wxPython/wx/lib/scrolledpanel.py

   1 #----------------------------------------------------------------------------
   2 # Name:         wxScrolledPanel.py
   3 # Author:       Will Sadkin
   4 # Created:      03/21/2003
   5 # Copyright:    (c) 2003 by Will Sadkin
   6 # RCS-ID:       $Id$
   7 # License:      wxWindows license
   8 #----------------------------------------------------------------------------
   9 #
  10
  11 from wxPython.wx import *
  12
  13
  14 class wxScrolledPanel( wxScrolledWindow ):
  15     """
  16 wxScrolledPanel fills a "hole" in the implementation of wxScrolledWindow,
  17 providing automatic scrollbar and scrolling behavior and the tab traversal
  18 management that wxScrolledWindow lacks.  This code was based on the original
  19 demo code showing how to do this, but is now available for general use
  20 as a proper class (and the demo is now converted to just use it.)
  21 """
  22     def __init__(self, parent, id=-1,
  23                  pos = wxDefaultPosition, size = wxDefaultSize,
  24                  style = wxTAB_TRAVERSAL, name = "scrolledpanel"):
  25
  26         wxScrolledWindow.__init__(self, parent, -1,
  27                                   pos=pos, size=size,
  28                                   style=style, name=name)
  29
  30         EVT_CHILD_FOCUS(self, self.OnChildFocus)
  31
  32
  33     def SetupScrolling(self, scroll_x=True, scroll_y=True, rate_x=20, rate_y=20):
  34         """
  35         This function sets up the event handling necessary to handle
  36         scrolling properly. It should be called within the __init__
  37         function of any class that is derived from wxScrolledPanel,
  38         once the controls on the panel have been constructed and
  39         thus the size of the scrolling area can be determined.
  40
  41         """
  42         # The following is all that is needed to integrate the sizer and the
  43         # scrolled window.
  44         if not scroll_x: rate_x = 0
  45         if not scroll_y: rate_y = 0
  46
  47         # Round up the virtual size to be a multiple of the scroll rate
  48         sizer = self.GetSizer()
  49         if sizer:
  50             w, h = sizer.GetMinSize()
  51             if rate_x:
  52                 w += rate_x - (w % rate_x)
  53             if rate_y:
  54                 h += rate_y - (h % rate_y)
  55             self.SetVirtualSize( (w, h) )
  56             self.SetVirtualSizeHints( w, h )
  57
  58         self.SetScrollRate(rate_x, rate_y)
  59         wxCallAfter(self.Scroll, 0, 0) # scroll back to top after initial events
  60
  61
  62     def OnChildFocus(self, evt):
  63         # If the child window that gets the focus is not visible,
  64         # this handler will try to scroll enough to see it.
  65         evt.Skip()
  66         child = evt.GetWindow()
  67
  68         sppu_x, sppu_y = self.GetScrollPixelsPerUnit()
  69         vs_x, vs_y   = self.GetViewStart()
  70         cpos = child.GetPosition()
  71         csz  = child.GetSize()
  72         new_vs_x, new_vs_y = -1, -1
  73
  74         # is it before the left edge?
  75         if cpos.x < 0 and sppu_x > 0:
  76             new_vs_x = vs_x + (cpos.x / sppu_x)
  77
  78         # is it above the top?
  79         if cpos.y < 0 and sppu_y > 0:
  80             new_vs_y = vs_y + (cpos.y / sppu_y)
  81
  82
  83         # is it past the right edge ?
  84         if cpos.x + csz.width > self.GetClientSize().width and sppu_x > 0:
  85             diff = (cpos.x + csz.width - self.GetClientSize().width) / sppu_x
  86             new_vs_x = vs_x + diff + 1
  87
  88         # is it below the bottom ?
  89         if cpos.y + csz.height > self.GetClientSize().height and sppu_y > 0:
  90             diff = (cpos.y + csz.height - self.GetClientSize().height) / sppu_y
  91             new_vs_y = vs_y + diff + 1
  92
  93         # if we need to adjust
  94         if new_vs_x != -1 or new_vs_y != -1:
  95             self.Scroll(new_vs_x, new_vs_y)