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 and Markus Holzem
   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 #ifdef __WXMSW__
  24 #include <wx/pnghand.h>
  25 #endif
  26
  27 #include "pngdemo.h"
  28
  29 MyFrame   *frame = (MyFrame *) NULL;
  30 wxBitmap  *g_TestBitmap = (wxBitmap *) NULL;
  31
  32 IMPLEMENT_APP(MyApp)
  33
  34 MyApp::MyApp()
  35 {
  36 }
  37
  38 bool MyApp::OnInit(void)
  39 {
  40 #ifdef __WXMSW__
  41   wxBitmap::AddHandler(new wxPNGFileHandler);
  42 #endif
  43
  44   // Create the main frame window
  45   frame = new MyFrame((wxFrame *) NULL, "wxPNGBitmap Demo", wxPoint(0, 0), wxSize(300, 300));
  46
  47   // Give it a status line
  48   frame->CreateStatusBar(2);
  49
  50   // Make a menubar
  51   wxMenu *file_menu = new wxMenu;
  52   wxMenu *help_menu = new wxMenu;
  53
  54   file_menu->Append(PNGDEMO_LOAD_FILE, "&Load file",                "Load file");
  55   file_menu->Append(PNGDEMO_SAVE_FILE, "&Save file",                "Save file");
  56   file_menu->Append(PNGDEMO_QUIT, "E&xit",                "Quit program");
  57   help_menu->Append(PNGDEMO_ABOUT, "&About",              "About PNG demo");
  58
  59   wxMenuBar *menu_bar = new wxMenuBar;
  60
  61   menu_bar->Append(file_menu, "&File");
  62   menu_bar->Append(help_menu, "&Help");
  63
  64   // Associate the menu bar with the frame
  65   frame->SetMenuBar(menu_bar);
  66
  67   MyCanvas *canvas = new MyCanvas(frame, wxPoint(0, 0), wxSize(100, 100));
  68
  69   // Give it scrollbars: the virtual canvas is 20 * 50 = 1000 pixels in each direction
  70 //  canvas->SetScrollbars(20, 20, 50, 50, 4, 4);
  71   frame->canvas = canvas;
  72
  73   frame->Show(TRUE);
  74
  75   frame->SetStatusText("Hello, wxWindows");
  76
  77   return TRUE;
  78 }
  79
  80 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
  81     EVT_MENU(PNGDEMO_QUIT,      MyFrame::OnQuit)
  82     EVT_MENU(PNGDEMO_ABOUT,     MyFrame::OnAbout)
  83     EVT_MENU(PNGDEMO_LOAD_FILE, MyFrame::OnLoadFile)
  84     EVT_MENU(PNGDEMO_SAVE_FILE, MyFrame::OnSaveFile)
  85 END_EVENT_TABLE()
  86
  87 // Define my frame constructor
  88 MyFrame::MyFrame(wxFrame *frame, const wxString& title, const wxPoint& pos, const wxSize& size):
  89   wxFrame(frame, -1, title, pos, size)
  90 {
  91   canvas = (MyCanvas *) NULL;
  92 }
  93
  94 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
  95 {
  96     Close(TRUE);
  97 }
  98
  99 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 100 {
 101     (void)wxMessageBox("PNG demo\nJulian Smart (c) 1998",
 102             "About PNG Demo", wxOK);
 103 }
 104
 105 void MyFrame::OnSaveFile(wxCommandEvent& WXUNUSED(event))
 106 {
 107   char *f = wxFileSelector( "Save Image", (const char *)NULL, (const char *)NULL,
 108                             "png", "PNG files (*.png)|*.png" );
 109
 110   if (!f)  return;
 111
 112   wxBitmap *backstore = new wxBitmap( 150, 150 );
 113
 114   wxMemoryDC memDC;
 115   memDC.SelectObject( *backstore );
 116   memDC.Clear();
 117   memDC.SetBrush( *wxBLACK_BRUSH );
 118   memDC.SetPen( *wxWHITE_PEN );
 119   memDC.DrawRectangle( 0, 0, 150, 150 );
 120   memDC.SetPen( *wxBLACK_PEN );
 121   memDC.DrawLine( 0, 0, 0, 10 );
 122   memDC.SetTextForeground( *wxWHITE );
 123   memDC.DrawText( "This is a memory dc.", 10, 10 );
 124
 125   memDC.SelectObject( wxNullBitmap );
 126
 127   backstore->SaveFile( f, wxBITMAP_TYPE_PNG, (wxPalette*)NULL );
 128
 129   delete backstore;
 130 }
 131
 132 void MyFrame::OnLoadFile(wxCommandEvent& WXUNUSED(event))
 133 {
 134         // Show file selector.
 135         char *f = wxFileSelector("Open Image", (const char *) NULL, (const char *) NULL,"png",
 136                   "PNG files (*.png)|*.png");
 137
 138         if (!f)
 139           return;
 140
 141     if ( g_TestBitmap )
 142         delete g_TestBitmap;
 143     g_TestBitmap = new wxBitmap(f, wxBITMAP_TYPE_PNG);
 144     if (!g_TestBitmap->Ok())
 145     {
 146         delete g_TestBitmap;
 147         g_TestBitmap = (wxBitmap *) NULL;
 148     }
 149
 150     canvas->Refresh();
 151 }
 152
 153 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 154     EVT_PAINT(MyCanvas::OnPaint)
 155 END_EVENT_TABLE()
 156
 157 // Define a constructor for my canvas
 158 MyCanvas::MyCanvas(wxWindow *parent, const wxPoint& pos, const wxSize& size):
 159  wxScrolledWindow(parent, -1, pos, size)
 160 {
 161 }
 162
 163 MyCanvas::~MyCanvas(void)
 164 {
 165 }
 166
 167 // Define the repainting behaviour
 168 void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
 169 {
 170   wxPaintDC dc(this);
 171   dc.SetPen(* wxRED_PEN);
 172
 173   int i;
 174   for ( i = 0; i < 500; i += 10)
 175   {
 176     dc.DrawLine(0, i, 800, i);
 177   }
 178   if ( g_TestBitmap && g_TestBitmap->Ok() )
 179   {
 180     wxMemoryDC memDC;
 181     if ( g_TestBitmap->GetColourMap() )
 182     {
 183         memDC.SetPalette(* g_TestBitmap->GetColourMap());
 184         dc.SetPalette(* g_TestBitmap->GetColourMap());
 185     }
 186     memDC.SelectObject(* g_TestBitmap);
 187
 188     // Normal, non-transparent blitting
 189     dc.Blit(20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, FALSE);
 190
 191     memDC.SelectObject(wxNullBitmap);
 192   }
 193
 194   if ( g_TestBitmap && g_TestBitmap->Ok() )
 195   {
 196     wxMemoryDC memDC;
 197     memDC.SelectObject(* g_TestBitmap);
 198
 199     // Transparent blitting if there's a mask in the bitmap
 200     dc.Blit(20 + g_TestBitmap->GetWidth() + 20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC,
 201       0, 0, wxCOPY, TRUE);
 202
 203     memDC.SelectObject(wxNullBitmap);
 204   }
 205 }
 206
 207 // Define the behaviour for the frame closing
 208 // - must delete all frames except for the main one.
 209 bool MyFrame::OnClose(void)
 210 {
 211   Show(FALSE);
 212
 213   return TRUE;
 214 }
 215