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.text;

import java.util.Iterator;

import org.eclipse.draw2d.Figure;

import org.eclipse.draw2d.IFigure;

import org.eclipse.draw2d.geometry.Rectangle;

/**

 * The base implementation for text flow figures. A flow figure is used to

 * render a document in which elements are laid out horizontally within a "line"

 * until that line is filled. Layout continues on the next line.

 * 

 * <p>

 * WARNING: This class is not intended to be subclassed by clients. Future

 * versions may contain additional abstract methods.

 * 

 * @author hudsonr

 * @since 2.1

 */

public abstract class FlowFigure extends Figure {

	/**

	 * integer indicating whether selection should be displayed.

	 */

	protected int selectionStart = -1;

	/**

	 * Constructs a new FlowFigure.

	 */

	public FlowFigure() {

		setLayoutManager(createDefaultFlowLayout());

	}

	/**

	 * If the child is a <code>FlowFigure</code>, its FlowContext is passed to

	 * it.

	 * 

	 * @see org.eclipse.draw2d.IFigure#add(IFigure, Object, int)

	 */

	public void add(IFigure child, Object constraint, int index) {

		super.add(child, constraint, index);

		// If this layout manager is a FlowContext, then the child *must* be a

		// FlowFigure

		if (getLayoutManager() instanceof FlowContext)

			((FlowFigure) child)

					.setFlowContext((FlowContext) getLayoutManager());

		revalidateBidi(this);

	}

	/**

	 * Calculates the width of text before the next line-break is encountered.

	 * <p>

	 * Default implementation treats each FlowFigure as a line-break. It adds no

	 * width and returns <code>true</code>. Sub-classes should override as

	 * needed.

	 * 

	 * @param width

	 *            the width before the next line-break (if one's found; all the

	 *            width, otherwise) will be added on to the first int in the

	 *            given array

	 * @return boolean indicating whether or not a line-break was found

	 * @since 3.1

	 */

	public boolean addLeadingWordRequirements(int[] width) {

		return true;

	}

	/**

	 * FlowFigures can contribute text for their block to the given

	 * {@link BidiProcessor}, which will process the contributions to determine

	 * Bidi levels and shaping requirements.

	 * <p>

	 * This method is invoked as part of validating Bidi.

	 * <p>

	 * Sub-classes that cache the BidiInfo and/or the bidi level in ContentBoxes

	 * should clear the cached values when this method is invoked.

	 * 

	 * @param proc

	 *            the BidiProcessor to which contributions should be made

	 * @see BidiProcessor#add(FlowFigure, String)

	 * @since 3.1

	 */

	protected void contributeBidi(BidiProcessor proc) {

		for (Iterator iter = getChildren().iterator(); iter.hasNext();)

			((FlowFigure) iter.next()).contributeBidi(proc);

	}

	/**

	 * Creates the default layout manager

	 * 

	 * @return The default layout

	 */

	protected abstract FlowFigureLayout createDefaultFlowLayout();

	/**

	 * Called after validate has occurred. This is used to update the bounds of

	 * the FlowFigure to encompass its new flow boxed created during validate.

	 */

	public abstract void postValidate();

	/**

	 * Overridden to revalidateBidi when fragments are removed.

	 * 

	 * @see org.eclipse.draw2d.IFigure#remove(org.eclipse.draw2d.IFigure)

	 */

	public void remove(IFigure figure) {

		super.remove(figure);

		revalidateBidi(this);

	}

	/**

	 * This method should be invoked whenever a change that can potentially

	 * affect the Bidi evaluation is made (eg., adding or removing children,

	 * changing text, etc.).

	 * <p>

	 * The default implementation delegates the revalidation task to the parent.

	 * Only {@link BlockFlow#revalidateBidi(IFigure) blocks} perform the actual

	 * revalidation.

	 * <p>

	 * The given IFigure is the one that triggered the revalidation. This can be

	 * used to optimize bidi evaluation.

	 * 

	 * @param origin

	 *            the figure that was revalidated

	 * @since 3.1

	 */

	protected void revalidateBidi(IFigure origin) {

		if (getParent() != null)

			((FlowFigure) getParent()).revalidateBidi(origin);

	}

	/**

	 * Sets the bidi information for this figure. A flow figure contributes bidi

	 * text in {@link #contributeBidi(BidiProcessor)}. If the figure contributes

	 * text associated with it, this method is called back to indicate the bidi

	 * properties for that text within its block.

	 * 

	 * @param info

	 *            the BidiInfo for this figure

	 * @since 3.1

	 */

	public void setBidiInfo(BidiInfo info) {

	}

	/**

	 * FlowFigures override setBounds() to prevent translation of children.

	 * "bounds" is a derived property for FlowFigures, calculated from the

	 * fragments that make up the FlowFigure.

	 * 

	 * @see Figure#setBounds(Rectangle)

	 */

	public void setBounds(Rectangle r) {

		if (bounds.equals(r))

			return;

		if (!r.contains(bounds))

			erase();

		bounds.x = r.x;

		bounds.y = r.y;

		bounds.width = r.width;

		bounds.height = r.height;

		fireFigureMoved();

		if (isCoordinateSystem())

			fireCoordinateSystemChanged();

		repaint();

	}

	/**

	 * Sets the flow context.

	 * 

	 * @param flowContext

	 *            the flow context for this flow figure

	 */

	public void setFlowContext(FlowContext flowContext) {

		((FlowFigureLayout) getLayoutManager()).setFlowContext(flowContext);

	}

	/**

	 * Sets the selection or a range of selection. A start value of -1 is used

	 * to indicate no selection. A start value >=0 indicates show selection. A

	 * start and end value can be used to represent a range of offsets which

	 * should render selection.

	 * 

	 * @param start

	 *            the start offset

	 * @param end

	 *            the end offset

	 * @since 3.1

	 */

	public void setSelection(int start, int end) {

		if (selectionStart == start)

			return;

		selectionStart = start;

		repaint();

	}

}