org.opengis.go.display.canvas

Interface CanvasHandler

public interface CanvasHandler

The CanvasHandler interface provides programmers with a mechanism to change Canvas properties. When a handler is passed in to Canvas.enableHandler(CanvasHandler), the Canvas will give it the active CanvasController. The active controller allows the handler to change the canvas, until the handler is removed.

Method Summary

Modifier and Type	Method and Description
void	handlerEnabled(CanvasController controller) Enables this CanvasHandler, giving it the active CanvasController and thus the ability to modify the Canvas that enabled it.
void	handlerRemoved() Removes this CanvasHandler, meaning that calling methods on its CanvasController will no longer affect the Canvas.

Method Detail

handlerEnabled

void handlerEnabled(CanvasController controller)

Enables this CanvasHandler, giving it the active CanvasController and thus the ability to modify the Canvas that enabled it.

Parameters:

controller - the active CanvasController.

handlerRemoved

void handlerRemoved()

Removes this CanvasHandler, meaning that calling methods on its CanvasController will no longer affect the Canvas. A CanvasHandler should never attempt to re-enable itself after it has been removed.