Outline with JDT LS LightWeight mode

headless-services/commons/commons-java/src/main/java/org/springframework/ide/vscode/commons/languageserver/java/CompositeProjectOvserver.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2017 Pivotal, Inc.
+ * Copyright (c) 2017, 2021 Pivotal, Inc.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -36,4 +36,9 @@ public class CompositeProjectOvserver implements ProjectObserver {
 		observers.forEach(o -> o.removeListener(listener));
 	}
 
+	@Override
+	public boolean isSupported() {
+		return observers.stream().map(o -> o.isSupported()).reduce(false, (a, b) -> a || b);
+	}
+
 }

headless-services/commons/commons-java/src/main/java/org/springframework/ide/vscode/commons/languageserver/java/FutureProjectFinder.java

@@ -42,6 +42,14 @@ public class FutureProjectFinder implements DisposableBean {
 		@Override
 		public void changed(IJavaProject project) {
 		}
+
+		@Override
+		public void supported() {
+			if (!projectObserver.isSupported()) {
+				resolveAllPendingRquests();
+			}
+		}
+		
 	};
 	
 	
@@ -52,6 +60,14 @@ public class FutureProjectFinder implements DisposableBean {
 			this.projectObserver.addListener(LISTENER);
 		}
 	}
+	
+	synchronized private void resolveAllPendingRquests() {
+		for (Map.Entry<URI, CompletableFuture<IJavaProject>> e : pendingFindProjectRequests.entrySet()) {
+			Optional<IJavaProject> jp = projectFinder.find(new TextDocumentIdentifier(e.getKey().toString()));
+			e.getValue().complete(jp.orElse(null));
+			pendingFindProjectRequests.remove(e.getKey());
+		}
+	}
 
 	synchronized private void resolvePendingRequests(IJavaProject project) {
 		for (Map.Entry<URI, CompletableFuture<IJavaProject>> e : pendingFindProjectRequests.entrySet()) {
@@ -79,12 +95,16 @@ public class FutureProjectFinder implements DisposableBean {
 			if (projectObserver == null) {
 				throw new IllegalStateException("Future project lookup not supported without ProjectObserver bean present");
 			}
-			CompletableFuture<IJavaProject> cf = pendingFindProjectRequests.get(uri);
-			if (cf == null) {
-				cf = new CompletableFuture<IJavaProject>();
-				pendingFindProjectRequests.put(uri, cf);
+			if (projectObserver.isSupported()) {
+				CompletableFuture<IJavaProject> cf = pendingFindProjectRequests.get(uri);
+				if (cf == null) {
+					cf = new CompletableFuture<IJavaProject>();
+					pendingFindProjectRequests.put(uri, cf);
+				}
+				return cf;
+			} else {
+				return CompletableFuture.completedFuture(null);
 			}
-			return cf;
 		}
 	}
 

headless-services/commons/commons-java/src/main/java/org/springframework/ide/vscode/commons/languageserver/java/ProjectObserver.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2017 Pivotal, Inc.
+ * Copyright (c) 2017, 2021 Pivotal, Inc.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -26,7 +26,9 @@ public interface ProjectObserver {
 		void created(IJavaProject project);
 		void changed(IJavaProject project);
 		void deleted(IJavaProject project);
+		default void supported() { }
 	}
+	default boolean isSupported() { return true; };
 	void addListener(Listener listener);
 	void removeListener(Listener listener);
 
@@ -38,6 +40,11 @@ public interface ProjectObserver {
 		@Override
 		public void removeListener(Listener listener) {
 		}
+
+		@Override
+		public boolean isSupported() {
+			return false;
+		}
 	};
 
 	/**