org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/template/contentassist/TemplateEngine.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * 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
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Nicolaj Hoess <nicohoess@gmail.com> - Make some internal methods accessible to help Postfix Code Completion plug-in - https://bugs.eclipse.org/433500
  *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 486899, 486903
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.text.template.contentassist;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;

 import org.eclipse.core.runtime.Assert;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.Region;
 import org.eclipse.jface.text.templates.GlobalTemplateVariables;
 import org.eclipse.jface.text.templates.Template;
 import org.eclipse.jface.text.templates.TemplateContextType;

 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaProject;

 import org.eclipse.jdt.internal.corext.template.java.CompilationUnitContext;
 import org.eclipse.jdt.internal.corext.template.java.CompilationUnitContextType;
 import org.eclipse.jdt.internal.corext.template.java.SWTContextType;
 import org.eclipse.jdt.internal.corext.util.JavaModelUtil;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.JavaPluginImages;


 public class TemplateEngine {

 	private static final Pattern $_LINE_SELECTION_PATTERN= Pattern.compile("\\$\\{(.*:)?" + GlobalTemplateVariables.LineSelection.NAME + "(\\(.*\\))?\\}"); //$NON-NLS-1$ //$NON-NLS-2$

 	private static final Pattern $_WORD_SELECTION_PATTERN= Pattern.compile("\\$\\{(.*:)?" + GlobalTemplateVariables.WordSelection.NAME + "(\\(.*\\))?\\}"); //$NON-NLS-1$ //$NON-NLS-2$

 	private static String Switch_Name = "switch"; //$NON-NLS-1$
 	private static String Switch_Default = "switch case statement"; //$NON-NLS-1$

 	/** The context type. */
 	private TemplateContextType fContextType;
 	/** The result proposals. */
 	private ArrayList<TemplateProposal> fProposals= new ArrayList<>();
 	/** Positions created on the key documents to remove in reset. */
 	private final Map<IDocument, Position> fPositions= new HashMap<>();

 	/**
 	 * Creates the template engine for the given <code>contextType</code>.
 	 * <p>
 	 * The <code>JavaPlugin.getDefault().getTemplateContextRegistry()</code>
 	 * defines the supported context types.</p>
 	 *
 	 * @param contextType the context type
 	 */
 	public TemplateEngine(TemplateContextType contextType) {
 		Assert.isNotNull(contextType);
 		fContextType= contextType;
 	}

 	/**
 	 * Empties the collector.
 	 */
 	public void reset() {
 		fProposals.clear();
 		for (Entry<IDocument, Position> entry : fPositions.entrySet()) {
 			IDocument doc= entry.getKey();
 			Position position= entry.getValue();
 			doc.removePosition(position);
 		}
 		fPositions.clear();
 	}

 	/**
 	 * Returns the array of matching templates.
 	 *
 	 * @return the template proposals
 	 */
 	public TemplateProposal[] getResults() {
 		return fProposals.toArray(new TemplateProposal[fProposals.size()]);
 	}

 	/**
 	 * Inspects the context of the compilation unit around <code>completionPosition</code>
 	 * and feeds the collector with proposals.
 	 * @param viewer the text viewer
 	 * @param completionPosition the context position in the document of the text viewer
 	 * @param compilationUnit the compilation unit (may be <code>null</code>)
 	 */
 	public void complete(ITextViewer viewer, int completionPosition, ICompilationUnit compilationUnit) {
 	    IDocument document= viewer.getDocument();

 		if (!(fContextType instanceof CompilationUnitContextType))
 			return;

 		Point selection= viewer.getSelectedRange();
 		Position position= new Position(completionPosition, selection.y);

 		// remember selected text
 		String selectedText= null;
 		if (selection.y != 0) {
 			try {
 				selectedText= document.get(selection.x, selection.y);
 				document.addPosition(position);
 				fPositions.put(document, position);
 			} catch (BadLocationException e) {}
 		}

 		CompilationUnitContext context= (CompilationUnitContext) ((CompilationUnitContextType) fContextType).createContext(document, position, compilationUnit);
 		context.setVariable("selection", selectedText); //$NON-NLS-1$
 		int start= context.getStart();
 		int end= context.getEnd();
 		IRegion region= new Region(start, end - start);

 		Template[] templates= JavaPlugin.getDefault().getTemplateStore().getTemplates();
 		boolean needsCheck= !isJava12OrHigherProject(compilationUnit);
 		if (selection.y == 0) {
 			for (int i= 0; i != templates.length; i++) {
 				Template template= templates[i];
 				if (canEvaluate(context, template, needsCheck)) {
 					fProposals.add(new TemplateProposal(template, context, region, getImage()));
 				}
 			}
 		} else {

 			if (context.getKey().length() == 0)
 				context.setForceEvaluation(true);

 			boolean multipleLinesSelected= areMultipleLinesSelected(viewer);

 			for (int i= 0; i != templates.length; i++) {
 				Template template= templates[i];
 				if (canEvaluate(context, template, needsCheck))
 				{
 					Matcher wordSelectionMatcher= $_WORD_SELECTION_PATTERN.matcher(template.getPattern());
 					Matcher lineSelectionMatcher= $_LINE_SELECTION_PATTERN.matcher(template.getPattern());
 					if ((!multipleLinesSelected && wordSelectionMatcher.find()) || (multipleLinesSelected && lineSelectionMatcher.find())) {
 						fProposals.add(new TemplateProposal(templates[i], context, region, getImage()));
 					}
 				}
 			}
 		}
 	}

 	protected TemplateContextType getContextType() {
 		return fContextType;
 	}

 	protected ArrayList<TemplateProposal> getProposals() {
 		return fProposals;
 	}

 	protected Image getImage() {
 		if (fContextType instanceof SWTContextType)
 			return JavaPluginImages.get(JavaPluginImages.IMG_OBJS_SWT_TEMPLATE);
 		else
 			return JavaPluginImages.get(JavaPluginImages.IMG_OBJS_TEMPLATE);
 	}

 	private boolean isJava12OrHigherProject(ICompilationUnit compUnit) {
 		if (compUnit != null) {
 			IJavaProject javaProject= compUnit.getJavaProject();
 			return JavaModelUtil.is12OrHigher(javaProject);
 		}
 		return false;
 	}

 	private boolean isTemplateAllowed(Template template) {
 		if (Switch_Name.equals(template.getName())) {
 			if (Switch_Default.equals(template.getDescription())) {
 				return true;
 			}
 			return false;
 		}
 		return true;
 	}

 	private boolean canEvaluate(CompilationUnitContext context, Template template, boolean needsCheck) {
 		if (!needsCheck) {
 			return context.canEvaluate(template);
 		}
 		if (isTemplateAllowed(template)) {
 			return context.canEvaluate(template);
 		}
 		return false;
 	}

 	/**
 	 * Returns <code>true</code> if one line is completely selected or if multiple lines are selected.
 	 * Being completely selected means that all characters except the new line characters are
 	 * selected.
 	 *
 	 * @param viewer the text viewer
 	 * @return <code>true</code> if one or multiple lines are selected
 	 * @since 2.1
 	 */
 	private boolean areMultipleLinesSelected(ITextViewer viewer) {
 		if (viewer == null)
 			return false;

 		Point s= viewer.getSelectedRange();
 		if (s.y == 0)
 			return false;

 		try {

 			IDocument document= viewer.getDocument();
 			int startLine= document.getLineOfOffset(s.x);
 			int endLine= document.getLineOfOffset(s.x + s.y);
 			IRegion line= document.getLineInformation(startLine);
 			return startLine != endLine || (s.x == line.getOffset() && s.y == line.getLength());

 		} catch (BadLocationException x) {
 			return false;
 		}
 	}
 }
	/*******************************************************************************
	* 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
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Nicolaj Hoess <nicohoess@gmail.com> - Make some internal methods accessible to help Postfix Code Completion plug-in - https://bugs.eclipse.org/433500
	* Lars Vogel <Lars.Vogel@vogella.com> - Bug 486899, 486903
	*******************************************************************************/
	package org.eclipse.jdt.internal.ui.text.template.contentassist;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Map.Entry;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;

	import org.eclipse.core.runtime.Assert;

	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.ITextViewer;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.Region;
	import org.eclipse.jface.text.templates.GlobalTemplateVariables;
	import org.eclipse.jface.text.templates.Template;
	import org.eclipse.jface.text.templates.TemplateContextType;

	import org.eclipse.jdt.core.ICompilationUnit;
	import org.eclipse.jdt.core.IJavaProject;

	import org.eclipse.jdt.internal.corext.template.java.CompilationUnitContext;
	import org.eclipse.jdt.internal.corext.template.java.CompilationUnitContextType;
	import org.eclipse.jdt.internal.corext.template.java.SWTContextType;
	import org.eclipse.jdt.internal.corext.util.JavaModelUtil;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.JavaPluginImages;


	public class TemplateEngine {

	private static final Pattern $_LINE_SELECTION_PATTERN= Pattern.compile("\\$\\{(.:)?" + GlobalTemplateVariables.LineSelection.NAME + "(\\(.\\))?\\}"); //$NON-NLS-1$ //$NON-NLS-2$

	private static final Pattern $_WORD_SELECTION_PATTERN= Pattern.compile("\\$\\{(.:)?" + GlobalTemplateVariables.WordSelection.NAME + "(\\(.\\))?\\}"); //$NON-NLS-1$ //$NON-NLS-2$

	private static String Switch_Name = "switch"; //$NON-NLS-1$
	private static String Switch_Default = "switch case statement"; //$NON-NLS-1$

	/** The context type. */
	private TemplateContextType fContextType;
	/** The result proposals. */
	private ArrayList<TemplateProposal> fProposals= new ArrayList<>();
	/** Positions created on the key documents to remove in reset. */
	private final Map<IDocument, Position> fPositions= new HashMap<>();

	/**
	* Creates the template engine for the given <code>contextType</code>.
	* <p>
	* The <code>JavaPlugin.getDefault().getTemplateContextRegistry()</code>
	* defines the supported context types.</p>
	*
	* @param contextType the context type
	*/
	public TemplateEngine(TemplateContextType contextType) {
	Assert.isNotNull(contextType);
	fContextType= contextType;
	}

	/**
	* Empties the collector.
	*/
	public void reset() {
	fProposals.clear();
	for (Entry<IDocument, Position> entry : fPositions.entrySet()) {
	IDocument doc= entry.getKey();
	Position position= entry.getValue();
	doc.removePosition(position);
	}
	fPositions.clear();
	}

	/**
	* Returns the array of matching templates.
	*
	* @return the template proposals
	*/
	public TemplateProposal[] getResults() {
	return fProposals.toArray(new TemplateProposal[fProposals.size()]);
	}

	/**
	* Inspects the context of the compilation unit around <code>completionPosition</code>
	* and feeds the collector with proposals.
	* @param viewer the text viewer
	* @param completionPosition the context position in the document of the text viewer
	* @param compilationUnit the compilation unit (may be <code>null</code>)
	*/
	public void complete(ITextViewer viewer, int completionPosition, ICompilationUnit compilationUnit) {
	IDocument document= viewer.getDocument();

	if (!(fContextType instanceof CompilationUnitContextType))
	return;

	Point selection= viewer.getSelectedRange();
	Position position= new Position(completionPosition, selection.y);

	// remember selected text
	String selectedText= null;
	if (selection.y != 0) {
	try {
	selectedText= document.get(selection.x, selection.y);
	document.addPosition(position);
	fPositions.put(document, position);
	} catch (BadLocationException e) {}
	}

	CompilationUnitContext context= (CompilationUnitContext) ((CompilationUnitContextType) fContextType).createContext(document, position, compilationUnit);
	context.setVariable("selection", selectedText); //$NON-NLS-1$
	int start= context.getStart();
	int end= context.getEnd();
	IRegion region= new Region(start, end - start);

	Template[] templates= JavaPlugin.getDefault().getTemplateStore().getTemplates();
	boolean needsCheck= !isJava12OrHigherProject(compilationUnit);
	if (selection.y == 0) {
	for (int i= 0; i != templates.length; i++) {
	Template template= templates[i];
	if (canEvaluate(context, template, needsCheck)) {
	fProposals.add(new TemplateProposal(template, context, region, getImage()));
	}
	}
	} else {

	if (context.getKey().length() == 0)
	context.setForceEvaluation(true);

	boolean multipleLinesSelected= areMultipleLinesSelected(viewer);

	for (int i= 0; i != templates.length; i++) {
	Template template= templates[i];
	if (canEvaluate(context, template, needsCheck))
	{
	Matcher wordSelectionMatcher= $_WORD_SELECTION_PATTERN.matcher(template.getPattern());
	Matcher lineSelectionMatcher= $_LINE_SELECTION_PATTERN.matcher(template.getPattern());
	if ((!multipleLinesSelected && wordSelectionMatcher.find()) \|\| (multipleLinesSelected && lineSelectionMatcher.find())) {
	fProposals.add(new TemplateProposal(templates[i], context, region, getImage()));
	}
	}
	}
	}
	}

	protected TemplateContextType getContextType() {
	return fContextType;
	}

	protected ArrayList<TemplateProposal> getProposals() {
	return fProposals;
	}

	protected Image getImage() {
	if (fContextType instanceof SWTContextType)
	return JavaPluginImages.get(JavaPluginImages.IMG_OBJS_SWT_TEMPLATE);
	else
	return JavaPluginImages.get(JavaPluginImages.IMG_OBJS_TEMPLATE);
	}

	private boolean isJava12OrHigherProject(ICompilationUnit compUnit) {
	if (compUnit != null) {
	IJavaProject javaProject= compUnit.getJavaProject();
	return JavaModelUtil.is12OrHigher(javaProject);
	}
	return false;
	}

	private boolean isTemplateAllowed(Template template) {
	if (Switch_Name.equals(template.getName())) {
	if (Switch_Default.equals(template.getDescription())) {
	return true;
	}
	return false;
	}
	return true;
	}

	private boolean canEvaluate(CompilationUnitContext context, Template template, boolean needsCheck) {
	if (!needsCheck) {
	return context.canEvaluate(template);
	}
	if (isTemplateAllowed(template)) {
	return context.canEvaluate(template);
	}
	return false;
	}

	/**
	* Returns <code>true</code> if one line is completely selected or if multiple lines are selected.
	* Being completely selected means that all characters except the new line characters are
	* selected.
	*
	* @param viewer the text viewer
	* @return <code>true</code> if one or multiple lines are selected
	* @since 2.1
	*/
	private boolean areMultipleLinesSelected(ITextViewer viewer) {
	if (viewer == null)
	return false;

	Point s= viewer.getSelectedRange();
	if (s.y == 0)
	return false;

	try {

	IDocument document= viewer.getDocument();
	int startLine= document.getLineOfOffset(s.x);
	int endLine= document.getLineOfOffset(s.x + s.y);
	IRegion line= document.getLineInformation(startLine);
	return startLine != endLine \|\| (s.x == line.getOffset() && s.y == line.getLength());

	} catch (BadLocationException x) {
	return false;
	}
	}
	}