Lib/stdwin/TransParent.py

   1 # A class that sits transparently between a parent and one child.
   2 # First create the parent, then this thing, then the child.
   3 # Use this as a base class for objects that are almost transparent.
   4 # Don't use as a base class for parents with multiple children.
   5
   6 Error = 'TransParent.Error'     # Exception
   7
   8 class ManageOneChild:
   9         #
  10         # Upcalls shared with other single-child parents
  11         #
  12         def addchild(self, child):
  13                 if self.child:
  14                         raise Error, 'addchild: one child only'
  15                 if not child:
  16                         raise Error, 'addchild: bad child'
  17                 self.child = child
  18         #
  19         def delchild(self, child):
  20                 if not self.child:
  21                         raise Error, 'delchild: no child'
  22                 if child <> self.child:
  23                         raise Error, 'delchild: not my child'
  24                 self.child = 0
  25
  26 class TransParent(ManageOneChild):
  27         #
  28         # Calls from creator
  29         # NB derived classes may add parameters to create()
  30         #
  31         def create(self, parent):
  32                 parent.addchild(self)
  33                 self.parent = parent
  34                 self.child = None # No child yet
  35                 return self
  36         #
  37         # Downcalls from parent to child
  38         #
  39         def destroy(self):
  40                 del self.parent
  41                 if self.child: self.child.destroy()
  42                 del self.child
  43         #
  44         def getminsize(self, args):
  45                 if not self.child:
  46                         m, size = args
  47                         return size
  48                 else:
  49                         return self.child.getminsize(args)
  50         def getbounds(self, bounds):
  51                 if not self.child:
  52                         raise Error, 'getbounds w/o child'
  53                 else:
  54                         return self.child.getbounds()
  55         def setbounds(self, bounds):
  56                 if not self.child:
  57                         raise Error, 'setbounds w/o child'
  58                 else:
  59                         self.child.setbounds(bounds)
  60         def realize(self):
  61                 if self.child:
  62                         self.child.realize()
  63         def draw(self, d, area):
  64                 if self.child:
  65                         self.child.draw(d, area)
  66         def altdraw(self, area):
  67                 if self.child:
  68                         self.child.altdraw(area)
  69         #
  70         # Downcalls only made after certain upcalls
  71         #
  72         def mouse_down(self, detail):
  73                 if self.child: self.child.mouse_down(detail)
  74         def mouse_move(self, detail):
  75                 if self.child: self.child.mouse_move(detail)
  76         def mouse_up(self, detail):
  77                 if self.child: self.child.mouse_up(detail)
  78         #
  79         def keybd(self, type_detail):
  80                 self.child.keybd(type_detail)
  81         def activate(self):
  82                 self.child.activate()
  83         def deactivate(self):
  84                 self.child.deactivate()
  85         #
  86         def timer(self):
  87                 if self.child: self.child.timer()
  88         #
  89         # Upcalls from child to parent
  90         #
  91         def need_mouse(self, child):
  92                 self.parent.need_mouse(self)
  93         def no_mouse(self, child):
  94                 self.parent.no_mouse(self)
  95         #
  96         def need_timer(self, child):
  97                 self.parent.need_timer(self)
  98         def no_timer(self, child):
  99                 self.parent.no_timer(self)
 100         #
 101         def need_altdraw(self, child):
 102                 self.parent.need_altdraw(self)
 103         def no_altdraw(self, child):
 104                 self.parent.no_altdraw(self)
 105         #
 106         def need_keybd(self, child):
 107                 self.parent.need_keybd(self)
 108         def no_keybd(self, child):
 109                 self.parent.no_keybd(self)
 110         #
 111         def begindrawing(self):
 112                 return self.parent.begindrawing()
 113         def beginmeasuring(self):
 114                 return self.parent.beginmeasuring()
 115         def getwindow(self):
 116                 return self.parent.getwindow()
 117         #
 118         def change(self, area):
 119                 self.parent.change(area)
 120         def scroll(self, area, vector):
 121                 self.parent.scroll(area, vector)
 122         def settimer(self, itimer):
 123                 self.parent.settimer(itimer)