com.google.gwt.media.client.Video.java Source code

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Here is the source code for com.google.gwt.media.client.Video.java

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/*
 * 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.Document;
import com.google.gwt.dom.client.VideoElement;

/**
 * <p>
 * A widget representing a &lt;video&gt; element.
 *
 * <p>
 * <span style="color:red">Experimental API: This API is still under development
 * and is subject to change. </span>
 * </p>
 *
 * This widget may not be supported on all browsers.
 */
public class Video extends MediaBase {
    /**
     * Detector for permutations that might support {@link VideoElement}.
     */
    @SuppressWarnings("unused")
    private static class VideoElementSupportDetectedMaybe extends VideoElementSupportDetector {
        /**
         * Using a compile-time check, return true if {@link VideoElement} might be
         * supported.
         *
         * @return true if might be supported, false otherwise.
         */
        @Override
        boolean isSupportedCompileTime() {
            return true;
        }
    }

    /**
     * Detector for permutations that do not support {@link VideoElement}.
     */
    @SuppressWarnings("unused")
    private static class VideoElementSupportDetectedNo extends VideoElementSupportDetector {
        /**
         * Using a compile-time check, return true if {@link VideoElement} might be
         * supported.
         *
         * @return true if might be supported, false otherwise.
         */
        @Override
        boolean isSupportedCompileTime() {
            return false;
        }
    }

    /**
     * Detector for browser support of {@link VideoElement}.
     */
    private static class VideoElementSupportDetector {
        /**
         * Using a run-time check, return true if the {@link VideoElement} is
         * supported.
         *
         * @return true if supported, false otherwise.
         */
        static native boolean isSupportedRunTime(VideoElement element) /*-{
                                                                       return !!element.canPlayType;
                                                                       }-*/;

        /**
         * Using a compile-time check, return true if {@link VideoElement} might be
         * supported.
         *
         * @return true if might be supported, false otherwise.
         */
        boolean isSupportedCompileTime() {
            // will be true in VideoElementSupportDetectedMaybe
            // will be false in VideoElementSupportDetectedNo
            return false;
        }
    }

    private static VideoElementSupportDetector detector;

    /**
     * Return a new {@link Video} if supported, and null otherwise.
     *
     * @return a new {@link Video} if supported, and null otherwise
     */
    public static Video createIfSupported() {
        if (detector == null) {
            detector = GWT.create(VideoElementSupportDetector.class);
        }
        if (!detector.isSupportedCompileTime()) {
            return null;
        }
        VideoElement element = Document.get().createVideoElement();
        if (!detector.isSupportedRunTime(element)) {
            return null;
        }
        return new Video(element);
    }

    /**
     * Runtime check for whether the video element is supported in this browser.
     *
     * @return whether the video element is supported
     */
    public static boolean isSupported() {
        if (detector == null) {
            detector = GWT.create(VideoElementSupportDetector.class);
        }
        if (!detector.isSupportedCompileTime()) {
            return false;
        }
        VideoElement element = Document.get().createVideoElement();
        if (!detector.isSupportedRunTime(element)) {
            return false;
        }
        return true;
    }

    /**
     * Protected constructor. Use {@link #createIfSupported()} to create a Video.
     */
    protected Video(VideoElement element) {
        super(element);
    }

    /**
     * Creates a Video widget with a given source URL.
     *
     * @param src a String URL.
     * @deprecated use {@link #createIfSupported()}.
     */
    @Deprecated
    public Video(String src) {
        super(Document.get().createVideoElement());
        getMediaElement().setSrc(src);
    }

    /**
     * Returns a poster URL.
     *
     * @return a URL containing a poster image
     *
     * @see #setPoster(String)
     */
    public String getPoster() {
        return getVideoElement().getPoster();
    }

    /**
     * Returns the attached VideoElement.
     *
     * @return the VideoElement
     */
    public VideoElement getVideoElement() {
        return getMediaElement().cast();
    }

    /**
     * Gets the intrinsic height of video within the element.
     *
     * To get the element height, use {@link VideoElement#getOffsetHeight()}
     *
     * @return the height, in pixels
     */
    public int getVideoHeight() {
        return getVideoElement().getVideoHeight();
    }

    /**
     * Gets the instrinsic width of the video within the element.
     *
     * To get the element width, use {@link VideoElement#getOffsetWidth()}
     *
     * @return the width, in pixels
     */
    public int getVideoWidth() {
        return getVideoElement().getVideoWidth();
    }

    /**
     * Sets the poster URL.
     *
     * @param url the poster image URL
     * @see #getPoster
     */
    public void setPoster(String url) {
        getVideoElement().setPoster(url);
    }
}