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
  14 from wxPython.wx import wxLayoutConstraints, wxTop, wxLeft, wxBottom, wxRight, \
  15                         wxHeight, wxWidth
  16
  17 class LayoutAnchors(wxLayoutConstraints):
  18     """ A class that implements Delphi's Anchors with wxLayoutConstraints.
  19
  20         Anchored sides maintain the distance from the edge of the
  21         control to the same edge of the parent.
  22         When neither side is selected, the control keeps the same
  23         relative position to both sides.
  24
  25         The current position and size of the control and it's parent
  26         is used when setting up the constraints. To change the size or
  27         position of an already anchored control, set the constraints to
  28         None, reposition or resize and reapply the anchors.
  29
  30         Examples:
  31
  32         Let's anchor the right and bottom edge of a control and
  33         resize it's parent.
  34
  35         ctrl.SetConstraints(LayoutAnchors(ctrl, left=0, top=0, right=1, bottom=1))
  36
  37         +=========+         +===================+
  38         | +-----+ |         |                   |
  39         | |     * |   ->    |                   |
  40         | +--*--+ |         |           +-----+ |
  41         +---------+         |           |     * |
  42                             |           +--*--+ |
  43                             +-------------------+
  44         * = anchored edge
  45
  46         When anchored on both sides the control will stretch horizontally.
  47
  48         ctrl.SetConstraints(LayoutAnchors(ctrl, 1, 0, 1, 1))
  49
  50         +=========+         +===================+
  51         | +-----+ |         |                   |
  52         | *     * |   ->    |                   |
  53         | +--*--+ |         | +---------------+ |
  54         +---------+         | *     ctrl      * |
  55                             | +-------*-------+ |
  56                             +-------------------+
  57         * = anchored edge
  58     """
  59     def __init__(self, control, left = 1, top = 1, right = 0, bottom = 0):
  60         wxLayoutConstraints.__init__(self)
  61         parent = control.GetParent()
  62         if not parent: return
  63
  64         pPos, pSize = parent.GetPosition(), parent.GetClientSize()
  65         cPos, cSize = control.GetPosition(), control.GetSize()
  66
  67         self.setConstraintSides(self.left, wxLeft, left,
  68                                 self.right, wxRight, right,
  69                                 self.width, wxWidth, self.centreX,
  70                                 cPos.x, cSize.width, pSize.width, parent)
  71
  72         self.setConstraintSides(self.top, wxTop, top,
  73                                 self.bottom, wxBottom, bottom,
  74                                 self.height, wxHeight, self.centreY,
  75                                 cPos.y, cSize.height, pSize.height, parent)
  76
  77     def setConstraintSides(self, side1, side1Edge, side1Anchor,
  78                                  side2, side2Edge, side2Anchor,
  79                                  size, sizeEdge, centre,
  80                                  cPos, cSize, pSize, parent):
  81         if side2Anchor:
  82             side2.SameAs(parent, side2Edge, pSize - (cPos + cSize))
  83         if side1Anchor:
  84             side1.SameAs(parent, side1Edge, cPos)
  85             if not side2Anchor:
  86                 size.AsIs()
  87         else:
  88             size.AsIs()
  89             if not side2Anchor:
  90                 centre.PercentOf(parent, sizeEdge,
  91                                  int(((cPos + cSize / 2.0) / pSize)*100))