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