eu.esdihumboldt.hale.ui.views.data.internal.MetadataActionProvider.java Source code

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Here is the source code for eu.esdihumboldt.hale.ui.views.data.internal.MetadataActionProvider.java

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/*
 * Copyright (c) 2012 Data Harmonisation Panel
 * 
 * All rights reserved. This program and the accompanying materials are made
 * available under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Contributors:
 *     HUMBOLDT EU Integrated Project #030962
 *     Data Harmonisation Panel <http://www.dhpanel.eu>
 */

package eu.esdihumboldt.hale.ui.views.data.internal;

import java.net.URL;
import java.util.List;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.TreeEditor;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;
import org.eclipse.swt.widgets.TreeItem;

import de.fhg.igd.slf4jplus.ALogger;
import de.fhg.igd.slf4jplus.ALoggerFactory;
import eu.esdihumboldt.hale.common.instance.extension.metadata.MetadataActionExtension;
import eu.esdihumboldt.hale.common.instance.extension.metadata.MetadataActionFactory;
import eu.esdihumboldt.util.Pair;

/**
 * Provides metadata actions for {@link TreeViewer}s
 * 
 * @author Sebastian Reinhardt
 */
public abstract class MetadataActionProvider {

    private static ALogger _log = ALoggerFactory.getLogger(MetadataActionProvider.class);

    private final TreeViewer treeViewer;

    /**
     * Standard Constructor
     * 
     * @param treeViewer the TreeViewer to which the action will be applied
     */
    public MetadataActionProvider(TreeViewer treeViewer) {
        this.treeViewer = treeViewer;
    }

    /**
     * Retrieves the key and value of a certain meta datum from a
     * {@link ViewerCell}
     * 
     * @param cell the ViewerCell
     * @return a Pair containing the key and the value of a meta datum
     */
    protected abstract Pair<Object, Object> retrieveMetadata(ViewerCell cell);

    /**
     * Adds the action to the certain TreeViewer cell
     */
    public void setup() {

        final TreeEditor metaEditor = new TreeEditor(treeViewer.getTree());
        metaEditor.horizontalAlignment = SWT.LEFT;
        metaEditor.verticalAlignment = SWT.TOP;

        treeViewer.getTree().addMouseMoveListener(new MouseMoveListener() {

            @Override
            public void mouseMove(MouseEvent e) {
                final ViewerCell cell = treeViewer.getCell(new Point(e.x, e.y));

                // Selected cell changed?
                if (cell == null || metaEditor.getItem() != cell.getItem()
                        || metaEditor.getColumn() != cell.getColumnIndex()) {
                    // Clean up any previous editor control
                    Control oldmetaEditor = metaEditor.getEditor();
                    if (oldmetaEditor != null) {
                        oldmetaEditor.dispose();
                        metaEditor.setEditor(null, null, 0);
                    }
                }

                // No selected cell or selected cell didn't change.
                if (cell == null || cell.getColumnIndex() == 0 || (metaEditor.getItem() == cell.getItem()
                        && metaEditor.getColumn() == cell.getColumnIndex())) {
                    return;
                }

                // Initiate the extension-point
                MetadataActionExtension mae = MetadataActionExtension.getInstance();
                final Pair<Object, Object> data = retrieveMetadata(cell);
                if (data == null) {
                    return;
                }

                // get all defined actions
                final List<MetadataActionFactory> actionSources = mae
                        .getMetadataActions(data.getFirst().toString());

                if (actionSources == null || actionSources.isEmpty()) {
                    return;
                }
                // Tool-bar used to view and trigger the different possible
                // actions
                ToolBar tooli = new ToolBar(treeViewer.getTree(), SWT.NONE);

                for (final MetadataActionFactory source : actionSources) {
                    ToolItem actionItem = new ToolItem(tooli, SWT.PUSH);

                    // get the Icon of the action
                    URL iconURL = source.getIconURL();
                    Image image = ImageDescriptor.createFromURL(iconURL).createImage();
                    actionItem.setImage(image);
                    actionItem.setToolTipText(source.getDisplayName());

                    actionItem.addSelectionListener(new SelectionAdapter() {

                        @Override
                        public void widgetSelected(SelectionEvent e) {

                            try {
                                source.createExtensionObject().execute(data.getFirst(), data.getSecond());
                            } catch (Exception e1) {
                                _log.userError("error creating metadata action", e1);
                            }
                        }
                    });
                }
                metaEditor.setEditor(tooli, (TreeItem) cell.getItem(), cell.getColumnIndex());
                tooli.pack();
            }
        });

    }

}