| /* |
| * Copyright 2006 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.user.client; |
| |
| /** |
| * This class can be used as a substitute for {@link java.util.Random}. The |
| * semantics differ in that the underlying browser's implementation is used. The |
| * random generator cannot be seeded or otherwise used to reproduce a particular |
| * sequence of results. |
| */ |
| public final class Random { |
| |
| /** |
| * Returns true or false with roughly equal probability. The underlying |
| * browser's random implementation is used. |
| */ |
| public static native boolean nextBoolean() /*-{ |
| return Math.random() < 0.5; |
| }-*/; |
| |
| /** |
| * Returns a random <code>double</code> between 0 (inclusive) and 1 |
| * (exclusive). The underlying browser's random implementation is used. |
| */ |
| public static native double nextDouble() /*-{ |
| return Math.random(); |
| }-*/; |
| |
| /** |
| * Returns a random <code>int</code> between -2147483648 and 2147483647 |
| * (inclusive) with roughly equal probability of returning any particular |
| * <code>int</code> in this range. The underlying browser's random |
| * implementation is used. |
| */ |
| public static native int nextInt() /*-{ |
| // "~~" forces the value to a 32 bit integer. |
| return ~~(Math.floor(Math.random() * 4294967296) - 2147483648); |
| }-*/; |
| |
| /** |
| * Returns a random <code>int</code> between 0 (inclusive) and |
| * <code>upperBound</code> (exclusive) with roughly equal probability of |
| * returning any particular <code>int</code> in this range. The underlying |
| * browser's random implementation is used. |
| */ |
| public static native int nextInt(int upperBound) /*-{ |
| // "~~" forces the value to a 32 bit integer. |
| return ~~(Math.floor(Math.random() * upperBound)); |
| }-*/; |
| |
| /** |
| * Not instantiable. Having different instances of this class would not be |
| * meaningful because no state is stored and the common browser implementation |
| * is shared. |
| */ |
| private Random() { |
| } |
| } |