samples/png/pngdemo.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        pngdemo.cpp
   3 // Purpose:     Demos PNG reading
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation "pngdemo.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20 #pragma hdrstop
  21 #endif
  22
  23 #include "wx/image.h"
  24
  25 #include "pngdemo.h"
  26
  27 MyFrame   *frame = (MyFrame *) NULL;
  28 wxBitmap  *g_TestBitmap = (wxBitmap *) NULL;
  29
  30 IMPLEMENT_APP(MyApp)
  31
  32 bool MyApp::OnInit(void)
  33 {
  34   wxImage::AddHandler(new wxPNGHandler);
  35
  36   // Create the main frame window
  37   frame = new MyFrame((wxFrame *) NULL, _T("wxPNGBitmap Demo"), wxPoint(0, 0), wxSize(300, 300));
  38
  39 #if wxUSE_STATUSBAR
  40   // Give it a status line
  41   frame->CreateStatusBar(2);
  42 #endif // wxUSE_STATUSBAR
  43
  44   // Make a menubar
  45   wxMenu *file_menu = new wxMenu;
  46   wxMenu *help_menu = new wxMenu;
  47
  48   file_menu->Append(PNGDEMO_LOAD_FILE, _T("&Load file"),                _T("Load file"));
  49   file_menu->Append(PNGDEMO_SAVE_FILE, _T("&Save file"),                _T("Save file"));
  50   file_menu->Append(PNGDEMO_QUIT, _T("E&xit"),                _T("Quit program"));
  51   help_menu->Append(PNGDEMO_ABOUT, _T("&About"),              _T("About PNG demo"));
  52
  53   wxMenuBar *menu_bar = new wxMenuBar;
  54
  55   menu_bar->Append(file_menu, _T("&File"));
  56   menu_bar->Append(help_menu, _T("&Help"));
  57
  58   // Associate the menu bar with the frame
  59   frame->SetMenuBar(menu_bar);
  60
  61   MyCanvas *canvas = new MyCanvas(frame, wxPoint(0, 0), wxSize(100, 100));
  62
  63   // Give it scrollbars: the virtual canvas is 20 * 50 = 1000 pixels in each direction
  64 //  canvas->SetScrollbars(20, 20, 50, 50, 4, 4);
  65   frame->canvas = canvas;
  66
  67   frame->Show(true);
  68
  69 #if wxUSE_STATUSBAR
  70   frame->SetStatusText(_T("Hello, wxWidgets"));
  71 #endif // wxUSE_STATUSBAR
  72
  73   return true;
  74 }
  75
  76 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
  77     EVT_MENU(PNGDEMO_QUIT,      MyFrame::OnQuit)
  78     EVT_MENU(PNGDEMO_ABOUT,     MyFrame::OnAbout)
  79     EVT_MENU(PNGDEMO_LOAD_FILE, MyFrame::OnLoadFile)
  80     EVT_MENU(PNGDEMO_SAVE_FILE, MyFrame::OnSaveFile)
  81 END_EVENT_TABLE()
  82
  83 // Define my frame constructor
  84 MyFrame::MyFrame(wxFrame *frame, const wxString& title, const wxPoint& pos, const wxSize& size):
  85   wxFrame(frame, wxID_ANY, title, pos, size)
  86 {
  87   canvas = (MyCanvas *) NULL;
  88 }
  89
  90 // frame destructor
  91 MyFrame::~MyFrame()
  92 {
  93     if (g_TestBitmap)
  94     {
  95         delete g_TestBitmap;
  96         g_TestBitmap = (wxBitmap *) NULL;
  97     }
  98 }
  99
 100 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 101 {
 102     Close(true);
 103 }
 104
 105 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 106 {
 107     (void)wxMessageBox(_T("PNG demo\nJulian Smart (c) 1998"),
 108             _T("About PNG Demo"), wxOK);
 109 }
 110
 111 void MyFrame::OnSaveFile(wxCommandEvent& WXUNUSED(event))
 112 {
 113   wxString f = wxFileSelector( wxT("Save Image"), (const wxChar *)NULL,
 114                                (const wxChar *)NULL,
 115                                wxT("png"), wxT("PNG files (*.png)|*.png") );
 116
 117   if (f == _T(""))  return;
 118
 119   wxBitmap *backstore = new wxBitmap( 150, 150 );
 120
 121   wxMemoryDC memDC;
 122   memDC.SelectObject( *backstore );
 123   memDC.Clear();
 124   memDC.SetBrush( *wxBLACK_BRUSH );
 125   memDC.SetPen( *wxWHITE_PEN );
 126   memDC.DrawRectangle( 0, 0, 150, 150 );
 127   memDC.SetPen( *wxBLACK_PEN );
 128   memDC.DrawLine( 0, 0, 0, 10 );
 129   memDC.SetTextForeground( *wxWHITE );
 130   memDC.DrawText( _T("This is a memory dc."), 10, 10 );
 131
 132   memDC.SelectObject( wxNullBitmap );
 133
 134   backstore->SaveFile( f, wxBITMAP_TYPE_PNG, (wxPalette*)NULL );
 135
 136   delete backstore;
 137 }
 138
 139 void MyFrame::OnLoadFile(wxCommandEvent& WXUNUSED(event))
 140 {
 141     // Show file selector.
 142     wxString f = wxFileSelector(wxT("Open Image"), (const wxChar *) NULL,
 143                                     (const wxChar *) NULL, wxT("png"),
 144                                     wxT("PNG files (*.png)|*.png"));
 145
 146     if (f == _T(""))
 147         return;
 148
 149     if ( g_TestBitmap )
 150         delete g_TestBitmap;
 151
 152     g_TestBitmap = new wxBitmap(f, wxBITMAP_TYPE_PNG);
 153     if (!g_TestBitmap->Ok())
 154     {
 155         delete g_TestBitmap;
 156         g_TestBitmap = (wxBitmap *) NULL;
 157     }
 158
 159     canvas->Refresh();
 160 }
 161
 162 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 163     EVT_PAINT(MyCanvas::OnPaint)
 164 END_EVENT_TABLE()
 165
 166 // Define a constructor for my canvas
 167 MyCanvas::MyCanvas(wxWindow *parent, const wxPoint& pos, const wxSize& size):
 168  wxScrolledWindow(parent, wxID_ANY, pos, size)
 169 {
 170 }
 171
 172 // Define the repainting behaviour
 173 void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
 174 {
 175   wxPaintDC dc(this);
 176   dc.SetPen(* wxRED_PEN);
 177
 178   int i;
 179   for ( i = 0; i < 500; i += 10)
 180   {
 181     dc.DrawLine(0, i, 800, i);
 182   }
 183   if ( g_TestBitmap && g_TestBitmap->Ok() )
 184   {
 185     wxMemoryDC memDC;
 186     if ( g_TestBitmap->GetPalette() )
 187     {
 188         memDC.SetPalette(* g_TestBitmap->GetPalette());
 189         dc.SetPalette(* g_TestBitmap->GetPalette());
 190     }
 191     memDC.SelectObject(* g_TestBitmap);
 192
 193     // Normal, non-transparent blitting
 194     dc.Blit(20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, false);
 195
 196     memDC.SelectObject(wxNullBitmap);
 197   }
 198
 199   if ( g_TestBitmap && g_TestBitmap->Ok() )
 200   {
 201     wxMemoryDC memDC;
 202     memDC.SelectObject(* g_TestBitmap);
 203
 204     // Transparent blitting if there's a mask in the bitmap
 205     dc.Blit(20 + g_TestBitmap->GetWidth() + 20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC,
 206       0, 0, wxCOPY, true);
 207
 208     memDC.SelectObject(wxNullBitmap);
 209   }
 210 }
 211
 212