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