bundles/org.simantics.ui/src/org/simantics/ui/workbench/handler/e4/UndoRedoTester.java

   1 package org.simantics.ui.workbench.handler.e4;\r
   2 \r
   3 import org.eclipse.swt.widgets.Display;\r
   4 import org.eclipse.ui.PlatformUI;\r
   5 import org.eclipse.ui.contexts.IContextActivation;\r
   6 import org.eclipse.ui.contexts.IContextService;\r
   7 import org.simantics.DatabaseJob;\r
   8 import org.simantics.Simantics;\r
   9 import org.simantics.db.Session;\r
  10 import org.simantics.db.UndoContext;\r
  11 import org.simantics.db.exception.DatabaseException;\r
  12 import org.simantics.db.management.ISessionContext;\r
  13 import org.simantics.db.service.UndoRedoSupport;\r
  14 import org.simantics.ui.SimanticsUI;\r
  15 import org.simantics.utils.ui.ErrorLogger;\r
  16 import org.simantics.utils.ui.SWTUtils;\r
  17 \r
  18 public class UndoRedoTester {\r
  19 \r
  20     private static final boolean DEBUG = false;\r
  21     private static final String SIMANTICS_UNDO_CONTEXT = "org.simantics.ui.undoContext";\r
  22     public static final String UNDO_ENABLED = "org.simantics.undo.enabled";\r
  23     \r
  24     private static UndoRedoSupport undoSupport = null;\r
  25     private static UndoChangeListener changeListener = new UndoChangeListener();\r
  26     private static IContextActivation activation = null;\r
  27     \r
  28     private static class UndoChangeListener implements UndoRedoSupport.ChangeListener {\r
  29 \r
  30         private int oldUndo = 0;\r
  31         private int oldRedo = 0;\r
  32         \r
  33         @Override\r
  34         public void onChanged() {\r
  35             if (DEBUG)\r
  36                 System.out.println("UndoPropertyTester: on change.");\r
  37             Display display = PlatformUI.getWorkbench().getDisplay();\r
  38             SWTUtils.asyncExec(display, new Runnable() {\r
  39                 @Override\r
  40                 public void run() {\r
  41                     handleChange();\r
  42                 }\r
  43             });\r
  44         }\r
  45         \r
  46         private void handleChange() {\r
  47             int newUndo = oldUndo;\r
  48             int newRedo = oldRedo;\r
  49             try {\r
  50                 ISessionContext ctx = SimanticsUI.getSessionContext();\r
  51                 if (DEBUG)\r
  52                     System.out.println("UndoPropertyTester: handle change, ctx=" + ctx);\r
  53                 if (ctx == null)\r
  54                     return;\r
  55                 Session session = ctx.peekSession();\r
  56                 if (DEBUG)\r
  57                     System.out.println("UndoPropertyTester: handle change, session=" + session);\r
  58                 if (session == null)\r
  59                     return;\r
  60                 UndoContext uc = undoSupport.getUndoContext(session);\r
  61                 if (uc == null)\r
  62                     return;\r
  63                 newUndo = uc.getAll().size();\r
  64                 newRedo = uc.getRedoList().size();\r
  65                 if (DEBUG) {\r
  66                     System.out.println("on undo change: " + oldUndo + "->" + newUndo);\r
  67                     System.out.println("on redo change: " + oldRedo + "->" + newRedo);\r
  68                 }\r
  69                 boolean undoOn = oldUndo == 0 && newUndo == 1;\r
  70                 boolean undoOff = oldUndo > 0 && newUndo == 0;\r
  71                 boolean redoOn = oldRedo == 0 && newRedo == 1;\r
  72                 boolean redoOff = oldRedo > 0 && newRedo == 0;\r
  73                 if (undoOn || undoOff || redoOn || redoOff)\r
  74                     toggleContext();\r
  75             } catch (DatabaseException e) {\r
  76                 ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);\r
  77             }\r
  78             oldUndo = newUndo;\r
  79             oldRedo = newRedo;\r
  80         }\r
  81         private void toggleContext() {\r
  82             IContextService contextService = (IContextService)PlatformUI.getWorkbench().getService(IContextService.class);\r
  83             if (null != activation) {\r
  84                 if (DEBUG)\r
  85                     System.out.println("UndoPropertyTester: deactivate.");\r
  86                 try {\r
  87                     contextService.deactivateContext(activation);\r
  88                 } catch (Throwable t) {\r
  89                     ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);\r
  90                 }\r
  91                 activation = null;\r
  92                 if (DEBUG)\r
  93                     System.out.println("UndoPropertyTester: deactivated.");\r
  94             } else {\r
  95                 if (DEBUG)\r
  96                     System.out.println("UndoPropertyTester: activate.");\r
  97                 try {\r
  98                     activation = contextService.activateContext(SIMANTICS_UNDO_CONTEXT);\r
  99                 } catch (Throwable t) {\r
 100                     ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);\r
 101                     activation = null;\r
 102                 }\r
 103                 if (DEBUG)\r
 104                     System.out.println("UndoPropertyTester: activated=" + activation);\r
 105             }\r
 106         }\r
 107         \r
 108     }\r
 109     \r
 110     private UndoRedoTester() {\r
 111     }\r
 112     \r
 113     public static boolean canUndo() {\r
 114         String undoEnabled = System.getProperty(UNDO_ENABLED);\r
 115         if(undoEnabled != null && "false".equals(undoEnabled))\r
 116             return false;\r
 117         \r
 118         ISessionContext ctx = Simantics.getSessionContext();\r
 119         if (ctx == null) {\r
 120             if (DEBUG)\r
 121                 System.out.println("UndoPropertyTester: no can do undo.");\r
 122             return false;\r
 123         }\r
 124         try {\r
 125             Session s = ctx.peekSession();\r
 126             if (null == s) {\r
 127                 if (DEBUG)\r
 128                     System.out.println("UndoPropertyTester: session is null, no can do undo.");\r
 129                 return false;\r
 130             }\r
 131             if (DatabaseJob.inProgress())\r
 132                 return true;\r
 133             if (null == undoSupport) {\r
 134                 undoSupport = s.getService(UndoRedoSupport.class);\r
 135                 undoSupport.subscribe(changeListener);\r
 136             }\r
 137             UndoContext uc = undoSupport.getUndoContext(s);\r
 138             if (uc == null)\r
 139                 return false;\r
 140             boolean ret = !uc.getAll().isEmpty();\r
 141             if (DEBUG)\r
 142                 System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do undo.");\r
 143             return ret;\r
 144         } catch (Exception e) {\r
 145             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);\r
 146             if (DEBUG)\r
 147                 System.out.println("UndoPropertyTester: no can do undo");\r
 148             return false;\r
 149         }\r
 150     }\r
 151     \r
 152     public static boolean canRedo() {\r
 153         ISessionContext ctx = Simantics.getSessionContext();\r
 154         if (ctx == null) {\r
 155             if (DEBUG)\r
 156                 System.out.println("UndoPropertyTester: no can do redo.");\r
 157             return false;\r
 158         }\r
 159         try {\r
 160             Session s = ctx.peekSession();\r
 161             if (null == s) {\r
 162                 if (DEBUG)\r
 163                     System.out.println("UndoPropertyTester: session is null, no can do redo.");\r
 164                 return false;\r
 165             }\r
 166             if (DatabaseJob.inProgress())\r
 167                 return true;\r
 168             if (null == undoSupport) {\r
 169                 undoSupport = s.getService(UndoRedoSupport.class);\r
 170                 undoSupport.subscribe(changeListener);\r
 171             }\r
 172             UndoContext uc = undoSupport.getUndoContext(s);\r
 173             if (uc == null)\r
 174                 return false;\r
 175             boolean ret = !uc.getRedoList().isEmpty();\r
 176             if (DEBUG)\r
 177                 System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do redo.");\r
 178             return ret;\r
 179         } catch (Exception e) {\r
 180             ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);\r
 181             if (DEBUG)\r
 182                 System.out.println("UndoPropertyTester: no can do redo.");\r
 183             return false;\r
 184         }\r
 185     }\r
 186 \r
 187 }\r