utils/wxPython/lib/sizers/box.py

   1 #----------------------------------------------------------------------
   2 # Name:        wxPython.lib.sizers.box
   3 # Purpose:     A sizer/layout managers for wxPython that places items in
   4 #              a stretchable box
   5 #
   6 # Author:      Robin Dunn and Dirk Holtwick
   7 #
   8 # Created:     17-May-1999
   9 # RCS-ID:      $Id$
  10 # Copyright:   (c) 1998 by Total Control Software
  11 # Licence:     wxWindows license
  12 #----------------------------------------------------------------------
  13
  14 from sizer       import wxSizer
  15 from wxPython.wx import wxVERTICAL, wxHORIZONTAL
  16
  17 #----------------------------------------------------------------------
  18
  19
  20 class wxBoxSizer(wxSizer):
  21     """
  22     wxBoxSizer
  23
  24     A Sizer that lays components out in a box, in the order they are
  25     added to the layout manager, with a given orientation.  The
  26     orientation is specified in the constructor with either wxVERTICAL
  27     or wxHORIZONTAL.
  28
  29     The optional parameter to the Add method (for this sizer it's
  30     called the stretch flag) can be used to flag one or more components
  31     as stretchable, meaning that they will expand to fill available
  32     space in the given orientation.  The default is zero, or not
  33     stretchable.
  34
  35     If the stretch flag is non-zero then the widget will stretch. If
  36     the sizer holds more than one item that is stretchable then they
  37     share the available space.
  38
  39     If the strech flag is greater than 1 then it serves as a weighting
  40     factor.  Widgets with a flag of 2 will get twice as much space as
  41     widgets with 1, etc.
  42     """
  43     def __init__(self, orientation, size = None):
  44         wxSizer.__init__(self, size)
  45         self.orientation = orientation
  46
  47
  48     def CalcMin(self):
  49         self.stretchable = 0   # number of stretchable items
  50         self.minWidth    = 0   # minimal size
  51         self.minHeight   = 0
  52         self.fixedWidth  = 0   # size without stretched widgets
  53         self.fixedHeight = 0
  54
  55         # iterate through children
  56         for (isSizer, widget, width, height, stretch) in self.children:
  57             weight = 1
  58             if stretch:
  59                 weight = stretch
  60
  61             if isSizer:
  62                 # let sub-sizers recalc their required space
  63                 width, height = widget.CalcMin()
  64
  65             # minimal size
  66             if self.orientation == wxVERTICAL:
  67                 self.minHeight = self.minHeight + (height * weight)
  68                 self.minWidth  = max(self.minWidth, width)
  69             else:
  70                 self.minWidth  = self.minWidth + (width * weight)
  71                 self.minHeight = max(self.minHeight, height)
  72
  73             # stretchable items
  74             if stretch:
  75                 self.stretchable = self.stretchable + weight
  76             else:
  77                 if self.orientation == wxVERTICAL:
  78                     self.fixedHeight = self.fixedHeight + height
  79                     self.fixedWidth = max(self.fixedWidth, width)
  80                 else:
  81                     self.fixedWidth = self.fixedWidth + width
  82                     self.fixedHeight = max(self.fixedHeight, height)
  83
  84         return self.minWidth, self.minHeight
  85
  86
  87
  88     def RecalcSizes(self):
  89         # get current dimensions, save for performance
  90         myWidth  = self.size.width
  91         myHeight = self.size.height
  92
  93         # relative recent positions & sizes
  94         px = self.origin.x
  95         py = self.origin.y
  96         newWidth = 0
  97         newHeight = 0
  98
  99         # calculate space for one stretched item
 100         if self.stretchable:
 101             if self.orientation == wxHORIZONTAL:
 102                 delta = (myWidth - self.fixedWidth) / self.stretchable
 103                 extra = (myWidth - self.fixedWidth) % self.stretchable
 104             else:
 105                 delta = (myHeight - self.fixedHeight) / self.stretchable
 106                 extra = (myHeight - self.fixedHeight) % self.stretchable
 107
 108         # iterate children ...
 109         for (isSizer, widget, width, height, stretch) in self.children:
 110             weight = 1
 111             if stretch:
 112                 weight = stretch
 113
 114             if isSizer:
 115                 width, height = widget.CalcMin()
 116
 117             # ... vertical
 118             if self.orientation == wxVERTICAL:
 119                 newHeight = height
 120                 if stretch:
 121                     newHeight = (delta * weight) + extra  # first stretchable gets extra pixels
 122                     extra = 0
 123                 widget.SetDimensions(px, py, myWidth, newHeight)
 124
 125             # ... horizontal
 126             elif self.orientation == wxHORIZONTAL:
 127                 newWidth = width
 128                 if stretch:
 129                     newWidth = (delta * weight) + extra  # first stretchable gets extra pixels
 130                     extra = 0
 131                 widget.SetDimensions(px, py, newWidth, myHeight)
 132
 133             px = px + newWidth
 134             py = py + newHeight
 135
 136
 137 #----------------------------------------------------------------------