bundles/org.eclipse.draw2d/src/org/eclipse/draw2d/GridData.java

/*******************************************************************************
 * 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
 *     Asim Ullah - Ported for use in draw2d (c.f Bugzilla 71684).[Sep 10, 2004]
 *******************************************************************************/
package org.eclipse.draw2d;


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

/**
 * <code>GridData</code> is the layout data object associated with
 * <code>GridLayout</code>. To set a <code>GridData</code> object into a
 * <code>Figure</code>, you use the <code>setConstraint()</code> method of
 * <code>GridLayout</code> to map the <code>Figure</code> to its layout
 * <code>GridData</code>.
 * <p>
 * There are two ways to create a <code>GridData</code> object with certain
 * fields set. The first is to set the fields directly, like this:
 * 
 * <pre>
 * GridData gridData = new GridData();
 * gridData.horizontalAlignment = GridData.FILL;
 * gridData.grabExcessHorizontalSpace = true;
 * 
 * // associate the figure to the GridData object
 * myGridlayout.setConstraint(myFigure, gridData);
 * </pre>
 * 
 * The second is to take advantage of convenience style bits defined by
 * <code>GridData</code>:
 * 
 * <pre>
 * GridData gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL
 * 		| GridData.GRAB_HORIZONTAL);
 * </pre>
 * 
 * </p>
 * <p>
 * NOTE: Do not reuse <code>GridData</code> objects. Every child in the parent
 * <code>Figure</code> that is managed by the <code>GridLayout</code> must have
 * a unique <code>GridData</code> object. If the layout data for a Grid member
 * in a <code>GridLayout</code> is null at layout time, a unique
 * <code>GridData</code> object is created for it.
 * </p>
 * 
 * @see GridLayout
 */
public final class GridData {
	/**
	 * verticalAlignment specifies how figures will be positioned vertically
	 * within a cell.
	 * 
	 * The default value is CENTER.
	 * 
	 * Possible values are:
	 * 
	 * SWT.BEGINNING (or SWT.TOP): Position the figure at the top of the cell
	 * SWT.CENTER: Position the figure in the vertical center of the cell
	 * SWT.END (or SWT.BOTTOM): Position the figure at the bottom of the cell
	 * SWT.FILL: Resize the figure to fill the cell vertically
	 */
	public int verticalAlignment = CENTER;

	/**
	 * horizontalAlignment specifies how figures will be positioned horizontally
	 * within a cell.
	 * 
	 * The default value is BEGINNING.
	 * 
	 * Possible values are:
	 * 
	 * SWT.BEGINNING (or SWT.LEFT): Position the figure at the left of the cell
	 * SWT.CENTER: Position the figure in the horizontal center of the cell
	 * SWT.END (or SWT.RIGHT): Position the figure at the right of the cell
	 * SWT.FILL: Resize the figure to fill the cell horizontally
	 */
	public int horizontalAlignment = BEGINNING;

	/**
	 * widthHint specifies a minimum width for the column. A value of
	 * SWT.DEFAULT indicates that no minimum width is specified.
	 * 
	 * The default value is SWT.DEFAULT.
	 */
	public int widthHint = SWT.DEFAULT;

	/**
	 * heightHint specifies a minimum height for the row. A value of SWT.DEFAULT
	 * indicates that no minimum height is specified.
	 * 
	 * The default value is SWT.DEFAULT.
	 */
	public int heightHint = SWT.DEFAULT;

	/**
	 * horizontalIndent specifies the number of pixels of indentation that will
	 * be placed along the left side of the cell.
	 * 
	 * The default value is 0.
	 */
	public int horizontalIndent = 0;

	/**
	 * horizontalSpan specifies the number of column cells that the figure will
	 * take up.
	 * 
	 * The default value is 1.
	 */
	public int horizontalSpan = 1;

	/**
	 * verticalSpan specifies the number of row cells that the figure will take
	 * up.
	 * 
	 * The default value is 1.
	 */
	public int verticalSpan = 1;

	/**
	 * grabExcessHorizontalSpace specifies whether the cell will be made wide
	 * enough to fit the remaining horizontal space.
	 * 
	 * The default value is false.
	 */
	public boolean grabExcessHorizontalSpace = false;

	/**
	 * grabExcessVerticalSpace specifies whether the cell will be made tall
	 * enough to fit the remaining vertical space.
	 * 
	 * The default value is false.
	 */
	public boolean grabExcessVerticalSpace = false;

	/**
	 * Value for horizontalAlignment or verticalAlignment. Position the figure
	 * at the top or left of the cell. Not recommended. Use SWT.BEGINNING,
	 * SWT.TOP or SWT.LEFT instead.
	 */
	public static final int BEGINNING = SWT.BEGINNING;

	/**
	 * Value for horizontalAlignment or verticalAlignment. Position the figure
	 * in the vertical or horizontal center of the cell Not recommended. Use
	 * SWT.CENTER instead.
	 */
	public static final int CENTER = 2;

	/**
	 * Value for horizontalAlignment or verticalAlignment. Position the figure
	 * at the bottom or right of the cell Not recommended. Use SWT.END,
	 * SWT.BOTTOM or SWT.RIGHT instead.
	 */
	public static final int END = 3;

	/**
	 * Value for horizontalAlignment or verticalAlignment. Resize the figure to
	 * fill the cell horizontally or vertically. Not recommended. Use SWT.FILL
	 * instead.
	 */
	public static final int FILL = SWT.FILL;

	/**
	 * Style bit for <code>new GridData(int)</code>. Position the figure at the
	 * top of the cell. Not recommended. Use
	 * <code>new GridData(int, SWT.BEGINNING, boolean, boolean)</code> instead.
	 */
	public static final int VERTICAL_ALIGN_BEGINNING = 1 << 1;

	/**
	 * Style bit for <code>new GridData(int)</code> to position the figure in
	 * the vertical center of the cell. Not recommended. Use
	 * <code>new GridData(int, SWT.CENTER, boolean, boolean)</code> instead.
	 */
	public static final int VERTICAL_ALIGN_CENTER = 1 << 2;

	/**
	 * Style bit for <code>new GridData(int)</code> to position the figure at
	 * the bottom of the cell. Not recommended. Use
	 * <code>new GridData(int, SWT.END, boolean, boolean)</code> instead.
	 */
	public static final int VERTICAL_ALIGN_END = 1 << 3;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fill
	 * the cell vertically. Not recommended. Use
	 * <code>new GridData(int, SWT.FILL, boolean, boolean)</code> instead
	 */
	public static final int VERTICAL_ALIGN_FILL = 1 << 4;

	/**
	 * Style bit for <code>new GridData(int)</code> to position the figure at
	 * the left of the cell. Not recommended. Use
	 * <code>new GridData(SWT.BEGINNING, int, boolean, boolean)</code> instead.
	 */
	public static final int HORIZONTAL_ALIGN_BEGINNING = 1 << 5;

	/**
	 * Style bit for <code>new GridData(int)</code> to position the figure in
	 * the horizontal center of the cell. Not recommended. Use
	 * <code>new GridData(SWT.CENTER, int, boolean, boolean)</code> instead.
	 */
	public static final int HORIZONTAL_ALIGN_CENTER = 1 << 6;

	/**
	 * Style bit for <code>new GridData(int)</code> to position the figure at
	 * the right of the cell. Not recommended. Use
	 * <code>new GridData(SWT.END, int, boolean, boolean)</code> instead.
	 */
	public static final int HORIZONTAL_ALIGN_END = 1 << 7;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fill
	 * the cell horizontally. Not recommended. Use
	 * <code>new GridData(SWT.FILL, int, boolean, boolean)</code> instead.
	 */
	public static final int HORIZONTAL_ALIGN_FILL = 1 << 8;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fit
	 * the remaining horizontal space. Not recommended. Use
	 * <code>new GridData(int, int, true, boolean)</code> instead.
	 */
	public static final int GRAB_HORIZONTAL = 1 << 9;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fit
	 * the remaining vertical space. Not recommended. Use
	 * <code>new GridData(int, int, boolean, true)</code> instead.
	 */
	public static final int GRAB_VERTICAL = 1 << 10;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fill
	 * the cell vertically and to fit the remaining vertical space.
	 * FILL_VERTICAL = VERTICAL_ALIGN_FILL | GRAB_VERTICAL Not recommended. Use
	 * <code>new GridData(int, SWT.FILL, boolean, true)</code> instead.
	 */
	public static final int FILL_VERTICAL = VERTICAL_ALIGN_FILL | GRAB_VERTICAL;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fill
	 * the cell horizontally and to fit the remaining horizontal space.
	 * FILL_HORIZONTAL = HORIZONTAL_ALIGN_FILL | GRAB_HORIZONTAL Not
	 * recommended. Use <code>new GridData(SWT.FILL, int, true, boolean)</code>
	 * instead.
	 */
	public static final int FILL_HORIZONTAL = HORIZONTAL_ALIGN_FILL
			| GRAB_HORIZONTAL;

	/**
	 * Style bit for <code>new GridData(int)</code> to resize the figure to fill
	 * the cell horizontally and vertically and to fit the remaining horizontal
	 * and vertical space. FILL_BOTH = FILL_VERTICAL | FILL_HORIZONTAL Not
	 * recommended. Use
	 * <code>new GridData(SWT.FILL, SWT.FILL, true, true)</code> instead.
	 */
	public static final int FILL_BOTH = FILL_VERTICAL | FILL_HORIZONTAL;

	int cacheWidth = -1, cacheHeight = -1;
	int[][] cache = new int[2][4];
	int cacheIndex = -1;

	/**
	 * Constructs a new instance of GridData using default values.
	 */
	public GridData() {
		super();
	}

	/**
	 * Constructs a new instance based on the GridData style. This constructor
	 * is not recommended.
	 * 
	 * @param style
	 *            the GridData style
	 */
	public GridData(int style) {
		super();
		if ((style & VERTICAL_ALIGN_BEGINNING) != 0)
			verticalAlignment = BEGINNING;
		if ((style & VERTICAL_ALIGN_CENTER) != 0)
			verticalAlignment = CENTER;
		if ((style & VERTICAL_ALIGN_FILL) != 0)
			verticalAlignment = FILL;
		if ((style & VERTICAL_ALIGN_END) != 0)
			verticalAlignment = END;
		if ((style & HORIZONTAL_ALIGN_BEGINNING) != 0)
			horizontalAlignment = BEGINNING;
		if ((style & HORIZONTAL_ALIGN_CENTER) != 0)
			horizontalAlignment = CENTER;
		if ((style & HORIZONTAL_ALIGN_FILL) != 0)
			horizontalAlignment = FILL;
		if ((style & HORIZONTAL_ALIGN_END) != 0)
			horizontalAlignment = END;
		grabExcessHorizontalSpace = (style & GRAB_HORIZONTAL) != 0;
		grabExcessVerticalSpace = (style & GRAB_VERTICAL) != 0;
	}

	/**
	 * Constructs a new instance of GridData according to the parameters.
	 * 
	 * @param horizontalAlignment
	 *            how figure will be positioned horizontally within a cell
	 * @param verticalAlignment
	 *            how figure will be positioned vertically within a cell
	 * @param grabExcessHorizontalSpace
	 *            whether cell will be made wide enough to fit the remaining
	 *            horizontal space
	 * @param grabExcessVerticalSpace
	 *            whether cell will be made high enough to fit the remaining
	 *            vertical space
	 * 
	 */
	public GridData(int horizontalAlignment, int verticalAlignment,
			boolean grabExcessHorizontalSpace, boolean grabExcessVerticalSpace) {
		this(horizontalAlignment, verticalAlignment, grabExcessHorizontalSpace,
				grabExcessVerticalSpace, 1, 1);
	}

	/**
	 * Constructs a new instance of GridData according to the parameters.
	 * 
	 * @param horizontalAlignment
	 *            how figure will be positioned horizontally within a cell
	 * @param verticalAlignment
	 *            how figure will be positioned vertically within a cell
	 * @param grabExcessHorizontalSpace
	 *            whether cell will be made wide enough to fit the remaining
	 *            horizontal space
	 * @param grabExcessVerticalSpace
	 *            whether cell will be made high enough to fit the remaining
	 *            vertical space
	 * @param horizontalSpan
	 *            the number of column cells that the figure will take up
	 * @param verticalSpan
	 *            the number of row cells that the figure will take up
	 * 
	 */
	public GridData(int horizontalAlignment, int verticalAlignment,
			boolean grabExcessHorizontalSpace, boolean grabExcessVerticalSpace,
			int horizontalSpan, int verticalSpan) {
		super();
		this.horizontalAlignment = horizontalAlignment;
		this.verticalAlignment = verticalAlignment;
		this.grabExcessHorizontalSpace = grabExcessHorizontalSpace;
		this.grabExcessVerticalSpace = grabExcessVerticalSpace;
		this.horizontalSpan = horizontalSpan;
		this.verticalSpan = verticalSpan;
	}

	/**
	 * Constructs a new instance of GridData according to the parameters. A
	 * value of SWT.DEFAULT indicates that no minimum width or no minumum height
	 * is specified.
	 * 
	 * @param width
	 *            a minimum width for the column
	 * @param height
	 *            a minimum height for the row
	 * 
	 */
	public GridData(int width, int height) {
		super();
		this.widthHint = width;
		this.heightHint = height;
	}

	Dimension computeSize(IFigure figure, boolean flushCache) {
		if (cacheWidth != -1 && cacheHeight != -1) {
			return new Dimension(cacheWidth, cacheHeight);
		}
		for (int i = 0; i < cacheIndex + 1; i++) {
			if (cache[i][0] == widthHint && cache[i][1] == heightHint) {
				cacheWidth = cache[i][2];
				cacheHeight = cache[i][3];
				return new Dimension(cacheWidth, cacheHeight);
			}
		}

		Dimension size = figure.getPreferredSize(widthHint, heightHint)
				.getCopy();
		if (widthHint != -1)
			size.width = widthHint;
		if (heightHint != -1)
			size.height = heightHint;

		if (cacheIndex < cache.length - 1)
			cacheIndex++;
		cache[cacheIndex][0] = widthHint;
		cache[cacheIndex][1] = heightHint;
		cacheWidth = cache[cacheIndex][2] = size.width;
		cacheHeight = cache[cacheIndex][3] = size.height;
		return size;
	}

	void flushCache() {
		cacheWidth = cacheHeight = -1;
		cacheIndex = -1;
	}

	String getName() {
		String string = getClass().getName();
		int index = string.lastIndexOf('.');
		if (index == -1)
			return string;
		return string.substring(index + 1, string.length());
	}

	public String toString() {

		String hAlign = ""; //$NON-NLS-1$
		switch (horizontalAlignment) {
		case SWT.FILL:
			hAlign = "SWT.FILL"; //$NON-NLS-1$
			break;
		case SWT.BEGINNING:
			hAlign = "SWT.BEGINNING"; //$NON-NLS-1$
			break;
		case SWT.LEFT:
			hAlign = "SWT.LEFT"; //$NON-NLS-1$
			break;
		case SWT.END:
			hAlign = "SWT.END"; //$NON-NLS-1$
			break;
		case END:
			hAlign = "GridData.END"; //$NON-NLS-1$
			break;
		case SWT.RIGHT:
			hAlign = "SWT.RIGHT"; //$NON-NLS-1$
			break;
		case SWT.CENTER:
			hAlign = "SWT.CENTER"; //$NON-NLS-1$
			break;
		case CENTER:
			hAlign = "GridData.CENTER"; //$NON-NLS-1$
			break;
		default:
			hAlign = "Undefined " + horizontalAlignment; //$NON-NLS-1$
			break;
		}
		String vAlign = ""; //$NON-NLS-1$
		switch (verticalAlignment) {
		case SWT.FILL:
			vAlign = "SWT.FILL"; //$NON-NLS-1$
			break;
		case SWT.BEGINNING:
			vAlign = "SWT.BEGINNING"; //$NON-NLS-1$
			break;
		case SWT.TOP:
			vAlign = "SWT.TOP"; //$NON-NLS-1$
			break;
		case SWT.END:
			vAlign = "SWT.END"; //$NON-NLS-1$
			break;
		case END:
			vAlign = "GridData.END"; //$NON-NLS-1$
			break;
		case SWT.BOTTOM:
			vAlign = "SWT.BOTTOM"; //$NON-NLS-1$
			break;
		case SWT.CENTER:
			vAlign = "SWT.CENTER"; //$NON-NLS-1$
			break;
		case CENTER:
			vAlign = "GridData.CENTER"; //$NON-NLS-1$
			break;
		default:
			vAlign = "Undefined " + verticalAlignment; //$NON-NLS-1$
			break;
		}
		String string = getName() + " {"; //$NON-NLS-1$
		string += "horizontalAlignment=" + hAlign + " "; //$NON-NLS-1$ //$NON-NLS-2$
		if (horizontalIndent != 0)
			string += "horizontalIndent=" + horizontalIndent + " "; //$NON-NLS-1$ //$NON-NLS-2$
		if (horizontalSpan != 1)
			string += "horizontalSpan=" + horizontalSpan + " "; //$NON-NLS-1$//$NON-NLS-2$
		if (grabExcessHorizontalSpace)
			string += "grabExcessHorizontalSpace=" + grabExcessHorizontalSpace //$NON-NLS-1$
					+ " "; //$NON-NLS-1$
		if (widthHint != SWT.DEFAULT)
			string += "widthHint=" + widthHint + " "; //$NON-NLS-1$ //$NON-NLS-2$
		string += "verticalAlignment=" + vAlign + " "; //$NON-NLS-1$ //$NON-NLS-2$
		if (verticalSpan != 1)
			string += "verticalSpan=" + verticalSpan + " "; //$NON-NLS-1$ //$NON-NLS-2$
		if (grabExcessVerticalSpace)
			string += "grabExcessVerticalSpace=" + grabExcessVerticalSpace //$NON-NLS-1$
					+ " "; //$NON-NLS-1$
		if (heightHint != SWT.DEFAULT)
			string += "heightHint=" + heightHint + " "; //$NON-NLS-1$ //$NON-NLS-2$
		string = string.trim();
		string += "}"; //$NON-NLS-1$
		return string;

	}

}