SimpleLinkTextViewer wraps a StyledText and supports appending text and clickable links

1 files changed, 206 insertions, 0 deletions

diff --git a/framework/bundles/org.eclipse.ecf.ui/src/org/eclipse/ecf/ui/views/SimpleLinkTextViewer.java b/framework/bundles/org.eclipse.ecf.ui/src/org/eclipse/ecf/ui/views/SimpleLinkTextViewer.java
new file mode 100644
index 000000000..4b313f086
--- /dev/null
+++ b/framework/bundles/org.eclipse.ecf.ui/src/org/eclipse/ecf/ui/views/SimpleLinkTextViewer.java
@@ -0,0 +1,206 @@
+/*******************************************************************************
+ * Copyright (c) 2005 IBM Corporation and others.
+ * 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:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ecf.ui.views;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.custom.StyleRange;
+import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.events.MouseAdapter;
+import org.eclipse.swt.events.MouseEvent;
+import org.eclipse.swt.events.MouseMoveListener;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.graphics.Cursor;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.layout.FillLayout;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.swt.widgets.Text;
+
+/**
+ * A simple link text viewer wraps a read-only SWT StyledText and allows plain
+ * text and links to be appended to the text. For each link, a runnable is
+ * maintained that will be run when the user clicks on the link.
+ * 
+ * @since 0.5.4
+ * 
+ */
+public class SimpleLinkTextViewer {
+
+	private static Color hyperlinkColor = null;
+
+	private static Color getHyperlinkColor() {
+		if (hyperlinkColor == null) {
+			hyperlinkColor = new Color(Display.getDefault(), 0, 0, 255);
+		}
+		return hyperlinkColor;
+	}
+
+	private Cursor cursor;
+
+	private List links = new ArrayList();
+
+	private StyledText styledText;
+
+	/**
+	 * Creates a new chat text viewer in the given composite.
+	 * 
+	 * @param composite
+	 */
+	public SimpleLinkTextViewer(Composite composite) {
+		styledText = new StyledText(composite, SWT.V_SCROLL | SWT.H_SCROLL
+				| SWT.WRAP | SWT.BORDER | SWT.READ_ONLY);
+		styledText.addMouseListener(new MouseAdapter() {
+			public void mouseUp(MouseEvent e) {
+				LinkInfo linkInfo = findLinkInfo(e);
+				if (linkInfo != null) {
+					linkInfo.runnable.run();
+				}
+			}
+		});
+		styledText.addMouseMoveListener(new MouseMoveListener() {
+			public void mouseMove(MouseEvent e) {
+				LinkInfo linkInfo = findLinkInfo(e);
+				if (linkInfo != null) {
+					setHandCursor();
+				} else {
+					resetCursor();
+				}
+			}
+		});
+	}
+
+	/**
+	 * Appends the given text to the underlying StyledText widget.
+	 * 
+	 * @param text
+	 */
+	public void append(String text) {
+		styledText.append(text);
+	}
+
+	/**
+	 * Appends the given text as a link to the underlying StyledText widget. The
+	 * given runnable will be run when the user clicks on the link.
+	 * 
+	 * @param text
+	 */
+	public void appendLink(String text, Runnable onClick) {
+		int start = styledText.getCharCount();
+		styledText.replaceTextRange(start, 0, text);
+		StyleRange styleRange = new StyleRange();
+		styleRange.start = start;
+		styleRange.length = text.length();
+		styleRange.foreground = getHyperlinkColor();
+		styleRange.underline = true;
+		styledText.setStyleRange(styleRange);
+		addLink(start, text.length(), onClick);
+	}
+
+	private void addLink(int start, int length, Runnable onClick) {
+		links.add(new LinkInfo(start, length, onClick));
+	}
+
+	private LinkInfo findLinkInfo(int offset) {
+		// TODO replace with binary search
+		for (Iterator it = links.iterator(); it.hasNext();) {
+			LinkInfo linkInfo = (LinkInfo) it.next();
+			if (linkInfo.start <= offset
+					&& offset <= linkInfo.start + linkInfo.length) {
+				return linkInfo;
+			}
+		}
+		return null;
+	}
+
+	private LinkInfo findLinkInfo(MouseEvent e) {
+		Point point = new Point(e.x, e.y);
+		LinkInfo linkInfo = null;
+		if (styledText.getBounds().contains(point)
+				&& styledText.getCharCount() > 0) {
+			try {
+				int offset = styledText.getOffsetAtLocation(point);
+				linkInfo = findLinkInfo(offset);
+			} catch (IllegalArgumentException ex) {
+				// ignore - event was not over character
+			}
+		}
+		return linkInfo;
+	}
+
+	private void resetCursor() {
+		styledText.setCursor(null);
+		if (cursor != null) {
+			cursor.dispose();
+			cursor = null;
+		}
+	}
+
+	private void setHandCursor() {
+		Display display = styledText.getDisplay();
+		if (cursor == null)
+			cursor = new Cursor(display, SWT.CURSOR_HAND);
+		styledText.setCursor(cursor);
+	}
+
+	/**
+	 * main method for testing purposes (right-click and select Run As->SWT
+	 * Application)
+	 * 
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		Display display = new Display();
+		Shell shell = new Shell(display);
+		shell.setText(SimpleLinkTextViewer.class.getName());
+		shell.setLayout(new FillLayout());
+		SimpleLinkTextViewer chatTextViewer = new SimpleLinkTextViewer(shell);
+		chatTextViewer.append("Hello world\n");
+		chatTextViewer.append("Hello ");
+		chatTextViewer.appendLink("linked", new Runnable() {
+
+			public void run() {
+				System.out.println("clicked!");
+			}
+		});
+		chatTextViewer.append(" world\n");
+		chatTextViewer.append("Hello world\n");
+		Text secondText = new Text(shell, SWT.BORDER);
+		secondText.setText("some other focusable text");
+		secondText.forceFocus();
+		shell.layout();
+		shell.open();
+		while (!shell.isDisposed()) {
+			if (!display.readAndDispatch())
+				display.sleep();
+		}
+		display.dispose();
+	}
+
+	private static class LinkInfo {
+		private final int start;
+
+		private final int length;
+
+		private final Runnable runnable;
+
+		private LinkInfo(int start, int length, Runnable runnable) {
+			this.start = start;
+			this.length = length;
+			this.runnable = runnable;
+		}
+	}
+
+}