tapestry/tapestry-contrib/src/java/org/apache/tapestry/contrib/components/Choose.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 org.apache.tapestry.contrib.components;

import org.apache.tapestry.IRender;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.components.Conditional;

/**
 * This component is a container for {@link When} or Otherwise components; it
 * provides the context for mutually exclusive conditional evaluation. [<a
 * href="../../../../../../ComponentReference/contrib.Choose.html">Component
 * Reference</a>]
 * 
 * @author David Solis
 */
public abstract class Choose extends Conditional
{

    public void addBody(IRender element)
    {
        super.addBody(element);
        if (element instanceof When) ((When) element).setChoose(this);
    }

    protected void cleanupAfterRender(IRequestCycle cycle)
    {
        setConditionMet(false);
        super.cleanupAfterRender(cycle);
    }

    protected boolean evaluateCondition()
    {
        return getCondition();
    }

    public boolean getInvert()
    {
        // This component doesn't require invert parameter.
        return false;
    }

    public abstract boolean getCondition();

    public abstract boolean isConditionMet();

    public abstract void setConditionMet(boolean value);
}