plugins/org.eclipse.dltk.sh.ui/src/org/eclipse/dltk/sh/internal/ui/text/hyperlink/SourceHyperlinkDetector.java

/*******************************************************************************
 * Copyright (c) 2017 Red Hat Inc. and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Alexander Kurtakov - initial API and implementation
 *******************************************************************************/
package org.eclipse.dltk.sh.internal.ui.text.hyperlink;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
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.Region;
import org.eclipse.jface.text.hyperlink.AbstractHyperlinkDetector;
import org.eclipse.jface.text.hyperlink.IHyperlink;
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.FileEditorInput;
import org.eclipse.ui.texteditor.ITextEditor;

public class SourceHyperlinkDetector extends AbstractHyperlinkDetector {

	private static final String SOURCE = "source";

	@Override
	public IHyperlink[] detectHyperlinks(ITextViewer textViewer, IRegion inputRegion,
			boolean canShowMultipleHyperlinks) {
		if ((inputRegion == null) || (textViewer == null)) {
			return null;
		}
		try {
			final IDocument doc = textViewer.getDocument();
			final int lineNumber = doc.getLineOfOffset(inputRegion.getOffset());
			final IRegion region = doc.getLineInformation(lineNumber);
			final String line = doc.get(region.getOffset(), region.getLength());
			if ((line != null) && (line.length() != 0)) {
				final IHyperlink link = checkLine(region.getOffset(), line);
				if (link != null) {
					return new IHyperlink[] { link };
				}
			}
		} catch (BadLocationException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Checks if the specified line matches the <code>require</code> statement
	 *
	 * @param offset
	 * @param line
	 */
	private IHyperlink checkLine(int offset, final String line) {
		int begin = 0;
		int end = line.length();
		while ((begin < end) && Character.isWhitespace(line.charAt(begin))) {
			++begin;
		}
		while ((begin < end) && Character.isWhitespace(line.charAt(end - 1))) {
			--end;
		}
		if (((begin + SOURCE.length()) < end) && line.startsWith(SOURCE, begin)) {
			begin += SOURCE.length();
			while ((begin < end) && Character.isWhitespace(line.charAt(begin))) {
				++begin;
			}
			if (((begin + 2) < end) && (line.charAt(begin) == '(') && (line.charAt(end - 1) == ')')) {
				++begin;
				--end;
				while ((begin < end) && Character.isWhitespace(line.charAt(begin))) {
					++begin;
				}
				while ((begin < end) && Character.isWhitespace(line.charAt(end - 1))) {
					--end;
				}
			}

			return createLink(offset, line, begin, end);
		}
		return null;
	}

	/**
	 * Creates {@link IHyperlink} instance.
	 *
	 * This method is extracted to simplify testing.
	 *
	 * @param offset
	 * @param line
	 * @param begin
	 * @param end
	 * @return
	 */
	private IHyperlink createLink(int offset, final String line, int begin, int end) {
		final ITextEditor editor = getAdapter(ITextEditor.class);
		if (editor != null) {
			final String requiredFile = line.substring(begin, end);
			final Region region = new Region(offset + begin, end - begin);
			IContainer container = ((FileEditorInput) getAdapter(ITextEditor.class).getEditorInput()).getFile()
					.getParent();
			IResource resourceToOpen = container.findMember(requiredFile);
			if ((resourceToOpen != null) && (resourceToOpen.getType() == IResource.FILE)) {
				return new IHyperlink() {

					@Override
					public void open() {
						IWorkbenchPage page = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
						try {
							IDE.openEditor(page, (IFile) resourceToOpen);
						} catch (PartInitException e) {
						}

					}

					@Override
					public String getTypeLabel() {
						return "Shell: source";
					}

					@Override
					public String getHyperlinkText() {
						return requiredFile;
					}

					@Override
					public IRegion getHyperlinkRegion() {
						return region;
					}
				};
			}
		}
		return null;
	}

}