import com.google.gwt.event.dom.client.HasKeyDownHandlers; //导入依赖的package包/类
public void setKeyPressed(JavaScriptObject aValue) {
	if (keyPressed != aValue) {
		if (keyDownReg != null) {
			keyDownReg.removeHandler();
			keyDownReg = null;
		}
		keyPressed = aValue;
		if (keyPressed != null && component instanceof HasKeyDownHandlers) {
			keyDownReg = ((HasKeyDownHandlers) component).addKeyDownHandler(new KeyDownHandler() {
				@Override
				public void onKeyDown(KeyDownEvent event) {
					if (keyPressed != null) {
						event.stopPropagation();
						executeEvent(keyPressed, EventsPublisher.publish(event));
					}
				}
			});
		}
	}
}
 

import com.google.gwt.event.dom.client.HasKeyDownHandlers; //导入依赖的package包/类
private void fixHandlers(final FilterBox box, Widget w) {
	if (w instanceof HasBlurHandlers)
		((HasBlurHandlers)w).addBlurHandler(box.iBlurHandler);
	if (w instanceof HasFocusHandlers)
		((HasFocusHandlers)w).addFocusHandler(box.iFocusHandler);
	if (w instanceof HasKeyDownHandlers)
		((HasKeyDownHandlers)w).addKeyDownHandler(new KeyDownHandler() {
			@Override
			public void onKeyDown(KeyDownEvent event) {
				if (event.getNativeEvent().getKeyCode() == KeyCodes.KEY_ESCAPE)
					if (box.isFilterPopupShowing()) box.hideFilterPopup();
			}
		});
}
 

import com.google.gwt.event.dom.client.HasKeyDownHandlers; //导入依赖的package包/类
/**
 * Sets the KeyDown event handler in many widgets
 * @param handler the handler
 * @param widgets the widgets
 */
public static void addKeyDownHandler(final KeyDownHandler handler,final HasKeyDownHandlers... widgets) {
	if (handler != null && widgets != null && widgets.length > 0) {
		for (HasKeyDownHandlers w : widgets) {
			if (w != null) w.addKeyDownHandler(handler);
		}
	}
}