import images
+BUFFERED = 1
+
#---------------------------------------------------------------------------
class MyCanvas(wxScrolledWindow):
self.lines = []
self.maxWidth = 1000
self.maxHeight = 1000
- self.count = 0
+ self.x = self.y = 0
+ self.curLine = []
+ self.drawing = false
self.SetBackgroundColour("WHITE")
EVT_LEFT_DOWN(self, self.OnLeftButtonEvent)
self.SetScrollbars(20, 20, self.maxWidth/20, self.maxHeight/20)
+ if BUFFERED:
+ # Initialize the buffer bitmap. No real DC is needed at this point.
+ self.buffer = wxEmptyBitmap(self.maxWidth, self.maxHeight)
+ dc = wxBufferedDC(None, self.buffer)
+ dc.SetBackground(wxBrush(self.GetBackgroundColour()))
+ dc.Clear()
+ self.DoDrawing(dc)
+
def getWidth(self):
return self.maxWidth
def OnPaint(self, event):
- #self.count += 1
- #print self.count, "begin paint...",
- dc = wxPaintDC(self)
- self.PrepareDC(dc)
- self.DoDrawing(dc)
- #print "end paint"
+ if BUFFERED:
+ # Create a buffered paint DC. It will create the real
+ # wxPaintDC and then blit the bitmap to it when dc is
+ # deleted. Since we don't need to draw anything else
+ # here that's all there is to it.
+ dc = wxBufferedPaintDC(self, self.buffer)
+ else:
+ dc = wxPaintDC(self)
+ self.PrepareDC(dc)
+ # since we're not buffering in this case, we have to
+ # paint the whole window, potentially very time consuming.
+ self.DoDrawing(dc)
def DoDrawing(self, dc):
dc.SetPen(old_pen)
dc.DrawRectangle(490, 90, 20, 20)
-
self.DrawSavedLines(dc)
dc.EndDrawing()
self.SetXY(event)
self.curLine = []
self.CaptureMouse()
+ self.drawing = true
+
+ elif event.Dragging() and self.drawing:
+ if BUFFERED:
+ # If doing buffered drawing, create the buffered DC, giving it
+ # it a real DC to blit to when done.
+ cdc = wxClientDC(self)
+ self.PrepareDC(cdc)
+ dc = wxBufferedDC(cdc, self.buffer)
+ else:
+ dc = wxClientDC(self)
+ self.PrepareDC(dc)
- elif event.Dragging():
- dc = wxClientDC(self)
- self.PrepareDC(dc)
dc.BeginDrawing()
dc.SetPen(wxPen('MEDIUM FOREST GREEN', 4))
coords = (self.x, self.y) + self.ConvertEventCoords(event)
self.SetXY(event)
dc.EndDrawing()
- elif event.LeftUp():
+
+ elif event.LeftUp() and self.drawing:
self.lines.append(self.curLine)
self.curLine = []
self.ReleaseMouse()
+ self.drawing = false
## This is an example of what to do for the EVT_MOUSEWHEEL event,