>># 
>># Copyright 1990, 1991 by the Massachusetts Institute of Technology and
>># UniSoft Group Limited.
>># 
>># Permission to use, copy, modify, distribute, and sell this software and
>># its documentation for any purpose is hereby granted without fee,
>># provided that the above copyright notice appear in all copies and that
>># both that copyright notice and this permission notice appear in
>># supporting documentation, and that the names of MIT and UniSoft not be
>># used in advertising or publicity pertaining to distribution of the
>># software without specific, written prior permission.  MIT and UniSoft
>># make no representations about the suitability of this software for any
>># purpose.  It is provided "as is" without express or implied warranty.
>># 
>># $XConsortium: clrwdw.m,v 1.4 92/06/11 16:20:48 rws Exp $
>># 
>>#      SCCS:  @(#)  EMat1.mc Rel 1.5	    (10/25/91)
>>#      SCCS:  @(#)  EWin.mc Rel 1.4	    (7/19/91)
>>#
>>TITLE XClearWindow CH06
>>ASSERTION A XClearWindow-1
A call to XClearWindow paints the entire area in the window
specified by the w argument with the window's background
pixel or pixmap.
>>STRATEGY
Create window.
Set window's background pixel to 0.
Call XClearWindow.
Verify window is set.

Set window's background pixel to 1.
Call XClearWindow.
Verify window is set.

Set window background pixmap.
Verify that window is set.
>>ASSERTION A XClearWindow-2
On a call to XClearWindow the subwindow-mode is
ClipByChildren.
>>STRATEGY
Create window
Create overlapping child window.
Call XClearWindow.
Verify that the child has not been drawn upon.
>>ASSERTION - XClearWindow-3
When the window has a defined background tile, then the
rectangle is tiled with a plane-mask of all ones and the
GXCopy function.
>>ASSERTION A XClearWindow-4
When the window has a background_pixmap of None, then the
contents of the window are not changed.
>>STRATEGY
Create window.
Set background pixel to W_FG.
Set background pixmap to None.
Call XClearWindow.
Check that the whole window is left alone.
>>ASSERTION A XClearWindow-5
When the window has a background_pixmap of ParentRelative
and the parent has a background_pixmap of None, then the
contents of the window are not changed.
>>STRATEGY
Create parent window.
Create a child window covering the parent.
Draw pattern on the child window.
Set parent window background to none.
Set child window background pixmap to ParentRelative.
Clear area of child
Verify that there was no change to the child window.
>>ASSERTION A XClearWindow-6
When a drawable argument is an InputOnly window then a
BadMatch error occurs.
>>STRATEGY
Create an InputOnly window.
Call test function using InputOnly window as the drawable argument.
Verify that a BadMatch error occurs.
>>ASSERTION A XClearWindow-7
When a window argument does not name a valid Window, then a
BadWindow error occurs.
>>STRATEGY
Create a bad window by creating and destroying a window.
Call test function using bad window as the window argument.
Verify that a BadWindow error occurs.
