--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/lib-stdwin/Abstract.py	Mon Nov 05 19:44:36 1990 +0000
@@ -0,0 +1,53 @@
+# Abstract classes for parents and children.
+# Do not use as base class -- this is for documentation only.
+# Note that the tree must be built top down.
+
+class AbstractParent():
+	#
+	# Upcalls from child to parent
+	#
+	def addchild(self, child): unimpl()
+	def delchild(self, child): unimpl()
+	#
+	def need_mouse(self, child): unimpl()
+	def no_mouse(self, child): unimpl()
+	#
+	def need_timer(self, child): unimpl()
+	def no_timer(self, child): unimpl()
+	#
+	# XXX need_kbd, no_kbd; focus???
+	#
+	def begindrawing(self): return unimpl()
+	def beginmeasuring(self): return unimpl()
+	#
+	def change(self, area): unimpl()
+	def scroll(self, (area, (dh, dv))): unimpl()
+	def settimer(self, itimer): unimpl()
+
+class AbstractChild():
+	#
+	# Downcalls from parent to child
+	#
+	def destroy(self): unimpl()
+	#
+	def minsize(self, m): return unimpl()
+	def getbounds(self): return unimpl()
+	def setbounds(self, bounds): unimpl()
+	def draw(self, (d, area)): unimpl()
+	#
+	# Downcalls only made after certain upcalls
+	#
+	def mouse_down(self, detail): unimpl()
+	def mouse_move(self, detail): unimpl()
+	def mouse_up(self, detail): unimpl()
+	#
+	def timer(self): unimpl()
+
+# A "Split" is a child that manages one or more children.
+# (This terminology is due to DEC SRC, except for CSplits.)
+# A child of a split may be another split, a button, a slider, etc.
+# Certain upcalls and downcalls can be handled transparently, but
+# for others (e.g., all geometry related calls) this is not possible.
+
+class AbstractSplit() = AbstractChild(), AbstractParent():
+	pass