X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=bundles%2Forg.simantics.ui%2Fsrc%2Forg%2Fsimantics%2Fui%2Fworkbench%2Fhandler%2Fe4%2FUndoRedoTester.java;fp=bundles%2Forg.simantics.ui%2Fsrc%2Forg%2Fsimantics%2Fui%2Fworkbench%2Fhandler%2Fe4%2FUndoRedoTester.java;h=19538d4e2da09d2fee56d49579e83089304be5f4;hb=969bd23cab98a79ca9101af33334000879fb60c5;hp=0000000000000000000000000000000000000000;hpb=866dba5cd5a3929bbeae85991796acb212338a08;p=simantics%2Fplatform.git

diff --git a/bundles/org.simantics.ui/src/org/simantics/ui/workbench/handler/e4/UndoRedoTester.java b/bundles/org.simantics.ui/src/org/simantics/ui/workbench/handler/e4/UndoRedoTester.java
new file mode 100644
index 000000000..19538d4e2
--- /dev/null
+++ b/bundles/org.simantics.ui/src/org/simantics/ui/workbench/handler/e4/UndoRedoTester.java
@@ -0,0 +1,187 @@
+package org.simantics.ui.workbench.handler.e4;
+
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.ui.PlatformUI;
+import org.eclipse.ui.contexts.IContextActivation;
+import org.eclipse.ui.contexts.IContextService;
+import org.simantics.DatabaseJob;
+import org.simantics.Simantics;
+import org.simantics.db.Session;
+import org.simantics.db.UndoContext;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.management.ISessionContext;
+import org.simantics.db.service.UndoRedoSupport;
+import org.simantics.ui.SimanticsUI;
+import org.simantics.utils.ui.ErrorLogger;
+import org.simantics.utils.ui.SWTUtils;
+
+public class UndoRedoTester {
+
+    private static final boolean DEBUG = false;
+    private static final String SIMANTICS_UNDO_CONTEXT = "org.simantics.ui.undoContext";
+    public static final String UNDO_ENABLED = "org.simantics.undo.enabled";
+    
+    private static UndoRedoSupport undoSupport = null;
+    private static UndoChangeListener changeListener = new UndoChangeListener();
+    private static IContextActivation activation = null;
+    
+    private static class UndoChangeListener implements UndoRedoSupport.ChangeListener {
+
+        private int oldUndo = 0;
+        private int oldRedo = 0;
+        
+        @Override
+        public void onChanged() {
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: on change.");
+            Display display = PlatformUI.getWorkbench().getDisplay();
+            SWTUtils.asyncExec(display, new Runnable() {
+                @Override
+                public void run() {
+                    handleChange();
+                }
+            });
+        }
+        
+        private void handleChange() {
+            int newUndo = oldUndo;
+            int newRedo = oldRedo;
+            try {
+                ISessionContext ctx = SimanticsUI.getSessionContext();
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: handle change, ctx=" + ctx);
+                if (ctx == null)
+                    return;
+                Session session = ctx.peekSession();
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: handle change, session=" + session);
+                if (session == null)
+                    return;
+                UndoContext uc = undoSupport.getUndoContext(session);
+                if (uc == null)
+                    return;
+                newUndo = uc.getAll().size();
+                newRedo = uc.getRedoList().size();
+                if (DEBUG) {
+                    System.out.println("on undo change: " + oldUndo + "->" + newUndo);
+                    System.out.println("on redo change: " + oldRedo + "->" + newRedo);
+                }
+                boolean undoOn = oldUndo == 0 && newUndo == 1;
+                boolean undoOff = oldUndo > 0 && newUndo == 0;
+                boolean redoOn = oldRedo == 0 && newRedo == 1;
+                boolean redoOff = oldRedo > 0 && newRedo == 0;
+                if (undoOn || undoOff || redoOn || redoOff)
+                    toggleContext();
+            } catch (DatabaseException e) {
+                ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);
+            }
+            oldUndo = newUndo;
+            oldRedo = newRedo;
+        }
+        private void toggleContext() {
+            IContextService contextService = (IContextService)PlatformUI.getWorkbench().getService(IContextService.class);
+            if (null != activation) {
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: deactivate.");
+                try {
+                    contextService.deactivateContext(activation);
+                } catch (Throwable t) {
+                    ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);
+                }
+                activation = null;
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: deactivated.");
+            } else {
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: activate.");
+                try {
+                    activation = contextService.activateContext(SIMANTICS_UNDO_CONTEXT);
+                } catch (Throwable t) {
+                    ErrorLogger.getDefault().logError("Undo/Redo support failed.", t);
+                    activation = null;
+                }
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: activated=" + activation);
+            }
+        }
+        
+    }
+    
+    private UndoRedoTester() {
+    }
+    
+    public static boolean canUndo() {
+        String undoEnabled = System.getProperty(UNDO_ENABLED);
+        if(undoEnabled != null && "false".equals(undoEnabled))
+            return false;
+        
+        ISessionContext ctx = Simantics.getSessionContext();
+        if (ctx == null) {
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: no can do undo.");
+            return false;
+        }
+        try {
+            Session s = ctx.peekSession();
+            if (null == s) {
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: session is null, no can do undo.");
+                return false;
+            }
+            if (DatabaseJob.inProgress())
+                return true;
+            if (null == undoSupport) {
+                undoSupport = s.getService(UndoRedoSupport.class);
+                undoSupport.subscribe(changeListener);
+            }
+            UndoContext uc = undoSupport.getUndoContext(s);
+            if (uc == null)
+                return false;
+            boolean ret = !uc.getAll().isEmpty();
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do undo.");
+            return ret;
+        } catch (Exception e) {
+            ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: no can do undo");
+            return false;
+        }
+    }
+    
+    public static boolean canRedo() {
+        ISessionContext ctx = Simantics.getSessionContext();
+        if (ctx == null) {
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: no can do redo.");
+            return false;
+        }
+        try {
+            Session s = ctx.peekSession();
+            if (null == s) {
+                if (DEBUG)
+                    System.out.println("UndoPropertyTester: session is null, no can do redo.");
+                return false;
+            }
+            if (DatabaseJob.inProgress())
+                return true;
+            if (null == undoSupport) {
+                undoSupport = s.getService(UndoRedoSupport.class);
+                undoSupport.subscribe(changeListener);
+            }
+            UndoContext uc = undoSupport.getUndoContext(s);
+            if (uc == null)
+                return false;
+            boolean ret = !uc.getRedoList().isEmpty();
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: " + (ret ? "" : "no ")+ "can do redo.");
+            return ret;
+        } catch (Exception e) {
+            ErrorLogger.getDefault().logError("Undo/Redo support failed.", e);
+            if (DEBUG)
+                System.out.println("UndoPropertyTester: no can do redo.");
+            return false;
+        }
+    }
+
+}