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