samples/dragimag/dragimag.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dragimag.cpp
   3 // Purpose:     wxDragImage sample
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     28/2/2000
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx/wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16 #pragma hdrstop
  17 #endif
  18
  19 #ifndef WX_PRECOMP
  20 #include "wx/wx.h"
  21 #endif
  22
  23 #include "wx/image.h"
  24
  25 // Under Windows, change this to 1
  26 // to use wxGenericDragImage
  27
  28 #define wxUSE_GENERIC_DRAGIMAGE 1
  29
  30 #if wxUSE_GENERIC_DRAGIMAGE
  31 #include "wx/generic/dragimgg.h"
  32 #define wxDragImage wxGenericDragImage
  33 #else
  34 #include "wx/dragimag.h"
  35 #endif
  36
  37 #include "dragimag.h"
  38
  39 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__) || defined(__WXX11__)
  40 #include "mondrian.xpm"
  41 #include "dragicon.xpm"
  42 #endif
  43
  44 // main program
  45
  46 IMPLEMENT_APP(MyApp)
  47
  48 // MyCanvas
  49
  50 IMPLEMENT_CLASS(MyCanvas, wxScrolledWindow)
  51
  52 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
  53   EVT_PAINT(MyCanvas::OnPaint)
  54   EVT_ERASE_BACKGROUND(MyCanvas::OnEraseBackground)
  55   EVT_MOUSE_EVENTS(MyCanvas::OnMouseEvent)
  56 END_EVENT_TABLE()
  57
  58 MyCanvas::MyCanvas( wxWindow *parent, wxWindowID id,
  59                     const wxPoint &pos, const wxSize &size )
  60         : wxScrolledWindow( parent, id, pos, size, wxSUNKEN_BORDER )
  61 {
  62     SetBackgroundColour(* wxWHITE);
  63
  64     SetCursor(wxCursor(wxCURSOR_ARROW));
  65
  66     m_dragMode = TEST_DRAG_NONE;
  67     m_draggedShape = (DragShape*) NULL;
  68     m_dragImage = (wxDragImage*) NULL;
  69     m_currentlyHighlighted = (DragShape*) NULL;
  70 }
  71
  72 MyCanvas::~MyCanvas()
  73 {
  74     ClearShapes();
  75
  76     if (m_dragImage)
  77         delete m_dragImage;
  78 }
  79
  80 void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
  81 {
  82     wxPaintDC dc( this );
  83     PrepareDC( dc );
  84
  85     DrawShapes(dc);
  86 }
  87
  88 void MyCanvas::OnEraseBackground(wxEraseEvent& event)
  89 {
  90     if (wxGetApp().GetBackgroundBitmap().Ok())
  91     {
  92         wxSize sz = GetClientSize();
  93         wxRect rect(0, 0, sz.x, sz.y);
  94
  95         if (event.GetDC())
  96         {
  97             wxGetApp().TileBitmap(rect, *(event.GetDC()), wxGetApp().GetBackgroundBitmap());
  98         }
  99         else
 100         {
 101             wxClientDC dc(this);
 102             wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 103         }
 104     }
 105     else
 106         event.Skip(); // The official way of doing it
 107 }
 108
 109 void MyCanvas::OnMouseEvent(wxMouseEvent& event)
 110 {
 111     if (event.LeftDown())
 112     {
 113         DragShape* shape = FindShape(event.GetPosition());
 114         if (shape)
 115         {
 116             // We tentatively start dragging, but wait for
 117             // mouse movement before dragging properly.
 118
 119             m_dragMode = TEST_DRAG_START;
 120             m_dragStartPos = event.GetPosition();
 121             m_draggedShape = shape;
 122         }
 123     }
 124     else if (event.LeftUp() && m_dragMode != TEST_DRAG_NONE)
 125     {
 126         // Finish dragging
 127
 128         m_dragMode = TEST_DRAG_NONE;
 129
 130         if (!m_draggedShape || !m_dragImage)
 131             return;
 132
 133         m_draggedShape->SetPosition(m_draggedShape->GetPosition()
 134                                     + event.GetPosition() - m_dragStartPos);
 135
 136         m_dragImage->Hide();
 137         m_dragImage->EndDrag();
 138         delete m_dragImage;
 139         m_dragImage = NULL;
 140
 141         wxClientDC dc(this);
 142         if (m_currentlyHighlighted)
 143         {
 144             m_currentlyHighlighted->Draw(dc);
 145         }
 146         m_draggedShape->SetShow(true);
 147         m_draggedShape->Draw(dc);
 148
 149         m_currentlyHighlighted = (DragShape*) NULL;
 150
 151         m_draggedShape = (DragShape*) NULL;
 152     }
 153     else if (event.Dragging() && m_dragMode != TEST_DRAG_NONE)
 154     {
 155         if (m_dragMode == TEST_DRAG_START)
 156         {
 157             // We will start dragging if we've moved beyond a couple of pixels
 158
 159             int tolerance = 2;
 160             int dx = abs(event.GetPosition().x - m_dragStartPos.x);
 161             int dy = abs(event.GetPosition().y - m_dragStartPos.y);
 162             if (dx <= tolerance && dy <= tolerance)
 163                 return;
 164
 165             // Start the drag.
 166             m_dragMode = TEST_DRAG_DRAGGING;
 167
 168             if (m_dragImage)
 169                 delete m_dragImage;
 170
 171             // Erase the dragged shape from the canvas
 172             m_draggedShape->SetShow(false);
 173             wxClientDC dc(this);
 174             EraseShape(m_draggedShape, dc);
 175             DrawShapes(dc);
 176
 177             switch (m_draggedShape->GetDragMethod())
 178             {
 179                 case SHAPE_DRAG_BITMAP:
 180                 {
 181                     m_dragImage = new wxDragImage(m_draggedShape->GetBitmap(), wxCursor(wxCURSOR_HAND));
 182                     break;
 183                 }
 184                 case SHAPE_DRAG_TEXT:
 185                 {
 186                     m_dragImage = new wxDragImage(wxString(_T("Dragging some test text")), wxCursor(wxCURSOR_HAND));
 187                     break;
 188                 }
 189                 case SHAPE_DRAG_ICON:
 190                 {
 191                     m_dragImage = new wxDragImage(wxICON(dragicon), wxCursor(wxCURSOR_HAND));
 192                     break;
 193                 }
 194             }
 195
 196             bool fullScreen = wxGetApp().GetUseScreen();
 197
 198             // The offset between the top-left of the shape image and the current shape position
 199             wxPoint beginDragHotSpot = m_dragStartPos - m_draggedShape->GetPosition();
 200
 201             // Now we do this inside the implementation: always assume
 202             // coordinates relative to the capture window (client coordinates)
 203
 204             //if (fullScreen)
 205             //    beginDragHotSpot -= ClientToScreen(wxPoint(0, 0));
 206
 207             if (!m_dragImage->BeginDrag(beginDragHotSpot, this, fullScreen))
 208             {
 209                 delete m_dragImage;
 210                 m_dragImage = (wxDragImage*) NULL;
 211                 m_dragMode = TEST_DRAG_NONE;
 212
 213             } else
 214             {
 215                 m_dragImage->Move(event.GetPosition());
 216                 m_dragImage->Show();
 217             }
 218         }
 219         else if (m_dragMode == TEST_DRAG_DRAGGING)
 220         {
 221             // We're currently dragging. See if we're over another shape.
 222             DragShape* onShape = FindShape(event.GetPosition());
 223
 224             bool mustUnhighlightOld = false;
 225             bool mustHighlightNew = false;
 226
 227             if (m_currentlyHighlighted)
 228             {
 229                 if ((onShape == (DragShape*) NULL) || (m_currentlyHighlighted != onShape))
 230                     mustUnhighlightOld = true;
 231             }
 232
 233             if (onShape && (onShape != m_currentlyHighlighted) && onShape->IsShown())
 234                 mustHighlightNew = true;
 235
 236             if (mustUnhighlightOld || mustHighlightNew)
 237                 m_dragImage->Hide();
 238
 239             // Now with the drag image switched off, we can change the window contents.
 240
 241             if (mustUnhighlightOld)
 242             {
 243                 wxClientDC clientDC(this);
 244                 m_currentlyHighlighted->Draw(clientDC);
 245                 m_currentlyHighlighted = (DragShape*) NULL;
 246             }
 247             if (mustHighlightNew)
 248             {
 249                 wxClientDC clientDC(this);
 250                 m_currentlyHighlighted = onShape;
 251                 m_currentlyHighlighted->Draw(clientDC, wxINVERT);
 252             }
 253
 254             // Move and show the image again
 255             m_dragImage->Move(event.GetPosition());
 256
 257             if (mustUnhighlightOld || mustHighlightNew)
 258                  m_dragImage->Show();
 259         }
 260     }
 261 }
 262
 263 void MyCanvas::DrawShapes(wxDC& dc)
 264 {
 265     wxList::compatibility_iterator node = m_displayList.GetFirst();
 266     while (node)
 267     {
 268         DragShape* shape = (DragShape*) node->GetData();
 269         if (shape->IsShown())
 270           shape->Draw(dc);
 271         node = node->GetNext();
 272     }
 273 }
 274
 275 void MyCanvas::EraseShape(DragShape* shape, wxDC& dc)
 276 {
 277     wxSize sz = GetClientSize();
 278     wxRect rect(0, 0, sz.x, sz.y);
 279
 280     wxRect rect2(shape->GetRect());
 281     dc.SetClippingRegion(rect2.x, rect2.y, rect2.width, rect2.height);
 282
 283     wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 284
 285     dc.DestroyClippingRegion();
 286 }
 287
 288 void MyCanvas::ClearShapes()
 289 {
 290     wxList::compatibility_iterator node = m_displayList.GetFirst();
 291     while (node)
 292     {
 293         DragShape* shape = (DragShape*) node->GetData();
 294         delete shape;
 295         node = node->GetNext();
 296     }
 297     m_displayList.Clear();
 298 }
 299
 300 DragShape* MyCanvas::FindShape(const wxPoint& pt) const
 301 {
 302     wxList::compatibility_iterator node = m_displayList.GetFirst();
 303     while (node)
 304     {
 305         DragShape* shape = (DragShape*) node->GetData();
 306         if (shape->HitTest(pt))
 307             return shape;
 308         node = node->GetNext();
 309     }
 310     return (DragShape*) NULL;
 311 }
 312
 313 // MyFrame
 314 IMPLEMENT_DYNAMIC_CLASS( MyFrame, wxFrame )
 315
 316 BEGIN_EVENT_TABLE(MyFrame,wxFrame)
 317   EVT_MENU    (wxID_ABOUT, MyFrame::OnAbout)
 318   EVT_MENU    (wxID_EXIT,  MyFrame::OnQuit)
 319 END_EVENT_TABLE()
 320
 321 MyFrame::MyFrame()
 322 : wxFrame( (wxFrame *)NULL, wxID_ANY, _T("wxDragImage sample"),
 323           wxPoint(20,20), wxSize(470,360) )
 324 {
 325     wxMenu *file_menu = new wxMenu();
 326     file_menu->Append( wxID_ABOUT, _T("&About..."));
 327     file_menu->AppendCheckItem( TEST_USE_SCREEN, _T("&Use whole screen for dragging"), _T("Use whole screen"));
 328     file_menu->Append( wxID_EXIT, _T("E&xit"));
 329
 330     wxMenuBar *menu_bar = new wxMenuBar();
 331     menu_bar->Append(file_menu, _T("&File"));
 332
 333     SetIcon(wxICON(mondrian));
 334     SetMenuBar( menu_bar );
 335
 336 #if wxUSE_STATUSBAR
 337     CreateStatusBar(2);
 338     int widths[] = { -1, 100 };
 339     SetStatusWidths( 2, widths );
 340 #endif // wxUSE_STATUSBAR
 341
 342     m_canvas = new MyCanvas( this, wxID_ANY, wxPoint(0,0), wxSize(10,10) );
 343 }
 344
 345 void MyFrame::OnQuit( wxCommandEvent &WXUNUSED(event) )
 346 {
 347     Close( true );
 348 }
 349
 350 void MyFrame::OnAbout( wxCommandEvent &WXUNUSED(event) )
 351 {
 352     (void)wxMessageBox( _T("wxDragImage demo\n")
 353         _T("Julian Smart (c) 2000"),
 354         _T("About wxDragImage Demo"),
 355         wxICON_INFORMATION | wxOK );
 356 }
 357
 358 //-----------------------------------------------------------------------------
 359 // MyApp
 360 //-----------------------------------------------------------------------------
 361
 362 BEGIN_EVENT_TABLE(MyApp, wxApp)
 363     EVT_MENU(TEST_USE_SCREEN, MyApp::OnUseScreen)
 364 END_EVENT_TABLE()
 365
 366 MyApp::MyApp()
 367 {
 368     // Drag across whole screen
 369     m_useScreen = false;
 370 }
 371
 372 bool MyApp::OnInit()
 373 {
 374 #if wxUSE_LIBPNG
 375     wxImage::AddHandler( new wxPNGHandler );
 376 #endif
 377
 378     wxImage image;
 379     if (image.LoadFile(_T("backgrnd.png"), wxBITMAP_TYPE_PNG))
 380     {
 381         m_background = wxBitmap(image);
 382     }
 383
 384     MyFrame *frame = new MyFrame();
 385
 386     wxString rootName(_T("shape0"));
 387
 388     int i;
 389     for (i = 1; i < 4; i++)
 390     {
 391         wxString filename;
 392         filename.Printf(wxT("%s%d.png"), (const wxChar*)rootName, i);
 393     /* For some reason under wxX11, the 2nd LoadFile in this loop fails, with
 394        a BadMatch inside CreateFromImage (inside ConvertToBitmap). This happens even if you copy
 395        the first file over the second file. */
 396         if (image.LoadFile(filename, wxBITMAP_TYPE_PNG))
 397         {
 398             DragShape* newShape = new DragShape(wxBitmap(image));
 399             newShape->SetPosition(wxPoint(i*50, i*50));
 400
 401             if (i == 2)
 402                 newShape->SetDragMethod(SHAPE_DRAG_TEXT);
 403             else if (i == 3)
 404                 newShape->SetDragMethod(SHAPE_DRAG_ICON);
 405             else
 406                 newShape->SetDragMethod(SHAPE_DRAG_BITMAP);
 407             frame->GetCanvas()->GetDisplayList().Append(newShape);
 408         }
 409     }
 410
 411 #if 0
 412     // Under Motif or GTK, this demonstrates that
 413     // wxScreenDC only gets the root window content.
 414     // We need to be able to copy the overall content
 415     // for full-screen dragging to work.
 416     int w, h;
 417     wxDisplaySize(& w, & h);
 418     wxBitmap bitmap(w, h);
 419
 420     wxScreenDC dc;
 421     wxMemoryDC memDC;
 422     memDC.SelectObject(bitmap);
 423     memDC.Blit(0, 0, w, h, & dc, 0, 0);
 424     memDC.SelectObject(wxNullBitmap);
 425     m_background = bitmap;
 426 #endif
 427
 428     frame->Show( true );
 429
 430     return true;
 431 }
 432
 433 int MyApp::OnExit()
 434 {
 435     return 0;
 436 }
 437
 438 bool MyApp::TileBitmap(const wxRect& rect, wxDC& dc, wxBitmap& bitmap)
 439 {
 440     int w = bitmap.GetWidth();
 441     int h = bitmap.GetHeight();
 442
 443     int i, j;
 444     for (i = rect.x; i < rect.x + rect.width; i += w)
 445     {
 446         for (j = rect.y; j < rect.y + rect.height; j+= h)
 447             dc.DrawBitmap(bitmap, i, j);
 448     }
 449     return true;
 450 }
 451
 452 void MyApp::OnUseScreen(wxCommandEvent& WXUNUSED(event))
 453 {
 454     m_useScreen = !m_useScreen;
 455 }
 456
 457 // DragShape
 458
 459 DragShape::DragShape(const wxBitmap& bitmap)
 460 {
 461     m_bitmap = bitmap;
 462     m_pos.x = 0;
 463     m_pos.y = 0;
 464     m_dragMethod = SHAPE_DRAG_BITMAP;
 465     m_show = true;
 466 }
 467
 468 bool DragShape::HitTest(const wxPoint& pt) const
 469 {
 470     wxRect rect(GetRect());
 471     return rect.Contains(pt.x, pt.y);
 472 }
 473
 474 bool DragShape::Draw(wxDC& dc, int op)
 475 {
 476     if (m_bitmap.Ok())
 477     {
 478         wxMemoryDC memDC;
 479         memDC.SelectObject(m_bitmap);
 480
 481         dc.Blit(m_pos.x, m_pos.y, m_bitmap.GetWidth(), m_bitmap.GetHeight(),
 482             & memDC, 0, 0, op, true);
 483
 484         return true;
 485     }
 486     else
 487         return false;
 488 }
 489