org.metawidget.vaadin.ui.widgetprocessor.binding.reflection.ReflectionBindingProcessor.java Source code

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Here is the source code for org.metawidget.vaadin.ui.widgetprocessor.binding.reflection.ReflectionBindingProcessor.java

Source

// Metawidget
//
// For historical reasons, this file is licensed under the LGPL
// (http://www.gnu.org/licenses/lgpl-2.1.html).
//
// Most other files in Metawidget are licensed under both the
// LGPL/EPL and a commercial license. See http://metawidget.org
// for details.

package org.metawidget.vaadin.ui.widgetprocessor.binding.reflection;

import static org.metawidget.inspector.InspectionResultConstants.*;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Map;

import org.metawidget.util.ClassUtils;
import org.metawidget.util.WidgetBuilderUtils;
import org.metawidget.util.simple.PathUtils;
import org.metawidget.vaadin.ui.Stub;
import org.metawidget.vaadin.ui.VaadinMetawidget;
import org.metawidget.widgetprocessor.iface.WidgetProcessor;
import org.metawidget.widgetprocessor.iface.WidgetProcessorException;

import com.vaadin.ui.Button;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Button.ClickListener;
import com.vaadin.ui.Component;

/**
 * Action binding implementation based on reflection.
 *
 * @author Loghman Barari
 */

@SuppressWarnings("serial")
public class ReflectionBindingProcessor implements WidgetProcessor<Component, VaadinMetawidget>, Serializable {

    //
    // Public methods
    //

    public Component processWidget(final Component component, String elementName, Map<String, String> attributes,
            VaadinMetawidget metawidget) {

        // Only bind to non-read-only Actions

        if (!ACTION.equals(elementName)) {
            return component;
        }

        if (component instanceof Stub) {
            return component;
        }

        if (!(component instanceof Button)) {
            throw WidgetProcessorException
                    .newException("ReflectionBindingProcessor only supports binding actions to Buttons");
        }

        if (WidgetBuilderUtils.isReadOnly(attributes)) {
            return component;
        }

        if (metawidget == null) {
            return component;
        }

        Object toInspect = metawidget.getToInspect();

        if (toInspect == null) {
            return component;
        }

        Button button = (Button) component;

        // Traverse to the last Object...

        String[] names = PathUtils.parsePath(metawidget.getPath()).getNamesAsArray();

        for (String name : names) {
            toInspect = ClassUtils.getProperty(toInspect, name);

            if (toInspect == null) {
                return component;
            }
        }

        // ...and wire it up

        final Object fireActionOn = toInspect;
        final Class<?> fireActionOnClass = fireActionOn.getClass();
        final String actionName = attributes.get(NAME);

        button.addListener(new ClickListener() {

            public void buttonClick(ClickEvent event) {

                try {
                    Method method = fireActionOnClass.getMethod(actionName, (Class[]) null);
                    method.invoke(fireActionOn, (Object[]) null);
                } catch (Exception e) {
                    throw WidgetProcessorException.newException(e);
                }
            }
        });

        return component;
    }
}