bundles/org.simantics.ui/src/org/simantics/ui/tester/UndoPropertyTester.java

   1 /*******************************************************************************
   2  * Copyright (c) 2011 Association for Decentralized Information Management in
   3  * 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.ui.tester;
  13
  14 import org.eclipse.core.expressions.PropertyTester;
  15 import org.eclipse.swt.widgets.Display;
  16 import org.eclipse.ui.PlatformUI;
  17 import org.eclipse.ui.contexts.IContextActivation;
  18 import org.eclipse.ui.contexts.IContextService;
  19 import org.simantics.DatabaseJob;
  20 import org.simantics.Simantics;
  21 import org.simantics.db.Session;
  22 import org.simantics.db.UndoContext;
  23 import org.simantics.db.exception.DatabaseException;
  24 import org.simantics.db.management.ISessionContext;
  25 import org.simantics.db.service.UndoRedoSupport;
  26 import org.simantics.ui.SimanticsUI;
  27 import org.simantics.utils.ui.ErrorLogger;
  28 import org.simantics.utils.ui.SWTUtils;
  29
  30 /**
  31  * An eclipse property tester for org.simantics.db database undo/redoability.
  32  *
  33  * @author Kalle Kondelin
  34  */
  35 public class UndoPropertyTester extends PropertyTester implements UndoRedoSupport.ChangeListener {
  36
  37     private static final String PROP_CAN_REDO = "canRedo";
  38
  39     private static final String PROP_CAN_UNDO = "canUndo";
  40
  41     private static final String SIMANTICS_UNDO_CONTEXT = "org.simantics.ui.undoContext";
  42
  43     public static final boolean DEBUG = false;
  44
  45     public static final String UNDO_ENABLED = "org.simantics.undo.enabled";
  46
  47     UndoRedoSupport undoSupport = null;
  48     IContextActivation activation = null;
  49     public UndoPropertyTester() {
  50         if (DEBUG)
  51             System.out.println("UndoPropertyTester: " + this);
  52     }
  53     @Override
  54     public boolean test(Object receiver, String property, Object[] args, Object expectedValue) {
  55         if (DEBUG)
  56             System.out.println("UndoPropertyTester: receiver=" + receiver);
  57
  58         String undoEnabled = System.getProperty(UNDO_ENABLED);
  59         if(undoEnabled != null && "false".equals(undoEnabled))
  60             return false;
  61
  62         if (property.matches(PROP_CAN_UNDO))
  63             return canUndo();
  64         else if (property.matches(PROP_CAN_REDO))
  65             return canRedo();
  66         else
  67             return false;
  68     }
  69     private boolean canUndo() {
  70         ISessionContext ctx = Simantics.getSessionContext();
  71         if (ctx == null) {
  72             if (DEBUG)
  73                 System.out.println("UndoPropertyTester: no can do undo.");
  74             return false;
  75         }
  76         try {
  77             Session s = ctx.peekSession();
  78             if (null == s) {
  79                 if (DEBUG)
  80                     System.out.println("UndoPropertyTester: session is null, no can do undo.");
  81                 return false;
  82             }
  83             if (DatabaseJob.inProgress())
  84                 return true;
  85             if (null == undoSupport) {
  86                 undoSupport = s.getService(UndoRedoSupport.class);
  87                 undoSupport.subscribe(this);
  88             }
  89             UndoContext uc = undoSupport.getUndoContext(s);
  90             if (uc == null)
  91                 return false;
  92             boolean ret = !uc.getAll().isEmpty();
  93             if (DEBUG)
  94                 System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do undo.");
  95             return ret;
  96         } catch (Exception e) {
  97             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);
  98             if (DEBUG)
  99                 System.out.println("UndoPropertyTester: no can do undo");
 100             return false;
 101         }
 102     }
 103     private boolean canRedo() {
 104         ISessionContext ctx = Simantics.getSessionContext();
 105         if (ctx == null) {
 106             if (DEBUG)
 107                 System.out.println("UndoPropertyTester: no can do redo.");
 108             return false;
 109         }
 110         try {
 111             Session s = ctx.peekSession();
 112             if (null == s) {
 113                 if (DEBUG)
 114                     System.out.println("UndoPropertyTester: session is null, no can do redo.");
 115                 return false;
 116             }
 117             if (DatabaseJob.inProgress())
 118                 return true;
 119             if (null == undoSupport) {
 120                 undoSupport = s.getService(UndoRedoSupport.class);
 121                 undoSupport.subscribe(this);
 122             }
 123             UndoContext uc = undoSupport.getUndoContext(s);
 124             if (uc == null)
 125                 return false;
 126             boolean ret = !uc.getRedoList().isEmpty();
 127             if (DEBUG)
 128                 System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do redo.");
 129             return ret;
 130         } catch (Exception e) {
 131             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);
 132             if (DEBUG)
 133                 System.out.println("UndoPropertyTester: no can do redo.");
 134             return false;
 135         }
 136     }
 137     @Override
 138     public void onChanged() {
 139         if (DEBUG)
 140             System.out.println("UndoPropertyTester: on change.");
 141         Display display = PlatformUI.getWorkbench().getDisplay();
 142         SWTUtils.asyncExec(display, new Runnable() {
 143             @Override
 144             public void run() {
 145                 handleChange();
 146             }
 147         });
 148     }
 149     private int oldUndo = 0;
 150     private int oldRedo = 0;
 151     private void handleChange() {
 152         int newUndo = oldUndo;
 153         int newRedo = oldRedo;
 154         try {
 155             ISessionContext ctx = SimanticsUI.getSessionContext();
 156             if (DEBUG)
 157                 System.out.println("UndoPropertyTester: handle change, ctx=" + ctx);
 158             if (ctx == null)
 159                 return;
 160             Session session = ctx.peekSession();
 161             if (DEBUG)
 162                 System.out.println("UndoPropertyTester: handle change, session=" + session);
 163             if (session == null)
 164                 return;
 165             UndoContext uc = undoSupport.getUndoContext(session);
 166             if (uc == null)
 167                 return;
 168             newUndo = uc.getAll().size();
 169             newRedo = uc.getRedoList().size();
 170             if (DEBUG) {
 171                 System.out.println("on undo change: " + oldUndo + "->" + newUndo);
 172                 System.out.println("on redo change: " + oldRedo + "->" + newRedo);
 173             }
 174             boolean undoOn = oldUndo == 0 && newUndo == 1;
 175             boolean undoOff = oldUndo > 0 && newUndo == 0;
 176             boolean redoOn = oldRedo == 0 && newRedo == 1;
 177             boolean redoOff = oldRedo > 0 && newRedo == 0;
 178             if (undoOn || undoOff || redoOn || redoOff)
 179                 toggleContext();
 180         } catch (DatabaseException e) {
 181             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);
 182         }
 183         oldUndo = newUndo;
 184         oldRedo = newRedo;
 185     }
 186     private void toggleContext() {
 187         IContextService contextService = (IContextService)PlatformUI.getWorkbench().getService(IContextService.class);
 188         if (null != activation) {
 189             if (DEBUG)
 190                 System.out.println("UndoPropertyTester: deactivate.");
 191             try {
 192                 contextService.deactivateContext(activation);
 193             } catch (Throwable t) {
 194                 ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);
 195             }
 196             activation = null;
 197             if (DEBUG)
 198                 System.out.println("UndoPropertyTester: deactivated.");
 199         } else {
 200             if (DEBUG)
 201                 System.out.println("UndoPropertyTester: activate.");
 202             try {
 203                 activation = contextService.activateContext(SIMANTICS_UNDO_CONTEXT);
 204             } catch (Throwable t) {
 205                 ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);
 206                 activation = null;
 207             }
 208             if (DEBUG)
 209                 System.out.println("UndoPropertyTester: activated=" + activation);
 210         }
 211     }
 212 }