com.google.gwt.media.client.Audio Maven / Gradle / Ivy
/*
* 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.media.client;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.AudioElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.PartialSupport;
/**
*
* A widget representing an <audio> element.
*
*
* Experimental API: This API is still under development
* and is subject to change.
*
*
* This widget may not be supported on all browsers.
*/
@PartialSupport
public class Audio extends MediaBase {
/**
* Detector for permutations that might support {@link AudioElement}.
*/
@SuppressWarnings("unused")
private static class AudioElementSupportDetectedMaybe
extends AudioElementSupportDetector {
/**
* Using a compile-time check, return true if {@link AudioElement} might be
* supported.
*
* @return true if might be supported, false otherwise.
*/
@Override
boolean isSupportedCompileTime() {
return true;
}
}
/**
* Detector for permutations that do not support {@link AudioElement}.
*/
@SuppressWarnings("unused")
private static class AudioElementSupportDetectedNo
extends AudioElementSupportDetector {
/**
* Using a compile-time check, return true if {@link AudioElement} might be
* supported.
*
* @return true if might be supported, false otherwise.
*/
@Override
boolean isSupportedCompileTime() {
return false;
}
}
/**
* Detector for browser support of {@link AudioElement}.
*/
private static class AudioElementSupportDetector {
/**
* Using a run-time check, return true if the {@link AudioElement} is
* supported.
*
* @return true if supported, false otherwise.
*/
static native boolean isSupportedRunTime(AudioElement element) /*-{
return !!element.canPlayType;
}-*/;
/**
* Using a compile-time check, return true if {@link AudioElement} might be
* supported.
*
* @return true if might be supported, false otherwise.
*/
boolean isSupportedCompileTime() {
// will be true in AudioElementSupportDetectedMaybe
// will be false in AudioElementSupportDetectedNo
return false;
}
}
private static AudioElementSupportDetector detector;
/**
* Return a new {@link Audio} if supported, and null otherwise.
*
* @return a new {@link Audio} if supported, and null otherwise
*/
public static Audio createIfSupported() {
if (detector == null) {
detector = GWT.create(AudioElementSupportDetector.class);
}
if (!detector.isSupportedCompileTime()) {
return null;
}
AudioElement element = Document.get().createAudioElement();
if (!detector.isSupportedRunTime(element)) {
return null;
}
return new Audio(element);
}
/**
* Runtime check for whether the audio element is supported in this browser.
*
* @return whether the audio element is supported
*/
public static boolean isSupported() {
if (detector == null) {
detector = GWT.create(AudioElementSupportDetector.class);
}
if (!detector.isSupportedCompileTime()) {
return false;
}
AudioElement element = Document.get().createAudioElement();
if (!detector.isSupportedRunTime(element)) {
return false;
}
return true;
}
/**
* Protected constructor. Use {@link #createIfSupported()} to create an Audio.
*/
protected Audio(AudioElement element) {
super(element);
}
/**
* Returns the attached AudioElement.
*
* @return the AudioElement
*/
public AudioElement getAudioElement() {
return getMediaElement().cast();
}
}