com.google.common.collect.Platform Maven / Gradle / Ivy
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/*
* Copyright (C) 2008 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.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.lang.reflect.Array;
import java.util.List;
/**
* Methods factored out so that they can be emulated differently in GWT.
*
* @author Hayward Chan
*/
@GwtCompatible(emulated = true)
class Platform {
/**
* Calls {@link List#subList(int, int)}. Factored out so that it can be
* emulated in GWT.
*
* This method is not supported in GWT yet. See
* GWT issue 1791
*/
@GwtIncompatible("List.subList")
static List subList(List list, int fromIndex, int toIndex) {
return list.subList(fromIndex, toIndex);
}
/**
* Calls {@link Class#isInstance(Object)}. Factored out so that it can be
* emulated in GWT.
*/
@GwtIncompatible("Class.isInstance")
static boolean isInstance(Class clazz, Object obj) {
return clazz.isInstance(obj);
}
/**
* Clone the given array using {@link Object#clone()}. It is factored out so
* that it can be emulated in GWT.
*/
static T[] clone(T[] array) {
return array.clone();
}
/**
* Returns a new array of the given length with the specified component type.
*
* @param type the component type
* @param length the length of the new array
*/
@GwtIncompatible("Array.newInstance(Class, int)")
@SuppressWarnings("unchecked")
static T[] newArray(Class type, int length) {
return (T[]) Array.newInstance(type, length);
}
/**
* Returns a new array of the given length with the same type as a reference
* array.
*
* @param reference any array of the desired type
* @param length the length of the new array
*/
static T[] newArray(T[] reference, int length) {
Class type = reference.getClass().getComponentType();
// the cast is safe because
// result.getClass() == reference.getClass().getComponentType()
@SuppressWarnings("unchecked")
T[] result = (T[]) Array.newInstance(type, length);
return result;
}
private Platform() {}
}