Function

Summary

Validates the rectangle associated with the object, marks it as already drawn.

Package

graphics-ports

Signature

validate-rectangle object &optional x y width height
=> result

Arguments

object

An instance of a subclass of graphics-ports-mixin or a subclass of pinboard-object.

x

A real number.

y

A real number.

width

A real number.

height

A real number.

Values

result

A boolean.

Description

The given area of object is marked as not needing to be displayed. This can be useful if you want to draw that area immediately and avoid it being drawn again by the window system. By default it validates the whole rectangle, but this can be limited by passing the &optional arguments.

The result is non- nil if the function succeeds and nil if it fails (doing nothing).

Note: this function is not fully implemented on all platforms.

On Windows, it succeeds for all valid values of x , y , width and height .

On Cocoa, it fails if x , y , width and height are passed.

On Motif, it fails in all cases.

See also

invalidate-rectangle