home | career | drupal | java | mac | mysql | perl | scala | uml | unix

Groovy example source code file (PropertyBinding.java)

This example Groovy source code file (PropertyBinding.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Groovy tags/keywords

bean, javabean, missingmethodexception, missingmethodexception, object, object, propertybinding, propertychangelistener, propertyfullbinding, runtimeexception, sourcebinding, string, string, targetbinding, targetbinding, triggerbinding

The Groovy PropertyBinding.java source code

/*
 * Copyright 2007-2009 the original author or authors.
 *
 * 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.codehaus.groovy.binding;

import groovy.lang.MissingMethodException;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.runtime.InvokerInvocationException;
import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyVetoException;


/**
 * @author <a href="mailto:shemnon@yahoo.com">Danno Ferrin
 * @version $Revision: 21223 $
 * @since Groovy 1.1
 */
public class PropertyBinding implements SourceBinding, TargetBinding, TriggerBinding {

    Object bean;
    String propertyName;
    boolean nonChangeCheck;

    public PropertyBinding(Object bean, String propertyName) {
        this.bean = bean;
        this.propertyName = propertyName;
    }

    public void updateTargetValue(Object newValue) {
        if (nonChangeCheck) {
            if (DefaultTypeTransformation.compareEqual(getSourceValue(), newValue)) {
                // not a change, don't fire it
                return;
            }
        }
        try {
            InvokerHelper.setProperty(bean, propertyName, newValue);
        } catch (InvokerInvocationException iie) {
            if (!(iie.getCause() instanceof PropertyVetoException)) {
                throw iie;
            }
            // ignore veto exceptions, just let the binding fail like a validation does
        }
    }

    public boolean isNonChangeCheck() {
        return nonChangeCheck;
    }

    public void setNonChangeCheck(boolean nonChangeCheck) {
        this.nonChangeCheck = nonChangeCheck;
    }

    public Object getSourceValue() {
        return InvokerHelper.getPropertySafe(bean, propertyName);
    }

    public FullBinding createBinding(SourceBinding source, TargetBinding target) {
        return new PropertyFullBinding(source, target);
    }

    class PropertyFullBinding extends AbstractFullBinding implements PropertyChangeListener {

        Object boundBean;
        Object boundProperty;
        boolean bound;
        boolean boundToProperty;

        PropertyFullBinding(SourceBinding source, TargetBinding target) {
            setSourceBinding(source);
            setTargetBinding(target);
        }

        public void propertyChange(PropertyChangeEvent event) {
            if (boundToProperty || event.getPropertyName().equals(boundProperty)) {
                update();
            }
        }

        public void bind() {
            if (!bound) {
                bound = true;
                boundBean = bean;
                boundProperty = propertyName;
                try {
                    InvokerHelper.invokeMethodSafe(boundBean, "addPropertyChangeListener", new Object[] {boundProperty, this});
                    boundToProperty = true;
                } catch (MissingMethodException mme) {
                    try {
                        boundToProperty = false;
                        InvokerHelper.invokeMethodSafe(boundBean, "addPropertyChangeListener", new Object[] {this});
                    } catch (MissingMethodException mme2) {
                        throw new RuntimeException("Properties in beans of type " + bean.getClass().getName() + " are not observable in any capacity (no PropertyChangeListener support).");
                    }
                }
            }
        }

        public void unbind() {
            if (bound) {
                if (boundToProperty) {
                    try {
                        InvokerHelper.invokeMethodSafe(boundBean, "removePropertyChangeListener", new Object[] {boundProperty, this});
                    } catch (MissingMethodException mme) {
                        // ignore, too bad so sad they don't follow conventions, we'll just leave the listener attached
                    }
                } else {
                    try {
                        InvokerHelper.invokeMethodSafe(boundBean, "removePropertyChangeListener", new Object[] {this});
                    } catch (MissingMethodException mme2) {
                        // ignore, too bad so sad they don't follow conventions, we'll just leave the listener attached
                    }
                }
                boundBean = null;
                boundProperty = null;
                bound = false;
            }
        }

        public void rebind() {
            if (bound) {
                unbind();
                bind();
            }
        }
    }

    public Object getBean() {
        return bean;
    }

    public void setBean(Object bean) {
        this.bean = bean;
    }

    public String getPropertyName() {
        return propertyName;
    }

    public void setPropertyName(String propertyName) {
        this.propertyName = propertyName;
    }
}

Other Groovy examples (source code examples)

Here is a short list of links related to this Groovy PropertyBinding.java source code file:

new blog posts

 

Copyright 1998-2014 Alvin Alexander, alvinalexander.com
All Rights Reserved.