wxPython/wx/lib/anchors.py

   1 #----------------------------------------------------------------------
   2 # Name:        wxPython.lib.anchors
   3 # Purpose:     A class that provides an easy to use interface over layout
   4 #              constraints for anchored layout.
   5 #
   6 # Author:      Riaan Booysen
   7 #
   8 # Created:     15-Dec-2000
   9 # RCS-ID:      $Id$
  10 # Copyright:   (c) 2000 by Total Control Software
  11 # Licence:     wxWindows license
  12 #----------------------------------------------------------------------
  13 # 11/30/2003 - Jeff Grimmett (grimmtooth@softhome.net)
  14 #
  15 # o Updated for wx namespace
  16 # o Tested with updated demo
  17 #
  18 """
  19 `LayoutAnchors` is a class that implements Delphi's Anchors using
  20 `wx.LayoutConstraints`.
  21 """
  22
  23 import  wx
  24
  25 class LayoutAnchors(wx.LayoutConstraints):
  26     """
  27     A class that implements Delphi's Anchors with wx.LayoutConstraints.
  28
  29     Anchored sides maintain the distance from the edge of the control
  30     to the same edge of the parent.  When neither side is selected,
  31     the control keeps the same relative position to both sides.
  32
  33     The current position and size of the control and it's parent is
  34     used when setting up the constraints. To change the size or
  35     position of an already anchored control, set the constraints to
  36     None, reposition or resize and reapply the anchors.
  37
  38     Examples::
  39
  40         Let's anchor the right and bottom edge of a control and
  41         resize it's parent.
  42
  43         ctrl.SetConstraints(LayoutAnchors(ctrl, left=0, top=0, right=1, bottom=1))
  44
  45         +=========+         +===================+
  46         | +-----+ |         |                   |
  47         | |     * |   ->    |                   |
  48         | +--*--+ |         |           +-----+ |
  49         +---------+         |           |     * |
  50                             |           +--*--+ |
  51                             +-------------------+
  52         * = anchored edge
  53
  54         When anchored on both sides the control will stretch horizontally.
  55
  56         ctrl.SetConstraints(LayoutAnchors(ctrl, 1, 0, 1, 1))
  57
  58         +=========+         +===================+
  59         | +-----+ |         |                   |
  60         | *     * |   ->    |                   |
  61         | +--*--+ |         | +---------------+ |
  62         +---------+         | *     ctrl      * |
  63                             | +-------*-------+ |
  64                             +-------------------+
  65         * = anchored edge
  66
  67     """
  68     def __init__(self, control, left=1, top=1, right=0, bottom=0):
  69         wx.LayoutConstraints.__init__(self)
  70         parent = control.GetParent()
  71         if not parent: return
  72
  73         pPos, pSize = parent.GetPosition(), parent.GetClientSize()
  74         cPos, cSize = control.GetPosition(), control.GetSize()
  75
  76         self.setConstraintSides(self.left, wx.Left, left,
  77                                 self.right, wx.Right, right,
  78                                 self.width, wx.Width, self.centreX,
  79                                 cPos.x, cSize.width, pSize.width, parent)
  80
  81         self.setConstraintSides(self.top, wx.Top, top,
  82                                 self.bottom, wx.Bottom, bottom,
  83                                 self.height, wx.Height, self.centreY,
  84                                 cPos.y, cSize.height, pSize.height, parent)
  85
  86     def setConstraintSides(self, side1, side1Edge, side1Anchor,
  87                                  side2, side2Edge, side2Anchor,
  88                                  size, sizeEdge, centre,
  89                                  cPos, cSize, pSize, parent):
  90         if side2Anchor:
  91             side2.SameAs(parent, side2Edge, pSize - (cPos + cSize))
  92
  93         if side1Anchor:
  94             side1.SameAs(parent, side1Edge, cPos)
  95
  96             if not side2Anchor:
  97                 size.AsIs()
  98         else:
  99             size.AsIs()
 100
 101             if not side2Anchor:
 102                 centre.PercentOf(parent, sizeEdge,
 103                                  int(((cPos + cSize / 2.0) / pSize)*100))
 104