ich habe von wxPython in Action das Sketch Beispiel übernommen und abgewandelt. Ich habe "dragging"(linke Maustaste) und "zoom"(Mausrad) implementiert. Außerdem verwende ich GraphicsContext, da ich Antialiasing und später Transparenz verwenden möchte.
Wenn ich nun zoome (größer), lässt sich das ganze kaum mehr "draggen". Wenn ich das Ganze wieder verkleinere, dann habe ich full speed.
Was mache ich falsch? Hängt das mit dem event.Skip() zusammen?
Python: 2.4, Enthought edition
wxPython Version: wx-2.8-msw-ansi
Andi
Code: Alles auswählen
#!c:/python24/python
import wx
class Canvas(wx.Window):
def __init__(self, parent, ID):
wx.Window.__init__(self, parent, ID)
self.SetBackgroundColour("White")
self.color = "Black"
self.thickness = 2
self.pen = wx.Pen(self.color, self.thickness, wx.SOLID)
self.brush = wx.Brush(wx.Colour( 80, 80, 255, 255))
self.lines = [(-20,-20), (20,-20), (20,20), (-20,20), (-20,-20)]
self.zoom = 1.0
self.Bind(wx.EVT_MOTION, self.OnMotion)
self.Bind(wx.EVT_MOUSEWHEEL, self.OnMotion)
self.Bind(wx.EVT_SIZE, self.OnSize)
self.Bind(wx.EVT_IDLE, self.OnIdle)
self.Bind(wx.EVT_PAINT, self.OnPaint)
self.SetSizeandOrigin()
self.InitBuffer()
def InitBuffer(self):
self.buffer = wx.EmptyBitmap(self.width, self.height)
dc = wx.BufferedDC(None, self.buffer)
dc.SetMapMode(wx.MM_METRIC)
# Drawing upside down (i.e. natural orientation)
dc.SetAxisOrientation(True, True)
# Original position is top left of window
dc.SetDeviceOrigin(self.origin[0], self.origin[1])
dc.SetBackground(wx.Brush(self.GetBackgroundColour()))
dc.Clear()
gc = wx.GraphicsContext.Create(dc)
if self.lines:
self.DrawLines(gc)
# Prevent redraw in OnIdle
self.reInitBuffer = False
def OnPaint(self, event):
# For double buffered drawing; content of self.buffer is blit here to the DC
dc = wx.BufferedPaintDC(self, self.buffer)
def DrawLines(self, gc):
path = gc.CreatePath()
path.MoveToPoint(self.lines[0]) # Move to start point of airfoil
for index, coord in enumerate(self.lines):
#if index == 0: pass
path.AddLineToPoint(coord)
gc.SetPen(self.pen)
gc.SetBrush(self.brush)
gc.Scale(self.zoom, self.zoom)
gc.DrawPath(path)
def OnMotion(self, event):
# Drag
if event.Dragging() and event.LeftIsDown() and not event.m_controlDown:
actPos = event.GetPositionTuple()
xact = actPos[0]
yact = actPos[1]
xold = self.pos[0]
yold = self.pos[1]
vx = xact - xold
vy = yact - yold
self.origin = (self.origin[0] + vx, self.origin[1] + vy)
self.pos = actPos
self.InitBuffer()
self.Refresh(False)
# Zoom
elif event.GetWheelRotation():
self.zoom = self.zoom - event.GetWheelRotation()/float(self.height) # Change zoom factor
self.InitBuffer()
self.Refresh(False)
else:
self.pos = event.GetPositionTuple() # Initialize for dragging
event.Skip() # ???
def OnSize(self, event):
self.width, self.height = self.GetClientSize()
self.SetSizeandOrigin(0)
self.reInitBuffer = True # Redraw is automatically performed in OnIdle
def OnIdle(self, event):
if self.reInitBuffer:
self.InitBuffer()
self.Refresh(False) # generates EVT_PAINT; False means background not erased
def SetSizeandOrigin(self, fit=0):
self.width, self.height = self.GetClientSize()
if fit == 0:
or_x = 0.5*self.width # to be changed for all
or_y = 0.5*self.height # to be changed for all
self.zoom = 1.0
self.origin = (or_x, or_y)
class SketchFrame(wx.Frame):
def __init__(self, parent):
wx.Frame.__init__(self, parent, -1, "Test",
size=(800,600))
self.sketch = Canvas(self, -1)
if __name__ == '__main__':
app = wx.App(redirect=False)
frame = SketchFrame(None)
frame.Show(True)
app.MainLoop()
