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

   1 /*******************************************************************************\r
   2  * Copyright (c) 2011 Association for Decentralized Information Management in\r
   3  * Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.ui.tester;\r
  13 \r
  14 import org.eclipse.core.expressions.PropertyTester;\r
  15 import org.eclipse.swt.widgets.Display;\r
  16 import org.eclipse.ui.PlatformUI;\r
  17 import org.eclipse.ui.contexts.IContextActivation;\r
  18 import org.eclipse.ui.contexts.IContextService;\r
  19 import org.simantics.DatabaseJob;\r
  20 import org.simantics.Simantics;\r
  21 import org.simantics.db.Session;\r
  22 import org.simantics.db.UndoContext;\r
  23 import org.simantics.db.exception.DatabaseException;\r
  24 import org.simantics.db.management.ISessionContext;\r
  25 import org.simantics.db.service.UndoRedoSupport;\r
  26 import org.simantics.ui.SimanticsUI;\r
  27 import org.simantics.utils.ui.ErrorLogger;\r
  28 import org.simantics.utils.ui.SWTUtils;\r
  29 \r
  30 /**\r
  31  * An eclipse property tester for org.simantics.db database undo/redoability.\r
  32  * \r
  33  * @author Kalle Kondelin\r
  34  */\r
  35 public class UndoPropertyTester extends PropertyTester implements UndoRedoSupport.ChangeListener {\r
  36 \r
  37     private static final String PROP_CAN_REDO = "canRedo";\r
  38 \r
  39     private static final String PROP_CAN_UNDO = "canUndo";\r
  40 \r
  41     private static final String SIMANTICS_UNDO_CONTEXT = "org.simantics.ui.undoContext";\r
  42 \r
  43     public static final boolean DEBUG = false;\r
  44 \r
  45     public static final String UNDO_ENABLED = "org.simantics.undo.enabled";\r
  46     \r
  47     UndoRedoSupport undoSupport = null;\r
  48     IContextActivation activation = null;\r
  49     public UndoPropertyTester() {\r
  50         if (DEBUG)\r
  51             System.out.println("UndoPropertyTester: " + this);\r
  52     }\r
  53     @Override\r
  54     public boolean test(Object receiver, String property, Object[] args, Object expectedValue) {\r
  55         if (DEBUG)\r
  56             System.out.println("UndoPropertyTester: receiver=" + receiver);\r
  57         \r
  58         String undoEnabled = System.getProperty(UNDO_ENABLED);\r
  59         if(undoEnabled != null && "false".equals(undoEnabled))\r
  60             return false;\r
  61         \r
  62         if (property.matches(PROP_CAN_UNDO))\r
  63             return canUndo();\r
  64         else if (property.matches(PROP_CAN_REDO))\r
  65             return canRedo();\r
  66         else\r
  67             return false;\r
  68     }\r
  69     private boolean canUndo() {\r
  70         ISessionContext ctx = Simantics.getSessionContext();\r
  71         if (ctx == null) {\r
  72             if (DEBUG)\r
  73                 System.out.println("UndoPropertyTester: no can do undo.");\r
  74             return false;\r
  75         }\r
  76         try {\r
  77             Session s = ctx.peekSession();\r
  78             if (null == s) {\r
  79                 if (DEBUG)\r
  80                     System.out.println("UndoPropertyTester: session is null, no can do undo.");\r
  81                 return false;\r
  82             }\r
  83             if (DatabaseJob.inProgress())\r
  84                 return true;\r
  85             if (null == undoSupport) {\r
  86                 undoSupport = s.getService(UndoRedoSupport.class);\r
  87                 undoSupport.subscribe(this);\r
  88             }\r
  89             UndoContext uc = undoSupport.getUndoContext(s);\r
  90             if (uc == null)\r
  91                 return false;\r
  92             boolean ret = !uc.getAll().isEmpty();\r
  93             if (DEBUG)\r
  94                 System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do undo.");\r
  95             return ret;\r
  96         } catch (Exception e) {\r
  97             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);\r
  98             if (DEBUG)\r
  99                 System.out.println("UndoPropertyTester: no can do undo");\r
 100             return false;\r
 101         }\r
 102     }\r
 103     private boolean canRedo() {\r
 104         ISessionContext ctx = Simantics.getSessionContext();\r
 105         if (ctx == null) {\r
 106             if (DEBUG)\r
 107                 System.out.println("UndoPropertyTester: no can do redo.");\r
 108             return false;\r
 109         }\r
 110         try {\r
 111             Session s = ctx.peekSession();\r
 112             if (null == s) {\r
 113                 if (DEBUG)\r
 114                     System.out.println("UndoPropertyTester: session is null, no can do redo.");\r
 115                 return false;\r
 116             }\r
 117             if (DatabaseJob.inProgress())\r
 118                 return true;\r
 119             if (null == undoSupport) {\r
 120                 undoSupport = s.getService(UndoRedoSupport.class);\r
 121                 undoSupport.subscribe(this);\r
 122             }\r
 123             UndoContext uc = undoSupport.getUndoContext(s);\r
 124             if (uc == null)\r
 125                 return false;\r
 126             boolean ret = !uc.getRedoList().isEmpty();\r
 127             if (DEBUG)\r
 128                 System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do redo.");\r
 129             return ret;\r
 130         } catch (Exception e) {\r
 131             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);\r
 132             if (DEBUG)\r
 133                 System.out.println("UndoPropertyTester: no can do redo.");\r
 134             return false;\r
 135         }\r
 136     }\r
 137     @Override\r
 138     public void onChanged() {\r
 139         if (DEBUG)\r
 140             System.out.println("UndoPropertyTester: on change.");\r
 141         Display display = PlatformUI.getWorkbench().getDisplay();\r
 142         SWTUtils.asyncExec(display, new Runnable() {\r
 143             @Override\r
 144             public void run() {\r
 145                 handleChange();\r
 146             }\r
 147         });\r
 148     }\r
 149     private int oldUndo = 0;\r
 150     private int oldRedo = 0;\r
 151     private void handleChange() {\r
 152         int newUndo = oldUndo;\r
 153         int newRedo = oldRedo;\r
 154         try {\r
 155             ISessionContext ctx = SimanticsUI.getSessionContext();\r
 156             if (DEBUG)\r
 157                 System.out.println("UndoPropertyTester: handle change, ctx=" + ctx);\r
 158             if (ctx == null)\r
 159                 return;\r
 160             Session session = ctx.peekSession();\r
 161             if (DEBUG)\r
 162                 System.out.println("UndoPropertyTester: handle change, session=" + session);\r
 163             if (session == null)\r
 164                 return;\r
 165             UndoContext uc = undoSupport.getUndoContext(session);\r
 166             if (uc == null)\r
 167                 return;\r
 168             newUndo = uc.getAll().size();\r
 169             newRedo = uc.getRedoList().size();\r
 170             if (DEBUG) {\r
 171                 System.out.println("on undo change: " + oldUndo + "->" + newUndo);\r
 172                 System.out.println("on redo change: " + oldRedo + "->" + newRedo);\r
 173             }\r
 174             boolean undoOn = oldUndo == 0 && newUndo == 1;\r
 175             boolean undoOff = oldUndo > 0 && newUndo == 0;\r
 176             boolean redoOn = oldRedo == 0 && newRedo == 1;\r
 177             boolean redoOff = oldRedo > 0 && newRedo == 0;\r
 178             if (undoOn || undoOff || redoOn || redoOff)\r
 179                 toggleContext();\r
 180         } catch (DatabaseException e) {\r
 181             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);\r
 182         }\r
 183         oldUndo = newUndo;\r
 184         oldRedo = newRedo;\r
 185     }\r
 186     private void toggleContext() {\r
 187         IContextService contextService = (IContextService)PlatformUI.getWorkbench().getService(IContextService.class);\r
 188         if (null != activation) {\r
 189             if (DEBUG)\r
 190                 System.out.println("UndoPropertyTester: deactivate.");\r
 191             try {\r
 192                 contextService.deactivateContext(activation);\r
 193             } catch (Throwable t) {\r
 194                 ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);\r
 195             }\r
 196             activation = null;\r
 197             if (DEBUG)\r
 198                 System.out.println("UndoPropertyTester: deactivated.");\r
 199         } else {\r
 200             if (DEBUG)\r
 201                 System.out.println("UndoPropertyTester: activate.");\r
 202             try {\r
 203                 activation = contextService.activateContext(SIMANTICS_UNDO_CONTEXT);\r
 204             } catch (Throwable t) {\r
 205                 ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);\r
 206                 activation = null;\r
 207             }\r
 208             if (DEBUG)\r
 209                 System.out.println("UndoPropertyTester: activated=" + activation);\r
 210         }\r
 211     }\r
 212 }\r