Bug 541834 - [code mining] implementations not shown on methods

- add support for IMethod in JavaElementCodeMining when
  showImplentations is true
- add new FindDeclarationsInSubHierarchyAction which is similar
  to FindDeclarationsInHierarchyAction but restricts results
  to sub-types
- add support in JavaImplementationCodeMining for IMethods
  and use the new FindDeclarationsInSubHierarchyAction which
  will show results in Search View

Change-Id: I7ab708e09c43ad9e515833f391219952ca90f5d3
Signed-off-by: Jeff Johnston <jjohnstn@redhat.com>

3 files changed, 82 insertions, 18 deletions

diff --git a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaElementCodeMiningProvider.java b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaElementCodeMiningProvider.java
index 3f0f76e833..15c092d127 100644
--- a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaElementCodeMiningProvider.java
+++ b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaElementCodeMiningProvider.java
@@ -31,6 +31,7 @@ import org.eclipse.jface.text.source.ISourceViewerExtension5;
 import org.eclipse.ui.texteditor.ITextEditor;
 
 import org.eclipse.jdt.core.IJavaElement;
+import org.eclipse.jdt.core.IMethod;
 import org.eclipse.jdt.core.IType;
 import org.eclipse.jdt.core.ITypeRoot;
 import org.eclipse.jdt.core.JavaModelException;
@@ -163,15 +164,22 @@ public class JavaElementCodeMiningProvider extends AbstractCodeMiningProvider {
 				}
 			}
 			if (showImplementations) {
+				// support methods, classes, and interfaces
+				boolean addMining= false;
 				if (element instanceof IType) {
 					IType type= (IType) element;
 					if (type.isInterface() || type.isClass()) {
-						try {
-							minings.add(new JavaImplementationCodeMining(type, (JavaEditor) textEditor, viewer.getDocument(), this,
-									showAtLeastOne));
-						} catch (BadLocationException e) {
-							// Should never occur
-						}
+						addMining= true;
+					}
+				} else if (element instanceof IMethod) {
+					addMining= true;
+				}
+				if (addMining) {
+					try {
+						minings.add(new JavaImplementationCodeMining(element, (JavaEditor) textEditor, viewer.getDocument(), this,
+								showAtLeastOne));
+					} catch (BadLocationException e) {
+						// Should never occur
 					}
 				}
 			}
diff --git a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaImplementationCodeMining.java b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaImplementationCodeMining.java
index 654524daeb..46fae0c530 100644
--- a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaImplementationCodeMining.java
+++ b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/codemining/JavaImplementationCodeMining.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2018 Angelo Zerr and others.
+ * Copyright (c) 2019 Angelo Zerr and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -10,16 +10,20 @@
  *
  * Contributors:
  * - Angelo Zerr: initial API and implementation
+ * - Red Hat Inc. - add Method implementation support
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.javaeditor.codemining;
 
 import java.text.MessageFormat;
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import org.eclipse.swt.events.MouseEvent;
 
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 
 import org.eclipse.jface.viewers.StructuredSelection;
@@ -30,9 +34,11 @@ import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.codemining.ICodeMiningProvider;
 
 import org.eclipse.jdt.core.IJavaElement;
+import org.eclipse.jdt.core.IMethod;
 import org.eclipse.jdt.core.IType;
 import org.eclipse.jdt.core.JavaModelException;
 
+import org.eclipse.jdt.ui.actions.FindDeclarationsInHierarchyAction;
 import org.eclipse.jdt.ui.actions.OpenTypeHierarchyAction;
 
 import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor;
@@ -50,7 +56,7 @@ public class JavaImplementationCodeMining extends AbstractJavaElementLineHeaderC
 
 	private Consumer<MouseEvent> action;
 
-	public JavaImplementationCodeMining(IType element, JavaEditor editor, IDocument document, ICodeMiningProvider provider,
+	public JavaImplementationCodeMining(IJavaElement element, JavaEditor editor, IDocument document, ICodeMiningProvider provider,
 			boolean showImplementationsAtLeastOne) throws JavaModelException, BadLocationException {
 		super(element, document, provider, null);
 		this.editor= editor;
@@ -63,14 +69,27 @@ public class JavaImplementationCodeMining extends AbstractJavaElementLineHeaderC
 		return CompletableFuture.runAsync(() -> {
 			try {
 				IJavaElement element= super.getElement();
-				long implCount= countImplementations((IType) element, monitor);
-				action= implCount > 0 ? e -> new OpenTypeHierarchyAction(editor).run(new StructuredSelection(element)) : null;
-				if (implCount == 0 && showImplementationsAtLeastOne) {
-					super.setLabel(""); //$NON-NLS-1$
-				} else {
-					super.setLabel(MessageFormat.format(JavaCodeMiningMessages.JavaImplementationCodeMining_label, implCount));
+				long implCount = 0;
+				if (element instanceof IType) {
+					// for a type, count types implementing this type and show type hierarchy
+					implCount= countTypeImplementations((IType) element, monitor);
+					action= implCount > 0 ? e -> new OpenTypeHierarchyAction(editor).run(new StructuredSelection(element)) : null;
+					if (implCount == 0 && showImplementationsAtLeastOne) {
+						super.setLabel(""); //$NON-NLS-1$
+					} else {
+						super.setLabel(MessageFormat.format(JavaCodeMiningMessages.JavaImplementationCodeMining_label, implCount));
+					}
+				} else if (element instanceof IMethod) {
+					// for a method, count declarations in hierarchy and show search->declarations->hierarchy
+					implCount= countMethodImplementations((IMethod) element, monitor);
+					action= implCount > 0 ? e -> new FindDeclarationsInHierarchyAction(editor, true).run(element) : null;
+					if (implCount == 0 && showImplementationsAtLeastOne) {
+						super.setLabel(""); //$NON-NLS-1$
+					} else {
+						super.setLabel(MessageFormat.format(JavaCodeMiningMessages.JavaImplementationCodeMining_label, implCount));
+					}
 				}
-			} catch (JavaModelException e) {
+			} catch (CoreException e1) {
 				// Should never occur
 			}
 		});
@@ -89,9 +108,28 @@ public class JavaImplementationCodeMining extends AbstractJavaElementLineHeaderC
 	 * @return the count of implementation for the given java element type.
 	 * @throws JavaModelException throws when Java error
 	 */
-	private static long countImplementations(IType type, IProgressMonitor monitor) throws JavaModelException {
+	private static long countTypeImplementations(IType type, IProgressMonitor monitor) throws JavaModelException {
 		IType[] results= type.newTypeHierarchy(monitor).getAllSubtypes(type);
 		return Stream.of(results).filter(t -> t.getAncestor(IJavaElement.COMPILATION_UNIT) != null).count();
 	}
 
+	/**
+	 * Return the count of implementation for the java element method.
+	 *
+	 * @param method the java element method.
+	 * @param monitor the monitor
+	 * @return the count of implementation for the given java element type.
+	 * @throws CoreException throws when java error
+	 */
+	private static long countMethodImplementations(IMethod method, IProgressMonitor monitor) throws CoreException {
+		if (method == null) {
+			return 0;
+		}
+		IType type= method.getDeclaringType();
+		IType[] results= type.newTypeHierarchy(monitor).getAllSubtypes(type);
+		List<IType> list= Stream.of(results).filter(t -> t.getAncestor(IJavaElement.COMPILATION_UNIT) != null).collect(Collectors.toList());
+		long count= list.stream().filter(t -> t.getMethod(method.getElementName(), method.getParameterTypes()).exists()).count();
+		return count;
+	}
+
 }
diff --git a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindDeclarationsInHierarchyAction.java b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindDeclarationsInHierarchyAction.java
index c8b17bd29e..80e5f564c2 100644
--- a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindDeclarationsInHierarchyAction.java
+++ b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindDeclarationsInHierarchyAction.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2016 IBM Corporation and others.
+ * Copyright (c) 2000, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -10,6 +10,7 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Red Hat Inc. - add support for restricting to sub-types
  *******************************************************************************/
 package org.eclipse.jdt.ui.actions;
 
@@ -51,6 +52,8 @@ import org.eclipse.jdt.internal.ui.search.SearchMessages;
  */
 public class FindDeclarationsInHierarchyAction extends FindDeclarationsAction {
 
+	private boolean onlySubtypes;
+
 	/**
 	 * Creates a new <code>FindDeclarationsInHierarchyAction</code>. The action
 	 * requires that the selection provided by the site's selection provider is of type
@@ -72,6 +75,19 @@ public class FindDeclarationsInHierarchyAction extends FindDeclarationsAction {
 		super(editor);
 	}
 
+	/**
+	 * Note: This constructor is for internal use only. Clients should not call this constructor.
+	 * @param editor the Java editor
+	 * @param onlySubtypes true if only sub-types should be considered in search
+	 *
+	 * @noreference This constructor is not intended to be referenced by clients.
+	 * @since 3.18
+	 */
+	public FindDeclarationsInHierarchyAction(JavaEditor editor, boolean onlySubtypes) {
+		super(editor);
+		this.onlySubtypes= onlySubtypes;
+	}
+
 	@Override
 	Class<?>[] getValidTypes() {
 		return new Class[] { IField.class, IMethod.class, ILocalVariable.class, ITypeParameter.class };
@@ -93,7 +109,9 @@ public class FindDeclarationsInHierarchyAction extends FindDeclarationsAction {
 		if (type == null) {
 			return super.createQuery(element);
 		}
-		IJavaSearchScope scope= SearchEngine.createHierarchyScope(type);
+		IJavaSearchScope scope= onlySubtypes
+				? SearchEngine.createStrictHierarchyScope(null, type, true, false, null)
+				: SearchEngine.createHierarchyScope(type);
 		String description= factory.getHierarchyScopeDescription(type);
 		return new ElementQuerySpecification(element, getLimitTo(), scope, description);
 	}