org.eclipse.cdt.internal.ui.compare.AbstractMergeViewer.java Source code

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Here is the source code for org.eclipse.cdt.internal.ui.compare.AbstractMergeViewer.java

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/*******************************************************************************
 * Copyright (c) 2007, 2009 Wind River 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
 *
 * Contributors:
 *     Anton Leherbauer (Wind River Systems) - initial API and implementation
 *     Andrew Ferguson (Symbian)
 *******************************************************************************/

package org.eclipse.cdt.internal.ui.compare;

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.TextViewer;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.jface.text.source.SourceViewerConfiguration;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.texteditor.AbstractTextEditor;

import org.eclipse.cdt.ui.CUIPlugin;
import org.eclipse.cdt.ui.text.ICColorConstants;
import org.eclipse.cdt.ui.text.ICPartitions;

/**
 * Abstract implementation of a merge viewer.
 */
abstract class AbstractMergeViewer extends TextMergeViewer {

    private IPropertyChangeListener fPreferenceChangeListener;
    private IPreferenceStore fPreferenceStore;

    protected boolean fUseSystemColors;

    /**
     * Creates a color from the information stored in the given preference store.
     * Returns <code>null</code> if there is no such information available.
     */
    protected static RGB createColor(IPreferenceStore store, String key) {
        if (!store.contains(key))
            return null;
        if (store.isDefault(key))
            return PreferenceConverter.getDefaultColor(store, key);
        return PreferenceConverter.getColor(store, key);
    }

    /**
     * Create a new merge viewer.
     * 
     * @param parent
     * @param style
     * @param configuration
     */
    public AbstractMergeViewer(Composite parent, int style, CompareConfiguration configuration) {
        super(parent, style | SWT.LEFT_TO_RIGHT, configuration);

        IPreferenceStore store = getPreferenceStore();

        fUseSystemColors = store.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT);
        if (!fUseSystemColors) {
            RGB bg = createColor(store, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
            setBackgroundColor(bg);
            RGB fg = createColor(store, ICColorConstants.C_DEFAULT);
            setForegroundColor(fg);
        }

    }

    protected IPreferenceStore getPreferenceStore() {
        if (fPreferenceStore == null) {
            fPreferenceStore = CUIPlugin.getDefault().getCombinedPreferenceStore();
            fPreferenceChangeListener = new IPropertyChangeListener() {
                @Override
                public void propertyChange(PropertyChangeEvent event) {
                    handlePropertyChange(event);
                }
            };
            fPreferenceStore.addPropertyChangeListener(fPreferenceChangeListener);
        }
        return fPreferenceStore;
    }

    @Override
    protected void handleDispose(DisposeEvent event) {
        if (fPreferenceChangeListener != null) {
            fPreferenceStore.removePropertyChangeListener(fPreferenceChangeListener);
            fPreferenceChangeListener = null;
        }
        super.handleDispose(event);
    }

    protected void handlePropertyChange(PropertyChangeEvent event) {

        String key = event.getProperty();

        if (key.equals(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND)) {

            if (!fUseSystemColors) {
                RGB bg = createColor(fPreferenceStore, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
                setBackgroundColor(bg);
            }

        } else if (key.equals(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT)) {

            fUseSystemColors = fPreferenceStore
                    .getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT);
            if (fUseSystemColors) {
                setBackgroundColor(null);
                setForegroundColor(null);
            } else {
                RGB bg = createColor(fPreferenceStore, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
                setBackgroundColor(bg);
                RGB fg = createColor(fPreferenceStore, ICColorConstants.C_DEFAULT);
                setForegroundColor(fg);
            }
        } else if (key.equals(ICColorConstants.C_DEFAULT)) {

            if (!fUseSystemColors) {
                RGB fg = createColor(fPreferenceStore, ICColorConstants.C_DEFAULT);
                setForegroundColor(fg);
            }
        }
    }

    @Override
    protected String getDocumentPartitioning() {
        return ICPartitions.C_PARTITIONING;
    }

    @Override
    protected void configureTextViewer(TextViewer textViewer) {
        if (textViewer instanceof SourceViewer) {
            ((SourceViewer) textViewer).configure(getSourceViewerConfiguration());
        }
    }

    /*
     * @see org.eclipse.compare.contentmergeviewer.ContentMergeViewer#getTitle()
     */
    @Override
    public abstract String getTitle();

    /**
     * @return a source configuration for the viewer
     */
    protected abstract SourceViewerConfiguration getSourceViewerConfiguration();

}