org.eclipse.cdt.internal.ui.preferences.CSourcePreviewerUpdater.java Source code

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Here is the source code for org.eclipse.cdt.internal.ui.preferences.CSourcePreviewerUpdater.java

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/*******************************************************************************
 * Copyright (c) 2000, 2010 QNX Software Systems 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
 *
 * Contributors:
 *     QNX Software Systems - Initial API and implementation
 *     Anton Leherbauer (Wind River Systems)
 *******************************************************************************/
package org.eclipse.cdt.internal.ui.preferences;

import org.eclipse.core.runtime.Assert;
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 org.eclipse.cdt.ui.PreferenceConstants;
import org.eclipse.cdt.ui.text.CSourceViewerConfiguration;

public class CSourcePreviewerUpdater {

    /**
     * Handles editor font changes for source preview viewers.
     * 
     * @param viewer
     * @param configuration
     * @param store
     */
    public CSourcePreviewerUpdater(SourceViewer viewer, CSourceViewerConfiguration configuration,
            IPreferenceStore store) {
        registerPreviewer(viewer, configuration, store);
    }

    /**
     * Registers a source preview updater for the given viewer, configuration and preference store.
     *
     * @param viewer the viewer
     * @param configuration the configuration
     * @param preferenceStore the preference store
     */
    static public void registerPreviewer(final SourceViewer viewer, final CSourceViewerConfiguration 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)
             */
            @Override
            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)
             */
            @Override
            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)
             */
            @Override
            public void widgetDisposed(DisposeEvent e) {
                preferenceStore.removePropertyChangeListener(propertyChangeListener);
                JFaceResources.getFontRegistry().removeListener(fontChangeListener);
            }
        });
        JFaceResources.getFontRegistry().addListener(fontChangeListener);
        preferenceStore.addPropertyChangeListener(propertyChangeListener);
    }

}