DESIGN (xvobjects) functions
LIBRARY ROUTINE
xvw_create_canvas - create a canvas object
LIBRARY CALL
xvobject xvw_create_canvas(
xvobject parent,
char *name)
INPUT
- parent - parent of the canvas object; NULL will cause
a default toplevel to be created automatically
- name - a name for this particular instance of the object
(for use in app-defaults files, etc)
OUTPUT
none
RETURN VALUE
The canvas object on success, NULL on failure
DESCRIPTION
The canvas object is essentially a manager object
combined with a virtual window size. The virtual
window is a viewport where a canvas may contain a
vertical scrollbar, a horizontal scrollbar, or both.
In general, it is used to confine large visual displays
to a predefined area. The canvas object may have one
or many children; usually, the object(s) created inside
the canvas will take up more space than the canvas
itself, so that the scrollbar(s) of the canvas may be
used to view the entire display. The canvas object is
similar to the viewport object, except the canvas
provides an area for displaying graphical objects,
while the viewport object is typically only used to
contain GUI objects. The canvas object allows the
application to set a default width and height, while
the viewport will shrink its area to the minimum size
required to lay out all its children.
The canvas object also offers a global clipboard, which
acts as a common cut and paste area for use by all
canvas objects that may be displayed at the same time,
providing an easy method for the user to transfer
objects from one canvas to another.
ADDITIONAL INFORMATION
none
EXAMPLES
none
SIDE EFFECTS
none
RESTRICTIONS
none
MODIFICATION
none
FILES
$DESIGN/objects/library/xvobjects/src/Canvas.c
SEE ALSO
xvobjects(3)
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.