This method is called by the specified object when the instance of the class that implements this interface is removed from the object that is the source of the interest. This method is called by the specified object when the instance of the class that implements this interface is added to the object that is the source of the interest. The ImageDrawer expect this object to be some kind of java.awt.Component, in which case it will use that Components java.awt.Graphics object to draw the java.awt.Image that it presents in the redraw call. This method is called by the specified object when the instance of the class that implements this interface is removed from the object that is the source of the interest. The ImageDrawer expect this object to be some kind of java.awt.Component, in which case it will remove its capability to redraw its java.awt.Image in its redraw call.
All values are in pixels.
All values are in pixels. If the canvas is able to discern that only a part of the client's drawing area needs to be redrawn - then this area shall be passed in using the invalidRgn. Otherwise this will be null in which case the client should redraw itself entirely.