Java tutorial
/** * Copyright 2010 The ForPlay Authors * * 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 forplay.html; import com.google.gwt.core.client.Duration; import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.JavaScriptObject; import com.google.gwt.dom.client.Document; import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.Style.Cursor; import com.google.gwt.user.client.Window; import forplay.core.Storage; import forplay.core.Analytics; import forplay.core.Audio; import forplay.core.ForPlay; import forplay.core.Game; import forplay.core.Graphics; import forplay.core.Json; import forplay.core.Keyboard; import forplay.core.Log; import forplay.core.Net; import forplay.core.Platform; import forplay.core.Pointer; import forplay.core.Mouse; import forplay.core.Touch; import forplay.core.RegularExpression; import forplay.html.HtmlUrlParameters.Renderer; public class HtmlPlatform implements Platform { /** Used by {@link #register(Mode)}. */ public static enum Mode { WEBGL { public boolean useGL() { return true; } }, CANVAS { public boolean useGL() { return false; } }, AUTODETECT { public boolean useGL() { return shouldUseGL(); } }; public abstract boolean useGL(); } static final int DEFAULT_WIDTH = 640; static final int DEFAULT_HEIGHT = 480; private static final int LOG_FREQ = 2500; private static final float MAX_DELTA = 100; /** * Prepares the HTML platform for operation. */ public static HtmlPlatform register() { return register(Mode.AUTODETECT); } /** * Prepares the HTML platform for operation. * * @param mode indicates whether to force the use of WebGL, force the use of Canvas, or to * autodetect whether the browser supports WebGL and use it if possible. */ public static HtmlPlatform register(Mode mode) { HtmlPlatform platform = new HtmlPlatform(mode); ForPlay.setPlatform(platform); platform.init(); return platform; } static native void addEventListener(JavaScriptObject target, String name, EventHandler handler, boolean capture) /*-{ target.addEventListener(name, function(e) { handler.@forplay.html.EventHandler::handleEvent(Lcom/google/gwt/dom/client/NativeEvent;)(e); }, capture); }-*/; static void captureEvent(String name, EventHandler handler) { captureEvent(null, name, handler); } static void captureEvent(Element target, String name, EventHandler handler) { addEventListener((target == null ? Document.get() : target), name, handler, true); } private HtmlAssetManager assetManager = new HtmlAssetManager(); private HtmlAudio audio = new HtmlAudio(); private HtmlRegularExpression regularExpression = new HtmlRegularExpression(); private Game game; private HtmlGraphics graphics; private HtmlJson json = new HtmlJson(); private HtmlKeyboard keyboard = new HtmlKeyboard(); private HtmlLog log; private HtmlNet net = new HtmlNet(); private HtmlPointer pointer; private HtmlMouse mouse; private HtmlTouch touch; private HtmlStorage storage = new HtmlStorage(); private HtmlAnalytics analytics = new HtmlAnalytics(); private TimerCallback paintCallback; private TimerCallback updateCallback; // Non-instantiable. private HtmlPlatform(Mode mode) { // Setup logging first, so it can be used by other subsystems log = GWT.create(HtmlLog.class); if (!GWT.isProdMode()) { log.info("You are running in GWT Development Mode. " + "For optimal performance you may want to use an alternative method. " + "See http://code.google.com/p/forplay/wiki/GameDebuggingOptions"); } /* * Wrap remaining calls in try-catch, since the UncaughtExceptionHandler installed by HtmlLog * above won't take effect until we yield to the browser event loop. That means we have to catch * our own exceptions here. */ try { try { graphics = mode.useGL() ? new HtmlGraphicsGL() : new HtmlGraphicsDom(); } catch (RuntimeException e) { // HtmlGraphicsGL ctor throws a runtime exception if the context creation fails. log().info("Failed to create GL context. Falling back."); graphics = new HtmlGraphicsDom(); } pointer = new HtmlPointer(graphics.getRootElement()); mouse = new HtmlMouse(graphics.getRootElement()); touch = new HtmlTouch(graphics.getRootElement()); } catch (Throwable e) { log.error("init()", e); Window.alert("failed to init(): " + e.getMessage()); } } public void init() { analytics.init(); audio.init(); keyboard.init(); } @Override public HtmlAssetManager assetManager() { return assetManager; } @Override public Audio audio() { return audio; } @Override public Graphics graphics() { return graphics; } @Override public Json json() { return json; } @Override public Keyboard keyboard() { return keyboard; } @Override public Log log() { return log; } @Override public Net net() { return net; } @Override public Pointer pointer() { return pointer; } @Override public Mouse mouse() { return mouse; } @Override public Touch touch() { return touch; } @Override public Storage storage() { return storage; } @Override public Analytics analytics() { return analytics; } @Override public float random() { return (float) Math.random(); } @Override public RegularExpression regularExpression() { return regularExpression; } @Override public void run(final Game game) { final int updateRate = game.updateRate(); this.game = game; game.init(); // Game loop. paintCallback = new TimerCallback() { private float accum = updateRate; private double lastTime; @Override public void fire() { requestAnimationFrame(paintCallback); double now = time(); float delta = (float) (now - lastTime); if (delta > MAX_DELTA) { delta = MAX_DELTA; } lastTime = now; if (updateRate == 0) { game.update(delta); accum = 0; } else { accum += delta; while (accum > updateRate) { game.update(updateRate); accum -= updateRate; } } game.paint(accum / updateRate); graphics.updateLayers(); } }; requestAnimationFrame(paintCallback); } @Override public double time() { return Duration.currentTimeMillis(); } private native JavaScriptObject getWindow() /*-{ return $wnd; }-*/; private native void requestAnimationFrame(TimerCallback callback) /*-{ var fn = function() { callback.@forplay.html.TimerCallback::fire()(); }; if ($wnd.requestAnimationFrame) { $wnd.requestAnimationFrame(fn); } else if ($wnd.mozRequestAnimationFrame) { $wnd.mozRequestAnimationFrame(fn); } else if ($wnd.webkitRequestAnimationFrame) { $wnd.webkitRequestAnimationFrame(fn); } else { // 20ms => 50fps $wnd.setTimeout(fn, 20); } }-*/; private native int setInterval(TimerCallback callback, int ms) /*-{ return $wnd.setInterval(function() { callback.@forplay.html.TimerCallback::fire()(); }, ms); }-*/; private native int setTimeout(TimerCallback callback, int ms) /*-{ return $wnd.setTimeout(function() { callback.@forplay.html.TimerCallback::fire()(); }, ms); }-*/; /** * Gets the URL's parameter of the specified name. Note that if multiple parameters have been * specified with the same name, the last one will be returned. * * @param name the name of the URL's parameter * @return the value of the URL's parameter */ public String getUrlParameter(String name) { return Window.Location.getParameter(name); } /** * @see forplay.core.Platform#openURL(java.lang.String) */ @Override public void openURL(String url) { Window.open(url, "_blank", ""); } /** * Sets the title of the browser's window or tab. * * @param title the window title */ public void setTitle(String title) { Window.setTitle(title); } /** * Sets the {@code cursor} CSS property. * * @param cursor the {@link Cursor} to use, or null to hide the cursor. */ public static void setCursor(Cursor cursor) { Element rootElement = ((HtmlGraphics) ForPlay.graphics()).getRootElement(); if (cursor == null) { rootElement.getStyle().setProperty("cursor", "none"); } else { rootElement.getStyle().setCursor(cursor); } } /** * Disable the right-click context menu. */ public static void disableRightClickContextMenu() { Element rootElement = ((HtmlGraphics) ForPlay.graphics()).getRootElement(); disableRightClickImpl(rootElement); } /** * Return true if renderer query parameter equals {@link Renderer#GL} or is not set, and the * browser supports WebGL * * @return true if renderer query parameter equals {@link Renderer#GL} or is not set, and the * browser supports WebGL */ private static boolean shouldUseGL() { boolean useGlFromFlag = Renderer.shouldUseGL(); return (useGlFromFlag && hasGLSupport()); } /** * Return true if the browser supports WebGL * * Note: This test can have false positives depending on the graphics hardware. * * @return true if the browser supports WebGL */ private static native boolean hasGLSupport() /*-{ return !!$wnd.WebGLRenderingContext && // WebGL is slow on Chrome OSX 10.5 (!/Chrome/.test(navigator.userAgent) || !/OS X 10_5/.test(navigator.userAgent)); }-*/; private static native void disableRightClickImpl(JavaScriptObject target) /*-{ target.oncontextmenu = function() { return false; }; }-*/; }