icon
  37 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__) || defined(__WXX11__)
  38     #include "mondrian.xpm"
  39 #endif
  40
  41 // ----------------------------------------------------------------------------
  42 // private classes
  43 // ----------------------------------------------------------------------------
  44
  45 class MyApp : public wxApp
  46 {
  47 public:
  48     virtual bool OnInit();
  49 };
  50
  51
  52 class MyCanvas : public wxScrolledWindow
  53 {
  54 public:
  55     MyCanvas( wxFrame *parent );
  56
  57     void UseBuffer(bool useBuffer) { m_useBuffer = useBuffer; Refresh(); }
  58     void EraseBg(bool eraseBg) { m_eraseBg = eraseBg; Refresh(); }
  59
  60 private:
  61     void OnPaint( wxPaintEvent &event );
  62     void OnChar( wxKeyEvent &event );
  63     void OnEraseBackground( wxEraseEvent &event );
  64
  65     void DoPaint(wxDC& dc);
  66
  67
  68     wxBitmap    m_bitmap;
  69     wxString    m_text;
  70
  71     // use wxMemoryDC in OnPaint()?
  72     bool m_useBuffer;
  73
  74     // paint custom background in OnEraseBackground()?
  75     bool m_eraseBg;
  76
  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 OnEraseBg(wxCommandEvent& event);
  88     void OnQuit(wxCommandEvent& event);
  89     void OnAbout(wxCommandEvent& event);
  90
  91 private:
  92     MyCanvas *m_canvas;
  93
  94     DECLARE_EVENT_TABLE()
  95 };
  96
  97
  98 // ----------------------------------------------------------------------------
  99 // constants
 100 // ----------------------------------------------------------------------------
 101
 102 enum
 103 {
 104     // menu items
 105     Erase_Menu_UseBuffer = 100,
 106     Erase_Menu_EraseBg,
 107     Erase_Menu_Exit = wxID_EXIT,
 108     Erase_Menu_About = wxID_ABOUT
 109 };
 110
 111
 112 // ----------------------------------------------------------------------------
 113 // the application class
 114 // ----------------------------------------------------------------------------
 115
 116 IMPLEMENT_APP(MyApp)
 117
 118 bool MyApp::OnInit()
 119 {
 120     MyFrame *frame = new MyFrame;
 121
 122     frame->Show(true);
 123
 124     return true;
 125 }
 126
 127 // ----------------------------------------------------------------------------
 128 // main frame
 129 // ----------------------------------------------------------------------------
 130
 131 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 132     EVT_MENU(Erase_Menu_UseBuffer,  MyFrame::OnUseBuffer)
 133     EVT_MENU(Erase_Menu_EraseBg,  MyFrame::OnEraseBg)
 134     EVT_MENU(Erase_Menu_Exit,  MyFrame::OnQuit)
 135     EVT_MENU(Erase_Menu_About, MyFrame::OnAbout)
 136 END_EVENT_TABLE()
 137
 138 // frame constructor
 139 MyFrame::MyFrame()
 140        : wxFrame(NULL, wxID_ANY, _T("Erase sample"),
 141                  wxPoint(50, 50), wxSize(450, 340))
 142 {
 143     SetIcon(wxICON(mondrian));
 144
 145     wxMenu *menuFile = new wxMenu(_T(""), wxMENU_TEAROFF);
 146     menuFile->AppendCheckItem(Erase_Menu_UseBuffer, _T("&Use memory DC\tCtrl-M"));
 147     menuFile->AppendCheckItem(Erase_Menu_EraseBg, _T("Custom &background\tCtrl-B"));
 148     menuFile->AppendSeparator();
 149     menuFile->Append(Erase_Menu_Exit, _T("E&xit\tAlt-X"), _T("Quit this program"));
 150
 151
 152     wxMenu *helpMenu = new wxMenu;
 153     helpMenu->Append(Erase_Menu_About, _T("&About...\tCtrl-A"), _T("Show about dialog"));
 154
 155     wxMenuBar *menuBar = new wxMenuBar();
 156     menuBar->Append(menuFile, _T("&File"));
 157     menuBar->Append(helpMenu, _T("&Help"));
 158
 159     SetMenuBar(menuBar);
 160
 161 #if wxUSE_STATUSBAR
 162     // create a status bar just for fun (by default with 1 pane only)
 163     CreateStatusBar(2);
 164     SetStatusText(_T("Welcome to wxWidgets erase sample!"));
 165 #endif // wxUSE_STATUSBAR
 166
 167     m_canvas = new MyCanvas( this );
 168 }
 169
 170
 171 void MyFrame::OnUseBuffer(wxCommandEvent& event)
 172 {
 173     m_canvas->UseBuffer(event.IsChecked());
 174 }
 175
 176 void MyFrame::OnEraseBg(wxCommandEvent& event)
 177 {
 178     m_canvas->EraseBg(event.IsChecked());
 179 }
 180
 181 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 182 {
 183     Close(true);
 184 }
 185
 186 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 187 {
 188     wxMessageBox(_T("This sample shows how you can draw custom background."),
 189                  _T("About Erase Sample"), wxOK | wxICON_INFORMATION, this);
 190 }
 191
 192
 193 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 194     EVT_PAINT(  MyCanvas::OnPaint)
 195     EVT_CHAR(  MyCanvas::OnChar)
 196     EVT_ERASE_BACKGROUND(  MyCanvas::OnEraseBackground)
 197 END_EVENT_TABLE()
 198
 199 MyCanvas::MyCanvas( wxFrame *parent )
 200         : wxScrolledWindow( parent, wxID_ANY, wxDefaultPosition, wxDefaultSize,
 201                             wxScrolledWindowStyle | wxSUNKEN_BORDER )
 202 {
 203     m_eraseBg =
 204     m_useBuffer = false;
 205
 206     SetScrollbars( 10, 10, 40, 100, 0, 0 );
 207
 208     m_bitmap = wxBitmap( wxICON(mondrian) );
 209
 210     new wxStaticBitmap( this, wxID_ANY, m_bitmap, wxPoint(80,20) );
 211
 212     SetFocusIgnoringChildren();
 213 }
 214
 215 void MyCanvas::OnChar( wxKeyEvent &event )
 216 {
 217 #if wxUSE_UNICODE
 218     if (event.m_uniChar)
 219     {
 220         m_text += event.m_uniChar;
 221         Refresh();
 222         return;
 223     }
 224 #endif
 225
 226     // some test cases
 227     switch (event.m_keyCode)
 228     {
 229         case WXK_UP: m_text += wxT( "<UP>" ); break;
 230         case WXK_LEFT: m_text += wxT( "<LEFT>" ); break;
 231         case WXK_RIGHT: m_text += wxT( "<RIGHT>" ); break;
 232         case WXK_DOWN: m_text += wxT( "<DOWN>" ); break;
 233         case WXK_RETURN: m_text += wxT( "<ENTER>" ); break;
 234         default: m_text += (wxChar)event.m_keyCode; break;
 235     }
 236 }
 237
 238 void MyCanvas::DoPaint(wxDC& dc)
 239 {
 240     dc.SetBrush( *wxBLACK_BRUSH );
 241     dc.DrawRectangle( 10,10,200,50 );
 242
 243     dc.DrawBitmap( m_bitmap, 10, 20, true );
 244
 245     dc.SetTextForeground(*wxBLUE);
 246     dc.DrawText(_T("This text is drawn from OnPaint"), 65, 65);
 247
 248     wxString tmp;
 249     tmp.Printf( _T("Hit any key to display more text: %s"), m_text.c_str() );
 250     int w,h;
 251     dc.GetTextExtent( tmp, &w, &h );
 252     dc.SetBrush( *wxWHITE_BRUSH );
 253     dc.DrawRectangle( 65, 85, w, h );
 254     dc.DrawText( tmp, 65, 85 );
 255
 256 #if 0
 257     wxRegionIterator upd( GetUpdateRegion() );
 258     while (upd)
 259     {
 260         wxLogDebug( _T("Paint: %d %d %d %d"), upd.GetX(), upd.GetY(), upd.GetWidth(), upd.GetHeight() );
 261         upd ++;
 262     }
 263 #endif
 264
 265 #if 0
 266     wxSize size = GetSize();
 267     wxSize client_size = GetClientSize();
 268     wxLogDebug( _T("size %d %d client_size %d %d"), size.x, size.y, client_size.x, client_size.y );
 269 #endif
 270
 271 #if 0
 272     int i;
 273     dc.SetPen( *wxWHITE_PEN );
 274     for (i = 0; i < 20; i += 2)
 275        dc.DrawLine( i,i, i+100,i );
 276
 277     dc.SetPen( *wxWHITE_PEN );
 278     for (i = 200; i < 220; i += 2)
 279        dc.DrawLine( i-200,i, i-100,i );
 280
 281     wxRegion region( 110, 110, 80, 80 );
 282     wxRegion hole( 130, 130, 40, 1 );
 283     region.Intersect( hole );
 284     dc.SetClippingRegion( region );
 285
 286     dc.SetBrush( *wxRED_BRUSH );
 287     dc.DrawRectangle( 100, 100, 200, 200 );
 288
 289     dc.DestroyClippingRegion();
 290
 291     dc.SetPen( *wxTRANSPARENT_PEN );
 292
 293     wxRegion strip( 110, 200, 30, 1 );
 294     wxRegionIterator it( strip );
 295     while (it)
 296     {
 297         dc.DrawRectangle( it.GetX(), it.GetY(), it.GetWidth(), it.GetHeight() );
 298         it ++;
 299     }
 300 #endif // 0
 301 }
 302
 303 void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
 304 {
 305     wxPaintDC dcWin(this);
 306     PrepareDC( dcWin );
 307
 308     if ( m_useBuffer )
 309     {
 310         const wxSize size = GetClientSize();
 311         wxMemoryDC dc;
 312         wxBitmap bmp(size.x, size.y);
 313         dc.SelectObject(bmp);
 314         dc.Blit(0, 0, size.x, size.y, &dcWin, 0, 0);
 315         dc.DrawText(_T("(copy of background)"), 5, 120 );
 316
 317         DoPaint(dc);
 318
 319         dcWin.Blit(0, 0, size.x, size.y, &dc, 0, 0);
 320     }
 321     else
 322     {
 323         DoPaint(dcWin);
 324     }
 325 }
 326
 327 void MyCanvas::OnEraseBackground( wxEraseEvent& event )
 328 {
 329     if ( !m_eraseBg )
 330     {
 331         event.Skip();
 332         return;
 333     }
 334
 335     wxDC& dc = *event.GetDC();
 336     dc.SetPen(*wxGREEN_PEN);
 337
 338     PrepareDC( dc );
 339
 340     // clear any junk currently displayed
 341     dc.Clear();
 342
 343     const wxSize size = GetClientSize();
 344     for ( int x = 0; x < size.x; x += 15 )
 345     {
 346         dc.DrawLine(x, 0, x, size.y);
 347     }
 348
 349     for ( int y = 0; y < size.y; y += 15 )
 350     {
 351         dc.DrawLine(0, y, size.x, y);
 352     }
 353
 354     dc.SetTextForeground(*wxRED);
 355     dc.DrawText(_T("This text is drawn from OnEraseBackground"), 60, 160);
 356 }
 357