[431785] Correct synchronization mechanism

[EMFCompare2.git] / plugins / org.eclipse.emf.compare.rcp.ui / src / org / eclipse / emf / compare / rcp / ui / internal / structuremergeviewer / actions / FilterAction.java

/*******************************************************************************
 * Copyright (c) 2012, 2014 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.compare.rcp.ui.internal.structuremergeviewer.actions;

import com.google.common.collect.Sets;

import java.util.Set;

import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.emf.compare.rcp.ui.EMFCompareRCPUIPlugin;
import org.eclipse.emf.compare.rcp.ui.internal.EMFCompareRCPUIMessages;
import org.eclipse.emf.compare.rcp.ui.internal.preferences.FiltersPreferencePage;
import org.eclipse.emf.compare.rcp.ui.internal.structuremergeviewer.actions.ui.SynchronizerDialog;
import org.eclipse.emf.compare.rcp.ui.internal.structuremergeviewer.filters.StructureMergeViewerFilter;
import org.eclipse.emf.compare.rcp.ui.internal.structuremergeviewer.filters.impl.DifferenceFilterManager;
import org.eclipse.emf.compare.rcp.ui.structuremergeviewer.filters.IDifferenceFilter;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialogWithToggle;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.preferences.ScopedPreferenceStore;
import org.osgi.service.prefs.Preferences;

/**
 * These will be the actual actions displayed in the filter menu. Their sole purpose is to provide a Predicate
 * to the structure viewer's filter.
 * <p>
 * Do note that each distinct {@link FilterAction} in the {@link FilterActionMenu filter menu} is considered
 * as an "exclude" filter, and that they are OR'ed together (thus, any element must <b>not</b> meet the
 * selected filters' criteria in order to be displayed).
 * </p>
 * 
 * @author <a href="mailto:laurent.goubet@obeo.fr">Laurent Goubet</a>
 * @since 4.0
 */
public class FilterAction extends Action {

        /** The filter associated with this action. */
        private final IDifferenceFilter filter;

        /** The Filter that will be modified by the action. */
        private final StructureMergeViewerFilter structureMergeViewerFilter;

        /** Preferences holding the value of the synchronization behavior of filters. */
        private final Preferences preferences;

        /** {@link DifferenceFilterManager}. */
        private final DifferenceFilterManager filterManager;

        /**
         * The "default" constructor for this action.
         * 
         * @param text
         *            Will be used as the action's tooltip.
         * @param structureMergeViewerFilter
         *            The viewer filter that this action will need to update.
         * @param filter
         *            The filter associated with this action.
         */
        public FilterAction(String text, StructureMergeViewerFilter structureMergeViewerFilter,
                        IDifferenceFilter filter) {
                super(text, IAction.AS_CHECK_BOX);
                this.structureMergeViewerFilter = structureMergeViewerFilter;
                this.filter = filter;
                this.preferences = EMFCompareRCPUIPlugin.getDefault().getEMFCompareUIPreferences();
                this.filterManager = EMFCompareRCPUIPlugin.getDefault().getDifferenceFilterManager();
        }

        /**
         * {@inheritDoc}
         */
        @Override
        public void runWithEvent(Event event) {
                if (isChecked()) {
                        structureMergeViewerFilter.addFilter(filter);
                } else {
                        structureMergeViewerFilter.removeFilter(filter);
                }
                handleSynchronization(event);
        }

        /**
         * Handle synchronization with {@link DifferenceFilterManager}.
         * 
         * @param event
         *            Event.
         */
        private void handleSynchronization(Event event) {
                String sync = preferences.get(FiltersPreferencePage.SYNCHRONIZATION_BEHAVIOR,
                                MessageDialogWithToggle.PROMPT);
                final Shell shell = event.display.getActiveShell();
                if (MessageDialogWithToggle.PROMPT.equals(sync) && shell != null) {
                        shell.getDisplay().asyncExec(new SynchronizationBehaviorRunnable(shell));
                } else if (MessageDialogWithToggle.ALWAYS.equals(sync)) {
                        synchonizeFilters();
                }
        }

        /**
         * Synchronizes UI filter selection with the preferences.
         */
        private void synchonizeFilters() {
                Set<IDifferenceFilter> byDefaultFilters = Sets.newLinkedHashSet(filterManager
                                .getCurrentByDefaultFilters());
                //Add newly activated filters
                for (IDifferenceFilter activeFilter : structureMergeViewerFilter.getSelectedDifferenceFilters()) {
                        byDefaultFilters.add(activeFilter);
                }
                //Remove deactivated filters
                for (IDifferenceFilter toDeactivateFilter : structureMergeViewerFilter
                                .getUnSelectedDifferenceFilters()) {
                        byDefaultFilters.remove(toDeactivateFilter);
                }
                filterManager.setCurrentByDefaultFilters(byDefaultFilters);

        }

        /**
         * Runnable in charge of synchronizing selection in UI with the {@link DifferenceFilterManager}.
         * 
         * @author <a href="mailto:arthur.daussy@obeo.fr">Arthur Daussy</a>
         */
        private final class SynchronizationBehaviorRunnable implements Runnable {
                /** Shell of this runnable. */
                private final Shell shell;

                /**
                 * Constructor.
                 * 
                 * @param shell
                 *            Shell for this runnable.
                 */
                private SynchronizationBehaviorRunnable(Shell shell) {
                        this.shell = shell;
                }

                /**
                 * {@inheritDoc} Does not use InstanceScope#Instance for compatibility issues with Helios.
                 */
                @SuppressWarnings("deprecation")
                public void run() {
                        MessageDialogWithToggle dialog = new SynchronizerDialog(shell, EMFCompareRCPUIMessages
                                        .getString("FilterAction.synchronization.dialog.title"), //$NON-NLS-1$
                                        EMFCompareRCPUIMessages.getString("FilterAction.synchronization.dialog.message"), //$NON-NLS-1$
                                        FiltersPreferencePage.PAGE_ID);

                        dialog.setPrefKey(FiltersPreferencePage.SYNCHRONIZATION_BEHAVIOR);
                        dialog.setPrefStore(new ScopedPreferenceStore(new InstanceScope(),
                                        EMFCompareRCPUIPlugin.PLUGIN_ID));
                        if (dialog.open() == IDialogConstants.YES_ID) {
                                synchonizeFilters();
                        }
                }

        }
}