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Invalidates the specified drawing region prior to repainting or refreshing a windowless plug-in.


#include <npapi.h>

void NPN_InvalidateRegion(NPP instance,
                          NPRegion invalidRegion);


The function has the following parameters:

Pointer to the current plug-in instance.
The area to invalidate, specified in a coordinate system that originates at the top left of the plug-in.


Before a windowless plug-in can repaint or refresh part of its drawing area, the plug-in must first invalidate the area with either NPN_InvalidateRect() or NPN_InvalidateRegion().

NPN_InvalidateRegion() causes the NPP_HandleEvent() method to pass an update event or a paint message to the plug-in. If a plug-in calls this method, it receives a paint message later. The browser redraws invalid areas of the document and windowless plug-ins at regularly timed intervals. To force a paint message, the plug-in can call NPN_ForceRedraw() after calling this method.

See also