Trying to make jumpies work in lsp4e

This works 'in theory'. Alas, lsp4e doesn't seem to execute
commands from a completion items. So cursor doesn't move.
Also filtering in lsp4e is still bonkers too.

eclipse-language-servers/org.springframework.tooling.ls.eclipse.commons/src/org/springframework/tooling/ls/eclipse/commons/CursorMovement.java

@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2018 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.tooling.ls.eclipse.commons;
+
+import org.eclipse.lsp4j.Position;
+
+public class CursorMovement {
+	private String uri;
+	private Position position;
+
+	public CursorMovement() {
+	}
+
+	public CursorMovement(String uri, Position position) {
+		this.uri = uri;
+		this.position = position;
+	}
+
+	public String getUri() {
+		return uri;
+	}
+
+	public void setUri(String uri) {
+		this.uri = uri;
+	}
+
+	public Position getPosition() {
+		return position;
+	}
+
+	public void setPosition(Position position) {
+		this.position = position;
+	}
+
+}

eclipse-language-servers/org.springframework.tooling.ls.eclipse.commons/src/org/springframework/tooling/ls/eclipse/commons/STS4LanguageClient.java

@@ -30,8 +30,8 @@ public interface STS4LanguageClient extends LanguageClient {
 	@JsonNotification("sts/progress")
 	void progress(ProgressParams progressEvent);
 
-// TODO: @JsonRequest("sts/moveCursor")
-//	CompletableFuture<Object> moveCursor(CursorMovement cursorMovement);
+	@JsonRequest("sts/moveCursor")
+	CompletableFuture<Object> moveCursor(CursorMovement cursorMovement);
 
 	@JsonRequest("sts/addClasspathListener")
 	CompletableFuture<Object> addClasspathListener(ClasspathListenerParams params);

eclipse-language-servers/org.springframework.tooling.ls.eclipse.commons/src/org/springframework/tooling/ls/eclipse/commons/STS4LanguageClientImpl.java

@@ -18,6 +18,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 
+import org.apache.commons.lang3.tuple.Pair;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
@@ -25,10 +26,12 @@ import org.eclipse.jface.action.IStatusLineManager;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.Position;
+import org.eclipse.jface.text.TextSelection;
 import org.eclipse.jface.text.source.Annotation;
 import org.eclipse.jface.text.source.IAnnotationModel;
 import org.eclipse.jface.text.source.IAnnotationModelExtension;
 import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.lsp4e.LSPEclipseUtils;
 import org.eclipse.lsp4e.LanguageClientImpl;
 import org.eclipse.lsp4e.LanguageServiceAccessor;
@@ -224,4 +227,32 @@ public class STS4LanguageClientImpl extends LanguageClientImpl implements STS4La
 		return CompletableFuture.completedFuture(response);
 	}
 
+	@Override
+	public CompletableFuture<Object> moveCursor(CursorMovement cursorMovement) {
+		//WARNING: this code never ran. It is meant to be called by server 'moveCursor' command
+		// when appplying jumpy completions. But lsp4e doesn't execute commands from completions
+		// because they haven't implemented support for that part of the protocol yet.
+		Throwable problem = null;
+		for (Pair<IDocument, AbstractTextEditor> editorAndDoc : StsLspEclipseUtil.getTextEditorsForUri(cursorMovement.getUri())) {
+			try {
+				AbstractTextEditor editor = editorAndDoc.getRight();
+				IDocument doc = editorAndDoc.getLeft();
+				int cursor = LSPEclipseUtils.toOffset(cursorMovement.getPosition(), doc);
+				moveCursor(editor, cursor);
+			} catch (Exception e) {
+				if (problem==null) {
+					problem = e;
+				}
+			}
+		}
+		return problem == null
+				? CompletableFuture.completedFuture("ok")
+				: Futures.fail(problem);
+	}
+
+	private void moveCursor(AbstractTextEditor editor, int cursor) {
+		ISelectionProvider sp = editor.getSelectionProvider();
+		sp.setSelection(new TextSelection(cursor, 0));
+	}
+
 }

eclipse-language-servers/org.springframework.tooling.ls.eclipse.commons/src/org/springframework/tooling/ls/eclipse/commons/StsLspEclipseUtil.java

@@ -0,0 +1,62 @@
+/*******************************************************************************
+ * Copyright (c) 2018 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.tooling.ls.eclipse.commons;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import org.apache.commons.lang3.tuple.Pair;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.lsp4e.LSPEclipseUtils;
+import org.eclipse.lsp4e.LanguageServiceAccessor;
+import org.eclipse.lsp4e.LanguageServiceAccessor.LSPDocumentInfo;
+import org.eclipse.ui.IEditorInput;
+import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.IEditorReference;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.IWorkbenchWindow;
+import org.eclipse.ui.PartInitException;
+import org.eclipse.ui.PlatformUI;
+import org.eclipse.ui.texteditor.AbstractTextEditor;
+
+public class StsLspEclipseUtil {
+
+	public static List<Pair<IDocument, AbstractTextEditor>> getTextEditorsForUri(String uri) {
+		List<Pair<IDocument, AbstractTextEditor>> editors = new ArrayList<>(1); //Typical expectation is just one editor.
+		for (IWorkbenchWindow window : PlatformUI.getWorkbench().getWorkbenchWindows()) {
+			for (IWorkbenchPage page : window.getPages()) {
+				for (IEditorReference editor : page.getEditorReferences()) {
+					try {
+						IEditorInput input = editor.getEditorInput();
+						if (input!=null) {
+							IDocument doc = LSPEclipseUtils.getDocument(input);
+							Collection<LSPDocumentInfo> infos = LanguageServiceAccessor.getLSPDocumentInfosFor(doc, (x) -> true);
+							for (LSPDocumentInfo lspDoc : infos) {
+								if (uri.equals(lspDoc.getFileUri().toString())) {
+									boolean restore = false;
+									IEditorPart editorPart = editor.getEditor(restore );
+									if (editorPart instanceof AbstractTextEditor) {
+										editors.add(Pair.of(doc, (AbstractTextEditor) editorPart));
+									}
+								}
+							}
+						}
+					} catch (PartInitException e) {
+						LanguageServerCommonsActivator.logError(e, e.getMessage());
+					}
+				}
+			}
+		}
+		return editors;
+	}
+
+}