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