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show better technique for updating drawing from outside of EVT_PAINT handler

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git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@44551 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Robin Dunn
2007-02-21 23:40:24 +00:00
parent 65df1b5001
commit 30a04aa8cc
1 changed files with 21 additions and 12 deletions
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31
wxPython/demo/ScrolledWindow.py
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@@ -157,10 +157,8 @@ class MyCanvas(wx.ScrolledWindow):
self.x, self.y = self.ConvertEventCoords(event) self.x, self.y = self.ConvertEventCoords(event)
def ConvertEventCoords(self, event): def ConvertEventCoords(self, event):
xView, yView = self.GetViewStart() newpos = self.CalcUnscrolledPosition(event.GetX(), event.GetY())
xDelta, yDelta = self.GetScrollPixelsPerUnit() return newpos
return (event.GetX() + (xView * xDelta),
event.GetY() + (yView * yDelta))
def OnLeftButtonEvent(self, event): def OnLeftButtonEvent(self, event):
if event.LeftDown(): if event.LeftDown():
@@ -172,23 +170,34 @@ class MyCanvas(wx.ScrolledWindow):
elif event.Dragging() and self.drawing: elif event.Dragging() and self.drawing:
if BUFFERED: if BUFFERED:
# If doing buffered drawing, create the buffered DC, giving it # If doing buffered drawing we'll just update the
# it a real DC to blit to when done. # buffer here and then refresh that portion of the
cdc = wx.ClientDC(self) # window, then that portion of the buffer will be
self.PrepareDC(cdc) # redrawn in the EVT_PAINT handler.
dc = wx.BufferedDC(cdc, self.buffer) dc = wx.BufferedDC(None, self.buffer)
else: else:
# otherwise we'll draw directly to a wx.ClientDC
dc = wx.ClientDC(self) dc = wx.ClientDC(self)
self.PrepareDC(dc) self.PrepareDC(dc)
dc.BeginDrawing()
dc.SetPen(wx.Pen('MEDIUM FOREST GREEN', 4)) dc.SetPen(wx.Pen('MEDIUM FOREST GREEN', 4))
coords = (self.x, self.y) + self.ConvertEventCoords(event) coords = (self.x, self.y) + self.ConvertEventCoords(event)
self.curLine.append(coords) self.curLine.append(coords)
dc.DrawLine(*coords) dc.DrawLine(*coords)
self.SetXY(event) self.SetXY(event)
dc.EndDrawing()
if BUFFERED:
# figure out what part of the window to refresh
x1,y1, x2,y2 = dc.GetBoundingBox()
x1,y1 = self.CalcScrolledPosition(x1, y1)
x2,y2 = self.CalcScrolledPosition(x2, y2)
# make a rectangle
rect = wx.Rect()
rect.SetTopLeft((x1,y1))
rect.SetBottomRight((x2,y2))
rect.Inflate(2,2)
# refresh it
self.RefreshRect(rect)
elif event.LeftUp() and self.drawing: elif event.LeftUp() and self.drawing:
self.lines.append(self.curLine) self.lines.append(self.curLine)