| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * 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.android.dx.util; |
| |
| /** |
| * Very simple base class that implements a flag to control the mutability |
| * of instances. This class just provides the flag and a utility to check |
| * and throw the right exception, but it is up to subclasses to place calls |
| * to the checker in all the right places. |
| */ |
| public class MutabilityControl { |
| /** whether this instance is mutable */ |
| private boolean mutable; |
| |
| /** |
| * Constructs an instance. It is initially mutable. |
| */ |
| public MutabilityControl() { |
| mutable = true; |
| } |
| |
| /** |
| * Constructs an instance, explicitly indicating the mutability. |
| * |
| * @param mutable {@code true} iff this instance is mutable |
| */ |
| public MutabilityControl(boolean mutable) { |
| this.mutable = mutable; |
| } |
| |
| /** |
| * Makes this instance immutable. |
| */ |
| public void setImmutable() { |
| mutable = false; |
| } |
| |
| /** |
| * Checks to see whether or not this instance is immutable. This is the |
| * same as calling {@code !isMutable()}. |
| * |
| * @return {@code true} iff this instance is immutable |
| */ |
| public final boolean isImmutable() { |
| return !mutable; |
| } |
| |
| /** |
| * Checks to see whether or not this instance is mutable. |
| * |
| * @return {@code true} iff this instance is mutable |
| */ |
| public final boolean isMutable() { |
| return mutable; |
| } |
| |
| /** |
| * Throws {@link MutabilityException} if this instance is |
| * immutable. |
| */ |
| public final void throwIfImmutable() { |
| if (!mutable) { |
| throw new MutabilityException("immutable instance"); |
| } |
| } |
| |
| /** |
| * Throws {@link MutabilityException} if this instance is mutable. |
| */ |
| public final void throwIfMutable() { |
| if (mutable) { |
| throw new MutabilityException("mutable instance"); |
| } |
| } |
| } |