samples/swing/src/main/java/org/apache/polygene/sample/swing/binding/internal/AbstractBinding.java

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 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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,
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 *  See the License for the specific language governing permissions and
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package org.apache.polygene.sample.swing.binding.internal;

import org.apache.polygene.api.injection.scope.Service;
import org.apache.polygene.api.injection.scope.Structure;
import org.apache.polygene.api.injection.scope.Uses;
import org.apache.polygene.api.object.ObjectFactory;
import org.apache.polygene.sample.swing.binding.StateModel;
import org.apache.polygene.sample.swing.binding.SwingAdapter;
import org.apache.polygene.sample.swing.binding.SwingBinding;

import javax.swing.*;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

public abstract class AbstractBinding<T>
    implements SwingBinding
{

    private final Class<T> type;
    protected StateModel<T> stateModel;
    protected Set<JComponent> components;
    private PropertyFocusLostListener focusListener;
    protected HashMap<Class<? extends JComponent>, SwingAdapter> adapters;
    private String name;
    protected Method method;

    @SuppressWarnings( "unchecked" )
    public AbstractBinding( @Uses Method method, @Structure ObjectFactory objectBuilderFactory,
                            @Service Iterable<SwingAdapter> allAdapters )
        throws IllegalArgumentException
    {
        this.method = method;
        ParameterizedType parameterType = (ParameterizedType) method.getGenericReturnType();
        Type[] actualTypeArguments = parameterType.getActualTypeArguments();
        type = (Class<T>) actualTypeArguments[ 0 ];
        name = method.getName();
        stateModel = objectBuilderFactory.newObject( StateModel.class, type );
        components = new HashSet<JComponent>();
        setupAdapters( allAdapters );
    }

    public void to( final JComponent component )
    {
        if( components.add( component ) )
        {
            focusListener = new PropertyFocusLostListener( component );
            component.addFocusListener( focusListener );
        }
    }

    public String toString()
    {
        return name + "[" + type.getSimpleName() + "] -> " + stateModel.toString();
    }

    private void setupAdapters( Iterable<SwingAdapter> allAdapters )
    {
        adapters = new HashMap<Class<? extends JComponent>, SwingAdapter>();
        for( SwingAdapter adapterCandidate : allAdapters )
        {
            Set<SwingAdapter.Capabilities> canHandle = adapterCandidate.canHandle();
            for( SwingAdapter.Capabilities capabilities : canHandle )
            {
                if( requiredCapabilitySatisfied( capabilities ) )
                {
                    if( capabilities.type.equals( this.type ) )
                    {
                        Class<? extends JComponent> component = capabilities.component;
                        adapters.put( component, adapterCandidate );
                    }
                }
            }
        }
    }

    protected abstract boolean requiredCapabilitySatisfied( SwingAdapter.Capabilities capabilities );

    public final T get()
    {
        return stateModel.state();
    }

    public final Class type()
    {
        return type;
    }

    public void set( T newValue )
        throws IllegalArgumentException
    {
        throw new IllegalArgumentException( "set() is not allowed in binding templates." );
    }

}