intial source from ttp://www.sf.net/projects/wdte

[phpeclipse.git] / archive / net.sourceforge.phpeclipse.css.ui / src / net / sourceforge / phpeclipse / css / ui / internal / compare / CssMergeViewer.java

/*
 * Copyright (c) 2003-2004 Christopher Lenz and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     Christopher Lenz - initial API and implementation
 * 
 * $Id: CssMergeViewer.java,v 1.1 2004-09-02 18:11:49 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.css.ui.internal.compare;

import net.sourceforge.phpeclipse.css.ui.CssUI;
import net.sourceforge.phpeclipse.css.ui.internal.CssUIMessages;
import net.sourceforge.phpeclipse.css.ui.internal.CssUIPreferences;
import net.sourceforge.phpeclipse.css.ui.internal.text.CssSourceViewerConfiguration;
import net.sourceforge.phpeclipse.css.ui.text.CssTextTools;

import org.eclipse.compare.CompareConfiguration;
import org.eclipse.compare.contentmergeviewer.TextMergeViewer;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceConverter;
import org.eclipse.jface.text.IDocumentPartitioner;
import org.eclipse.jface.text.TextViewer;
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.graphics.RGB;
import org.eclipse.swt.widgets.Composite;

/**
 * Merge viewer for CSS files.
 */
public class CssMergeViewer extends TextMergeViewer {

        // Constants ---------------------------------------------------------------

        /**
         * Alias for the preference constant <code>EDITOR_BACKGROUND_COLOR</code>.
         */
        private static final String PREFERENCE_BACKGROUND_COLOR =
                CssUIPreferences.EDITOR_BACKGROUND_COLOR;

        /**
         * Alias for the preference constant
         * <code>EDITOR_BACKGROUND_DEFAULT_COLOR</code>.
         */
        private static final String PREFERENCE_BACKGROUND_DEFAULT_COLOR =
                CssUIPreferences.EDITOR_BACKGROUND_DEFAULT_COLOR;

        // Instance Variables ------------------------------------------------------

        /**
         * The preference store.
         */
        private IPreferenceStore preferenceStore;

        /**
         * The listener for changes to the preference store. 
         */
        private IPropertyChangeListener propertyChangeListener;

        /**
         * The CSS text tools.
         */
        private CssTextTools textTools;

        // Constructors ------------------------------------------------------------

        /**
         * Constructor.
         * 
         * @param parent the parent control
         * @param style SWT style bits for top level composite of this viewer
         * @param configuration the configuration object
         */
        public CssMergeViewer(Composite parent, int style,
                CompareConfiguration configuration) {
                super(parent, style, configuration);
        }

        // TextMergeViewer Implementation ------------------------------------------

        /*
         * @see TextMergeViewer#configureTextViewer()
         */
        protected void configureTextViewer(TextViewer textViewer) {

                CssUI plugin = CssUI.getDefault();

                this.preferenceStore = plugin.getPreferenceStore();
                if (preferenceStore != null) {
                         propertyChangeListener = new IPropertyChangeListener() {
                                public void propertyChange(PropertyChangeEvent event) {
                                        handlePreferenceStoreChanged(event);
                                }
                        };
                        preferenceStore.addPropertyChangeListener(propertyChangeListener);
                }

                textTools = plugin.getTextTools();
                if (textViewer instanceof SourceViewer) {
                        SourceViewer sourceViewer = (SourceViewer) textViewer;
                        sourceViewer.configure(new CssSourceViewerConfiguration(
                                textTools, preferenceStore));
                }

                updateBackgroundColor();
        }

        /*
         * @see TextMergeViewer#getDocumentPartitioner()
         */
        protected IDocumentPartitioner getDocumentPartitioner() {
                return textTools.createDocumentPartitioner();
        }

        /*
         * @see org.eclipse.compare.contentmergeviewer.ContentMergeViewer#getTitle()
         */
        public String getTitle() {
                return CssUIMessages.getString(
                        "CssMergeViewer.title"); //$NON-NLS-1$
        }

        /*
         * @see org.eclipse.jface.viewers.ContentViewer#handleDispose(org.eclipse.swt.events.DisposeEvent)
         */
        protected void handleDispose(DisposeEvent event) {
                if (propertyChangeListener != null) {
                        if (preferenceStore != null) {
                                preferenceStore.removePropertyChangeListener(
                                        propertyChangeListener);
                        }
                        propertyChangeListener = null;
                }
                super.handleDispose(event);
        }

        // Private Methods ---------------------------------------------------------

        /**
         * Called when the preference store notifies us about a change.
         * 
         * @param event the change event
         */
        protected void handlePreferenceStoreChanged(PropertyChangeEvent event) {
                String p = event.getProperty();
                if (PREFERENCE_BACKGROUND_COLOR.equals(p)
                 || PREFERENCE_BACKGROUND_DEFAULT_COLOR.equals(p)) {
                        updateBackgroundColor();
                } else if (textTools.affectsPresentation(event)) {
                        invalidateTextPresentation();
                }
        }

        /**
         * Updates the background color of the merge viewer to the value set in the
         * preferences.
         */
        private void updateBackgroundColor() {
                boolean defaultBackgroundColor = preferenceStore.getBoolean(
                        PREFERENCE_BACKGROUND_DEFAULT_COLOR);
                if (defaultBackgroundColor) {
                        setBackgroundColor(null);
                } else {
                        RGB backgroundColor = PreferenceConverter.getColor(
                                preferenceStore, CssUIPreferences.EDITOR_BACKGROUND_COLOR);
                        setBackgroundColor(backgroundColor);
                }
        }

}