#197, #196: Improve dirty state handling (#101)

The `SetDirtyStateAction` now also declares the reason which caused the dirty state change. 
Ensure that the `SetDirtyStateAction` is only sent once during a model update

Part of eclipse-glsp/glsp#197
Fixes eclipse-glsp/glsp#196

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/actions/SaveModelActionHandler.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019 EclipseSource and others.
+ * Copyright (c) 2019-2021 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -51,7 +51,7 @@ public List<Action> executeAction(final SaveModelAction action, final GModelStat
       } finally {
          modelSourceWatcher.continueWatching(modelState);
       }
-      return listOf(new SetDirtyStateAction(modelState.isDirty()));
+      return listOf(new SetDirtyStateAction(modelState.isDirty(), SetDirtyStateAction.Reason.SAVE));
    }
 
    protected void saveModelState(final GModelState modelState) {

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/actions/SetDirtyStateAction.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2020 EclipseSource and others.
+ * Copyright (c) 2020-2021 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -16,10 +16,10 @@
 package org.eclipse.glsp.server.actions;
 
 public class SetDirtyStateAction extends Action {
-
    public static final String ID = "setDirtyState";
 
    private boolean isDirty;
+   private String reason;
 
    public SetDirtyStateAction() {
       super(ID);
@@ -30,8 +30,25 @@ public SetDirtyStateAction(final boolean isDirty) {
       this.isDirty = isDirty;
    }
 
+   public SetDirtyStateAction(final boolean isDirty, final String reason) {
+      this(isDirty);
+      this.reason = reason;
+   }
+
    public boolean isDirty() { return isDirty; }
 
    public void setDirty(final boolean isDirty) { this.isDirty = isDirty; }
 
+   public String getReason() { return reason; }
+
+   public void setReason(final String reason) { this.reason = reason; }
+
+   public static class Reason {
+      public static final String OPERATION = "operation";
+      public static final String UNDO = "undo";
+      public static final String REDO = "redo";
+      public static final String SAVE = "save";
+      public static final String EXTERNAL = "external";
+   }
+
 }

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/diagram/DiagramConfiguration.java

@@ -48,4 +48,8 @@ default ShapeTypeHint createDefaultNodeTypeHint(final String elementId) {
    default boolean needsClientLayout() {
       return true;
    }
+
+   default boolean animatedUpdate() {
+      return true;
+   }
 }

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/core/model/ModelSubmissionHandler.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019 EclipseSource and others.
+ * Copyright (c) 2019-2021 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -15,6 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.features.core.model;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -55,28 +56,32 @@ public class ModelSubmissionHandler {
     * </p>
     *
     * @param modelState The model state to submit.
+    * @param reason     The optional reason that caused the model update.
     * @return A list of actions to be processed in order to submit the model.
     */
-   public List<Action> submitModel(final GModelState modelState) {
+   public List<Action> submitModel(final GModelState modelState, final String reason) {
       modelFactory.createGModel(modelState);
       modelState.getRoot().setRevision(modelState.getRoot().getRevision() + 1);
       DiagramConfiguration diagramConfiguration = diagramConfigurationRegistry.get(modelState);
-      if (diagramConfiguration.getLayoutKind() == ServerLayoutKind.AUTOMATIC) {
-         layoutEngine.layout(modelState);
-      }
-      if (diagramConfiguration.needsClientLayout()) {
+      boolean needsClientLayout = diagramConfiguration.needsClientLayout();
+      if (needsClientLayout) {
          synchronized (modelLock) {
             return Arrays.asList(new RequestBoundsAction(modelState.getRoot()),
-               new SetDirtyStateAction(modelState.isDirty()));
+               new SetDirtyStateAction(modelState.isDirty(), reason));
          }
       }
-      return submitModelDirectly(modelState);
+      return submitModelDirectly(modelState, reason);
+   }
+
+   public List<Action> submitModel(final GModelState modelState) {
+      return submitModel(modelState, null);
    }
 
    /**
     * Returns a list of actions to directly update the client-side model without any server- or client-side layouting.
     * <p>
-    * Typically {@link ActionHandler action handlers} don't invoke this method but use {@link #submitModel(GModelState)}
+    * Typically {@link ActionHandler action handlers} don't invoke this method but use
+    * {@link #submitModel(GModelState,String)}
     * instead, as this is only used to eventually submit the model on the client directly after all layouting is already
     * performed before. The only foreseen caller of this method is {@link ComputedBoundsActionHandler}.
     * </p>
@@ -87,15 +92,30 @@ public List<Action> submitModel(final GModelState modelState) {
     * </p>
     *
     * @param modelState The model state to submit.
+    * @param reason     The optional reason that caused the model update.
     * @return A list of actions to be processed in order to submit the model.
     */
-   public List<Action> submitModelDirectly(final GModelState modelState) {
+   public List<Action> submitModelDirectly(final GModelState modelState, final String reason) {
       GModelRoot gModel = modelState.getRoot();
-      Action action = gModel.getRevision() == 0 ? new SetModelAction(gModel) : new UpdateModelAction(gModel);
+      DiagramConfiguration diagramConfiguration = diagramConfigurationRegistry.get(modelState);
+      if (diagramConfiguration.getLayoutKind() == ServerLayoutKind.AUTOMATIC) {
+         layoutEngine.layout(modelState);
+      }
+      Action modelAction = gModel.getRevision() == 0 ? new SetModelAction(gModel)
+         : new UpdateModelAction(gModel, diagramConfiguration.animatedUpdate());
       synchronized (modelLock) {
-         return Arrays.asList(action, new SetDirtyStateAction(modelState.isDirty()));
+         List<Action> result = new ArrayList<>();
+         result.add(modelAction);
+         if (!diagramConfiguration.needsClientLayout()) {
+            result.add(new SetDirtyStateAction(modelState.isDirty(), reason));
+         }
+         return result;
       }
    }
 
+   public List<Action> submitModelDirectly(final GModelState modelState) {
+      return submitModelDirectly(modelState, null);
+   }
+
    public synchronized Object getModelLock() { return modelLock; }
 }

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/core/model/RequestModelActionHandler.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019 EclipseSource and others.
+ * Copyright (c) 2019-2021 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/features/undoredo/UndoRedoActionHandler.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019 EclipseSource and others.
+ * Copyright (c) 2019-2021 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -20,6 +20,7 @@
 import org.apache.log4j.Logger;
 import org.eclipse.glsp.server.actions.Action;
 import org.eclipse.glsp.server.actions.ActionHandler;
+import org.eclipse.glsp.server.actions.SetDirtyStateAction;
 import org.eclipse.glsp.server.features.core.model.ModelSubmissionHandler;
 import org.eclipse.glsp.server.model.GModelState;
 
@@ -36,10 +37,10 @@ public class UndoRedoActionHandler implements ActionHandler {
    public List<Action> execute(final Action action, final GModelState modelState) {
       if (action instanceof UndoAction && modelState.canUndo()) {
          modelState.undo();
-         return modelSubmissionHandler.submitModel(modelState);
+         return modelSubmissionHandler.submitModel(modelState, SetDirtyStateAction.Reason.UNDO);
       } else if (action instanceof RedoAction && modelState.canRedo()) {
          modelState.redo();
-         return modelSubmissionHandler.submitModel(modelState);
+         return modelSubmissionHandler.submitModel(modelState, SetDirtyStateAction.Reason.REDO);
       }
       LOG.warn("Cannot undo or redo");
       return none();

plugins/org.eclipse.glsp.server/src/org/eclipse/glsp/server/operations/OperationActionHandler.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2019 EclipseSource and others.
+ * Copyright (c) 2019-2021 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -20,6 +20,7 @@
 
 import org.eclipse.glsp.server.actions.Action;
 import org.eclipse.glsp.server.actions.BasicActionHandler;
+import org.eclipse.glsp.server.actions.SetDirtyStateAction;
 import org.eclipse.glsp.server.features.core.model.ModelSubmissionHandler;
 import org.eclipse.glsp.server.internal.gmodel.commandstack.GModelRecordingCommand;
 import org.eclipse.glsp.server.model.GModelState;
@@ -57,7 +58,7 @@ protected List<Action> executeHandler(final Operation operation, final Operation
       GModelRecordingCommand command = new GModelRecordingCommand(modelState.getRoot(), handler.getLabel(),
          () -> handler.execute(operation, modelState));
       modelState.execute(command);
-      return modelSubmissionHandler.submitModel(modelState);
+      return modelSubmissionHandler.submitModel(modelState, SetDirtyStateAction.Reason.OPERATION);
    }
 
    public static Optional<? extends OperationHandler> getOperationHandler(final Operation operation,