/*******************************************************************************
 * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others.  All rights reserved.
 *  
 *  This program and the accompanying materials are made available under the
 *  terms of the Eclipse Public License v1.0 which accompanies this distribution,
 *  and is available at http://www.eclipse.org/legal/epl-v10.html
 *  
 *******************************************************************************/
package com.cisco.yangide.editor.preferences;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jdt.ui.PreferenceConstants;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Font;

import com.cisco.yangide.editor.editors.YangSourceViewerConfiguration;

/**
 * @author Alexey Kholupko
 */
public class YangPreviewerUpdater {

    /**
     * Creates a Java source preview updater for the given viewer, configuration and preference
     * store.
     *
     * @param viewer the viewer
     * @param configuration the configuration
     * @param preferenceStore the preference store
     */
    public YangPreviewerUpdater(final SourceViewer viewer, final YangSourceViewerConfiguration configuration,
            final IPreferenceStore preferenceStore) {
        Assert.isNotNull(viewer);
        Assert.isNotNull(configuration);
        Assert.isNotNull(preferenceStore);
        final IPropertyChangeListener fontChangeListener = new IPropertyChangeListener() {
            /*
             * @see
             * org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util
             * .PropertyChangeEvent)
             */
            public void propertyChange(PropertyChangeEvent event) {
                if (event.getProperty().equals(PreferenceConstants.EDITOR_TEXT_FONT)) {
                    Font font = JFaceResources.getFont(PreferenceConstants.EDITOR_TEXT_FONT);
                    viewer.getTextWidget().setFont(font);
                }
            }
        };
        final IPropertyChangeListener propertyChangeListener = new IPropertyChangeListener() {
            /*
             * @see
             * org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util
             * .PropertyChangeEvent)
             */
            public void propertyChange(PropertyChangeEvent event) {
                if (configuration.affectsTextPresentation(event)) {
                    configuration.handlePropertyChangeEvent(event);
                    viewer.invalidateTextPresentation();
                }
            }
        };
        viewer.getTextWidget().addDisposeListener(new DisposeListener() {
            /*
             * @see
             * org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent
             * )
             */
            public void widgetDisposed(DisposeEvent e) {
                preferenceStore.removePropertyChangeListener(propertyChangeListener);
                JFaceResources.getFontRegistry().removeListener(fontChangeListener);
            }
        });
        JFaceResources.getFontRegistry().addListener(fontChangeListener);
        preferenceStore.addPropertyChangeListener(propertyChangeListener);
    }
}