wxPython/wx/lib/dragscroller.py

   1 #-----------------------------------------------------------------------------
   2 # Name:        dragscroller.py
   3 # Purpose:     Scrolls a wx.ScrollWindow by dragging
   4 #
   5 # Author:      Riaan Booysen
   6 #
   7 # Created:     2006/09/05
   8 # Copyright:   (c) 2006
   9 # Licence:     wxPython
  10 #-----------------------------------------------------------------------------
  11
  12 import wx
  13
  14 class DragScroller:
  15     """ Scrolls a wx.ScrollWindow in the direction and speed of a mouse drag.
  16
  17         Call Start with the position of the drag start.
  18         Call Stop on the drag release. """
  19
  20     def __init__(self, scrollwin, rate=30, sensitivity=0.75):
  21         self.scrollwin = scrollwin
  22         self.rate = rate
  23         self.sensitivity = sensitivity
  24
  25         self.pos = None
  26         self.timer = None
  27
  28     def GetScrollWindow(self):
  29         return self.scrollwin
  30     def SetScrollWindow(self, scrollwin):
  31         self.scrollwin = scrollwin
  32
  33     def GetUpdateRate(self):
  34         return self.rate
  35     def SetUpdateRate(self, rate):
  36         self.rate = rate
  37
  38     def GetSensitivity(self):
  39         return self.sensitivity
  40     def SetSensitivity(self, sensitivity):
  41         self.sensitivity = sensitivity
  42
  43     def Start(self, pos):
  44         """ Start a drag scroll operation """
  45         if not self.scrollwin:
  46             raise Exception, 'No ScrollWindow defined'
  47
  48         self.pos = pos
  49         self.scrollwin.SetCursor(wx.StockCursor(wx.CURSOR_SIZING))
  50         self.scrollwin.CaptureMouse()
  51
  52         self.timer = wx.Timer(self.scrollwin)
  53         self.scrollwin.Bind(wx.EVT_TIMER, self.OnTimerDoScroll, id=self.timer.GetId())
  54         self.timer.Start(self.rate)
  55
  56     def Stop(self):
  57         """ Stops a drag scroll operation """
  58         if self.timer and self.scrollwin:
  59             self.timer.Stop()
  60             self.scrollwin.Disconnect(self.timer.GetId())
  61             self.timer.Destroy()
  62             self.timer = None
  63
  64             self.scrollwin.SetCursor(wx.STANDARD_CURSOR)
  65             self.scrollwin.ReleaseMouse()
  66
  67     def OnTimerDoScroll(self, event):
  68         if self.pos is None or not self.timer or not self.scrollwin:
  69             return
  70
  71         new = self.scrollwin.ScreenToClient(wx.GetMousePosition())
  72         dx = int((new.x-self.pos.x)*self.sensitivity)
  73         dy = int((new.y-self.pos.y)*self.sensitivity)
  74         spx = self.scrollwin.GetScrollPos(wx.HORIZONTAL)
  75         spy = self.scrollwin.GetScrollPos(wx.VERTICAL)
  76
  77         self.scrollwin.Scroll(spx+dx, spy+dy)