com.google.gwt.user.client.Random Maven / Gradle / Ivy
/*
* 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 double 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 int between -2147483648 and 2147483647
* (inclusive) with roughly equal probability of returning any particular
* int 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 int between 0 (inclusive) and
* upperBound (exclusive) with roughly equal probability of
* returning any particular int 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() {
}
}