/** Restore the previously active Event handlers. */
final void restoreGui() {
clearGui();
for (final KeyListener l : canvasKeyListeners) canvas.addKeyListener(l);
for (final KeyListener l : windowKeyListeners) window.addKeyListener(l);
for (final KeyListener l : ijKeyListeners) ij.addKeyListener(l);
for (final MouseListener l : canvasMouseListeners) canvas.addMouseListener(l);
for (final MouseMotionListener l : canvasMouseMotionListeners)
canvas.addMouseMotionListener(l);
for (final MouseWheelListener l : windowMouseWheelListeners) window.addMouseWheelListener(l);
}
/** Add new event handlers. */
final void takeOverGui() {
canvas.addKeyListener(Panorama_View.this);
window.addKeyListener(Panorama_View.this);
canvas.addMouseMotionListener(Panorama_View.this);
canvas.addMouseListener(Panorama_View.this);
ij.addKeyListener(Panorama_View.this);
window.addMouseWheelListener(Panorama_View.this);
}