Support textDocument/selectionRange

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/InitHandler.java

@@ -215,6 +215,9 @@ InitializeResult initialize(InitializeParams param) {
 		if (!preferenceManager.getClientPreferences().isImplementationDynamicRegistered()) {
 			capabilities.setImplementationProvider(Boolean.TRUE);
 		}
+		if (!preferenceManager.getClientPreferences().isSelectionRangeDynamicRegistered()) {
+			capabilities.setSelectionRangeProvider(Boolean.TRUE);
+		}
 		TextDocumentSyncOptions textDocumentSyncOptions = new TextDocumentSyncOptions();
 		textDocumentSyncOptions.setOpenClose(Boolean.TRUE);
 		textDocumentSyncOptions.setSave(new SaveOptions(Boolean.TRUE));

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/JDTLanguageServer.java

@@ -109,6 +109,8 @@
 import org.eclipse.lsp4j.Registration;
 import org.eclipse.lsp4j.RegistrationParams;
 import org.eclipse.lsp4j.RenameParams;
+import org.eclipse.lsp4j.SelectionRange;
+import org.eclipse.lsp4j.SelectionRangeParams;
 import org.eclipse.lsp4j.SignatureHelp;
 import org.eclipse.lsp4j.SymbolInformation;
 import org.eclipse.lsp4j.TextDocumentIdentifier;
@@ -242,6 +244,9 @@ public void initialized(InitializedParams params) {
 		if (preferenceManager.getClientPreferences().isImplementationDynamicRegistered()) {
 			registerCapability(Preferences.IMPLEMENTATION_ID, Preferences.IMPLEMENTATION);
 		}
+		if (preferenceManager.getClientPreferences().isSelectionRangeDynamicRegistered()) {
+			registerCapability(Preferences.SELECTION_RANGE_ID, Preferences.SELECTION_RANGE);
+		}
 		// we do not have the user setting initialized yet at this point but we should
 		// still call to enable defaults in case client does not support configuration changes
 		syncCapabilitiesToSettings();
@@ -305,6 +310,9 @@ private void syncCapabilitiesToSettings() {
 		if (preferenceManager.getClientPreferences().isFoldgingRangeDynamicRegistered()) {
 			toggleCapability(preferenceManager.getPreferences().isFoldingRangeEnabled(), Preferences.FOLDINGRANGE_ID, Preferences.FOLDINGRANGE, null);
 		}
+		if (preferenceManager.getClientPreferences().isSelectionRangeDynamicRegistered()) {
+			toggleCapability(preferenceManager.getPreferences().isSelectionRangeEnabled(), Preferences.SELECTION_RANGE_ID, Preferences.SELECTION_RANGE, null);
+		}
 	}
 
 	private CodeActionOptions getCodeActionOptions() {
@@ -774,6 +782,15 @@ public CompletableFuture<List<FoldingRange>> foldingRange(FoldingRangeRequestPar
 		});
 	}
 
+	@Override
+	public CompletableFuture<List<SelectionRange>> selectionRange(SelectionRangeParams params) {
+		logInfo(">> document/selectionRange");
+		return computeAsyncWithClientProgress((monitor) -> {
+			waitForLifecycleJobs(monitor);
+			return new SelectionRangeHandler().selectionRange(params, monitor);
+		});
+	}
+
 	@Override
 	public CompletableFuture<OverridableMethodsResponse> listOverridableMethods(CodeActionParams params) {
 		logInfo(">> java/listOverridableMethods");

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/SelectionRangeHandler.java

@@ -0,0 +1,113 @@
+/*******************************************************************************
+ * Copyright (c) 2019 Microsoft Corporation and others.
+ * 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:
+ *     Microsoft Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.core.internal.handlers;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.ListIterator;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.jdt.core.ITypeRoot;
+import org.eclipse.jdt.core.JavaModelException;
+import org.eclipse.jdt.core.dom.ASTNode;
+import org.eclipse.jdt.core.dom.Comment;
+import org.eclipse.jdt.core.dom.CompilationUnit;
+import org.eclipse.jdt.core.dom.Javadoc;
+import org.eclipse.jdt.core.dom.NodeFinder;
+import org.eclipse.jdt.core.manipulation.CoreASTProvider;
+import org.eclipse.jdt.ls.core.internal.JDTUtils;
+import org.eclipse.lsp4j.Position;
+import org.eclipse.lsp4j.Range;
+import org.eclipse.lsp4j.SelectionRange;
+import org.eclipse.lsp4j.SelectionRangeParams;
+
+public class SelectionRangeHandler {
+
+	public List<SelectionRange> selectionRange(SelectionRangeParams params, IProgressMonitor monitor) {
+		if (params.getPositions() == null || params.getPositions().size() <= 0) {
+			return null;
+		}
+
+		ITypeRoot root = JDTUtils.resolveTypeRoot(params.getTextDocument().getUri());
+		if (root == null) {
+			return null;
+		}
+
+		CompilationUnit ast = CoreASTProvider.getInstance().getAST(root, CoreASTProvider.WAIT_YES, monitor);
+
+		// extra logic to check within the line comments and block comments, which are not parts of the AST
+		@SuppressWarnings("unchecked")
+		List<Comment> comments = new ArrayList<Comment>(ast.getCommentList());
+		comments.removeIf(comment -> {
+			return (comment instanceof Javadoc); // Javadoc nodes are already in the AST
+		});
+
+		List<SelectionRange> $ = new ArrayList<>();
+		for (Position pos : params.getPositions()) {
+			try {
+				int offset = JsonRpcHelpers.toOffset(root.getBuffer(), pos.getLine(), pos.getCharacter());
+				ASTNode node = NodeFinder.perform(ast, offset, 0);
+				if (node == null) {
+					continue;
+				}
+
+				// find all the ancestors
+				List<ASTNode> nodes = new ArrayList<>();
+				while (node != null) {
+					nodes.add(node);
+					node = node.getParent();
+				}
+
+				// find all the ranges corresponding to the parent nodes
+				SelectionRange selectionRange = null;
+				ListIterator<ASTNode> iterator = nodes.listIterator(nodes.size());
+				while (iterator.hasPrevious()) {
+					node = iterator.previous();
+					Range range = JDTUtils.toRange(root, node.getStartPosition(), node.getLength());
+					selectionRange = new SelectionRange(range, selectionRange);
+				}
+
+				// find in comments
+				ASTNode containingComment = containingComment(comments, offset);
+				if (containingComment != null) {
+					Range range = JDTUtils.toRange(root, containingComment.getStartPosition(), containingComment.getLength());
+					selectionRange = new SelectionRange(range, selectionRange);
+				}
+
+				if (selectionRange != null) {
+					$.add(selectionRange);
+				}
+			} catch (JavaModelException e) {
+				e.printStackTrace();
+			}
+		}
+
+		return $;
+	}
+
+	/**
+	 * Finds the comment that contains the specified position
+	 *
+	 * @param comments
+	 * @param offset
+	 * @return
+	 */
+	public ASTNode containingComment(List<Comment> comments, int offset) {
+		for (Comment comment : comments) {
+			ASTNode result = NodeFinder.perform(comment, offset, 0);
+			if (result != null) {
+				return result;
+			}
+		}
+
+		return null;
+	}
+}

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/ClientPreferences.java

@@ -149,6 +149,10 @@ public boolean isImplementationDynamicRegistered() {
 		return v3supported && isDynamicRegistrationSupported(capabilities.getTextDocument().getImplementation());
 	}
 
+	public boolean isSelectionRangeDynamicRegistered() {
+		return v3supported && isDynamicRegistrationSupported(capabilities.getTextDocument().getSelectionRange());
+	}
+
 	public boolean isWillSaveRegistered() {
 		return v3supported && capabilities.getTextDocument().getSynchronization() != null && isTrue(capabilities.getTextDocument().getSynchronization().getWillSave());
 	}

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/Preferences.java

@@ -169,6 +169,11 @@ public class Preferences {
 	 */
 	public static final String FOLDINGRANGE_ENABLED_KEY = "java.foldingRange.enabled";
 
+	/**
+	 * Preference key to enable/disable the selection range.
+	 */
+	public static final String SELECTIONRANGE_ENABLED_KEY = "java.selectionRange.enabled";
+
 	/**
 	 * A named preference that holds the favorite static members.
 	 * <p>
@@ -270,6 +275,7 @@ public class Preferences {
 	public static final String FOLDINGRANGE = "textDocument/foldingRange";
 	public static final String WORKSPACE_CHANGE_FOLDERS = "workspace/didChangeWorkspaceFolders";
 	public static final String IMPLEMENTATION = "textDocument/implementation";
+	public static final String SELECTION_RANGE = "textDocument/selectionRange";
 
 	public static final String FORMATTING_ID = UUID.randomUUID().toString();
 	public static final String FORMATTING_ON_TYPE_ID = UUID.randomUUID().toString();
@@ -291,6 +297,7 @@ public class Preferences {
 	public static final String WORKSPACE_CHANGE_FOLDERS_ID = UUID.randomUUID().toString();
 	public static final String WORKSPACE_WATCHED_FILES_ID = UUID.randomUUID().toString();
 	public static final String IMPLEMENTATION_ID = UUID.randomUUID().toString();
+	public static final String SELECTION_RANGE_ID = UUID.randomUUID().toString();
 
 	private Map<String, Object> configuration;
 	private Severity incompleteClasspathSeverity;
@@ -315,6 +322,7 @@ public class Preferences {
 	private boolean completionEnabled;
 	private boolean completionOverwrite;
 	private boolean foldingRangeEnabled;
+	private boolean selectionRangeEnabled;
 	private boolean guessMethodArguments;
 	private boolean javaFormatComments;
 	private boolean hashCodeEqualsTemplateUseJava7Objects;
@@ -428,6 +436,7 @@ public Preferences() {
 		completionEnabled = true;
 		completionOverwrite = true;
 		foldingRangeEnabled = true;
+		selectionRangeEnabled = true;
 		guessMethodArguments = false;
 		javaFormatComments = true;
 		hashCodeEqualsTemplateUseJava7Objects = false;
@@ -514,6 +523,9 @@ public static Preferences createFrom(Map<String, Object> configuration) {
 		boolean foldingRangeEnable = getBoolean(configuration, FOLDINGRANGE_ENABLED_KEY, true);
 		prefs.setFoldingRangeEnabled(foldingRangeEnable);
 
+		boolean selectionRangeEnabled = getBoolean(configuration, SELECTIONRANGE_ENABLED_KEY, true);
+		prefs.setSelectionRangeEnabled(selectionRangeEnabled);
+
 		boolean guessMethodArguments = getBoolean(configuration, JAVA_COMPLETION_GUESS_METHOD_ARGUMENTS_KEY, false);
 		prefs.setGuessMethodArguments(guessMethodArguments);
 
@@ -707,6 +719,11 @@ public Preferences setFoldingRangeEnabled(boolean enabled) {
 		return this;
 	}
 
+	public Preferences setSelectionRangeEnabled(boolean enabled) {
+		this.selectionRangeEnabled = enabled;
+		return this;
+	}
+
 	public Preferences setGuessMethodArguments(boolean guessMethodArguments) {
 		this.guessMethodArguments = guessMethodArguments;
 		return this;
@@ -901,6 +918,10 @@ public boolean isFoldingRangeEnabled() {
 		return foldingRangeEnabled;
 	}
 
+	public boolean isSelectionRangeEnabled() {
+		return selectionRangeEnabled;
+	}
+
 	public boolean isGuessMethodArguments() {
 		return guessMethodArguments;
 	}

org.eclipse.jdt.ls.target/org.eclipse.jdt.ls.tp.target

@@ -37,8 +37,8 @@
             <repository location="http://download.eclipse.org/releases/2019-06/"/>
         </location>
         <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
-           <unit id="org.eclipse.lsp4j.sdk.feature.group" version="0.7.2.v20190528-0935"/>
-           <repository location="http://download.eclipse.org/lsp4j/updates/releases/0.7.2"/>
+            <repository location="https://github.com/akaroml/lsp4j-latest/raw/master/p2/"/>
+            <unit id="org.eclipse.lsp4j.sdk.feature.group" version="0.8.0.v20190701-0317"/>
         </location>
         <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
             <unit id="org.jboss.tools.maven.apt.core" version="0.0.0"/>

org.eclipse.jdt.ls.tests/projects/maven/salut/src/main/java/java/Foo4.java

@@ -0,0 +1,32 @@
+package java;
+
+/**
+ * This is the test data for SelectionRangeHandlerTest. To ask for a selection range, we need to specify a position.
+ * To make those positions visible, >< pairs are used if possible, and a position is what's between > and <.
+ * All other positions are specified in the test code dierectly.
+ */
+class Foo4 {
+	/**
+	 * Class constructor to test >< Javadoc
+	 */
+	Foo4() {
+		System.out.println("string >< literal"); // test line >< comment
+
+		/* test block >< comment */
+		memberFunc(1, 0.0);
+	}
+
+	void memberFunc(int paramA/* test block >< comment in param list */, double paramB) {
+		try {
+			switch(paramA) {
+				case 0:
+					System.out.println(paramB);
+					break;
+				default:
+					System.out.println();
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+}