# A class that sits transparently between a parent and one child.
# First create the parent, then this thing, then the child.
# Use this as a base class for objects that are almost transparent.
# Don't use as a base class for parents with multiple children.
Error = 'TransParent.Error' # Exception
class ManageOneChild:
#
# Upcalls shared with other single-child parents
#
def addchild(self, child):
if self.child:
raise Error, 'addchild: one child only'
if not child:
raise Error, 'addchild: bad child'
self.child = child
#
def delchild(self, child):
if not self.child:
raise Error, 'delchild: no child'
if child <> self.child:
raise Error, 'delchild: not my child'
self.child = 0
class TransParent(ManageOneChild):
#
# Calls from creator
# NB derived classes may add parameters to create()
#
def create(self, parent):
parent.addchild(self)
self.parent = parent
self.child = None # No child yet
return self
#
# Downcalls from parent to child
#
def destroy(self):
del self.parent
if self.child: self.child.destroy()
del self.child
#
def getminsize(self, args):
if not self.child:
m, size = args
return size
else:
return self.child.getminsize(args)
def getbounds(self, bounds):
if not self.child:
raise Error, 'getbounds w/o child'
else:
return self.child.getbounds()
def setbounds(self, bounds):
if not self.child:
raise Error, 'setbounds w/o child'
else:
self.child.setbounds(bounds)
def realize(self):
if self.child:
self.child.realize()
def draw(self, d, area):
if self.child:
self.child.draw(d, area)
def altdraw(self, area):
if self.child:
self.child.altdraw(area)
#
# Downcalls only made after certain upcalls
#
def mouse_down(self, detail):
if self.child: self.child.mouse_down(detail)
def mouse_move(self, detail):
if self.child: self.child.mouse_move(detail)
def mouse_up(self, detail):
if self.child: self.child.mouse_up(detail)
#
def keybd(self, type_detail):
self.child.keybd(type_detail)
def activate(self):
self.child.activate()
def deactivate(self):
self.child.deactivate()
#
def timer(self):
if self.child: self.child.timer()
#
# Upcalls from child to parent
#
def need_mouse(self, child):
self.parent.need_mouse(self)
def no_mouse(self, child):
self.parent.no_mouse(self)
#
def need_timer(self, child):
self.parent.need_timer(self)
def no_timer(self, child):
self.parent.no_timer(self)
#
def need_altdraw(self, child):
self.parent.need_altdraw(self)
def no_altdraw(self, child):
self.parent.no_altdraw(self)
#
def need_keybd(self, child):
self.parent.need_keybd(self)
def no_keybd(self, child):
self.parent.no_keybd(self)
#
def begindrawing(self):
return self.parent.begindrawing()
def beginmeasuring(self):
return self.parent.beginmeasuring()
def getwindow(self):
return self.parent.getwindow()
#
def change(self, area):
self.parent.change(area)
def scroll(self, area, vector):
self.parent.scroll(area, vector)
def settimer(self, itimer):
self.parent.settimer(itimer)
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