XmObjectAtPoint --- A toolkit function that determines which child intersects or comes closest to a specified point
SYNOPSIS
#include <Xm/Xm.h>
Widget XmObjectAtPoint(
Widget widget,
Position x,
Position y);
DESCRIPTION
XmObjectAtPoint searches the child list of the specified
manager widget and returns the child most closely associated
with the specified x,y coordinate pair.
For the typical Motif manager widget, XmObjectAtPoint
uses the following rules to determine the returned object:
•
If one child intersects x,y, XmObjectAtPoint
returns the widget ID of that child.
•
If more than one child intersects x,y,
XmObjectAtPoint returns the widget ID of the visible child.
•
If no child intersects x,y, XmObjectAtPoint
returns NULL.
The preceding rules are only general. In fact, each manager
widget is free to define "most closely associated"
as it desires.
For example, if no child intersects x,y, a manager
might return the child closest to x,y.
widget
Specifies a manager widget.
x
Specifies the x-coordinate about which you are seeking child
information. The x-coordinate must be specified in pixels,
relative to the left side of manager.
y
Specifies the y-coordinate about which you are seeking child
information. The y-coordinate must be specified in pixels,
relative to the top side of manager.
RETURN
Returns the child of manager most closely associated
with x,y.
If none of its children are sufficiently associated with x,y,
returns NULL.