Add Filter Mechanism for Target in Move Refactoring - with caching (eclipse-jdt#2034)

* Add Filter Mechanism for Target in Move Refactoring eclipse-jdt#1337

- Text Search added to search withing the tree while moving (refactoring) the file to different package
- use caching to improve performance
- fixes eclipse-jdt#1337

---------

Co-authored-by: shahzaib.ibrahim <[email protected]>

Author: gzsombor

org.eclipse.jdt.ui/ui refactoring/org/eclipse/jdt/internal/ui/refactoring/reorg/DestinationContentProvider.java

@@ -14,8 +14,11 @@
 package org.eclipse.jdt.internal.ui.refactoring.reorg;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import org.eclipse.core.runtime.CoreException;
@@ -44,6 +47,7 @@
 public final class DestinationContentProvider extends StandardJavaElementContentProvider {
 
 	private IReorgDestinationValidator fValidator;
+	private final Map<IPath, Set<IPath>> classPathRoots = new HashMap<>();
 
 	public DestinationContentProvider(IReorgDestinationValidator validator) {
 		super(true);
@@ -71,8 +75,8 @@ public boolean hasChildren(Object element) {
 	@Override
 	public Object[] getChildren(Object element) {
 		try {
-			if (element instanceof IJavaModel) {
-				return concatenate(getJavaProjects((IJavaModel)element), getOpenNonJavaProjects((IJavaModel)element));
+			if (element instanceof IJavaModel javaModel) {
+				return concatenate(getJavaProjects(javaModel), getOpenNonJavaProjects(javaModel));
 			} else {
 				Object[] children= doGetChildren(element);
 				ArrayList<Object> result= new ArrayList<>(children.length);
@@ -91,8 +95,7 @@ public Object[] getChildren(Object element) {
 	}
 
 	private Object[] doGetChildren(Object parentElement) {
-		if (parentElement instanceof IContainer) {
-			final IContainer container= (IContainer) parentElement;
+		if (parentElement instanceof IContainer container) {
 			return getResources(container);
 		}
 		return super.getChildren(parentElement);
@@ -103,17 +106,12 @@ private Object[] getResources(IContainer container) {
 		try {
 			IResource[] members= container.members();
 			IJavaProject javaProject= JavaCore.create(container.getProject());
-			if (javaProject == null || !javaProject.exists())
+			if (javaProject == null || !javaProject.exists()) {
 				return members;
+			}
 			boolean isFolderOnClasspath = javaProject.isOnClasspath(container);
+			Set<IPath> classRootPaths= getClassPathRoots(javaProject);
 			List<IResource> nonJavaResources= new ArrayList<>();
-			Set<IPath> classRootPaths= new HashSet<>();
-			for (IPackageFragmentRoot classpathRoot : javaProject.getAllPackageFragmentRoots()) {
-				IPath classRootPath= classpathRoot.getPath();
-				if (classRootPath != null) {
-					classRootPaths.add(classRootPath);
-				}
-			}
 			// Can be on classpath but as a member of non-java resource folder
 			for (IResource member : members) {
 				// A resource can also be a java element
@@ -134,6 +132,24 @@ private Object[] getResources(IContainer container) {
 		}
 	}
 
+	private synchronized Set<IPath> getClassPathRoots(IJavaProject javaProject) {
+		return classPathRoots.computeIfAbsent(javaProject.getPath(), key -> {
+			Set<IPath> classRootPaths= new HashSet<>();
+			try {
+				for (IPackageFragmentRoot classpathRoot : javaProject.getAllPackageFragmentRoots()) {
+					IPath classRootPath= classpathRoot.getPath();
+					if (classRootPath != null) {
+						classRootPaths.add(classRootPath);
+					}
+				}
+				return classRootPaths;
+			} catch(JavaModelException e) {
+				// Nothing else to do, this was the original behavior too.
+				return Collections.emptySet();
+			}
+		});
+	}
+
 	private static Object[] getOpenNonJavaProjects(IJavaModel model) throws JavaModelException {
 		Object[] nonJavaProjects= model.getNonJavaResources();
 		ArrayList<IProject> result= new ArrayList<>(nonJavaProjects.length);

org.eclipse.jdt.ui/ui refactoring/org/eclipse/jdt/internal/ui/refactoring/reorg/ReorgUserInputPage.java

@@ -34,13 +34,17 @@
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.TreeViewer;
 
+import org.eclipse.ui.dialogs.FilteredTree;
+import org.eclipse.ui.dialogs.PatternFilter;
+
 import org.eclipse.ltk.core.refactoring.RefactoringStatus;
 import org.eclipse.ltk.ui.refactoring.UserInputWizardPage;
 
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.core.JavaModelException;
 
+import org.eclipse.jdt.internal.core.manipulation.util.BasicElementLabels;
 import org.eclipse.jdt.internal.corext.refactoring.reorg.IReorgDestinationValidator;
 import org.eclipse.jdt.internal.corext.util.Messages;
 
@@ -49,7 +53,6 @@
 import org.eclipse.jdt.ui.JavaElementLabels;
 
 import org.eclipse.jdt.internal.ui.JavaPlugin;
-import org.eclipse.jdt.internal.core.manipulation.util.BasicElementLabels;
 
 
 abstract class ReorgUserInputPage extends UserInputWizardPage{
@@ -143,7 +146,8 @@ private final void verifyDestination(Object selected, boolean initialVerificatio
 	}
 
 	private TreeViewer createViewer(Composite parent) {
-		TreeViewer treeViewer= new TreeViewer(parent, SWT.SINGLE | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER);
+		FilteredTree filteredTree = new FilteredTree(parent, SWT.SINGLE | SWT.H_SCROLL | SWT.BORDER, new PatternFilter(), true, true, 500);
+		TreeViewer treeViewer = filteredTree.getViewer();
 		GridData gd= new GridData(GridData.FILL_BOTH);
 		gd.widthHint= convertWidthInCharsToPixels(40);
 		gd.heightHint= convertHeightInCharsToPixels(15);