/*
* Copyright 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.sample.ui.client;
import com.google.gwt.event.logical.shared.HasAttachHandlers;
import com.google.gwt.user.client.Command;
import com.google.web.bindery.event.shared.HandlerRegistration;
/**
* Accepts {@link Command}s to be run when the browser window or device's
* orientation changes. Commands operate only while the associated widget is
* attached.
* TODO(rjrjr) just use the event bus
*/
public interface OrientationHelper {
/**
* Gives efficient on demand access to the orientation of the window or
* device.
*
* @return true for portrait, false for landscape
*/
boolean isPortrait();
/**
* Set commands to run on orientation change, one for portrait and one for
* landscape. The appropriate command is fired immediately if this method is
* called while the widget is attached.
* <p>
* Commands are also fired each time the widget is attached. If that is not
* desired a widget should call {@link HandlerRegistration#removeHandler()} on
* the returned object when it detaches.
*
* @param widget the widget to help
* @param forPortrait command to run when on shift to portrait
* @param forLandscape command to run when on shift to landscape
* @return registration object to be used to stop and dereference the commands
*/
HandlerRegistration setCommands(HasAttachHandlers widget, Command forPortrait,
Command forLandscape);
}