bool MyApp::OnInit()
{
#if wxUSE_LIBPNG
wxImage::AddHandler( new wxPNGHandler );
#endif
wxImage image;
if (image.LoadFile(_T("backgrnd.png"), wxBITMAP_TYPE_PNG))
{
m_background = wxBitmap(image);
}
MyFrame *frame = new MyFrame();
wxString rootName(_T("shape0"));
int i;
for (i = 1; i < 4; i++)
{
wxString filename;
filename.Printf(wxT("%s%d.png"), (const wxChar*)rootName, i);
/* For some reason under wxX11, the 2nd LoadFile in this loop fails, with
a BadMatch inside CreateFromImage (inside ConvertToBitmap). This happens even if you copy
the first file over the second file. */
if (image.LoadFile(filename, wxBITMAP_TYPE_PNG))
{
DragShape* newShape = new DragShape(wxBitmap(image));
newShape->SetPosition(wxPoint(i*50, i*50));
if (i == 2)
newShape->SetDragMethod(SHAPE_DRAG_TEXT);
else if (i == 3)
newShape->SetDragMethod(SHAPE_DRAG_ICON);
else
newShape->SetDragMethod(SHAPE_DRAG_BITMAP);
frame->GetCanvas()->GetDisplayList().Append(newShape);
}
}
#if 0
// Under Motif or GTK, this demonstrates that
// wxScreenDC only gets the root window content.
// We need to be able to copy the overall content
// for full-screen dragging to work.
int w, h;
wxDisplaySize(& w, & h);
wxBitmap bitmap(w, h);
wxScreenDC dc;
wxMemoryDC memDC;
memDC.SelectObject(bitmap);
memDC.Blit(0, 0, w, h, & dc, 0, 0);
memDC.SelectObject(wxNullBitmap);
m_background = bitmap;
#endif
frame->Show( true );
return true;
}
void MyCanvas::DrawShapes(wxDC& dc)
{
wxList::compatibility_iterator node = m_displayList.GetFirst();
while (node)
{
DragShape* shape = (DragShape*) node->GetData();
if (shape->IsShown())
shape->Draw(dc);
node = node->GetNext();
}
}
DragShape* MyCanvas::FindShape(const wxPoint& pt) const
{
wxList::compatibility_iterator node = m_displayList.GetFirst();
while (node)
{
DragShape* shape = (DragShape*) node->GetData();
if (shape->HitTest(pt))
return shape;
node = node->GetNext();
}
return (DragShape*) NULL;
}
void MyCanvas::DrawShapes(wxDC& dc)
{
wxList::compatibility_iterator node = m_displayList.GetFirst();
while (node)
{
DragShape* shape = (DragShape*) node->GetData();
if (shape->IsShown() && m_draggedShape != shape)
{
shape->Draw(dc, (m_currentlyHighlighted == shape));
}
node = node->GetNext();
}
}
void MyCanvas::OnMouseEvent(wxMouseEvent& event)
{
if (event.LeftDown())
{
DragShape* shape = FindShape(event.GetPosition());
if (shape)
{
// We tentatively start dragging, but wait for
// mouse movement before dragging properly.
m_dragMode = TEST_DRAG_START;
m_dragStartPos = event.GetPosition();
m_draggedShape = shape;
}
}
else if (event.LeftUp() && m_dragMode != TEST_DRAG_NONE)
{
// Finish dragging
m_dragMode = TEST_DRAG_NONE;
if (!m_draggedShape || !m_dragImage)
return;
m_draggedShape->SetPosition(m_draggedShape->GetPosition()
+ event.GetPosition() - m_dragStartPos);
m_dragImage->Hide();
m_dragImage->EndDrag();
delete m_dragImage;
m_dragImage = NULL;
wxClientDC dc(this);
if (m_currentlyHighlighted)
{
m_currentlyHighlighted->Draw(dc);
}
m_draggedShape->SetShow(true);
m_draggedShape->Draw(dc);
m_currentlyHighlighted = (DragShape*) NULL;
m_draggedShape = (DragShape*) NULL;
}
else if (event.Dragging() && m_dragMode != TEST_DRAG_NONE)
{
if (m_dragMode == TEST_DRAG_START)
{
// We will start dragging if we've moved beyond a couple of pixels
int tolerance = 2;
int dx = abs(event.GetPosition().x - m_dragStartPos.x);
int dy = abs(event.GetPosition().y - m_dragStartPos.y);
if (dx <= tolerance && dy <= tolerance)
return;
// Start the drag.
m_dragMode = TEST_DRAG_DRAGGING;
if (m_dragImage)
delete m_dragImage;
// Erase the dragged shape from the canvas
m_draggedShape->SetShow(false);
wxClientDC dc(this);
EraseShape(m_draggedShape, dc);
DrawShapes(dc);
switch (m_draggedShape->GetDragMethod())
{
case SHAPE_DRAG_BITMAP:
{
m_dragImage = new wxDragImage(m_draggedShape->GetBitmap(), wxCursor(wxCURSOR_HAND));
break;
}
case SHAPE_DRAG_TEXT:
{
m_dragImage = new wxDragImage(wxString(_T("Dragging some test text")), wxCursor(wxCURSOR_HAND));
break;
}
case SHAPE_DRAG_ICON:
{
m_dragImage = new wxDragImage(wxICON(dragicon), wxCursor(wxCURSOR_HAND));
break;
}
}
bool fullScreen = wxGetApp().GetUseScreen();
// The offset between the top-left of the shape image and the current shape position
wxPoint beginDragHotSpot = m_dragStartPos - m_draggedShape->GetPosition();
// Now we do this inside the implementation: always assume
// coordinates relative to the capture window (client coordinates)
//if (fullScreen)
// beginDragHotSpot -= ClientToScreen(wxPoint(0, 0));
if (!m_dragImage->BeginDrag(beginDragHotSpot, this, fullScreen))
{
delete m_dragImage;
m_dragImage = (wxDragImage*) NULL;
m_dragMode = TEST_DRAG_NONE;
} else
{
m_dragImage->Move(event.GetPosition());
m_dragImage->Show();
}
}
else if (m_dragMode == TEST_DRAG_DRAGGING)
{
// We're currently dragging. See if we're over another shape.
DragShape* onShape = FindShape(event.GetPosition());
bool mustUnhighlightOld = false;
bool mustHighlightNew = false;
if (m_currentlyHighlighted)
{
if ((onShape == (DragShape*) NULL) || (m_currentlyHighlighted != onShape))
mustUnhighlightOld = true;
}
if (onShape && (onShape != m_currentlyHighlighted) && onShape->IsShown())
mustHighlightNew = true;
if (mustUnhighlightOld || mustHighlightNew)
m_dragImage->Hide();
// Now with the drag image switched off, we can change the window contents.
if (mustUnhighlightOld)
{
wxClientDC clientDC(this);
m_currentlyHighlighted->Draw(clientDC);
m_currentlyHighlighted = (DragShape*) NULL;
}
if (mustHighlightNew)
{
wxClientDC clientDC(this);
m_currentlyHighlighted = onShape;
m_currentlyHighlighted->Draw(clientDC, wxINVERT);
}
// Move and show the image again
m_dragImage->Move(event.GetPosition());
if (mustUnhighlightOld || mustHighlightNew)
m_dragImage->Show();
}
}
}