Java EventHandler类代码示例

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
/**
 * Sets an event handler for an {@code Element}. All previous event handlers of this type of event are removed.
 * @param element The element to bind the event handler for
 * @param eventType The event type (e.g. {@code ClickEvent.getType()})
 * @param handler The handler that handler the event
 */
public static <H extends EventHandler> void setEventHandler(final Element element, DomEvent.Type<H> eventType, H handler) {
  if (element == null) {
    return;
  }
  HandlerManager hm = handlerManagers.get(element);
  if (hm == null) {
    handlerManagers.put(element, hm = new HandlerManager(element));
    DOM.setEventListener(element, new EventListener() {
      @Override
      public void onBrowserEvent(Event event) {
        DomEvent.fireNativeEvent(event, handlerManagers.get(element), element);
      }
    });
  }
  DOM.sinkBitlessEvent(element, eventType.getName());
  while (hm.getHandlerCount(eventType) > 0) {
    hm.removeHandler(eventType, hm.getHandler(eventType, 0));
  }
  hm.addHandler(eventType, handler);
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
protected <H extends EventHandler> void addHandler(Type<H> type) {
	// checks which kind of handler has been added
	if (type.equals(AnimationCompleteEvent.TYPE)) {
		// checks if property exist
		if (!has(Property.onComplete)) {
			// sets the java script code to get the event
			registerNativeCompleteHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onCompleteHandlers++;
	} else if (type.equals(AnimationProgressEvent.TYPE)) {
		// checks if property exist
		if (!has(Property.onProgress)) {
			// sets the java script code to get the event
			registerNativeProgressHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onProgressHandlers++;
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
protected <H extends EventHandler> void removeHandler(Type<H> type) {
	// checks which kind of handler has been removed
	if (type.equals(AnimationCompleteEvent.TYPE)) {
		// decrements amount of handlers
		onCompleteHandlers--;
		// if zero, no handler
		if (onCompleteHandlers == 0) {
			// therefore remove property
			remove(Property.onComplete);
		}
	} else if (type.equals(AnimationProgressEvent.TYPE)) {
		// decrements amount of handlers
		onProgressHandlers--;
		// if zero, no handler
		if (onProgressHandlers == 0) {
			// therefore remove property
			remove(Property.onProgress);
		}
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
protected <H extends EventHandler> void addHandler(Type<H> type) {
	// checks if type of added event handler is dataset selection or click
	if (type.equals(ChartClickEvent.TYPE)) {
		// if java script property is missing
		if (!has(Property.onClick)) {
			// adds the java script function to catch the event
			registerNativeClickHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onClickHandlers++;
	} else if (type.equals(ChartHoverEvent.TYPE)) {
		// if java script property is missing
		if (!has(Property.onHover)) {
			// adds the java script function to catch the event
			registerNativeHoverHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onHoverHandlers++;
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
protected <H extends EventHandler> void removeHandler(Type<H> type) {
	// checks if type of removed event handler is dataset selection or click
	if (type.equals(DatasetSelectionEvent.TYPE) || type.equals(ChartClickEvent.TYPE)) {
		// decrements the amount of handlers
		onClickHandlers--;
		// if there is not any handler
		if (onClickHandlers == 0) {
			// removes the java script object
			remove(Property.onClick);
		}
	} else if (type.equals(ChartHoverEvent.TYPE)) {
		// decrements the amount of handlers
		onHoverHandlers--;
		// if there is not any handler
		if (onHoverHandlers == 0) {
			// removes the java script object
			remove(Property.onHover);
		}
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
public void prepare() {
	canvas = new GWTCanvas(width, height);
	popupPanel.setWidget(canvas);
	for (Entry<EventHandler, DomEvent.Type<EventHandler>> entry : eventHandlers.entrySet()) {
		canvas.addDomHandler(entry.getKey(), entry.getValue());
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
public void addEvent(PointerEvent<? extends EventHandler> pointerEvent) {
    if (isFirstTouch(pointerEvent)) {
        pointersPoints.clear();
    }
    Point coordinates = new Point(pointerEvent.getClientX(), pointerEvent.getClientY());
    pointersPoints.put(pointerEvent.getPointerId(), coordinates);
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
protected <H extends EventHandler> void addHandler(Type<H> type) {
	// checks if type of added event handler is dataset selection or click
	if (type.equals(DatasetSelectionEvent.TYPE) || type.equals(ChartClickEvent.TYPE)) {
		// if java script property is missing
		if (!has(Property.onClick)) {
			// adds the java script function to catch the event
			registerNativeClickHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onClickHandlers++;
	} else if (type.equals(ChartHoverEvent.TYPE)) {
		// if java script property is missing
		if (!has(Property.onHover)) {
			// adds the java script function to catch the event
			registerNativeHoverHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onHoverHandlers++;
	} else if (type.equals(ChartResizeEvent.TYPE)) {
		// if java script property is missing
		if (!has(Property.onResize)) {
			// adds the java script function to catch the event
			registerNativeResizeHandler(getJavaScriptObject());
		}
		// increments amount of handlers
		onResizeHandlers++;
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
protected <H extends EventHandler> void removeHandler(Type<H> type) {
	// checks if type of removed event handler is dataset selection or click
	if (type.equals(DatasetSelectionEvent.TYPE) || type.equals(ChartClickEvent.TYPE)) {
		// decrements the amount of handlers
		onClickHandlers--;
		// if there is not any handler
		if (onClickHandlers == 0) {
			// removes the java script object
			remove(Property.onClick);
		}
	} else if (type.equals(ChartHoverEvent.TYPE)) {
		// decrements the amount of handlers
		onHoverHandlers--;
		// if there is not any handler
		if (onHoverHandlers == 0) {
			// removes the java script object
			remove(Property.onHover);
		}
	} else if (type.equals(ChartResizeEvent.TYPE)) {
		// decrements the amount of handlers
		onResizeHandlers--;
		// if there is not any handler
		if (onResizeHandlers == 0) {
			// removes the java script object
			remove(Property.onResize);
		}
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
public <H extends EventHandler> HandlerRegistration addHandler(Type<H> type, H handler) {
	// adds handler
	HandlerRegistration registration = super.addHandler(type, handler);
	// if the handler is a chart event handler one
	if (handler instanceof ChartEventHandler) {
		// sends the event
		fireEvent(new AddHandlerEvent(type));
	}
	return registration;
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
@Override
public <H extends EventHandler> void removeHandler(Type<H> type, H handler) {
	// removes handler
	super.removeHandler(type, handler);
	// if the handler is a chart event handler one
	if (handler instanceof ChartEventHandler) {
		// sends the event
		fireEvent(new RemoveHandlerEvent(type));
	}
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
public <T extends EventHandler> HandlerRegistration addHandler(Type<T> type,
        T handler) {
    return eventBus.addHandler(type, handler);
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
<H extends EventHandler> HandlerRegistration addHandler(
    final H handler, DomEvent.Type<H> type) {
  return addDomHandler(handler, type);
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
public <T extends EventHandler> HandlerRegistration addHandlerToSource(
        Type<T> type,
        Object source, T handler) {
    return eventBus.addHandlerToSource(type, source, handler);
}
 

import com.google.gwt.event.shared.EventHandler; //导入依赖的package包/类
/**
 * Clears all event handlers of a specific event type from an element.
 * @param element The element to clear the event handlers from
 * @param eventType The event type
 */
public static <H extends EventHandler> void clearEventHandlers(Element element, GwtEvent.Type<H> eventType) {
  HandlerManager hm = handlerManagers.get(element);
  while (hm != null && hm.getHandlerCount(eventType) > 0) {
    hm.removeHandler(eventType, hm.getHandler(eventType, 0));
  }
}