Enable handlers returning multiple actions to a client action

This is in preparation for #6.
eclipse-glsp · Jan 5, 2020 · d50f231 · d50f231
1 parent 3d06463
commit d50f231
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Showing 22 changed files with 120 additions and 99 deletions.
diff --git a/plugins/org.eclipse.glsp.api/src/org/eclipse/glsp/api/action/ActionProcessor.java b/plugins/org.eclipse.glsp.api/src/org/eclipse/glsp/api/action/ActionProcessor.java
@@ -15,9 +15,10 @@
  ********************************************************************************/
 package org.eclipse.glsp.api.action;
 
-import java.util.Optional;
+import static org.eclipse.glsp.api.action.kind.ResponseAction.respond;
 
-import org.eclipse.glsp.api.action.kind.ResponseAction;
+import java.util.Collections;
+import java.util.List;
 
 public interface ActionProcessor {
 
@@ -31,11 +32,8 @@ public interface ActionProcessor {
     * @param action   The action to process
     */
    default void process(final String clientId, final Action action) {
-      Optional<Action> responseOpt = dispatch(clientId, action);
-      if (responseOpt.isPresent()) {
-         // ensure request and response have same id if necessary
-         Action response = ResponseAction.respond(action, responseOpt.get());
-         send(clientId, response);
+      for (Action responseAction : dispatch(clientId, action)) {
+         send(clientId, respond(action, responseAction));
       }
    }
 
@@ -59,7 +57,7 @@ default void process(final ActionMessage message) {
     * @return An optional Action to be sent to the client as the result of handling
     *         the received <code>action</code>
     */
-   Optional<Action> dispatch(String clientId, Action action);
+   List<Action> dispatch(String clientId, Action action);
 
    /**
     * Send the given action to the specified clientId.
@@ -72,8 +70,8 @@ default void process(final ActionMessage message) {
    class NullImpl implements ActionProcessor {
 
       @Override
-      public Optional<Action> dispatch(final String clientId, final Action action) {
-         return Optional.empty();
+      public List<Action> dispatch(final String clientId, final Action action) {
+         return Collections.emptyList();
       }
 
       @Override

diff --git a/plugins/org.eclipse.glsp.api/src/org/eclipse/glsp/api/handler/ActionHandler.java b/plugins/org.eclipse.glsp.api/src/org/eclipse/glsp/api/handler/ActionHandler.java
@@ -15,12 +15,30 @@
  ********************************************************************************/
 package org.eclipse.glsp.api.handler;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 
 import org.eclipse.glsp.api.action.Action;
 
 public interface ActionHandler extends Handler<Action> {
 
-   Optional<Action> execute(String clientId, Action action);
+   List<Action> execute(String clientId, Action action);
+
+   default List<Action> listOf(final Action... action) {
+      return Arrays.asList(action);
+   }
+
+   default List<Action> listOf(final Optional<Action> optionalAction) {
+      List<Action> actions = new ArrayList<>();
+      optionalAction.ifPresent(action -> actions.add(action));
+      return actions;
+   }
+
+   default List<Action> none() {
+      return Collections.emptyList();
+   }
 
 }
diff --git a/plugins/org.eclipse.glsp.api/src/org/eclipse/glsp/api/handler/ServerCommandHandler.java b/plugins/org.eclipse.glsp.api/src/org/eclipse/glsp/api/handler/ServerCommandHandler.java
@@ -16,8 +16,8 @@
 package org.eclipse.glsp.api.handler;
 
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 
 import org.eclipse.glsp.api.action.Action;
 import org.eclipse.glsp.api.model.GraphicalModelState;
@@ -28,5 +28,5 @@ default void execute(final String commandId, final GraphicalModelState modelStat
       execute(commandId, Collections.emptyMap(), modelState);
    }
 
-   Optional<Action> execute(String commandId, Map<String, String> options, GraphicalModelState modelState);
+   List<Action> execute(String commandId, Map<String, String> options, GraphicalModelState modelState);
 }
diff --git a/....eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/AbstractActionHandler.java b/....eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/AbstractActionHandler.java
@@ -15,6 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
+import java.util.List;
 import java.util.Optional;
 
 import org.eclipse.glsp.api.action.Action;
@@ -37,16 +38,16 @@ public abstract class AbstractActionHandler implements ActionHandler {
     * the client. If no response to the client is need a NoOpAction is returned
     */
    @Override
-   public Optional<Action> execute(final String clientId, final Action action) {
+   public List<Action> execute(final String clientId, final Action action) {
       this.clientId = clientId;
       Optional<GraphicalModelState> modelState = modelStateProvider.getModelState(clientId);
       if (modelState.isPresent()) {
          return execute(action, modelState.get());
       }
       ServerStatus status = new ServerStatus(Severity.FATAL,
          "Could not retrieve the model state for client with id '" + clientId + "'");
-      return Optional.of(new ServerStatusAction(status));
+      return listOf(new ServerStatusAction(status));
    }
 
-   protected abstract Optional<Action> execute(Action action, GraphicalModelState modelState);
+   protected abstract List<Action> execute(Action action, GraphicalModelState modelState);
 }
diff --git a/...se.glsp.server/src/org/eclipse/glsp/server/actionhandler/CollapseExpandActionHandler.java b/...se.glsp.server/src/org/eclipse/glsp/server/actionhandler/CollapseExpandActionHandler.java
@@ -15,7 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
-import java.util.Optional;
+import java.util.List;
 import java.util.Set;
 
 import org.eclipse.glsp.api.action.Action;
@@ -36,18 +36,18 @@ public boolean handles(final Action action) {
    }
 
    @Override
-   public Optional<Action> execute(final Action action, final GraphicalModelState modelState) {
+   public List<Action> execute(final Action action, final GraphicalModelState modelState) {
       switch (action.getKind()) {
          case Action.Kind.COLLAPSE_EXPAND:
             return handleCollapseExpandAction((CollapseExpandAction) action, modelState);
          case Action.Kind.COLLAPSE_EXPAND_ALL:
             return handleCollapseExpandAllAction((CollapseExpandAllAction) action, modelState);
          default:
-            return Optional.empty();
+            return none();
       }
    }
 
-   private Optional<Action> handleCollapseExpandAllAction(final CollapseExpandAllAction action,
+   private List<Action> handleCollapseExpandAllAction(final CollapseExpandAllAction action,
       final GraphicalModelState modelState) {
       Set<String> expandedElements = modelState.getExpandedElements();
       expandedElements.clear();
@@ -57,10 +57,10 @@ private Optional<Action> handleCollapseExpandAllAction(final CollapseExpandAllAc
       if (expansionListener != null) {
          expansionListener.expansionChanged(action);
       }
-      return Optional.empty();
+      return none();
    }
 
-   private Optional<Action> handleCollapseExpandAction(final CollapseExpandAction action,
+   private List<Action> handleCollapseExpandAction(final CollapseExpandAction action,
       final GraphicalModelState modelState) {
       Set<String> expandedElements = modelState.getExpandedElements();
       if (action.getCollapseIds() != null) {
@@ -74,8 +74,7 @@ private Optional<Action> handleCollapseExpandAction(final CollapseExpandAction a
          expansionListener.expansionChanged(action);
       }
 
-      return Optional.empty();
-
+      return none();
    }
 
 }
diff --git a/...se.glsp.server/src/org/eclipse/glsp/server/actionhandler/ComputedBoundsActionHandler.java b/...se.glsp.server/src/org/eclipse/glsp/server/actionhandler/ComputedBoundsActionHandler.java
@@ -15,7 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
-import java.util.Optional;
+import java.util.List;
 
 import org.eclipse.glsp.api.action.Action;
 import org.eclipse.glsp.api.action.kind.ComputedBoundsAction;
@@ -35,7 +35,7 @@ public boolean handles(final Action action) {
    }
 
    @Override
-   public Optional<Action> execute(final Action action, final GraphicalModelState modelState) {
+   public List<Action> execute(final Action action, final GraphicalModelState modelState) {
       if (action instanceof ComputedBoundsAction) {
          ComputedBoundsAction computedBoundsAction = (ComputedBoundsAction) action;
 
@@ -47,7 +47,7 @@ public Optional<Action> execute(final Action action, final GraphicalModelState m
             }
          }
       }
-      return Optional.empty();
+      return none();
    }
 
 }
diff --git a/.../org.eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/DIActionProcessor.java b/.../org.eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/DIActionProcessor.java
@@ -15,6 +15,8 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
+import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 
 import org.eclipse.glsp.api.action.Action;
@@ -36,12 +38,12 @@ public class DIActionProcessor implements ActionProcessor {
    protected ActionHandlerProvider handlerProvider;
 
    @Override
-   public Optional<Action> dispatch(final String clientId, final Action action) {
+   public List<Action> dispatch(final String clientId, final Action action) {
       Optional<ActionHandler> handler = handlerProvider.getHandler(action);
       if (handler.isPresent()) {
          return handler.get().execute(clientId, action);
       }
-      return Optional.empty();
+      return Collections.emptyList();
    }
 
    @Override

diff --git a/...p.server/src/org/eclipse/glsp/server/actionhandler/ExecuteServerCommandActionHandler.java b/...p.server/src/org/eclipse/glsp/server/actionhandler/ExecuteServerCommandActionHandler.java
@@ -15,6 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
+import java.util.List;
 import java.util.Optional;
 
 import org.eclipse.glsp.api.action.Action;
@@ -35,15 +36,15 @@ public boolean handles(final Action action) {
    }
 
    @Override
-   public Optional<Action> execute(final Action action, final GraphicalModelState modelState) {
+   public List<Action> execute(final Action action, final GraphicalModelState modelState) {
       if (action instanceof ExecuteServerCommandAction) {
          ExecuteServerCommandAction commandAction = (ExecuteServerCommandAction) action;
          Optional<ServerCommandHandler> handler = commandHandlerProvider.getHandler(commandAction.getCommandId());
          if (handler.isPresent()) {
             return handler.get().execute(commandAction.getCommandId(), commandAction.getOptions(), modelState);
          }
       }
-      return Optional.empty();
+      return none();
    }
 
 }
diff --git a/...rg.eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/LayoutActionHandler.java b/...rg.eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/LayoutActionHandler.java
@@ -15,7 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
-import java.util.Optional;
+import java.util.List;
 
 import org.eclipse.glsp.api.action.Action;
 import org.eclipse.glsp.api.action.kind.LayoutAction;
@@ -41,13 +41,13 @@ public boolean handles(final Action action) {
    }
 
    @Override
-   protected Optional<Action> execute(final Action action, final GraphicalModelState modelState) {
+   protected List<Action> execute(final Action action, final GraphicalModelState modelState) {
       if (serverConfiguration.getLayoutKind() == ServerLayoutKind.MANUAL) {
          if (layoutEngine != null) {
             layoutEngine.layout(modelState);
          }
-         return Optional.of(new RequestBoundsAction(modelState.getRoot()));
+         return listOf(new RequestBoundsAction(modelState.getRoot()));
       }
-      return Optional.empty();
+      return none();
    }
 }
diff --git a/...eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/ModelSubmissionHandler.java b/...eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/ModelSubmissionHandler.java
@@ -15,7 +15,9 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
-import java.util.Optional;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 
 import org.eclipse.glsp.api.action.Action;
 import org.eclipse.glsp.api.action.kind.SetModelAction;
@@ -38,21 +40,20 @@ public class ModelSubmissionHandler {
    private final Object modelLock = new Object();
    private final int revision = 0;
 
-   public Optional<Action> doSubmitModel(final boolean update, final GraphicalModelState modelState) {
+   public List<Action> doSubmitModel(final boolean update, final GraphicalModelState modelState) {
       GModelRoot newRoot = modelState.getRoot();
       if (serverConfiguration.getLayoutKind() == ServerLayoutKind.AUTOMATIC) {
          layoutEngine.layout(modelState);
       }
       synchronized (modelLock) {
          if (newRoot.getRevision() == revision) {
             if (update) {
-               return Optional.of(new UpdateModelAction(newRoot, true));
-            } else {
-               return Optional.of(new SetModelAction(newRoot));
+               return Arrays.asList(new UpdateModelAction(newRoot, true));
             }
+            return Arrays.asList(new SetModelAction(newRoot));
          }
       }
-      return Optional.empty();
+      return Collections.emptyList();
    }
 
    public synchronized Object getModelLock() { return modelLock; }

diff --git a/.../org.eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/OpenActionHandler.java b/.../org.eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/OpenActionHandler.java
@@ -15,7 +15,7 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
-import java.util.Optional;
+import java.util.List;
 
 import org.eclipse.glsp.api.action.Action;
 import org.eclipse.glsp.api.action.kind.OpenAction;
@@ -34,13 +34,13 @@ public boolean handles(final Action action) {
    }
 
    @Override
-   public Optional<Action> execute(final Action action, final GraphicalModelState modelState) {
+   public List<Action> execute(final Action action, final GraphicalModelState modelState) {
       if (action instanceof OpenAction) {
          if (modelElementOpenListener != null) {
             modelElementOpenListener.elementOpened((OpenAction) action);
          }
       }
-      return Optional.empty();
+      return none();
    }
 
 }
diff --git a/...eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/OperationActionHandler.java b/...eclipse.glsp.server/src/org/eclipse/glsp/server/actionhandler/OperationActionHandler.java
@@ -15,7 +15,8 @@
  ********************************************************************************/
 package org.eclipse.glsp.server.actionhandler;
 
-import java.util.Optional;
+import java.util.Collections;
+import java.util.List;
 
 import org.eclipse.glsp.api.action.Action;
 import org.eclipse.glsp.api.action.kind.AbstractOperationAction;
@@ -37,24 +38,24 @@ public boolean handles(final Action action) {
    }
 
    @Override
-   public Optional<Action> execute(final Action action, final GraphicalModelState modelState) {
+   public List<Action> execute(final Action action, final GraphicalModelState modelState) {
       if (action instanceof AbstractOperationAction
          && operationHandlerProvider.isHandled((AbstractOperationAction) action)) {
          return doHandle((AbstractOperationAction) action, modelState);
       }
-      return Optional.empty();
+      return Collections.emptyList();
    }
 
-   public Optional<Action> doHandle(final AbstractOperationAction action, final GraphicalModelState modelState) {
+   public List<Action> doHandle(final AbstractOperationAction action, final GraphicalModelState modelState) {
       if (operationHandlerProvider.isHandled(action)) {
          OperationHandler handler = operationHandlerProvider.getHandler(action).get();
          String label = handler.getLabel(action);
          GModelRecordingCommand command = new GModelRecordingCommand(modelState.getRoot(), label,
             () -> handler.execute(action, modelState));
          modelState.execute(command);
-         return Optional.of(new RequestBoundsAction(modelState.getRoot()));
+         return listOf(new RequestBoundsAction(modelState.getRoot()));
       }
-      return Optional.empty();
+      return none();
    }
 
 }