Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.waveprotocol.wave.client.common.util; import com.google.gwt.core.client.JavaScriptObject; import org.waveprotocol.wave.model.util.ReadableStringMap.ProcV; /** * Presents a raw, direct view on a javascript object. Useful for exposing * properties that are not possible to modify with existing APIs. Also used as a * backend for browser-optimised data structures. * * @author danilatos@google.com (Daniel Danilatos) */ public final class JsoView extends JavaScriptObject { // As required by GWT protected JsoView() { } /** Construct an empty Jso */ public static native JsoView create() /*-{ return {}; }-*/; /** * Unsafely cast any jso to a JsoView, exposing its internals. * * @param jso * @return a JsoView of the input javascript object */ public static JsoView as(JavaScriptObject jso) { return jso.cast(); } /** * @param key * @return true if a value indexed by the given key is in the map */ public native boolean containsKey(String key) /*-{ return this[key] !== undefined; }-*/; /** * @param key * @return true if the given key exists in the map and is null */ public native boolean isNull(String key) /*-{ return this[key] === null; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a boolean. The method may fail at runtime if the type * is not correct. */ public native boolean getBoolean(String key) /*-{ return this[key]; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a string. The method may fail at runtime if the type * is not correct. */ public native String getString(String key) /*-{ return this[key]; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a string. The method may fail at runtime if the type * is not correct. */ public native String getString(int key) /*-{ return this[key]; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a primitive number. The method may fail at runtime if * the type is not correct. */ public native double getNumber(String key) /*-{ return this[key]; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a JSO. The method may fail at runtime if the type * is not correct. */ public native JavaScriptObject getJso(String key) /*-{ return this[key]; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a JSO. The method may fail at runtime if the type * is not correct. */ public native JavaScriptObject getJso(int key) /*-{ return this[key]; }-*/; /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a JSO. The method may fail at runtime if the type * is not correct. */ public JsoView getJsoView(String key) { JavaScriptObject jso = getJso(key); return jso == null ? null : JsoView.as(jso); } /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a JSO. The method may fail at runtime if the type * is not correct. */ public JsoView getJsoView(int key) { JavaScriptObject jso = getJso(key); return jso == null ? null : JsoView.as(jso); } /** * @param key * @return The value with the given key, or null if not present. The value is * assumed to be a "java" object. The method may fail at runtime if * the type is not correct. */ public native Object getObject(String key) /*-{ return this[key]; }-*/; /** * Same as {@link #getObject(String)} but does not require casting of the * return value */ public native <V> V getObjectUnsafe(String key) /*-{ return this[key]; }-*/; /** * Removes the given key from the map * @param key */ public native void remove(String key) /*-{ delete this[key]; }-*/; /** * Sets the value for the given key to null (does not remove it from the map) * @param key */ public native void setNull(String key) /*-{ this[key] = null; }-*/; /** * Sets the value for the key * @param key * @param value */ public native void setBoolean(String key, boolean value) /*-{ this[key] = value; }-*/; /** * Sets the value for the key * @param key * @param value */ public native void setString(String key, String value) /*-{ this[key] = value; }-*/; /** * Sets the value for the key * @param key * @param value */ public native void setNumber(String key, double value) /*-{ this[key] = value; }-*/; /** * Sets the value for the key * @param key * @param value */ public native void setJso(String key, JavaScriptObject value) /*-{ this[key] = value; }-*/; /** * Sets the value for the key * @param key * @param value */ public native void setObject(String key, Object value) /*-{ this[key] = value; }-*/; /** * Removes all entries from this jso. */ public final native void clear() /*-{ for (var key in this) { delete this[key]; } }-*/; /** * Tests whether this jso is empty. * * @return true if this map has no entries. */ public final native boolean isEmpty() /*-{ for (var k in this) { return false; } return true; }-*/; /** * Counts the number of entries in this jso. This is a linear time operation. */ public final native int countEntries() /*-{ var n = 0; for (var k in this) { n++; } return n; }-*/; /** * @return the first key in the iteration order, or null if the object is empty */ public final native String firstKey() /*-{ for (var k in this) { return k; } return null; }-*/; /** * Ruby/prototype.js style iterating idiom, using a callback. Equivalent to a * for-each loop. * * @param <T> The value type. It is up to the caller to make sure only values * of type T have been put into the Jso in the first place * @param proc */ public final native <T> void each(ProcV<T> proc) /*-{ for (var k in this) { proc. @org.waveprotocol.wave.model.util.ReadableStringMap.ProcV::apply(Ljava/lang/String;Ljava/lang/Object;) (k, this[k]); } }-*/; /** * Add all key value pairs from the source to the current map * * @param source */ public final native void putAll(JsoView source) /*-{ for (var k in source) { this[k] = source[k]; } }-*/; }