bundles/org.eclipse.e4.ui.dialogs/src/org/eclipse/e4/ui/internal/dialogs/about/AboutText.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2020 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v20.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Ralf Heydenreich - Bug 559694
  *******************************************************************************/
 package org.eclipse.e4.ui.internal.dialogs.about;

 import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
 import java.util.function.Supplier;

 import org.eclipse.jface.preference.JFacePreferences;
 import org.eclipse.jface.resource.JFaceColors;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyleRange;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.KeyAdapter;
 import org.eclipse.swt.events.KeyEvent;
 import org.eclipse.swt.events.MouseAdapter;
 import org.eclipse.swt.events.MouseEvent;
 import org.eclipse.swt.events.TraverseEvent;
 import org.eclipse.swt.events.TraverseListener;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Cursor;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.program.Program;

 /**
  * Manages links in styled text.
  */
 public class AboutText {

 	private String aboutProperty;
 	private StyledText styledText;

 	private Cursor handCursor;
 	private Cursor busyCursor;

 	private boolean mouseDown = false;
 	private boolean dragEvent = false;

 	private AboutItem item;

 	public AboutText(final Supplier<AboutItem> item) {
 		this.setItem(item.get());
 	}

 	public AboutText(StyledText text, final Supplier<AboutItem> item) {
 		this.styledText = text;
 		this.setItem(item.get());
 		createCursors();
 		addListeners();
 	}

 	public AboutText(String aboutProperty) {
 		this.aboutProperty = aboutProperty;
 	}

 	/**
 	 * Scan the contents of the about text
 	 *
 	 * @return
 	 */
 	private void createAboutItem() {
 		if (aboutProperty == null || aboutProperty.isEmpty()) {
 			return;
 		}

 		HyperlinkExtractor hyperlinkExtractor = new HyperlinkExtractor(aboutProperty);
 		setItem(new AboutItem(aboutProperty, hyperlinkExtractor.getLinkRanges(), hyperlinkExtractor.getLinks()));
 	}

 	private void createCursors() {
 		handCursor = new Cursor(styledText.getDisplay(), SWT.CURSOR_HAND);
 		busyCursor = new Cursor(styledText.getDisplay(), SWT.CURSOR_WAIT);
 		styledText.addDisposeListener((DisposeEvent e) -> {
 			handCursor.dispose();
 			handCursor = null;
 			busyCursor.dispose();
 			busyCursor = null;
 		});
 	}

 	/**
 	 * Adds listeners to the given styled text
 	 */
 	protected void addListeners() {
 		styledText.addMouseListener(new MouseAdapter() {
 			@Override
 			public void mouseDown(MouseEvent e) {
 				if (e.button != 1) {
 					return;
 				}
 				mouseDown = true;
 			}

 			@Override
 			public void mouseUp(MouseEvent e) {
 				mouseDown = false;
 				int offset = styledText.getCaretOffset();
 				if (dragEvent) {
 					// don't activate a link during a drag/mouse up operation
 					dragEvent = false;
 					if (item != null && item.isLinkAt(offset)) {
 						styledText.setCursor(handCursor);
 					}
 				} else if (item != null && item.isLinkAt(offset)) {
 					styledText.setCursor(busyCursor);
 					item.getLinkAt(offset).ifPresent(l -> Program.launch(l));
 					StyleRange selectionRange = getCurrentRange();
 					styledText.setSelectionRange(selectionRange.start, selectionRange.length);
 					styledText.setCursor(null);
 				}
 			}
 		});

 		styledText.addMouseMoveListener((MouseEvent e) -> {
 			// Do not change cursor on drag events
 			if (mouseDown) {
 				if (!dragEvent) {
 					StyledText text = (StyledText) e.widget;
 					text.setCursor(null);
 				}
 				dragEvent = true;
 				return;
 			}
 			StyledText text = (StyledText) e.widget;
 			int offset = -1;
 			try {
 				offset = text.getOffsetAtPoint(new Point(e.x, e.y));
 			} catch (IllegalArgumentException ex) {
 				// leave value as -1
 			}
 			if (offset == -1) {
 				text.setCursor(null);
 			} else if (item != null && item.isLinkAt(offset)) {
 				text.setCursor(handCursor);
 			} else {
 				text.setCursor(null);
 			}
 		});

 		styledText.addTraverseListener(new TraverseListener() {
 			@Override
 			public void keyTraversed(TraverseEvent e) {
 				switch (e.detail) {
 				case SWT.TRAVERSE_ESCAPE:
 					e.doit = true;
 					break;
 				case SWT.TRAVERSE_TAB_NEXT:
 					// Previously traverse out in the backward direction?
 					Point nextSelection = styledText.getSelection();
 					int charCount = styledText.getCharCount();
 					if ((nextSelection.x == charCount) && (nextSelection.y == charCount)) {
 						styledText.setSelection(0);
 					}
 					StyleRange nextRange = findNextRange();
 					if (nextRange == null) {
 						// Next time in start at beginning, also used by
 						// TRAVERSE_TAB_PREVIOUS to indicate we traversed out
 						// in the forward direction
 						styledText.setSelection(0);
 					} else {
 						styledText.setSelectionRange(nextRange.start, nextRange.length);
 						e.detail = SWT.TRAVERSE_NONE;
 					}
 					e.doit = true;
 					break;
 				case SWT.TRAVERSE_TAB_PREVIOUS:
 					// Previously traverse out in the forward direction?
 					Point previousSelection = styledText.getSelection();
 					if ((previousSelection.x == 0) && (previousSelection.y == 0)) {
 						styledText.setSelection(styledText.getCharCount());
 					}
 					StyleRange previousRange = findPreviousRange();
 					if (previousRange == null) {
 						// Next time in start at the end, also used by
 						// TRAVERSE_TAB_NEXT to indicate we traversed out
 						// in the backward direction
 						styledText.setSelection(styledText.getCharCount());
 					} else {
 						styledText.setSelectionRange(previousRange.start, previousRange.length);
 						e.detail = SWT.TRAVERSE_NONE;
 					}
 					e.doit = true;
 					break;
 				default:
 					break;
 				}
 			}
 		});

 		// Listen for Tab and Space to allow keyboard navigation
 		styledText.addKeyListener(new KeyAdapter() {
 			@Override
 			public void keyPressed(KeyEvent event) {
 				StyledText text = (StyledText) event.widget;
 				if (event.character == ' ' || event.character == SWT.CR) {
 					if (item != null) {
 						// Be sure we are in the selection
 						int offset = text.getSelection().x + 1;

 						if (item.isLinkAt(offset)) {
 							text.setCursor(busyCursor);
 							item.getLinkAt(offset).ifPresent(l -> Program.launch(l));
 							StyleRange selectionRange = getCurrentRange();
 							text.setSelectionRange(selectionRange.start, selectionRange.length);
 							text.setCursor(null);
 						}
 					}
 					return;
 				}
 			}
 		});
 	}

 	/**
 	 * Gets the about item.
 	 *
 	 * @return the about item
 	 */
 	public Optional<AboutItem> getAboutItem() {
 		if (item == null) {
 			createAboutItem();
 		}
 		return Optional.ofNullable(item);
 	}

 	/**
 	 * Sets the about item.
 	 *
 	 * @param item about item
 	 */
 	private void setItem(AboutItem item) {
 		this.item = item;
 		if (item != null && styledText != null) {
 			styledText.setText(item.getText());
 			setLinkRanges(item.getLinkRanges());
 		}
 	}

 	/**
 	 * Find the range of the current selection.
 	 */
 	private StyleRange getCurrentRange() {
 		StyleRange[] ranges = styledText.getStyleRanges();
 		int currentSelectionEnd = styledText.getSelection().y;
 		int currentSelectionStart = styledText.getSelection().x;

 		return Arrays.stream(ranges).filter(
 				range -> (currentSelectionStart >= range.start && currentSelectionEnd <= range.start + range.length))
 				.findFirst().orElse(null);
 	}

 	/**
 	 * Find the next range after the current selection.
 	 */
 	private StyleRange findNextRange() {
 		StyleRange[] ranges = styledText.getStyleRanges();
 		int currentSelectionEnd = styledText.getSelection().y;

 		return Arrays.stream(ranges).filter(range -> (range.start >= currentSelectionEnd)).findFirst().orElse(null);
 	}

 	/**
 	 * Find the previous range before the current selection.
 	 */
 	private StyleRange findPreviousRange() {
 		StyleRange[] ranges = styledText.getStyleRanges();
 		int currentSelectionStart = styledText.getSelection().x;

 		for (int i = ranges.length - 1; i > -1; i--) {
 			if ((ranges[i].start + ranges[i].length - 1) < currentSelectionStart) {
 				return ranges[i];
 			}
 		}
 		return null;
 	}

 	/**
 	 * Sets the styled text's link (blue) ranges
 	 */
 	private void setLinkRanges(final List<HyperlinkRange> linkRanges) {
 		Color fg = JFaceColors.getHyperlinkText(styledText.getShell().getDisplay());
 		if (fg == null) {
 			// TODO use CSS styling!
 			// fall back (update JFaceRegistry)
 			JFaceResources.getColorRegistry().put(JFacePreferences.HYPERLINK_COLOR, new RGB(0, 0, 128));
 			fg = JFaceColors.getHyperlinkText(styledText.getShell().getDisplay());
 		}
 		for (HyperlinkRange linkRange : linkRanges) {
 			StyleRange range = new StyleRange(linkRange.offset(), linkRange.length(), fg, null);
 			styledText.setStyleRange(range);
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2020 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v20.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Ralf Heydenreich - Bug 559694
	*******************************************************************************/
	package org.eclipse.e4.ui.internal.dialogs.about;

	import java.util.Arrays;
	import java.util.List;
	import java.util.Optional;
	import java.util.function.Supplier;

	import org.eclipse.jface.preference.JFacePreferences;
	import org.eclipse.jface.resource.JFaceColors;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyleRange;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.KeyAdapter;
	import org.eclipse.swt.events.KeyEvent;
	import org.eclipse.swt.events.MouseAdapter;
	import org.eclipse.swt.events.MouseEvent;
	import org.eclipse.swt.events.TraverseEvent;
	import org.eclipse.swt.events.TraverseListener;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.Cursor;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.RGB;
	import org.eclipse.swt.program.Program;

	/**
	* Manages links in styled text.
	*/
	public class AboutText {

	private String aboutProperty;
	private StyledText styledText;

	private Cursor handCursor;
	private Cursor busyCursor;

	private boolean mouseDown = false;
	private boolean dragEvent = false;

	private AboutItem item;

	public AboutText(final Supplier<AboutItem> item) {
	this.setItem(item.get());
	}

	public AboutText(StyledText text, final Supplier<AboutItem> item) {
	this.styledText = text;
	this.setItem(item.get());
	createCursors();
	addListeners();
	}

	public AboutText(String aboutProperty) {
	this.aboutProperty = aboutProperty;
	}

	/**
	* Scan the contents of the about text
	*
	* @return
	*/
	private void createAboutItem() {
	if (aboutProperty == null \|\| aboutProperty.isEmpty()) {
	return;
	}

	HyperlinkExtractor hyperlinkExtractor = new HyperlinkExtractor(aboutProperty);
	setItem(new AboutItem(aboutProperty, hyperlinkExtractor.getLinkRanges(), hyperlinkExtractor.getLinks()));
	}

	private void createCursors() {
	handCursor = new Cursor(styledText.getDisplay(), SWT.CURSOR_HAND);
	busyCursor = new Cursor(styledText.getDisplay(), SWT.CURSOR_WAIT);
	styledText.addDisposeListener((DisposeEvent e) -> {
	handCursor.dispose();
	handCursor = null;
	busyCursor.dispose();
	busyCursor = null;
	});
	}

	/**
	* Adds listeners to the given styled text
	*/
	protected void addListeners() {
	styledText.addMouseListener(new MouseAdapter() {
	@Override
	public void mouseDown(MouseEvent e) {
	if (e.button != 1) {
	return;
	}
	mouseDown = true;
	}

	@Override
	public void mouseUp(MouseEvent e) {
	mouseDown = false;
	int offset = styledText.getCaretOffset();
	if (dragEvent) {
	// don't activate a link during a drag/mouse up operation
	dragEvent = false;
	if (item != null && item.isLinkAt(offset)) {
	styledText.setCursor(handCursor);
	}
	} else if (item != null && item.isLinkAt(offset)) {
	styledText.setCursor(busyCursor);
	item.getLinkAt(offset).ifPresent(l -> Program.launch(l));
	StyleRange selectionRange = getCurrentRange();
	styledText.setSelectionRange(selectionRange.start, selectionRange.length);
	styledText.setCursor(null);
	}
	}
	});

	styledText.addMouseMoveListener((MouseEvent e) -> {
	// Do not change cursor on drag events
	if (mouseDown) {
	if (!dragEvent) {
	StyledText text = (StyledText) e.widget;
	text.setCursor(null);
	}
	dragEvent = true;
	return;
	}
	StyledText text = (StyledText) e.widget;
	int offset = -1;
	try {
	offset = text.getOffsetAtPoint(new Point(e.x, e.y));
	} catch (IllegalArgumentException ex) {
	// leave value as -1
	}
	if (offset == -1) {
	text.setCursor(null);
	} else if (item != null && item.isLinkAt(offset)) {
	text.setCursor(handCursor);
	} else {
	text.setCursor(null);
	}
	});

	styledText.addTraverseListener(new TraverseListener() {
	@Override
	public void keyTraversed(TraverseEvent e) {
	switch (e.detail) {
	case SWT.TRAVERSE_ESCAPE:
	e.doit = true;
	break;
	case SWT.TRAVERSE_TAB_NEXT:
	// Previously traverse out in the backward direction?
	Point nextSelection = styledText.getSelection();
	int charCount = styledText.getCharCount();
	if ((nextSelection.x == charCount) && (nextSelection.y == charCount)) {
	styledText.setSelection(0);
	}
	StyleRange nextRange = findNextRange();
	if (nextRange == null) {
	// Next time in start at beginning, also used by
	// TRAVERSE_TAB_PREVIOUS to indicate we traversed out
	// in the forward direction
	styledText.setSelection(0);
	} else {
	styledText.setSelectionRange(nextRange.start, nextRange.length);
	e.detail = SWT.TRAVERSE_NONE;
	}
	e.doit = true;
	break;
	case SWT.TRAVERSE_TAB_PREVIOUS:
	// Previously traverse out in the forward direction?
	Point previousSelection = styledText.getSelection();
	if ((previousSelection.x == 0) && (previousSelection.y == 0)) {
	styledText.setSelection(styledText.getCharCount());
	}
	StyleRange previousRange = findPreviousRange();
	if (previousRange == null) {
	// Next time in start at the end, also used by
	// TRAVERSE_TAB_NEXT to indicate we traversed out
	// in the backward direction
	styledText.setSelection(styledText.getCharCount());
	} else {
	styledText.setSelectionRange(previousRange.start, previousRange.length);
	e.detail = SWT.TRAVERSE_NONE;
	}
	e.doit = true;
	break;
	default:
	break;
	}
	}
	});

	// Listen for Tab and Space to allow keyboard navigation
	styledText.addKeyListener(new KeyAdapter() {
	@Override
	public void keyPressed(KeyEvent event) {
	StyledText text = (StyledText) event.widget;
	if (event.character == ' ' \|\| event.character == SWT.CR) {
	if (item != null) {
	// Be sure we are in the selection
	int offset = text.getSelection().x + 1;

	if (item.isLinkAt(offset)) {
	text.setCursor(busyCursor);
	item.getLinkAt(offset).ifPresent(l -> Program.launch(l));
	StyleRange selectionRange = getCurrentRange();
	text.setSelectionRange(selectionRange.start, selectionRange.length);
	text.setCursor(null);
	}
	}
	return;
	}
	}
	});
	}

	/**
	* Gets the about item.
	*
	* @return the about item
	*/
	public Optional<AboutItem> getAboutItem() {
	if (item == null) {
	createAboutItem();
	}
	return Optional.ofNullable(item);
	}

	/**
	* Sets the about item.
	*
	* @param item about item
	*/
	private void setItem(AboutItem item) {
	this.item = item;
	if (item != null && styledText != null) {
	styledText.setText(item.getText());
	setLinkRanges(item.getLinkRanges());
	}
	}

	/**
	* Find the range of the current selection.
	*/
	private StyleRange getCurrentRange() {
	StyleRange[] ranges = styledText.getStyleRanges();
	int currentSelectionEnd = styledText.getSelection().y;
	int currentSelectionStart = styledText.getSelection().x;

	return Arrays.stream(ranges).filter(
	range -> (currentSelectionStart >= range.start && currentSelectionEnd <= range.start + range.length))
	.findFirst().orElse(null);
	}

	/**
	* Find the next range after the current selection.
	*/
	private StyleRange findNextRange() {
	StyleRange[] ranges = styledText.getStyleRanges();
	int currentSelectionEnd = styledText.getSelection().y;

	return Arrays.stream(ranges).filter(range -> (range.start >= currentSelectionEnd)).findFirst().orElse(null);
	}

	/**
	* Find the previous range before the current selection.
	*/
	private StyleRange findPreviousRange() {
	StyleRange[] ranges = styledText.getStyleRanges();
	int currentSelectionStart = styledText.getSelection().x;

	for (int i = ranges.length - 1; i > -1; i--) {
	if ((ranges[i].start + ranges[i].length - 1) < currentSelectionStart) {
	return ranges[i];
	}
	}
	return null;
	}

	/**
	* Sets the styled text's link (blue) ranges
	*/
	private void setLinkRanges(final List<HyperlinkRange> linkRanges) {
	Color fg = JFaceColors.getHyperlinkText(styledText.getShell().getDisplay());
	if (fg == null) {
	// TODO use CSS styling!
	// fall back (update JFaceRegistry)
	JFaceResources.getColorRegistry().put(JFacePreferences.HYPERLINK_COLOR, new RGB(0, 0, 128));
	fg = JFaceColors.getHyperlinkText(styledText.getShell().getDisplay());
	}
	for (HyperlinkRange linkRange : linkRanges) {
	StyleRange range = new StyleRange(linkRange.offset(), linkRange.length(), fg, null);
	styledText.setStyleRange(range);
	}
	}
	}