| /* |
| * Copyright 2000-2014 JetBrains s.r.o. |
| * |
| * 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.intellij.util.xml.impl; |
| |
| import com.intellij.openapi.util.Comparing; |
| import com.intellij.openapi.util.Condition; |
| import com.intellij.openapi.util.Factory; |
| import com.intellij.util.containers.ContainerUtil; |
| import com.intellij.util.xml.MergedObject; |
| import com.intellij.util.xml.StableElement; |
| import net.sf.cglib.proxy.AdvancedProxy; |
| import net.sf.cglib.proxy.InvocationHandler; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| /** |
| * @author peter |
| */ |
| class StableInvocationHandler<T> implements InvocationHandler, StableElement { |
| private T myOldValue; |
| private T myCachedValue; |
| private final Set<Class> myClasses; |
| private final Factory<T> myProvider; |
| private final Condition<T> myValidator; |
| |
| public StableInvocationHandler(final T initial, final Factory<T> provider, Condition<T> validator) { |
| myProvider = provider; |
| myCachedValue = initial; |
| myOldValue = initial; |
| myValidator = validator; |
| final Class superClass = initial.getClass().getSuperclass(); |
| final Set<Class> classes = new HashSet<Class>(); |
| ContainerUtil.addAll(classes, initial.getClass().getInterfaces()); |
| ContainerUtil.addIfNotNull(superClass, classes); |
| classes.remove(MergedObject.class); |
| myClasses = classes; |
| } |
| |
| |
| @Override |
| public final Object invoke(Object proxy, final Method method, final Object[] args) throws Throwable { |
| if (StableElement.class.equals(method.getDeclaringClass())) { |
| try { |
| return method.invoke(this, args); |
| } |
| catch (InvocationTargetException e) { |
| throw e.getCause(); |
| } |
| } |
| |
| if (AdvancedProxy.FINALIZE_METHOD.equals(method)) return null; |
| |
| if (isNotValid(myCachedValue)) { |
| if (myCachedValue != null) { |
| myOldValue = myCachedValue; |
| } |
| myCachedValue = myProvider.create(); |
| if (isNotValid(myCachedValue)) { |
| if (AdvancedProxy.EQUALS_METHOD.equals(method)) { |
| |
| final Object arg = args[0]; |
| if (!(arg instanceof StableElement)) return false; |
| |
| final StableInvocationHandler handler = DomManagerImpl.getStableInvocationHandler(arg); |
| if (handler == null || handler.getWrappedElement() != null) return false; |
| |
| return Comparing.equal(myOldValue, handler.myOldValue); |
| } |
| |
| if (myOldValue != null && Object.class.equals(method.getDeclaringClass())) { |
| return method.invoke(myOldValue, args); |
| } |
| |
| if ("isValid".equals(method.getName())) { |
| return Boolean.FALSE; |
| } |
| throw new AssertionError("Calling methods on invalid value"); |
| } |
| } |
| |
| if (AdvancedProxy.EQUALS_METHOD.equals(method)) { |
| final Object arg = args[0]; |
| if (arg instanceof StableElement) { |
| return myCachedValue.equals(((StableElement)arg).getWrappedElement()); |
| } |
| return myCachedValue.equals(arg); |
| |
| } |
| if (AdvancedProxy.HASHCODE_METHOD.equals(method)) { |
| return myCachedValue.hashCode(); |
| } |
| |
| try { |
| return method.invoke(myCachedValue, args); |
| } |
| catch (InvocationTargetException e) { |
| throw e.getCause(); |
| } |
| } |
| |
| @Override |
| public final void revalidate() { |
| final T t = myProvider.create(); |
| if (!isNotValid(t) && !t.equals(myCachedValue)) { |
| myCachedValue = t; |
| } |
| } |
| |
| @Override |
| public final void invalidate() { |
| if (!isNotValid(myCachedValue)) { |
| myCachedValue = null; |
| } |
| } |
| |
| @Override |
| public final T getWrappedElement() { |
| if (isNotValid(myCachedValue)) { |
| myCachedValue = myProvider.create(); |
| } |
| return myCachedValue; |
| } |
| |
| public T getOldValue() { |
| return myOldValue; |
| } |
| |
| private boolean isNotValid(final T t) { |
| if (t == null || !myValidator.value(t)) return true; |
| for (final Class aClass : myClasses) { |
| if (!aClass.isInstance(t)) return true; |
| } |
| return false; |
| } |
| } |