Force redisplay of an output-pane or a pinboard-object.
capi
redisplay-element element &optional x y width height
element⇩ |
An output-pane or a pinboard-object. |
Positive reals or nil . Default nil . |
The function redisplay-element
causes element to be redisplayed. Redisplaying causes the display-callback of element to be called. When element is pinboard-object, the display-callback of its pinboard-layout is called.
redisplay-element
is special in that it can be called from any thread, as opposed to almost all of the other CAPI functions, which must be called from the thread to which element belongs.
x, y, width and height specify which part of element to redisplay. If x or y are nil
, they are set to 0. If width is nil
, it is set to the width of element minus x, and if height is nil
it is set to the height of element minus y. Thus if redisplay-element
is called with only element, it redisplays all of it.
redisplay-element
is the same as gp:invalidate-rectangle, except that redisplay-element
is safe to call from any thread, which gp:invalidate-rectangle is not.
The call to the display-callback is asynchronous, and there is no specific call to the display-callback that matches a given call to redisplay-element
. redisplay-element
just guarantees that, provided element is displayed and nothing is broken, at least one call to the display-callback will happen with the given rectangle or a rectangle that contains it.
This example shows use of redisplay-element
from a timer:
(example-edit-file "capi/graphics/metafile-rotation.lisp")
CAPI User Guide and Reference Manual (Unix version) - 01 Dec 2021 19:32:42