r/org.eclipse.statet.r.debug.ui/src/org/eclipse/statet/internal/r/debug/ui/actions/InspectHandler.java - statet/org.eclipse.statet-r - Git at Google

 /*=============================================================================#
  # Copyright (c) 2016, 2020 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.internal.r.debug.ui.actions;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.debug.core.DebugPlugin;
 import org.eclipse.debug.core.model.IErrorReportingExpression;
 import org.eclipse.debug.core.model.IExpression;
 import org.eclipse.debug.ui.DebugPopup;
 import org.eclipse.debug.ui.IDebugUIConstants;
 import org.eclipse.debug.ui.InspectPopupDialog;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.ITextSelection;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.source.SourceViewer;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.ITreeSelection;
 import org.eclipse.jface.viewers.StructuredViewer;
 import org.eclipse.jface.viewers.TreePath;
 import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IWorkbenchPart;

 import org.eclipse.statet.jcommons.lang.NonNull;
 import org.eclipse.statet.jcommons.lang.NonNullByDefault;
 import org.eclipse.statet.jcommons.lang.Nullable;

 import org.eclipse.statet.ecommons.debug.core.eval.IEvaluationListener;
 import org.eclipse.statet.ecommons.debug.core.eval.IEvaluationResult;
 import org.eclipse.statet.ecommons.debug.ui.ECommonsDebugUI;
 import org.eclipse.statet.ecommons.ui.components.StatusInfo;
 import org.eclipse.statet.ecommons.ui.util.UIAccess;
 import org.eclipse.statet.ecommons.ui.workbench.WorkbenchUIUtils;

 import org.eclipse.statet.internal.r.debug.ui.Messages;
 import org.eclipse.statet.internal.r.debug.ui.RDebugUIPlugin;
 import org.eclipse.statet.ltk.ui.sourceediting.ISourceEditor;
 import org.eclipse.statet.ltk.ui.util.LTKWorkbenchUIUtil;
 import org.eclipse.statet.r.core.data.CombinedRElement;
 import org.eclipse.statet.r.core.model.RElementName;
 import org.eclipse.statet.r.debug.core.IRElementVariable;
 import org.eclipse.statet.r.debug.core.IREvaluationResult;
 import org.eclipse.statet.r.debug.core.IRStackFrame;
 import org.eclipse.statet.r.debug.core.IRVariable;
 import org.eclipse.statet.r.debug.core.RDebugModel;
 import org.eclipse.statet.r.ui.editors.IRSourceEditor;


 @NonNullByDefault
 public class InspectHandler extends AbstractDebugHandler {


 	private static class RInspectPopupDialog extends InspectPopupDialog {


 		private final Viewer viewer;
 		private final ISelection savedSelection;


 		public RInspectPopupDialog(final Shell shell, final Point anchor, final String commandId,
 				final IExpression expression,
 				final Viewer viewer, final ISelection savedSelection) {
 			super(shell, anchor, commandId, expression);

 			this.viewer= viewer;
 			this.savedSelection= savedSelection;
 		}


 		@Override
 		protected Control createDialogArea(final Composite parent) {
 			final Control control= super.createDialogArea(parent);
 //			ViewerColumn viewerColumn= (ViewerColumn) control.getData("org.eclipse.jface.columnViewer");
 //			TreeModelViewer viewer= (TreeModelViewer) viewerColumn.getViewer();
 			return control;
 		}

 		@Override
 		public boolean close() {
 			final boolean closed= super.close();
 			if (UIAccess.isOkToUse(this.viewer) && this.savedSelection != null
 					&& !this.savedSelection.equals(this.viewer.getSelection()) ) {
 				this.viewer.setSelection(this.savedSelection);
 			}
 			return closed;
 		}

 	}


 	private class ResultHandler implements IEvaluationListener, Runnable {


 		protected final IWorkbenchPart workbenchPart;

 		protected final Display display;

 		protected @Nullable IErrorReportingExpression expression;


 		public ResultHandler(final IWorkbenchPart part) {
 			this.workbenchPart= part;
 			this.display= part.getSite().getShell().getDisplay();
 		}

 		protected void dispose() {
 			if (this.expression != null) {
 				this.expression.dispose();
 				this.expression= null;
 			}
 		}

 		@Override
 		public void evaluationFinished(@NonNull final IEvaluationResult result) {
 			if ((result.getValue() != null || result.getMessages() != null)
 					&& RDebugUIPlugin.getInstance() != null && !this.display.isDisposed() ) {
 				this.expression= RDebugModel.createExpression((@NonNull IREvaluationResult) result);
 				this.display.asyncExec(this);
 			}
 			else {
 				result.free();
 				dispose();
 			}
 		}

 		protected @Nullable Shell getShell() {
 			return this.workbenchPart.getSite().getShell();
 		}

 		@Override
 		public void run() {
 			DebugPlugin.getDefault().getExpressionManager().addExpression(this.expression);
 			showView(this.workbenchPart, IDebugUIConstants.ID_EXPRESSION_VIEW);
 		}

 	}

 	private class VariablePopupResultHandler extends ResultHandler {


 		private final IStructuredSelection selection;


 		public VariablePopupResultHandler(final IWorkbenchPart part, final IStructuredSelection selection) {
 			super(part);

 			this.selection= selection;
 		}


 		@Override
 		public void run() {
 			try {
 				final Shell shell= getShell();
 				if (UIAccess.isOkToUse(shell)
 						&& this.workbenchPart.getSite().getPage().isPartVisible(this.workbenchPart)) {
 					final StructuredViewer viewer= getStructuredViewer(this.workbenchPart);
 					final ISelection savedSelection= (viewer != null) ? viewer.getSelection() : null;
 					final Point anchor= (viewer != null) ?
 							preparePopup(viewer, this.selection) :
 							preparePopup(this.workbenchPart);

 					final DebugPopup popup= new RInspectPopupDialog(shell, anchor,
 							getCommandId(), this.expression,
 							viewer, savedSelection );
 					popup.open();
 					this.expression= null;
 				}
 			}
 			finally {
 				dispose();
 			}
 		}

 	}

 	private class SourceEditorPopupResultHandler extends ResultHandler {


 		private final ISourceEditor editor;

 		private final IDocument document;
 		private final @Nullable Position position;


 		public SourceEditorPopupResultHandler(final ISourceEditor editor) {
 			super(editor.getWorkbenchPart());
 			this.editor= editor;

 			this.document= editor.getViewer().getDocument();
 			this.position= markExpressionPosition(this.document);
 		}


 		@Override
 		protected void dispose() {
 			super.dispose();
 			disposePosition(this.document, this.position);
 		}

 		@Override
 		public void run() {
 			try {
 				final Shell shell= getShell();
 				final SourceViewer viewer= this.editor.getViewer();
 				if (UIAccess.isOkToUse(shell)
 						&& this.workbenchPart.getSite().getPage().isPartVisible(this.workbenchPart)
 						&& UIAccess.isOkToUse(viewer) && viewer.getDocument() == this.document) {
 					final ISelection savedSelection= viewer.getSelection();
 					final Point anchor= preparePopup(viewer, this.position);
 					final DebugPopup popup= new RInspectPopupDialog(getShell(), anchor,
 							getCommandId(), this.expression,
 							viewer, savedSelection );
 					popup.open();
 					this.expression= null;
 				}
 			}
 			finally {
 				dispose();
 			}
 		}

 	}


 	public InspectHandler() {
 	}


 	private boolean isExpressionElementVariable(final TreePath treePath) {
 		final Object firstSegment= treePath.getFirstSegment();
 		if (!(firstSegment instanceof IExpression)
 				|| ((IExpression) firstSegment).getExpressionText().isEmpty() ) {
 			return false;
 		}
 		for (int i= 1; i < treePath.getSegmentCount(); i++) {
 			final Object segment= treePath.getSegment(i);
 			if (!(segment instanceof IRVariable)) {
 				return false;
 			}
 		}
 		return true;
 	}

 	private @Nullable String getExpressionElementVariableExpression(final TreePath treePath) {
 		final Object firstSegment= treePath.getFirstSegment();
 		final String expressionText;
 		if (!(firstSegment instanceof IExpression)
 				|| (expressionText= ((IExpression) firstSegment).getExpressionText()).isEmpty() ) {
 			return null;
 		}
 		final List<RElementName> segments= new ArrayList<>();
 		segments.add(RElementName.create(RElementName.MAIN_DEFAULT, "expr")); //$NON-NLS-1$
 		for (int i= 1; i < treePath.getSegmentCount(); i++) {
 			final Object segment= treePath.getSegment(i);
 			if (!(segment instanceof IRVariable)) {
 				return null;
 			}
 			if (segment instanceof IRElementVariable) {
 				final CombinedRElement element= ((IRElementVariable) segment).getElement();
 				segments.add(element.getElementName());
 			}
 		}
 		if (segments.size() == 1) {
 			return null;
 		}
 		final String subName= RElementName.create(segments).getDisplayName(RElementName.DISPLAY_EXACT);
 		if (subName == null) {
 			return null;
 		}
 		return expressionText + subName.substring(4);
 	}

 	@Override
 	public void setEnabled(final Object evaluationContext) {
 		final IWorkbenchPart part= WorkbenchUIUtils.getActivePart(evaluationContext);
 		final ISelection selection= WorkbenchUIUtils.getCurrentSelection(evaluationContext);
 		if (part != null && selection != null
 				&& getContextElement(null, part) != null) {
 			if (selection instanceof IStructuredSelection) {
 				final IStructuredSelection structSelection= (IStructuredSelection) selection;
 				if (structSelection.size() != 1) {
 					setBaseEnabled(false);
 					return;
 				}
 				final Object obj= structSelection.getFirstElement();
 				if (obj instanceof IExpression) {
 					setBaseEnabled(!((IExpression) obj).getExpressionText().isEmpty());
 					return;
 				}
 				if (obj instanceof IRElementVariable) {
 					if (((IRElementVariable) obj).getFQElementName() != null) {
 						setBaseEnabled(true);
 					}
 					else if (selection instanceof ITreeSelection
 							&& isExpressionElementVariable(((ITreeSelection) selection).getPaths()[0])) {
 						setBaseEnabled(true);
 					}
 					else {
 						setBaseEnabled(false);
 					}
 					return;
 				}
 				else {
 					setBaseEnabled(false);
 					return;
 				}
 			}
 			else if (selection instanceof ITextSelection && part instanceof IRSourceEditor) {
 //				final ISourceEditor sourceEditor= (ISourceEditor) part;
 //				final ITextSelection textSelection= (ITextSelection) selection;
 				setBaseEnabled(true);
 				return;
 			}
 		}
 		setBaseEnabled(false);
 	}


 	@Override
 	public @Nullable Object execute(final ExecutionEvent event) throws ExecutionException {
 		final IWorkbenchPart part= WorkbenchUIUtils.getActivePart(event.getApplicationContext());
 		final ISelection selection= WorkbenchUIUtils.getCurrentSelection(event.getApplicationContext());
 		if (part != null && selection != null) {
 			if (selection instanceof IStructuredSelection) {
 				final IStructuredSelection structSelection= (IStructuredSelection) selection;
 				final Object obj= structSelection.getFirstElement();
 				String expression= null;
 				if (obj instanceof IExpression) {
 					expression= ((IExpression) obj).getExpressionText();
 				}
 				if (obj instanceof IRElementVariable) {
 					expression= getExpressionText((@NonNull IRElementVariable) obj);
 					if (expression == null && selection instanceof ITreeSelection) {
 						expression= getExpressionElementVariableExpression(((ITreeSelection) selection).getPaths()[0]);
 					}
 				}
 				if (expression != null) {
 					final IRStackFrame stackFrame= getContextStackFrame(part);
 					if (stackFrame == null) {
 						LTKWorkbenchUIUtil.indicateStatus(
 								new StatusInfo(IStatus.ERROR, Messages.Expression_Context_Missing_message),
 								event );
 						return null;
 					}
 					final String commandExpression= toCommandExpression(expression);
 					final ResultHandler resultHandler= (commandExpression != expression) ?
 							new VariablePopupResultHandler(part, structSelection) :
 							new ResultHandler(part);
 					stackFrame.getThread().evaluate(commandExpression, stackFrame, false,
 							resultHandler );
 				}
 			}
 			else if (selection instanceof ITextSelection && part instanceof IRSourceEditor) {
 				final ISourceEditor sourceEditor= (ISourceEditor) part;
 				final ITextSelection textSelection= (ITextSelection) selection;
 				final String expression= getExpressionText(textSelection, sourceEditor);
 				if (expression != null
 						&& sourceEditor.getWorkbenchPart() != null) {
 					final IRStackFrame stackFrame= getContextStackFrame(part);
 					if (stackFrame == null) {
 						LTKWorkbenchUIUtil.indicateStatus(
 								new StatusInfo(IStatus.ERROR, Messages.Expression_Context_Missing_message),
 								event );
 						return null;
 					}
 					final String commandExpression= toCommandExpression(expression);
 					final ResultHandler resultHandler= new SourceEditorPopupResultHandler(
 							sourceEditor );
 					stackFrame.getThread().evaluate(commandExpression, stackFrame, false,
 							resultHandler );
 				}
 			}
 		}

 		return null;
 	}


 	protected String getCommandId() {
 		return ECommonsDebugUI.INSPECT_COMMAND_ID;
 	}

 	protected String toCommandExpression(final String expression) {
 		return expression;
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2016, 2020 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.internal.r.debug.ui.actions;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.core.commands.ExecutionEvent;
	import org.eclipse.core.commands.ExecutionException;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.debug.core.DebugPlugin;
	import org.eclipse.debug.core.model.IErrorReportingExpression;
	import org.eclipse.debug.core.model.IExpression;
	import org.eclipse.debug.ui.DebugPopup;
	import org.eclipse.debug.ui.IDebugUIConstants;
	import org.eclipse.debug.ui.InspectPopupDialog;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.ITextSelection;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.source.SourceViewer;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.ITreeSelection;
	import org.eclipse.jface.viewers.StructuredViewer;
	import org.eclipse.jface.viewers.TreePath;
	import org.eclipse.jface.viewers.Viewer;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.ui.IWorkbenchPart;

	import org.eclipse.statet.jcommons.lang.NonNull;
	import org.eclipse.statet.jcommons.lang.NonNullByDefault;
	import org.eclipse.statet.jcommons.lang.Nullable;

	import org.eclipse.statet.ecommons.debug.core.eval.IEvaluationListener;
	import org.eclipse.statet.ecommons.debug.core.eval.IEvaluationResult;
	import org.eclipse.statet.ecommons.debug.ui.ECommonsDebugUI;
	import org.eclipse.statet.ecommons.ui.components.StatusInfo;
	import org.eclipse.statet.ecommons.ui.util.UIAccess;
	import org.eclipse.statet.ecommons.ui.workbench.WorkbenchUIUtils;

	import org.eclipse.statet.internal.r.debug.ui.Messages;
	import org.eclipse.statet.internal.r.debug.ui.RDebugUIPlugin;
	import org.eclipse.statet.ltk.ui.sourceediting.ISourceEditor;
	import org.eclipse.statet.ltk.ui.util.LTKWorkbenchUIUtil;
	import org.eclipse.statet.r.core.data.CombinedRElement;
	import org.eclipse.statet.r.core.model.RElementName;
	import org.eclipse.statet.r.debug.core.IRElementVariable;
	import org.eclipse.statet.r.debug.core.IREvaluationResult;
	import org.eclipse.statet.r.debug.core.IRStackFrame;
	import org.eclipse.statet.r.debug.core.IRVariable;
	import org.eclipse.statet.r.debug.core.RDebugModel;
	import org.eclipse.statet.r.ui.editors.IRSourceEditor;


	@NonNullByDefault
	public class InspectHandler extends AbstractDebugHandler {


	private static class RInspectPopupDialog extends InspectPopupDialog {


	private final Viewer viewer;
	private final ISelection savedSelection;


	public RInspectPopupDialog(final Shell shell, final Point anchor, final String commandId,
	final IExpression expression,
	final Viewer viewer, final ISelection savedSelection) {
	super(shell, anchor, commandId, expression);

	this.viewer= viewer;
	this.savedSelection= savedSelection;
	}


	@Override
	protected Control createDialogArea(final Composite parent) {
	final Control control= super.createDialogArea(parent);
	// ViewerColumn viewerColumn= (ViewerColumn) control.getData("org.eclipse.jface.columnViewer");
	// TreeModelViewer viewer= (TreeModelViewer) viewerColumn.getViewer();
	return control;
	}

	@Override
	public boolean close() {
	final boolean closed= super.close();
	if (UIAccess.isOkToUse(this.viewer) && this.savedSelection != null
	&& !this.savedSelection.equals(this.viewer.getSelection()) ) {
	this.viewer.setSelection(this.savedSelection);
	}
	return closed;
	}

	}


	private class ResultHandler implements IEvaluationListener, Runnable {


	protected final IWorkbenchPart workbenchPart;

	protected final Display display;

	protected @Nullable IErrorReportingExpression expression;


	public ResultHandler(final IWorkbenchPart part) {
	this.workbenchPart= part;
	this.display= part.getSite().getShell().getDisplay();
	}

	protected void dispose() {
	if (this.expression != null) {
	this.expression.dispose();
	this.expression= null;
	}
	}

	@Override
	public void evaluationFinished(@NonNull final IEvaluationResult result) {
	if ((result.getValue() != null \|\| result.getMessages() != null)
	&& RDebugUIPlugin.getInstance() != null && !this.display.isDisposed() ) {
	this.expression= RDebugModel.createExpression((@NonNull IREvaluationResult) result);
	this.display.asyncExec(this);
	}
	else {
	result.free();
	dispose();
	}
	}

	protected @Nullable Shell getShell() {
	return this.workbenchPart.getSite().getShell();
	}

	@Override
	public void run() {
	DebugPlugin.getDefault().getExpressionManager().addExpression(this.expression);
	showView(this.workbenchPart, IDebugUIConstants.ID_EXPRESSION_VIEW);
	}

	}

	private class VariablePopupResultHandler extends ResultHandler {


	private final IStructuredSelection selection;


	public VariablePopupResultHandler(final IWorkbenchPart part, final IStructuredSelection selection) {
	super(part);

	this.selection= selection;
	}


	@Override
	public void run() {
	try {
	final Shell shell= getShell();
	if (UIAccess.isOkToUse(shell)
	&& this.workbenchPart.getSite().getPage().isPartVisible(this.workbenchPart)) {
	final StructuredViewer viewer= getStructuredViewer(this.workbenchPart);
	final ISelection savedSelection= (viewer != null) ? viewer.getSelection() : null;
	final Point anchor= (viewer != null) ?
	preparePopup(viewer, this.selection) :
	preparePopup(this.workbenchPart);

	final DebugPopup popup= new RInspectPopupDialog(shell, anchor,
	getCommandId(), this.expression,
	viewer, savedSelection );
	popup.open();
	this.expression= null;
	}
	}
	finally {
	dispose();
	}
	}

	}

	private class SourceEditorPopupResultHandler extends ResultHandler {


	private final ISourceEditor editor;

	private final IDocument document;
	private final @Nullable Position position;


	public SourceEditorPopupResultHandler(final ISourceEditor editor) {
	super(editor.getWorkbenchPart());
	this.editor= editor;

	this.document= editor.getViewer().getDocument();
	this.position= markExpressionPosition(this.document);
	}


	@Override
	protected void dispose() {
	super.dispose();
	disposePosition(this.document, this.position);
	}

	@Override
	public void run() {
	try {
	final Shell shell= getShell();
	final SourceViewer viewer= this.editor.getViewer();
	if (UIAccess.isOkToUse(shell)
	&& this.workbenchPart.getSite().getPage().isPartVisible(this.workbenchPart)
	&& UIAccess.isOkToUse(viewer) && viewer.getDocument() == this.document) {
	final ISelection savedSelection= viewer.getSelection();
	final Point anchor= preparePopup(viewer, this.position);
	final DebugPopup popup= new RInspectPopupDialog(getShell(), anchor,
	getCommandId(), this.expression,
	viewer, savedSelection );
	popup.open();
	this.expression= null;
	}
	}
	finally {
	dispose();
	}
	}

	}


	public InspectHandler() {
	}


	private boolean isExpressionElementVariable(final TreePath treePath) {
	final Object firstSegment= treePath.getFirstSegment();
	if (!(firstSegment instanceof IExpression)
	\|\| ((IExpression) firstSegment).getExpressionText().isEmpty() ) {
	return false;
	}
	for (int i= 1; i < treePath.getSegmentCount(); i++) {
	final Object segment= treePath.getSegment(i);
	if (!(segment instanceof IRVariable)) {
	return false;
	}
	}
	return true;
	}

	private @Nullable String getExpressionElementVariableExpression(final TreePath treePath) {
	final Object firstSegment= treePath.getFirstSegment();
	final String expressionText;
	if (!(firstSegment instanceof IExpression)
	\|\| (expressionText= ((IExpression) firstSegment).getExpressionText()).isEmpty() ) {
	return null;
	}
	final List<RElementName> segments= new ArrayList<>();
	segments.add(RElementName.create(RElementName.MAIN_DEFAULT, "expr")); //$NON-NLS-1$
	for (int i= 1; i < treePath.getSegmentCount(); i++) {
	final Object segment= treePath.getSegment(i);
	if (!(segment instanceof IRVariable)) {
	return null;
	}
	if (segment instanceof IRElementVariable) {
	final CombinedRElement element= ((IRElementVariable) segment).getElement();
	segments.add(element.getElementName());
	}
	}
	if (segments.size() == 1) {
	return null;
	}
	final String subName= RElementName.create(segments).getDisplayName(RElementName.DISPLAY_EXACT);
	if (subName == null) {
	return null;
	}
	return expressionText + subName.substring(4);
	}

	@Override
	public void setEnabled(final Object evaluationContext) {
	final IWorkbenchPart part= WorkbenchUIUtils.getActivePart(evaluationContext);
	final ISelection selection= WorkbenchUIUtils.getCurrentSelection(evaluationContext);
	if (part != null && selection != null
	&& getContextElement(null, part) != null) {
	if (selection instanceof IStructuredSelection) {
	final IStructuredSelection structSelection= (IStructuredSelection) selection;
	if (structSelection.size() != 1) {
	setBaseEnabled(false);
	return;
	}
	final Object obj= structSelection.getFirstElement();
	if (obj instanceof IExpression) {
	setBaseEnabled(!((IExpression) obj).getExpressionText().isEmpty());
	return;
	}
	if (obj instanceof IRElementVariable) {
	if (((IRElementVariable) obj).getFQElementName() != null) {
	setBaseEnabled(true);
	}
	else if (selection instanceof ITreeSelection
	&& isExpressionElementVariable(((ITreeSelection) selection).getPaths()[0])) {
	setBaseEnabled(true);
	}
	else {
	setBaseEnabled(false);
	}
	return;
	}
	else {
	setBaseEnabled(false);
	return;
	}
	}
	else if (selection instanceof ITextSelection && part instanceof IRSourceEditor) {
	// final ISourceEditor sourceEditor= (ISourceEditor) part;
	// final ITextSelection textSelection= (ITextSelection) selection;
	setBaseEnabled(true);
	return;
	}
	}
	setBaseEnabled(false);
	}


	@Override
	public @Nullable Object execute(final ExecutionEvent event) throws ExecutionException {
	final IWorkbenchPart part= WorkbenchUIUtils.getActivePart(event.getApplicationContext());
	final ISelection selection= WorkbenchUIUtils.getCurrentSelection(event.getApplicationContext());
	if (part != null && selection != null) {
	if (selection instanceof IStructuredSelection) {
	final IStructuredSelection structSelection= (IStructuredSelection) selection;
	final Object obj= structSelection.getFirstElement();
	String expression= null;
	if (obj instanceof IExpression) {
	expression= ((IExpression) obj).getExpressionText();
	}
	if (obj instanceof IRElementVariable) {
	expression= getExpressionText((@NonNull IRElementVariable) obj);
	if (expression == null && selection instanceof ITreeSelection) {
	expression= getExpressionElementVariableExpression(((ITreeSelection) selection).getPaths()[0]);
	}
	}
	if (expression != null) {
	final IRStackFrame stackFrame= getContextStackFrame(part);
	if (stackFrame == null) {
	LTKWorkbenchUIUtil.indicateStatus(
	new StatusInfo(IStatus.ERROR, Messages.Expression_Context_Missing_message),
	event );
	return null;
	}
	final String commandExpression= toCommandExpression(expression);
	final ResultHandler resultHandler= (commandExpression != expression) ?
	new VariablePopupResultHandler(part, structSelection) :
	new ResultHandler(part);
	stackFrame.getThread().evaluate(commandExpression, stackFrame, false,
	resultHandler );
	}
	}
	else if (selection instanceof ITextSelection && part instanceof IRSourceEditor) {
	final ISourceEditor sourceEditor= (ISourceEditor) part;
	final ITextSelection textSelection= (ITextSelection) selection;
	final String expression= getExpressionText(textSelection, sourceEditor);
	if (expression != null
	&& sourceEditor.getWorkbenchPart() != null) {
	final IRStackFrame stackFrame= getContextStackFrame(part);
	if (stackFrame == null) {
	LTKWorkbenchUIUtil.indicateStatus(
	new StatusInfo(IStatus.ERROR, Messages.Expression_Context_Missing_message),
	event );
	return null;
	}
	final String commandExpression= toCommandExpression(expression);
	final ResultHandler resultHandler= new SourceEditorPopupResultHandler(
	sourceEditor );
	stackFrame.getThread().evaluate(commandExpression, stackFrame, false,
	resultHandler );
	}
	}
	}

	return null;
	}


	protected String getCommandId() {
	return ECommonsDebugUI.INSPECT_COMMAND_ID;
	}

	protected String toCommandExpression(final String expression) {
	return expression;
	}

	}