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 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, _T("wxPNGBitmap Demo"), wxPoint(0, 0), wxSize(300, 300));
  42
  43 #if wxUSE_STATUSBAR
  44   // Give it a status line
  45   frame->CreateStatusBar(2);
  46 #endif // wxUSE_STATUSBAR
  47
  48   // Make a menubar
  49   wxMenu *file_menu = new wxMenu;
  50   wxMenu *help_menu = new wxMenu;
  51
  52   file_menu->Append(PNGDEMO_LOAD_FILE, _T("&Load file"),                _T("Load file"));
  53   file_menu->Append(PNGDEMO_SAVE_FILE, _T("&Save file"),                _T("Save file"));
  54   file_menu->Append(PNGDEMO_QUIT, _T("E&xit"),                _T("Quit program"));
  55   help_menu->Append(PNGDEMO_ABOUT, _T("&About"),              _T("About PNG demo"));
  56
  57   wxMenuBar *menu_bar = new wxMenuBar;
  58
  59   menu_bar->Append(file_menu, _T("&File"));
  60   menu_bar->Append(help_menu, _T("&Help"));
  61
  62   // Associate the menu bar with the frame
  63   frame->SetMenuBar(menu_bar);
  64
  65   MyCanvas *canvas = new MyCanvas(frame, wxPoint(0, 0), wxSize(100, 100));
  66
  67   // Give it scrollbars: the virtual canvas is 20 * 50 = 1000 pixels in each direction
  68 //  canvas->SetScrollbars(20, 20, 50, 50, 4, 4);
  69   frame->canvas = canvas;
  70
  71   frame->Show(true);
  72
  73 #if wxUSE_STATUSBAR
  74   frame->SetStatusText(_T("Hello, wxWidgets"));
  75 #endif // wxUSE_STATUSBAR
  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, wxID_ANY, title, pos, size)
  90 {
  91   canvas = (MyCanvas *) NULL;
  92 }
  93
  94 // frame destructor
  95 MyFrame::~MyFrame()
  96 {
  97     if (g_TestBitmap)
  98     {
  99         delete g_TestBitmap;
 100         g_TestBitmap = (wxBitmap *) NULL;
 101     }
 102 }
 103
 104 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 105 {
 106     Close(true);
 107 }
 108
 109 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 110 {
 111     (void)wxMessageBox(_T("PNG demo\nJulian Smart (c) 1998"),
 112             _T("About PNG Demo"), wxOK);
 113 }
 114
 115 void MyFrame::OnSaveFile(wxCommandEvent& WXUNUSED(event))
 116 {
 117   wxString f = wxFileSelector( wxT("Save Image"), (const wxChar *)NULL,
 118                                (const wxChar *)NULL,
 119                                wxT("png"), wxT("PNG files (*.png)|*.png") );
 120
 121   if (f == _T(""))  return;
 122
 123   wxBitmap *backstore = new wxBitmap( 150, 150 );
 124
 125   wxMemoryDC memDC;
 126   memDC.SelectObject( *backstore );
 127   memDC.Clear();
 128   memDC.SetBrush( *wxBLACK_BRUSH );
 129   memDC.SetPen( *wxWHITE_PEN );
 130   memDC.DrawRectangle( 0, 0, 150, 150 );
 131   memDC.SetPen( *wxBLACK_PEN );
 132   memDC.DrawLine( 0, 0, 0, 10 );
 133   memDC.SetTextForeground( *wxWHITE );
 134   memDC.DrawText( _T("This is a memory dc."), 10, 10 );
 135
 136   memDC.SelectObject( wxNullBitmap );
 137
 138   backstore->SaveFile( f, wxBITMAP_TYPE_PNG, (wxPalette*)NULL );
 139
 140   delete backstore;
 141 }
 142
 143 void MyFrame::OnLoadFile(wxCommandEvent& WXUNUSED(event))
 144 {
 145     // Show file selector.
 146     wxString f = wxFileSelector(wxT("Open Image"), (const wxChar *) NULL,
 147                                     (const wxChar *) NULL, wxT("png"),
 148                                     wxT("PNG files (*.png)|*.png"));
 149
 150     if (f == _T(""))
 151         return;
 152
 153     if ( g_TestBitmap )
 154         delete g_TestBitmap;
 155
 156     g_TestBitmap = new wxBitmap(f, wxBITMAP_TYPE_PNG);
 157     if (!g_TestBitmap->Ok())
 158     {
 159         delete g_TestBitmap;
 160         g_TestBitmap = (wxBitmap *) NULL;
 161     }
 162
 163     canvas->Refresh();
 164 }
 165
 166 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 167     EVT_PAINT(MyCanvas::OnPaint)
 168 END_EVENT_TABLE()
 169
 170 // Define a constructor for my canvas
 171 MyCanvas::MyCanvas(wxWindow *parent, const wxPoint& pos, const wxSize& size):
 172  wxScrolledWindow(parent, wxID_ANY, pos, size)
 173 {
 174 }
 175
 176 MyCanvas::~MyCanvas(void)
 177 {
 178 }
 179
 180 // Define the repainting behaviour
 181 void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
 182 {
 183   wxPaintDC dc(this);
 184   dc.SetPen(* wxRED_PEN);
 185
 186   int i;
 187   for ( i = 0; i < 500; i += 10)
 188   {
 189     dc.DrawLine(0, i, 800, i);
 190   }
 191   if ( g_TestBitmap && g_TestBitmap->Ok() )
 192   {
 193     wxMemoryDC memDC;
 194     if ( g_TestBitmap->GetPalette() )
 195     {
 196         memDC.SetPalette(* g_TestBitmap->GetPalette());
 197         dc.SetPalette(* g_TestBitmap->GetPalette());
 198     }
 199     memDC.SelectObject(* g_TestBitmap);
 200
 201     // Normal, non-transparent blitting
 202     dc.Blit(20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, false);
 203
 204     memDC.SelectObject(wxNullBitmap);
 205   }
 206
 207   if ( g_TestBitmap && g_TestBitmap->Ok() )
 208   {
 209     wxMemoryDC memDC;
 210     memDC.SelectObject(* g_TestBitmap);
 211
 212     // Transparent blitting if there's a mask in the bitmap
 213     dc.Blit(20 + g_TestBitmap->GetWidth() + 20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC,
 214       0, 0, wxCOPY, true);
 215
 216     memDC.SelectObject(wxNullBitmap);
 217   }
 218 }
 219
 220