wxPython/wx/lib/scrolledpanel.py

   1 #----------------------------------------------------------------------------
   2 # Name:         scrolledpanel.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 # 12/11/2003 - Jeff Grimmett (grimmtooth@softhome.net)
  10 #
  11 # o 2.5 compatability update.
  12 #
  13 # 12/21/2003 - Jeff Grimmett (grimmtooth@softhome.net)
  14 #
  15 # o wxScrolledPanel -> ScrolledPanel
  16 #
  17
  18 import  wx
  19
  20
  21 class ScrolledPanel( wx.PyScrolledWindow ):
  22
  23     """ ScrolledPanel fills a "hole" in the implementation of
  24     wx.ScrolledWindow, providing automatic scrollbar and scrolling
  25     behavior and the tab traversal management that wxScrolledWindow
  26     lacks.  This code was based on the original demo code showing how
  27     to do this, but is now available for general use as a proper class
  28     (and the demo is now converted to just use it.)
  29
  30     It is assumed that the ScrolledPanel will have a sizer, as it is
  31     used to calculate the minimal virtual size of the panel and etc.
  32     """
  33
  34     def __init__(self, parent, id=-1, pos = wx.DefaultPosition,
  35                  size = wx.DefaultSize, style = wx.TAB_TRAVERSAL,
  36                  name = "scrolledpanel"):
  37
  38         wx.PyScrolledWindow.__init__(self, parent, id,
  39                                      pos=pos, size=size,
  40                                      style=style, name=name)
  41         self.SetInitialSize(size)
  42         self.Bind(wx.EVT_CHILD_FOCUS, self.OnChildFocus)
  43
  44
  45     def SetupScrolling(self, scroll_x=True, scroll_y=True, rate_x=20, rate_y=20):
  46         """
  47         This function sets up the event handling necessary to handle
  48         scrolling properly. It should be called within the __init__
  49         function of any class that is derived from ScrolledPanel,
  50         once the controls on the panel have been constructed and
  51         thus the size of the scrolling area can be determined.
  52
  53         """
  54         # The following is all that is needed to integrate the sizer and the
  55         # scrolled window.
  56         if not scroll_x: rate_x = 0
  57         if not scroll_y: rate_y = 0
  58
  59         # Round up the virtual size to be a multiple of the scroll rate
  60         sizer = self.GetSizer()
  61         if sizer:
  62             w, h = sizer.GetMinSize()
  63             if rate_x:
  64                 w += rate_x - (w % rate_x)
  65             if rate_y:
  66                 h += rate_y - (h % rate_y)
  67             self.SetVirtualSize( (w, h) )
  68         self.SetScrollRate(rate_x, rate_y)
  69         wx.CallAfter(self._SetupAfter) # scroll back to top after initial events
  70
  71
  72     def _SetupAfter(self):
  73         self.SetVirtualSize(self.GetBestVirtualSize())
  74         self.Scroll(0,0)
  75
  76
  77     def OnChildFocus(self, evt):
  78         # If the child window that gets the focus is not visible,
  79         # this handler will try to scroll enough to see it.
  80         evt.Skip()
  81         child = evt.GetWindow()
  82
  83         sppu_x, sppu_y = self.GetScrollPixelsPerUnit()
  84         vs_x, vs_y   = self.GetViewStart()
  85         cr = child.GetRect()
  86         clntsz = self.GetClientSize()
  87         new_vs_x, new_vs_y = -1, -1
  88
  89         # is it before the left edge?
  90         if cr.x < 0 and sppu_x > 0:
  91             new_vs_x = vs_x + (cr.x / sppu_x)
  92
  93         # is it above the top?
  94         if cr.y < 0 and sppu_y > 0:
  95             new_vs_y = vs_y + (cr.y / sppu_y)
  96
  97         # For the right and bottom edges, scroll enough to show the
  98         # whole control if possible, but if not just scroll such that
  99         # the top/left edges are still visible
 100
 101         # is it past the right edge ?
 102         if cr.right > clntsz.width and sppu_x > 0:
 103             diff = (cr.right - clntsz.width) / sppu_x
 104             if cr.x - diff * sppu_x > 0:
 105                 new_vs_x = vs_x + diff + 1
 106             else:
 107                 new_vs_x = vs_x + (cr.x / sppu_x)
 108
 109         # is it below the bottom ?
 110         if cr.bottom > clntsz.height and sppu_y > 0:
 111             diff = (cr.bottom - clntsz.height) / sppu_y
 112             if cr.y - diff * sppu_y > 0:
 113                 new_vs_y = vs_y + diff + 1
 114             else:
 115                 new_vs_y = vs_y + (cr.y / sppu_y)
 116
 117         # if we need to adjust
 118         if new_vs_x != -1 or new_vs_y != -1:
 119             #print "%s: (%s, %s)" % (self.GetName(), new_vs_x, new_vs_y)
 120             self.Scroll(new_vs_x, new_vs_y)