utils/wxPython/lib/sizers/shape.py

   1 #----------------------------------------------------------------------
   2 # Name:        wxPython.lib.sizers.shape
   3 # Purpose:     A Sizer that preserves the shape (proportions)
   4 #              of the managed window
   5 #
   6 # Created:     7-October-1999
   7 # RCS-ID:      $Id$
   8 # Copyright:   SIA "ANK"
   9 # Licence:     wxWindows license
  10 #----------------------------------------------------------------------
  11
  12 from sizer       import wxSizer
  13
  14 wxANCHOR_NONE  = 0
  15 wxANCHOR_NORTH = 1
  16 wxANCHOR_SOUTH = 2
  17 wxANCHOR_EAST  = 4
  18 wxANCHOR_WEST  = 8
  19 wxANCHOR_NW = wxANCHOR_NORTH | wxANCHOR_WEST
  20 wxANCHOR_NE = wxANCHOR_NORTH | wxANCHOR_EAST
  21 wxANCHOR_SW = wxANCHOR_SOUTH | wxANCHOR_WEST
  22 wxANCHOR_SE = wxANCHOR_SOUTH | wxANCHOR_EAST
  23
  24 #----------------------------------------------------------------------
  25
  26 class wxShapeSizer(wxSizer):
  27     """
  28     wxShapeSizer
  29
  30     This sizer preserves the proportional dimensions of the managed
  31     window, leaving empty space either in horizontal or vertical
  32     dimension.
  33
  34     By default, the managed window is centered within allowed size.
  35     You may specify an anchor parameter to leave all of the extra
  36     space on one side: wxANCHOR_NORTH and wxANCHOR_SOUTH manage
  37     vertical dimension, leaving extra space on the bottom or top side,
  38     respectively; wxANCHOR_EAST and wxANCHOR_WEST do the same in
  39     horizontal dimension.  wxANCHOR_NW, wxANCHOR_NE, wxANCHOR_SW
  40     and wxANCHOR_SE are short-cut names for combinations north+west,
  41     north+east, south+west, south+east.
  42
  43     If both anchors are specified in either direction, south and east
  44     take precedence over north and west, respectively.  (Because of
  45     gravity, widgets tend to fall down.)
  46     """
  47     def __init__(self, anchor =wxANCHOR_NONE):
  48         wxSizer.__init__(self)
  49         self.anchor =anchor
  50
  51     def Add(self, widget):
  52         if self.children:
  53             raise ValueError("wxShapeSizer can only contain one child.")
  54
  55         wxSizer.Add(self, widget)
  56
  57     def CalcMin(self):
  58         isSizer, widget, width, height, borderSize = self.children[0]
  59
  60         if isSizer:
  61             width, height = widget.CalcMin()
  62
  63         return width, height
  64
  65     def RecalcSizes(self):
  66         isSizer, widget, width, height, borderSize = self.children[0]
  67         width =self.size.width
  68         height =self.size.height
  69         px =self.origin.x
  70         py =self.origin.y
  71         anchor =self.anchor
  72         # get current dimensions of the managed window
  73         w, h =self.CalcMin()
  74         ratio =float(w) /h
  75         # in what direction space should be added:
  76         #   -1: horisontal
  77         #    1: vertical
  78         #    0: shape is ok
  79         dir =cmp(ratio /width *height, 1)
  80         if dir <0:
  81             # recalculate width
  82             old_width =width
  83             width =height *ratio
  84             if anchor & wxANCHOR_EAST:
  85                 px =px +old_width -width
  86             elif not (anchor & wxANCHOR_WEST):
  87                 px =px +(old_width -width) /2
  88         elif dir >0:
  89             # recalculate height
  90             old_height =height
  91             height =width /ratio
  92             if anchor & wxANCHOR_SOUTH:
  93                 py =py +old_height -height
  94             elif not (anchor & wxANCHOR_NORTH):
  95                 py =py +(old_height -height) /2
  96
  97         widget.SetDimensions(px, py, width, height)