EDIT

/*******************************************************************************

 * Copyright (c) 2000, 2010 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.draw2d.widgets;

import org.eclipse.swt.accessibility.ACC;

import org.eclipse.swt.accessibility.AccessibleAdapter;

import org.eclipse.swt.accessibility.AccessibleControlAdapter;

import org.eclipse.swt.accessibility.AccessibleControlEvent;

import org.eclipse.swt.accessibility.AccessibleEvent;

import org.eclipse.swt.events.KeyAdapter;

import org.eclipse.swt.events.KeyEvent;

import org.eclipse.swt.graphics.Font;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.draw2d.Border;

import org.eclipse.draw2d.ColorConstants;

import org.eclipse.draw2d.FigureCanvas;

import org.eclipse.draw2d.FocusEvent;

import org.eclipse.draw2d.Graphics;

import org.eclipse.draw2d.MarginBorder;

import org.eclipse.draw2d.Viewport;

import org.eclipse.draw2d.geometry.Point;

import org.eclipse.draw2d.rap.swt.SWT;

import org.eclipse.draw2d.text.FlowPage;

import org.eclipse.draw2d.text.TextFlow;

/**

 * A widget for displaying a multi-line string. The label will have a vertical

 * or horizontal scrollbar when needed. Unlike the platform Label, this label is

 * focusable and accessible to screen-readers.

 * 

 * @author hudsonr

 */

public final class MultiLineLabel extends FigureCanvas {

	private TextFlow textFlow;

	static final Border MARGIN = new MarginBorder(2);

	private Image image;

	class FocusableViewport extends Viewport {

		FocusableViewport() {

			super(true);

			setFocusTraversable(true);

			setBorder(MARGIN);

		}

		public void handleFocusGained(FocusEvent event) {

			super.handleFocusGained(event);

			repaint();

		}

		public void handleFocusLost(FocusEvent event) {

			super.handleFocusLost(event);

			repaint();

		}

		protected void paintBorder(Graphics graphics) {

			super.paintBorder(graphics);

			if (hasFocus()) {

				graphics.setForegroundColor(ColorConstants.black);

				graphics.setBackgroundColor(ColorConstants.white);

				graphics.drawFocus(getBounds().getResized(-1, -1));

			}

		}

	}

	/**

	 * Constructs a new MultiLineLabel with the given parent.

	 * 

	 * @param parent

	 *            the parent

	 */

	public MultiLineLabel(Composite parent) {

		super(parent);

		setViewport(new FocusableViewport());

		FlowPage page = new FlowPage();

		textFlow = new TextFlow();

		page.add(textFlow);

		setContents(page);

		getViewport().setContentsTracksWidth(true);

		addAccessibility();

	}

	private void addAccessibility() {

		getAccessible().addAccessibleControlListener(

				new AccessibleControlAdapter() {

					public void getRole(AccessibleControlEvent e) {

						e.detail = ACC.ROLE_LABEL;

					}

					public void getState(AccessibleControlEvent e) {

						e.detail = ACC.STATE_READONLY;

					}

				});

		getAccessible().addAccessibleListener(new AccessibleAdapter() {

			public void getName(AccessibleEvent e) {

				e.result = getText();

			}

		});

		addKeyListener(new KeyAdapter() {

			public void keyPressed(KeyEvent e) {

				Point p = getViewport().getViewLocation();

				int dy = getFont().getFontData()[0].getHeight();

				int dx = dy * 3 / 2;

				boolean mirrored = (e.widget.getStyle() & SWT.MIRRORED) != 0;

				if (e.keyCode == SWT.ARROW_DOWN) {

					scrollToY(p.y + dy / 2);

					scrollToY(p.y + dy);

					scrollToY(p.y + dy * 3 / 2);

					scrollToY(p.y + dy * 2);

				} else if (e.keyCode == SWT.ARROW_UP) {

					scrollToY(p.y - dy / 2);

					scrollToY(p.y - dy);

					scrollToY(p.y - dy * 3 / 2);

					scrollToY(p.y - dy * 2);

				} else if ((!mirrored && e.keyCode == SWT.ARROW_RIGHT)

						|| (mirrored && e.keyCode == SWT.ARROW_LEFT)) {

					scrollToX(p.x + dx);

					scrollToX(p.x + dx * 2);

					scrollToX(p.x + dx * 3);

				} else if ((!mirrored && e.keyCode == SWT.ARROW_LEFT)

						|| (mirrored && e.keyCode == SWT.ARROW_RIGHT)) {

					scrollToX(p.x - dx);

					scrollToX(p.x - dx * 2);

					scrollToX(p.x - dx * 3);

				}

			}

		});

	}

	/**

	 * @see org.eclipse.swt.widgets.Control#setEnabled(boolean)

	 */

	public void setEnabled(boolean enabled) {

		super.setEnabled(enabled);

		textFlow.setEnabled(getEnabled());

	}

	/**

	 * @return the Image for this label, or <code>null</code> if there is none

	 * @see #setImage(Image)

	 */

	public Image getImage() {

		return image;

	}

	/**

	 * Returns the text in this label.

	 * 

	 * @return the text

	 */

	public String getText() {

		return textFlow.getText();

	}

	/**

	 * @see org.eclipse.swt.widgets.Canvas#setFont(org.eclipse.swt.graphics.Font)

	 */

	public void setFont(Font font) {

		super.setFont(font);

		textFlow.revalidate();

	}

	/**

	 * @param image

	 *            The <code>Image</code> to be used for this label. It can be

	 *            <code>null</code>.

	 */

	public void setImage(Image image) {

		this.image = image;

		if (image != null)

			setBorder(new ImageBorder(image));

		else

			setBorder(null);

	}

	/**

	 * Sets the text for this label.

	 * 

	 * @param text

	 *            the new text

	 */

	public void setText(String text) {

		textFlow.setText(text);

	}

}