001// Copyright 2011 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.plastic;
016
017import org.apache.tapestry5.internal.plastic.asm.Label;
018import org.apache.tapestry5.plastic.InstructionBuilder;
019import org.apache.tapestry5.plastic.InstructionBuilderCallback;
020import org.apache.tapestry5.plastic.TryCatchBlock;
021import org.apache.tapestry5.plastic.TryCatchCallback;
022
023public class TryCatchBlockImpl extends Lockable implements TryCatchBlock
024{
025    private final InstructionBuilder builder;
026
027    private final InstructionBuilderState state;
028
029    private final Label startLabel, endLabel;
030
031    TryCatchBlockImpl(InstructionBuilder builder, InstructionBuilderState state)
032    {
033        this.builder = builder;
034        this.state = state;
035
036        this.startLabel = new Label();
037        this.endLabel = new Label();
038    }
039
040    @Override
041    public void addTry(InstructionBuilderCallback callback)
042    {
043        state.visitor.visitLabel(startLabel);
044
045        callback.doBuild(builder);
046
047        state.visitor.visitLabel(endLabel);
048    }
049
050    @Override
051    public void addCatch(String exceptionClassName, InstructionBuilderCallback callback)
052    {
053        assert exceptionClassName != null;
054
055        doCatch(state.nameCache.toInternalName(exceptionClassName), callback);
056    }
057
058    private void doCatch(String exceptionInternalName, InstructionBuilderCallback callback)
059    {
060        check();
061
062        Label handler = state.newLabel();
063
064        callback.doBuild(builder);
065
066        state.visitor.visitTryCatchBlock(startLabel, endLabel, handler, exceptionInternalName);
067    }
068
069    @Override
070    public void addFinally(InstructionBuilderCallback callback)
071    {
072        doCatch(null, callback);
073    }
074
075    void doCallback(TryCatchCallback callback)
076    {
077        assert callback != null;
078
079        callback.doBlock(this);
080
081        lock();
082    }
083
084}