added workspace symbol handler infrastructure

headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/SimpleLanguageServer.java

@@ -248,6 +248,9 @@ public abstract class SimpleLanguageServer implements LanguageServer, LanguageCl
 					CODE_ACTION_COMMAND_ID
 			)));
 		}
+		if (hasWorkspaceSymbolHandler()) {
+			c.setWorkspaceSymbolProvider(true);
+		}
 
 		return c;
 	}
@@ -272,6 +275,10 @@ public abstract class SimpleLanguageServer implements LanguageServer, LanguageCl
 		return quickfixRegistry!=null && quickfixRegistry.hasFixes();
 	}
 
+	private boolean hasWorkspaceSymbolHandler() {
+		return getWorkspaceService().hasWorkspaceSymbolHandler();
+	}
+
 	@Override
 	public CompletableFuture<Object> shutdown() {
 		return CompletableFuture.completedFuture(new Object());
@@ -299,7 +306,7 @@ public abstract class SimpleLanguageServer implements LanguageServer, LanguageCl
 	}
 
 	public SimpleWorkspaceService createWorkspaceService() {
-		return new SimpleWorkspaceService();
+		return new SimpleWorkspaceService(this);
 	}
 
 	@Override

headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/SimpleWorkspaceService.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2016-2017 Pivotal, Inc.
+ * Copyright (c) 2016, 2017 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
@@ -8,7 +8,6 @@
  * Contributors:
  *     Pivotal, Inc. - initial API and implementation
  *******************************************************************************/
-
 package org.springframework.ide.vscode.commons.languageserver.util;
 
 import java.util.List;
@@ -23,14 +22,34 @@ import org.eclipse.lsp4j.WorkspaceSymbolParams;
 import org.eclipse.lsp4j.services.WorkspaceService;
 import org.springframework.ide.vscode.commons.util.Assert;
 
+import com.google.common.collect.ImmutableList;
+
+import reactor.core.publisher.Mono;
+
 public class SimpleWorkspaceService implements WorkspaceService {
 
+	private SimpleLanguageServer server;
+
 	private ListenerList<Settings> configurationListeners = new ListenerList<>();
 	private ExecuteCommandHandler executeCommandHandler;
+	private WorkspaceSymbolHandler workspaceSymbolHandler;
+
+	public SimpleWorkspaceService(SimpleLanguageServer server) {
+		this.server = server;
+	}
 
 	@Override
 	public CompletableFuture<List<? extends SymbolInformation>> symbol(WorkspaceSymbolParams params) {
-		throw new UnsupportedOperationException();
+		WorkspaceSymbolHandler workspaceSymbolHandler = this.workspaceSymbolHandler;
+		if (workspaceSymbolHandler==null) {
+			return CompletableFuture.completedFuture(ImmutableList.of());
+		}
+		return Mono.fromCallable(() -> {
+			server.waitForReconcile();
+			return workspaceSymbolHandler.handle(params);
+		})
+		.toFuture()
+		.thenApply(l -> (List<? extends SymbolInformation>)l);
 	}
 
 	@Override
@@ -58,4 +77,14 @@ public class SimpleWorkspaceService implements WorkspaceService {
 		Assert.isNull("A executeCommandHandler is already set, multiple handlers not supported yet", this.executeCommandHandler);
 		this.executeCommandHandler = handler;
 	}
+
+	public synchronized void onWorkspaceSymbol(WorkspaceSymbolHandler h) {
+		Assert.isNull("A WorkspaceSymbolHandler is already set, multiple handlers not supported yet", workspaceSymbolHandler);
+		this.workspaceSymbolHandler = h;
+	}
+
+	public boolean hasWorkspaceSymbolHandler() {
+		return this.workspaceSymbolHandler != null;
+	}
+
 }

headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/WorkspaceSymbolHandler.java

@@ -0,0 +1,27 @@
+/*******************************************************************************
+ * Copyright (c) 2017 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Pivotal, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.commons.languageserver.util;
+
+import java.util.List;
+
+import org.eclipse.lsp4j.SymbolInformation;
+import org.eclipse.lsp4j.WorkspaceSymbolParams;
+
+import com.google.common.collect.ImmutableList;
+
+@FunctionalInterface
+public interface WorkspaceSymbolHandler {
+
+	WorkspaceSymbolHandler NO_SYMBOLS = (params) -> ImmutableList.of();
+
+	List<? extends SymbolInformation> handle(WorkspaceSymbolParams params);
+
+}