bundles/org.simantics.diagram/src/org/simantics/diagram/handler/ExpandSelectionHandler.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.diagram.handler;
  13
  14 import java.util.Set;
  15
  16 import org.eclipse.jface.action.IStatusLineManager;
  17 import org.eclipse.swt.widgets.Display;
  18 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;
  19 import org.simantics.g2d.diagram.participant.AbstractDiagramParticipant;
  20 import org.simantics.g2d.diagram.participant.Selection;
  21 import org.simantics.g2d.element.IElement;
  22 import org.simantics.g2d.utils.TopologicalSelectionExpander;
  23 import org.simantics.scenegraph.g2d.events.EventHandlerReflection.EventHandler;
  24 import org.simantics.scenegraph.g2d.events.command.CommandEvent;
  25 import org.simantics.scenegraph.g2d.events.command.Commands;
  26
  27 /**
  28  * This handler responds to the EXPAND_SELECTION command. It attempts to expand
  29  * the current selection for pointer 0, meaning {@link Selection#SELECTION0}.
  30  *
  31  * @see TopologicalSelectionExpander
  32  * @see Selection the current diagram selection source
  33  *
  34  * @author Tuukka Lehtonen
  35  */
  36 public class ExpandSelectionHandler extends AbstractDiagramParticipant {
  37
  38         private final IStatusLineManager statusLine;
  39
  40     @Dependency Selection selection;
  41
  42     public ExpandSelectionHandler(IStatusLineManager statusLine) {
  43         this.statusLine = statusLine;
  44     }
  45
  46     @EventHandler(priority = 0)
  47     public boolean handleExpand(CommandEvent event) {
  48         if (Commands.EXPAND_SELECTION.equals( event.command )) {
  49             return expandSelection(0);
  50         }
  51         return false;
  52     }
  53
  54     /**
  55      * @param selectionId the id of the selection to expand
  56      * @return <code>true</code> if the selection changed as a result of the
  57      *         expansion, <code>false</code> if not
  58      */
  59     public boolean expandSelection(int selectionId) {
  60         Set<IElement> start = selection.getSelection(selectionId);
  61         TopologicalSelectionExpander expander = new TopologicalSelectionExpander(diagram, start);
  62         final Set<IElement> expanded = expander.expandedIfChanged();
  63         if (expanded == null)
  64             return false;
  65         selection.setSelection(selectionId, expanded);
  66         if(statusLine != null) {
  67                 Display.getDefault().asyncExec(new Runnable() {
  68
  69                                 @Override
  70                                 public void run() {
  71                                 statusLine.setMessage("Expanded selection to include " + expanded.size() + " (from " + diagram.getElements().size() + ") items.");
  72                                 }
  73
  74                 });
  75         }
  76         return true;
  77     }
  78
  79 }