org.eclipse.lsp4e/src/org/eclipse/lsp4e/LSPEclipseUtils.java - lsp4e/lsp4e - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016 Red Hat Inc. 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:
  *  Mickael Istria (Red Hat Inc.) - initial implementation
  *  Michał Niewrzał (Rogue Wave Software Inc.)
  *  Lucas Bullen (Red Hat Inc.) - Get IDocument from IEditorInput
  *  Angelo Zerr <angelo.zerr@gmail.com> - Bug 525400 - [rename] improve rename support with ltk UI
  *******************************************************************************/
 package org.eclipse.lsp4e;

 import java.io.File;
 import java.lang.reflect.Method;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.core.filebuffers.FileBuffers;
 import org.eclipse.core.filebuffers.ITextFileBuffer;
 import org.eclipse.core.filebuffers.ITextFileBufferManager;
 import org.eclipse.core.filebuffers.LocationKind;
 import org.eclipse.core.filesystem.EFS;
 import org.eclipse.core.filesystem.IFileInfo;
 import org.eclipse.core.filesystem.IFileStore;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IMarker;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.RewriteSessionEditProcessor;
 import org.eclipse.jface.text.TextSelection;
 import org.eclipse.lsp4j.DiagnosticSeverity;
 import org.eclipse.lsp4j.Location;
 import org.eclipse.lsp4j.Position;
 import org.eclipse.lsp4j.TextDocumentIdentifier;
 import org.eclipse.lsp4j.TextDocumentPositionParams;
 import org.eclipse.lsp4j.TextEdit;
 import org.eclipse.lsp4j.WorkspaceEdit;
 import org.eclipse.ltk.core.refactoring.CompositeChange;
 import org.eclipse.ltk.core.refactoring.DocumentChange;
 import org.eclipse.ltk.core.refactoring.PerformChangeOperation;
 import org.eclipse.text.edits.MalformedTreeException;
 import org.eclipse.text.edits.MultiTextEdit;
 import org.eclipse.text.edits.ReplaceEdit;
 import org.eclipse.text.undo.DocumentUndoManagerRegistry;
 import org.eclipse.text.undo.IDocumentUndoManager;
 import org.eclipse.ui.IEditorInput;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IFileEditorInput;
 import org.eclipse.ui.IPathEditorInput;
 import org.eclipse.ui.IURIEditorInput;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.ide.IDE;
 import org.eclipse.ui.part.MultiPageEditorPart;
 import org.eclipse.ui.texteditor.AbstractTextEditor;
 import org.eclipse.ui.texteditor.ITextEditor;

 import com.google.gson.Gson;

 /**
  * Some utility methods to convert between Eclipse and LS-API types
  */
 public class LSPEclipseUtils {

 	private LSPEclipseUtils() {
 		// this class shouldn't be instantiated
 	}

 	public static ITextEditor getActiveTextEditor() {
 		IEditorPart editorPart = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage().getActiveEditor();
 		if(editorPart instanceof ITextEditor) {
 			return (ITextEditor) editorPart;
 		} else if (editorPart instanceof MultiPageEditorPart) {
 			MultiPageEditorPart multiPageEditorPart = (MultiPageEditorPart) editorPart;
 			Object page = multiPageEditorPart.getSelectedPage();
 			if (page instanceof ITextEditor) {
 				return (ITextEditor) page;
 			}
 		}
 		return null;
 	}

 	public static Position toPosition(int offset, IDocument document) throws BadLocationException {
 		Position res = new Position();
 		res.setLine(document.getLineOfOffset(offset));
 		res.setCharacter(offset - document.getLineInformationOfOffset(offset).getOffset());
 		return res;
 	}

 	public static int toOffset(Position position, IDocument document) throws BadLocationException {
 		return document.getLineInformation(position.getLine()).getOffset() + position.getCharacter();
 	}

 	public static TextDocumentPositionParams toTextDocumentPosistionParams(URI fileUri, int offset, IDocument document)
 			throws BadLocationException {
 		Position start = toPosition(offset, document);
 		TextDocumentPositionParams param = new TextDocumentPositionParams();
 		param.setPosition(start);
 		param.setUri(fileUri.toString());
 		TextDocumentIdentifier id = new TextDocumentIdentifier();
 		id.setUri(fileUri.toString());
 		param.setTextDocument(id);
 		return param;
 	}

 	public static int toEclipseMarkerSeverity(DiagnosticSeverity lspSeverity) {
 		if (lspSeverity == null) {
 			// if severity is empty it is up to the client to interpret diagnostics
 			return IMarker.SEVERITY_ERROR;
 		}
 		switch (lspSeverity) {
 		case Error:
 			return IMarker.SEVERITY_ERROR;
 		case Warning:
 			return IMarker.SEVERITY_WARNING;
 		default:
 			return IMarker.SEVERITY_INFO;
 		}
 	}


 	@Nullable
 	public static IResource findResourceFor(@Nullable String uri) {
 		if (uri == null || uri.isEmpty()) {
 			return null;
 		}
 		String convertedUri = uri.replace("file:///", "file:/"); //$NON-NLS-1$//$NON-NLS-2$
 		convertedUri = convertedUri.replace("file://", "file:/"); //$NON-NLS-1$//$NON-NLS-2$
 		IPath path = Path.fromOSString(new File(URI.create(convertedUri)).getAbsolutePath());
 		IProject project = null;
 		for (IProject aProject : ResourcesPlugin.getWorkspace().getRoot().getProjects()) {
 			IPath location = aProject.getLocation();
 			if (location != null && location.isPrefixOf(path)
 					&& (project == null || project.getLocation().segmentCount() < location.segmentCount())) {
 				project = aProject;
 			}
 		}
 		if (project == null) {
 			return null;
 		}
 		IPath projectRelativePath = path.removeFirstSegments(project.getLocation().segmentCount());
 		if (projectRelativePath.isEmpty()) {
 			return project;
 		} else {
 			return project.findMember(projectRelativePath);
 		}
 	}

 	public static void applyEdit(TextEdit textEdit, IDocument document) throws BadLocationException {
 		document.replace(
 				LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document),
 				LSPEclipseUtils.toOffset(textEdit.getRange().getEnd(), document) - LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document),
 				textEdit.getNewText());
 	}

 	/**
 	 * Method will apply all edits to document as single modification. Needs to
 	 * be executed in UI thread.
 	 *
 	 * @param document
 	 *            document to modify
 	 * @param edits
 	 *            list of LSP TextEdits
 	 */
 	public static void applyEdits(IDocument document, List<? extends TextEdit> edits) {
 		if (document == null || edits.isEmpty()) {
 			return;
 		}

 		IDocumentUndoManager manager = DocumentUndoManagerRegistry.getDocumentUndoManager(document);
 		if (manager != null) {
 			manager.beginCompoundChange();
 		}

 		MultiTextEdit edit = new MultiTextEdit();
 		for (TextEdit textEdit : edits) {
 			if (textEdit != null) {
 				try {
 					int offset = LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document);
 					int length = LSPEclipseUtils.toOffset(textEdit.getRange().getEnd(), document) - offset;
 					edit.addChild(new ReplaceEdit(offset, length, textEdit.getNewText()));
 				} catch (BadLocationException e) {
 					LanguageServerPlugin.logError(e);
 				}
 			}
 		}
 		try {
 			RewriteSessionEditProcessor editProcessor = new RewriteSessionEditProcessor(document, edit,
 					org.eclipse.text.edits.TextEdit.NONE);
 			editProcessor.performEdits();
 		} catch (MalformedTreeException | BadLocationException e) {
 			LanguageServerPlugin.logError(e);
 		}
 		if (manager != null) {
 			manager.endCompoundChange();
 		}
 	}

 	@Nullable
 	public static IDocument getDocument(@Nullable IResource resource) {
 		if (resource == null) {
 			return null;
 		}

 		ITextFileBufferManager bufferManager = FileBuffers.getTextFileBufferManager();
 		IDocument document = null;
 		ITextFileBuffer buffer = bufferManager.getTextFileBuffer(resource.getFullPath(), LocationKind.IFILE);
 		if (buffer != null) {
 			document = buffer.getDocument();
 		} else if (resource.getType() == IResource.FILE) {
 			try {
 				bufferManager.connect(resource.getFullPath(), LocationKind.IFILE, new NullProgressMonitor());
 			} catch (CoreException e) {
 				LanguageServerPlugin.logError(e);
 				return document;
 			}
 			buffer = bufferManager.getTextFileBuffer(resource.getFullPath(), LocationKind.IFILE);
 			if (buffer != null) {
 				document = buffer.getDocument();
 			}
 		}
 		return document;
 	}

 	public static void openInEditor(Location location, IWorkbenchPage page) {
 		IEditorPart part = null;
 		IDocument targetDocument = null;
 		IResource targetResource = LSPEclipseUtils.findResourceFor(location.getUri());
 		try {
 			if (targetResource != null && targetResource.getType() == IResource.FILE) {
 				part = IDE.openEditor(page, (IFile) targetResource);
 				targetDocument = FileBuffers.getTextFileBufferManager()
 				        .getTextFileBuffer(targetResource.getFullPath(), LocationKind.IFILE).getDocument();
 			} else {
 				URI fileUri = URI.create(location.getUri()).normalize();
 				IFileStore fileStore =  EFS.getLocalFileSystem().getStore(fileUri);
 				IFileInfo fetchInfo = fileStore.fetchInfo();
 				if (!fetchInfo.isDirectory() && fetchInfo.exists()) {
 					part = IDE.openEditorOnFileStore(page, fileStore);
 					ITextFileBuffer fileStoreTextFileBuffer = FileBuffers.getTextFileBufferManager()
 							.getFileStoreTextFileBuffer(fileStore);
 					targetDocument = fileStoreTextFileBuffer.getDocument();
 				}
 			}
 		} catch (PartInitException e) {
 			LanguageServerPlugin.logError(e);
 		}
 		try {
 			if (part instanceof AbstractTextEditor) {
 				AbstractTextEditor editor = (AbstractTextEditor) part;
 				int offset = LSPEclipseUtils.toOffset(location.getRange().getStart(), targetDocument);
 				int endOffset = LSPEclipseUtils.toOffset(location.getRange().getEnd(), targetDocument);
 				editor.getSelectionProvider()
 				        .setSelection(new TextSelection(offset, endOffset > offset ? endOffset - offset : 0));
 			}
 		} catch (BadLocationException e) {
 			LanguageServerPlugin.logError(e);
 		}
 	}

 	public static IDocument getDocument(ITextEditor editor) {
 		try {
 			Method getSourceViewerMethod= AbstractTextEditor.class.getDeclaredMethod("getSourceViewer"); //$NON-NLS-1$
 			getSourceViewerMethod.setAccessible(true);
 			ITextViewer viewer = (ITextViewer) getSourceViewerMethod.invoke(editor);
 			return viewer.getDocument();
 		} catch (Exception ex) {
 			LanguageServerPlugin.logError(ex);
 			return null;
 		}
 	}

 	public static IDocument getDocument(IEditorInput editorInput) {
 		if(editorInput instanceof IFileEditorInput) {
 			IFileEditorInput fileEditorInput = (IFileEditorInput)editorInput;
 				return getDocument(fileEditorInput.getFile());
 		}else if(editorInput instanceof IPathEditorInput) {
 			IPathEditorInput pathEditorInput = (IPathEditorInput)editorInput;
 			return getDocument(ResourcesPlugin.getWorkspace().getRoot().getFile(pathEditorInput.getPath()));
 		}else if(editorInput instanceof IURIEditorInput) {
 			IURIEditorInput uriEditorInput = (IURIEditorInput)editorInput;
 			return getDocument(findResourceFor(uriEditorInput.getURI().toString()));
 		}
 		return null;
 	}

 	/**
 	 * Applies a workspace edit. It does simply change the underlying documents.
 	 *
 	 * @param wsEdit
 	 */
 	public static void applyWorkspaceEdit(WorkspaceEdit wsEdit) {
 		CompositeChange change = toCompositeChange(wsEdit);
 		PerformChangeOperation changeOperation = new PerformChangeOperation(change);
 		try {
 			ResourcesPlugin.getWorkspace().run(changeOperation, new NullProgressMonitor());
 		} catch (CoreException e) {
 			LanguageServerPlugin.logError(e);
 		}
 	}

 	/**
 	 * Returns a ltk {@link CompositeChange} from a lsp {@link WorkspaceEdit}.
 	 *
 	 * @param wsEdit
 	 * @return a ltk {@link CompositeChange} from a lsp {@link WorkspaceEdit}.
 	 */
 	public static CompositeChange toCompositeChange(WorkspaceEdit wsEdit) {
 		CompositeChange change = new CompositeChange("LSP Workspace Edit"); //$NON-NLS-1$
 		for (java.util.Map.Entry<String, List<TextEdit>> edit : wsEdit.getChanges().entrySet()) {
 			String uri = edit.getKey();
 			IDocument document = LSPEclipseUtils.getDocument(LSPEclipseUtils.findResourceFor(uri));
 			for (TextEdit textEdit : edit.getValue()) {
 				try {
 					int offset = LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document);
 					int length = LSPEclipseUtils.toOffset(textEdit.getRange().getEnd(), document) - offset;
 					DocumentChange documentChange = new DocumentChange("Change in document " + uri, document); //$NON-NLS-1$
 					documentChange.initializeValidationData(new NullProgressMonitor());
 					documentChange.setEdit(new ReplaceEdit(offset, length, textEdit.getNewText()));
 					change.add(documentChange);
 				} catch (BadLocationException e) {
 					LanguageServerPlugin.logError(e);
 				}
 			}
 		}
 		return change;
 	}

 	public static URI toUri(IPath absolutePath) {
 		return toUri(absolutePath.toFile());
 	}

 	public static URI toUri(IResource resource) {
 		return toUri(resource.getLocation());
 	}

 	public static URI toUri(File file) {
 		// URI scheme specified by language server protocol and LSP
 		try {
 			return new URI("file", "", file.getAbsoluteFile().toURI().getPath(), null); //$NON-NLS-1$ //$NON-NLS-2$
 		} catch (URISyntaxException e) {
 			LanguageServerPlugin.logError(e);
 			return file.getAbsoluteFile().toURI();
 		}
 	}

 	// TODO consider using Entry/SimpleEntry instead
 	private static final class Pair<K, V> {
 		K key;
 		V value;
 		Pair(K key,V value) {
 			this.key = key;
 			this.value = value;
 		}
 	}

 	/**
 	 * Very empirical and unsafe heuristic to turn unknown command arguments
 	 * into a workspace edit...
 	 */
 	public static WorkspaceEdit createWorkspaceEdit(List<Object> commandArguments, IResource initialResource) {
 		WorkspaceEdit res = new WorkspaceEdit();
 		Map<String, List<TextEdit>> changes = new HashMap<>();
 		res.setChanges(changes);
 		Pair<IResource, List<TextEdit>> currentEntry = new Pair<>(initialResource, new ArrayList<>());
 		commandArguments.stream().flatMap(item -> {
 			if (item instanceof List) {
 				return ((List<?>)item).stream();
 			} else {
 				return Collections.singleton(item).stream();
 			}
 		}).forEach(arg -> {
 			if (arg instanceof String) {
 				changes.put(currentEntry.key.getLocationURI().toString(), currentEntry.value);
 				IResource resource = LSPEclipseUtils.findResourceFor((String)arg);
 				if (resource != null) {
 					currentEntry.key = resource;
 					currentEntry.value = new ArrayList<>();
 				}
 			} else if (arg instanceof WorkspaceEdit) {
 				changes.putAll(((WorkspaceEdit)arg).getChanges());
 			} else if (arg instanceof TextEdit) {
 				currentEntry.value.add((TextEdit)arg);
 			} else if (arg instanceof Map) {
 				Gson gson = new Gson(); // TODO? retrieve the GSon used by LS
 				TextEdit edit = gson.fromJson(gson.toJson(arg), TextEdit.class);
 				if (edit != null) {
 					currentEntry.value.add(edit);
 				}
 			}
 		});
 		changes.put(currentEntry.key.getLocationURI().toString(), currentEntry.value);
 		return res;
 	}

 	@Nullable public static IFile getFile(IDocument document) {
 		ITextFileBuffer buffer = FileBuffers.getTextFileBufferManager().getTextFileBuffer(document);
 		if (buffer == null) {
 			return null;
 		}
 		final IPath location = buffer.getLocation();
 		return ResourcesPlugin.getWorkspace().getRoot().getFile(location);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2016 Red Hat Inc. 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:
	* Mickael Istria (Red Hat Inc.) - initial implementation
	* Michał Niewrzał (Rogue Wave Software Inc.)
	* Lucas Bullen (Red Hat Inc.) - Get IDocument from IEditorInput
	* Angelo Zerr <angelo.zerr@gmail.com> - Bug 525400 - [rename] improve rename support with ltk UI
	*******************************************************************************/
	package org.eclipse.lsp4e;

	import java.io.File;
	import java.lang.reflect.Method;
	import java.net.URI;
	import java.net.URISyntaxException;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.core.filebuffers.FileBuffers;
	import org.eclipse.core.filebuffers.ITextFileBuffer;
	import org.eclipse.core.filebuffers.ITextFileBufferManager;
	import org.eclipse.core.filebuffers.LocationKind;
	import org.eclipse.core.filesystem.EFS;
	import org.eclipse.core.filesystem.IFileInfo;
	import org.eclipse.core.filesystem.IFileStore;
	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IMarker;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.jdt.annotation.Nullable;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.ITextViewer;
	import org.eclipse.jface.text.RewriteSessionEditProcessor;
	import org.eclipse.jface.text.TextSelection;
	import org.eclipse.lsp4j.DiagnosticSeverity;
	import org.eclipse.lsp4j.Location;
	import org.eclipse.lsp4j.Position;
	import org.eclipse.lsp4j.TextDocumentIdentifier;
	import org.eclipse.lsp4j.TextDocumentPositionParams;
	import org.eclipse.lsp4j.TextEdit;
	import org.eclipse.lsp4j.WorkspaceEdit;
	import org.eclipse.ltk.core.refactoring.CompositeChange;
	import org.eclipse.ltk.core.refactoring.DocumentChange;
	import org.eclipse.ltk.core.refactoring.PerformChangeOperation;
	import org.eclipse.text.edits.MalformedTreeException;
	import org.eclipse.text.edits.MultiTextEdit;
	import org.eclipse.text.edits.ReplaceEdit;
	import org.eclipse.text.undo.DocumentUndoManagerRegistry;
	import org.eclipse.text.undo.IDocumentUndoManager;
	import org.eclipse.ui.IEditorInput;
	import org.eclipse.ui.IEditorPart;
	import org.eclipse.ui.IFileEditorInput;
	import org.eclipse.ui.IPathEditorInput;
	import org.eclipse.ui.IURIEditorInput;
	import org.eclipse.ui.IWorkbenchPage;
	import org.eclipse.ui.PartInitException;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.ide.IDE;
	import org.eclipse.ui.part.MultiPageEditorPart;
	import org.eclipse.ui.texteditor.AbstractTextEditor;
	import org.eclipse.ui.texteditor.ITextEditor;

	import com.google.gson.Gson;

	/**
	* Some utility methods to convert between Eclipse and LS-API types
	*/
	public class LSPEclipseUtils {

	private LSPEclipseUtils() {
	// this class shouldn't be instantiated
	}

	public static ITextEditor getActiveTextEditor() {
	IEditorPart editorPart = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage().getActiveEditor();
	if(editorPart instanceof ITextEditor) {
	return (ITextEditor) editorPart;
	} else if (editorPart instanceof MultiPageEditorPart) {
	MultiPageEditorPart multiPageEditorPart = (MultiPageEditorPart) editorPart;
	Object page = multiPageEditorPart.getSelectedPage();
	if (page instanceof ITextEditor) {
	return (ITextEditor) page;
	}
	}
	return null;
	}

	public static Position toPosition(int offset, IDocument document) throws BadLocationException {
	Position res = new Position();
	res.setLine(document.getLineOfOffset(offset));
	res.setCharacter(offset - document.getLineInformationOfOffset(offset).getOffset());
	return res;
	}

	public static int toOffset(Position position, IDocument document) throws BadLocationException {
	return document.getLineInformation(position.getLine()).getOffset() + position.getCharacter();
	}

	public static TextDocumentPositionParams toTextDocumentPosistionParams(URI fileUri, int offset, IDocument document)
	throws BadLocationException {
	Position start = toPosition(offset, document);
	TextDocumentPositionParams param = new TextDocumentPositionParams();
	param.setPosition(start);
	param.setUri(fileUri.toString());
	TextDocumentIdentifier id = new TextDocumentIdentifier();
	id.setUri(fileUri.toString());
	param.setTextDocument(id);
	return param;
	}

	public static int toEclipseMarkerSeverity(DiagnosticSeverity lspSeverity) {
	if (lspSeverity == null) {
	// if severity is empty it is up to the client to interpret diagnostics
	return IMarker.SEVERITY_ERROR;
	}
	switch (lspSeverity) {
	case Error:
	return IMarker.SEVERITY_ERROR;
	case Warning:
	return IMarker.SEVERITY_WARNING;
	default:
	return IMarker.SEVERITY_INFO;
	}
	}


	@Nullable
	public static IResource findResourceFor(@Nullable String uri) {
	if (uri == null \|\| uri.isEmpty()) {
	return null;
	}
	String convertedUri = uri.replace("file:///", "file:/"); //$NON-NLS-1$//$NON-NLS-2$
	convertedUri = convertedUri.replace("file://", "file:/"); //$NON-NLS-1$//$NON-NLS-2$
	IPath path = Path.fromOSString(new File(URI.create(convertedUri)).getAbsolutePath());
	IProject project = null;
	for (IProject aProject : ResourcesPlugin.getWorkspace().getRoot().getProjects()) {
	IPath location = aProject.getLocation();
	if (location != null && location.isPrefixOf(path)
	&& (project == null \|\| project.getLocation().segmentCount() < location.segmentCount())) {
	project = aProject;
	}
	}
	if (project == null) {
	return null;
	}
	IPath projectRelativePath = path.removeFirstSegments(project.getLocation().segmentCount());
	if (projectRelativePath.isEmpty()) {
	return project;
	} else {
	return project.findMember(projectRelativePath);
	}
	}

	public static void applyEdit(TextEdit textEdit, IDocument document) throws BadLocationException {
	document.replace(
	LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document),
	LSPEclipseUtils.toOffset(textEdit.getRange().getEnd(), document) - LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document),
	textEdit.getNewText());
	}

	/**
	* Method will apply all edits to document as single modification. Needs to
	* be executed in UI thread.
	*
	* @param document
	* document to modify
	* @param edits
	* list of LSP TextEdits
	*/
	public static void applyEdits(IDocument document, List<? extends TextEdit> edits) {
	if (document == null \|\| edits.isEmpty()) {
	return;
	}

	IDocumentUndoManager manager = DocumentUndoManagerRegistry.getDocumentUndoManager(document);
	if (manager != null) {
	manager.beginCompoundChange();
	}

	MultiTextEdit edit = new MultiTextEdit();
	for (TextEdit textEdit : edits) {
	if (textEdit != null) {
	try {
	int offset = LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document);
	int length = LSPEclipseUtils.toOffset(textEdit.getRange().getEnd(), document) - offset;
	edit.addChild(new ReplaceEdit(offset, length, textEdit.getNewText()));
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	}
	}
	try {
	RewriteSessionEditProcessor editProcessor = new RewriteSessionEditProcessor(document, edit,
	org.eclipse.text.edits.TextEdit.NONE);
	editProcessor.performEdits();
	} catch (MalformedTreeException \| BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	if (manager != null) {
	manager.endCompoundChange();
	}
	}

	@Nullable
	public static IDocument getDocument(@Nullable IResource resource) {
	if (resource == null) {
	return null;
	}

	ITextFileBufferManager bufferManager = FileBuffers.getTextFileBufferManager();
	IDocument document = null;
	ITextFileBuffer buffer = bufferManager.getTextFileBuffer(resource.getFullPath(), LocationKind.IFILE);
	if (buffer != null) {
	document = buffer.getDocument();
	} else if (resource.getType() == IResource.FILE) {
	try {
	bufferManager.connect(resource.getFullPath(), LocationKind.IFILE, new NullProgressMonitor());
	} catch (CoreException e) {
	LanguageServerPlugin.logError(e);
	return document;
	}
	buffer = bufferManager.getTextFileBuffer(resource.getFullPath(), LocationKind.IFILE);
	if (buffer != null) {
	document = buffer.getDocument();
	}
	}
	return document;
	}

	public static void openInEditor(Location location, IWorkbenchPage page) {
	IEditorPart part = null;
	IDocument targetDocument = null;
	IResource targetResource = LSPEclipseUtils.findResourceFor(location.getUri());
	try {
	if (targetResource != null && targetResource.getType() == IResource.FILE) {
	part = IDE.openEditor(page, (IFile) targetResource);
	targetDocument = FileBuffers.getTextFileBufferManager()
	.getTextFileBuffer(targetResource.getFullPath(), LocationKind.IFILE).getDocument();
	} else {
	URI fileUri = URI.create(location.getUri()).normalize();
	IFileStore fileStore = EFS.getLocalFileSystem().getStore(fileUri);
	IFileInfo fetchInfo = fileStore.fetchInfo();
	if (!fetchInfo.isDirectory() && fetchInfo.exists()) {
	part = IDE.openEditorOnFileStore(page, fileStore);
	ITextFileBuffer fileStoreTextFileBuffer = FileBuffers.getTextFileBufferManager()
	.getFileStoreTextFileBuffer(fileStore);
	targetDocument = fileStoreTextFileBuffer.getDocument();
	}
	}
	} catch (PartInitException e) {
	LanguageServerPlugin.logError(e);
	}
	try {
	if (part instanceof AbstractTextEditor) {
	AbstractTextEditor editor = (AbstractTextEditor) part;
	int offset = LSPEclipseUtils.toOffset(location.getRange().getStart(), targetDocument);
	int endOffset = LSPEclipseUtils.toOffset(location.getRange().getEnd(), targetDocument);
	editor.getSelectionProvider()
	.setSelection(new TextSelection(offset, endOffset > offset ? endOffset - offset : 0));
	}
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	}

	public static IDocument getDocument(ITextEditor editor) {
	try {
	Method getSourceViewerMethod= AbstractTextEditor.class.getDeclaredMethod("getSourceViewer"); //$NON-NLS-1$
	getSourceViewerMethod.setAccessible(true);
	ITextViewer viewer = (ITextViewer) getSourceViewerMethod.invoke(editor);
	return viewer.getDocument();
	} catch (Exception ex) {
	LanguageServerPlugin.logError(ex);
	return null;
	}
	}

	public static IDocument getDocument(IEditorInput editorInput) {
	if(editorInput instanceof IFileEditorInput) {
	IFileEditorInput fileEditorInput = (IFileEditorInput)editorInput;
	return getDocument(fileEditorInput.getFile());
	}else if(editorInput instanceof IPathEditorInput) {
	IPathEditorInput pathEditorInput = (IPathEditorInput)editorInput;
	return getDocument(ResourcesPlugin.getWorkspace().getRoot().getFile(pathEditorInput.getPath()));
	}else if(editorInput instanceof IURIEditorInput) {
	IURIEditorInput uriEditorInput = (IURIEditorInput)editorInput;
	return getDocument(findResourceFor(uriEditorInput.getURI().toString()));
	}
	return null;
	}

	/**
	* Applies a workspace edit. It does simply change the underlying documents.
	*
	* @param wsEdit
	*/
	public static void applyWorkspaceEdit(WorkspaceEdit wsEdit) {
	CompositeChange change = toCompositeChange(wsEdit);
	PerformChangeOperation changeOperation = new PerformChangeOperation(change);
	try {
	ResourcesPlugin.getWorkspace().run(changeOperation, new NullProgressMonitor());
	} catch (CoreException e) {
	LanguageServerPlugin.logError(e);
	}
	}

	/**
	* Returns a ltk {@link CompositeChange} from a lsp {@link WorkspaceEdit}.
	*
	* @param wsEdit
	* @return a ltk {@link CompositeChange} from a lsp {@link WorkspaceEdit}.
	*/
	public static CompositeChange toCompositeChange(WorkspaceEdit wsEdit) {
	CompositeChange change = new CompositeChange("LSP Workspace Edit"); //$NON-NLS-1$
	for (java.util.Map.Entry<String, List<TextEdit>> edit : wsEdit.getChanges().entrySet()) {
	String uri = edit.getKey();
	IDocument document = LSPEclipseUtils.getDocument(LSPEclipseUtils.findResourceFor(uri));
	for (TextEdit textEdit : edit.getValue()) {
	try {
	int offset = LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document);
	int length = LSPEclipseUtils.toOffset(textEdit.getRange().getEnd(), document) - offset;
	DocumentChange documentChange = new DocumentChange("Change in document " + uri, document); //$NON-NLS-1$
	documentChange.initializeValidationData(new NullProgressMonitor());
	documentChange.setEdit(new ReplaceEdit(offset, length, textEdit.getNewText()));
	change.add(documentChange);
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	}
	}
	return change;
	}

	public static URI toUri(IPath absolutePath) {
	return toUri(absolutePath.toFile());
	}

	public static URI toUri(IResource resource) {
	return toUri(resource.getLocation());
	}

	public static URI toUri(File file) {
	// URI scheme specified by language server protocol and LSP
	try {
	return new URI("file", "", file.getAbsoluteFile().toURI().getPath(), null); //$NON-NLS-1$ //$NON-NLS-2$
	} catch (URISyntaxException e) {
	LanguageServerPlugin.logError(e);
	return file.getAbsoluteFile().toURI();
	}
	}

	// TODO consider using Entry/SimpleEntry instead
	private static final class Pair<K, V> {
	K key;
	V value;
	Pair(K key,V value) {
	this.key = key;
	this.value = value;
	}
	}

	/**
	* Very empirical and unsafe heuristic to turn unknown command arguments
	* into a workspace edit...
	*/
	public static WorkspaceEdit createWorkspaceEdit(List<Object> commandArguments, IResource initialResource) {
	WorkspaceEdit res = new WorkspaceEdit();
	Map<String, List<TextEdit>> changes = new HashMap<>();
	res.setChanges(changes);
	Pair<IResource, List<TextEdit>> currentEntry = new Pair<>(initialResource, new ArrayList<>());
	commandArguments.stream().flatMap(item -> {
	if (item instanceof List) {
	return ((List<?>)item).stream();
	} else {
	return Collections.singleton(item).stream();
	}
	}).forEach(arg -> {
	if (arg instanceof String) {
	changes.put(currentEntry.key.getLocationURI().toString(), currentEntry.value);
	IResource resource = LSPEclipseUtils.findResourceFor((String)arg);
	if (resource != null) {
	currentEntry.key = resource;
	currentEntry.value = new ArrayList<>();
	}
	} else if (arg instanceof WorkspaceEdit) {
	changes.putAll(((WorkspaceEdit)arg).getChanges());
	} else if (arg instanceof TextEdit) {
	currentEntry.value.add((TextEdit)arg);
	} else if (arg instanceof Map) {
	Gson gson = new Gson(); // TODO? retrieve the GSon used by LS
	TextEdit edit = gson.fromJson(gson.toJson(arg), TextEdit.class);
	if (edit != null) {
	currentEntry.value.add(edit);
	}
	}
	});
	changes.put(currentEntry.key.getLocationURI().toString(), currentEntry.value);
	return res;
	}

	@Nullable public static IFile getFile(IDocument document) {
	ITextFileBuffer buffer = FileBuffers.getTextFileBufferManager().getTextFileBuffer(document);
	if (buffer == null) {
	return null;
	}
	final IPath location = buffer.getLocation();
	return ResourcesPlugin.getWorkspace().getRoot().getFile(location);
	}
	}