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, -1,
  39                                      pos=pos, size=size,
  40                                      style=style, name=name)
  41         self.SetBestFittingSize(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.SetVirtualSizeHints( w, h )
  69
  70         self.SetScrollRate(rate_x, rate_y)
  71         wx.CallAfter(self.Scroll, 0, 0) # scroll back to top after initial events
  72
  73
  74     def OnChildFocus(self, evt):
  75         # If the child window that gets the focus is not visible,
  76         # this handler will try to scroll enough to see it.
  77         evt.Skip()
  78         child = evt.GetWindow()
  79
  80         sppu_x, sppu_y = self.GetScrollPixelsPerUnit()
  81         vs_x, vs_y   = self.GetViewStart()
  82         cr = child.GetRect()
  83         clntsz = self.GetClientSize()
  84         new_vs_x, new_vs_y = -1, -1
  85
  86         # is it before the left edge?
  87         if cr.x < 0 and sppu_x > 0:
  88             new_vs_x = vs_x + (cr.x / sppu_x)
  89
  90         # is it above the top?
  91         if cr.y < 0 and sppu_y > 0:
  92             new_vs_y = vs_y + (cr.y / sppu_y)
  93
  94
  95         # For the right and bottom edges, scroll enough to show the
  96         # whole control if possible, but if not just scroll such that
  97         # the top/left edges are still visible
  98
  99         # is it past the right edge ?
 100         if cr.right > clntsz.width and sppu_x > 0:
 101             diff = (cr.right - clntsz.width) / sppu_x
 102             if cr.x - diff * sppu_x > 0:
 103                 new_vs_x = vs_x + diff + 1
 104             else:
 105                 new_vs_x = vs_x + (cr.x / sppu_x)
 106
 107         # is it below the bottom ?
 108         if cr.bottom > clntsz.height and sppu_y > 0:
 109             diff = (cr.bottom - clntsz.height) / sppu_y
 110             if cr.y - diff * sppu_y > 0:
 111                 new_vs_y = vs_y + diff + 1
 112             else:
 113                 new_vs_y = vs_y + (cr.y / sppu_y)
 114
 115
 116         # if we need to adjust
 117         if new_vs_x != -1 or new_vs_y != -1:
 118             #print "%s: (%s, %s)" % (self.GetName(), new_vs_x, new_vs_y)
 119             self.Scroll(new_vs_x, new_vs_y)