/*
 * Copyright (c) 2000, 2006 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
 *     Declarative Engineering - Major additions (overlays & minimum sizing) + maintenance, formatting, & commenting.
 */
package com.foundation.view.swt.layout;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * <code>GridData</code> is the layout data object associated with 
 * <code>GridLayout</code>. To set a <code>GridData</code> object into a 
 * control, you use the <code>Control.setLayoutData(Object)</code> method. 
 * <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;
 * 		button1.setLayoutData(gridData);
 * </pre>
 * The second is to take advantage of convenience style bits defined 
 * by <code>GridData</code>:
 * <pre>
 *      button1.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.GRAB_HORIZONTAL));
 * </pre>
 * </p>
 * <p>
 * NOTE: Do not reuse <code>GridData</code> objects. Every control in a 
 * <code>Composite</code> that is managed by a <code>GridLayout</code>
 * must have a unique <code>GridData</code> object. If the layout data 
 * for a control in a <code>GridLayout</code> is null at layout time, 
 * a unique <code>GridData</code> object is created for it.
 * </p>
 * 
 * @see GridLayout
 * @see Control#setLayoutData
 */
public final class GridData {
	/**
	 * verticalAlignment specifies how controls will be positioned 
	 * vertically within a cell. 
	 *
	 * The default value is CENTER.
	 *
	 * Possible values are: <ul>
	 *    <li>SWT.BEGINNING (or SWT.TOP): Position the control at the top of the cell</li>
	 *    <li>SWT.CENTER: Position the control in the vertical center of the cell</li>
	 *    <li>SWT.END (or SWT.BOTTOM): Position the control at the bottom of the cell</li>
	 *    <li>SWT.FILL: Resize the control to fill the cell vertically</li>
	 * </ul>
	 */
	public int verticalAlignment = CENTER;

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

	/**
	 * widthHint specifies the preferred width in pixels. This value
	 * is the wHint passed into Control.computeSize(int, int, boolean) 
	 * to determine the preferred size of the control.
	 *
	 * The default value is SWT.DEFAULT.
	 * 
	 * @see Control#computeSize(int, int, boolean)
	 */
	public int widthHint = SWT.DEFAULT;

	/**
	 * heightHint specifies the preferred height in pixels. This value
	 * is the hHint passed into Control.computeSize(int, int, boolean) 
	 * to determine the preferred size of the control.
	 *
	 * The default value is SWT.DEFAULT.
	 * 
	 * @see Control#computeSize(int, int, boolean)
	 */
	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;

	/**
	 * verticalIndent specifies the number of pixels of indentation
	 * that will be placed along the top side of the cell.
	 *
	 * The default value is 0.
	 * 
	 * @since 3.1
	 */
	public int verticalIndent = 0;

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

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

	/**
	 * <p>grabExcessHorizontalSpace specifies whether the width of the cell 
	 * changes depending on the size of the parent Composite.  If 
	 * grabExcessHorizontalSpace is <code>true</code>, the following rules
	 * apply to the width of the cell:</p>
	 * <ul>
	 * <li>If extra horizontal space is available in the parent, the cell will 
	 * grow to be wider than its preferred width.  The new width 
	 * will be "preferred width + delta" where delta is the extra 
	 * horizontal space divided by the number of grabbing columns.</li>
	 * <li>If there is not enough horizontal space available in the parent, the 
	 * cell will shrink until it reaches its minimum width as specified by 
	 * GridData.minimumWidth. The new width will be the maximum of 
	 * "minimumWidth" and "preferred width - delta", where delta is 
	 * the amount of space missing divided by the number of grabbing columns.</li>
	 * <li>If the parent is packed, the cell will be its preferred width 
	 * as specified by GridData.widthHint.</li>
	 * <li>If the control spans multiple columns and there are no other grabbing 
	 * controls in any of the spanned columns, the last column in the span will
	 * grab the extra space.  If there is at least one other grabbing control
	 * in the span, the grabbing will be spread over the columns already 
	 * marked as grabExcessHorizontalSpace.</li>
	 * </ul>
	 * 
	 * <p>The default value is false.</p>
	 * 
	 * @see GridData#minimumWidth
	 * @see GridData#widthHint
	 */
	public boolean grabExcessHorizontalSpace = false;

	/**
	 * <p>grabExcessVerticalSpace specifies whether the height of the cell 
	 * changes depending on the size of the parent Composite.  If 
	 * grabExcessVerticalSpace is <code>true</code>, the following rules
	 * apply to the height of the cell:</p>
	 * <ul>
	 * <li>If extra vertical space is available in the parent, the cell will 
	 * grow to be taller than its preferred height.  The new height 
	 * will be "preferred height + delta" where delta is the extra 
	 * vertical space divided by the number of grabbing rows.</li>
	 * <li>If there is not enough vertical space available in the parent, the 
	 * cell will shrink until it reaches its minimum height as specified by 
	 * GridData.minimumHeight. The new height will be the maximum of 
	 * "minimumHeight" and "preferred height - delta", where delta is 
	 * the amount of space missing divided by the number of grabbing rows.</li>
	 * <li>If the parent is packed, the cell will be its preferred height 
	 * as specified by GridData.heightHint.</li>
	 * <li>If the control spans multiple rows and there are no other grabbing 
	 * controls in any of the spanned rows, the last row in the span will
	 * grab the extra space.  If there is at least one other grabbing control
	 * in the span, the grabbing will be spread over the rows already 
	 * marked as grabExcessVerticalSpace.</li>
	 * </ul>
	 * 
	 * <p>The default value is false.</p>
	 * 
	 * @see GridData#minimumHeight
	 * @see GridData#heightHint
	 */
	public boolean grabExcessVerticalSpace = false;

	/**
	 * <p>TODO: This should really default to -1, and a value of -1 should be using the control's minimum.  Currently 0 or -1 uses the control's minimum, but not for the layout - only for reporting a total minimum for the layout.</p>
	 * minimumWidth specifies the minimum width in pixels.  This value
	 * applies only if grabExcessHorizontalSpace is true. A value of 
	 * SWT.DEFAULT means that the minimum width will be the result
	 * of Control.computeSize(int, int, boolean) where wHint is 
	 * determined by GridData.widthHint.
	 *
	 * The default value is 0.
	 *
	 * @since 3.1
	 * @see Control#computeSize(int, int, boolean)
	 * @see GridData#widthHint
	 */
	public int minimumWidth = 0;

	/**
	 * <p>TODO: This should really default to -1, and a value of -1 should be using the control's minimum.  Currently 0 or -1 uses the control's minimum, but not for the layout - only for reporting a total minimum for the layout.</p>
	 * minimumHeight specifies the minimum height in pixels.  This value
	 * applies only if grabExcessVerticalSpace is true.  A value of 
	 * SWT.DEFAULT means that the minimum height will be the result
	 * of Control.computeSize(int, int, boolean) where hHint is 
	 * determined by GridData.heightHint.
	 *
	 * The default value is 0.
	 *
	 * @since 3.1
	 * @see Control#computeSize(int, int, boolean)
	 * @see GridData#heightHint
	 */
	public int minimumHeight = 0;

	/**
	 * exclude informs the layout to ignore this control when sizing
	 * and positioning controls.  If this value is <code>true</code>,
	 * the size and position of the control will not be managed by the
	 * layout.  If this	value is <code>false</code>, the size and 
	 * position of the control will be computed and assigned.
	 * 
	 * The default value is <code>false</code>.
	 * 
	 * @since 3.1
	 */
	public boolean exclude = false;

	/**
	 * Value for horizontalAlignment or verticalAlignment.
	 * Position the control 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 control 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 control 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 control 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 control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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 
	 * control 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;
	int cacheHeight = -1;
	int defaultWhint;
	int defaultHhint;
	int defaultWidth = -1;
	int defaultHeight = -1;
	int currentWhint;
	int currentHhint;
	int currentWidth = -1;
	int currentHeight = -1;
	//Declarative Engineering//
	int cacheHSpan = -1;
	int cacheVSpan = -1;
/**
 * Constructs a new instance of GridData using default values.
 */
public GridData() {
	super();
}//GridData()//
/**
 * 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;
}//GridData()//
/**
 * Constructs a new instance of GridData according to the parameters.
 * 
 * @param horizontalAlignment how control will be positioned horizontally within a cell
 * @param verticalAlignment how control 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
 * 
 * @since 3.0
 */
public GridData(int horizontalAlignment, int verticalAlignment, boolean grabExcessHorizontalSpace, boolean grabExcessVerticalSpace) {
	this(horizontalAlignment, verticalAlignment, grabExcessHorizontalSpace, grabExcessVerticalSpace, 1, 1);
}//GridData()//
/**
 * Constructs a new instance of GridData according to the parameters.
 *  
 * @param horizontalAlignment how control will be positioned horizontally within a cell
 * @param verticalAlignment how control 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 control will take up
 * @param verticalSpan the number of row cells that the control will take up
 * 
 * @since 3.0
 */
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;
}//GridData()//
/**
 * Computes the size of given control, described by this grid data.
 * @param control The control referencing this grid data.
 * @param wHint The width hint.
 * @param hHint The height hint.
 * @param flushCache Whether to flush the cache.
 */
void computeSize(Control control, int wHint, int hHint, boolean flushCache) {
	if(cacheWidth == -1 || cacheHeight == -1) {
		if(wHint == this.widthHint && hHint == this.heightHint) {
			if(defaultWidth == -1 || defaultHeight == -1 || wHint != defaultWhint || hHint != defaultHhint) {
				Point size = control.computeSize(wHint, hHint, flushCache);
				
				defaultWhint = wHint;
				defaultHhint = hHint;
				defaultWidth = size.x;
				defaultHeight = size.y;
			}//if//
			
			cacheWidth = defaultWidth;
			cacheHeight = defaultHeight;
			
			return;
		}//if//
		
		if(currentWidth == -1 || currentHeight == -1 || wHint != currentWhint || hHint != currentHhint) {
			Point size = control.computeSize(wHint, hHint, flushCache);
			
			currentWhint = wHint;
			currentHhint = hHint;
			currentWidth = size.x;
			currentHeight = size.y;
		}//if//
		
		cacheWidth = currentWidth;
		cacheHeight = currentHeight;
	}//if//
}//computeSize()//
/**
 * Clears any cached values.
 */
void flushCache() {
	cacheWidth = cacheHeight = -1;
	defaultWidth = defaultHeight = -1;
	currentWidth = currentHeight = -1;
}//flushCache()//
/* (non-Javadoc)
 * @see java.lang.Object#toString()
 */
public String toString() {
	String hAlign = "";
	String vAlign = "";
	String string;
	
	switch(horizontalAlignment) {
		case SWT.FILL:
			hAlign = "SWT.FILL";
			break;
		case SWT.BEGINNING:
			hAlign = "SWT.BEGINNING";
			break;
		case SWT.LEFT:
			hAlign = "SWT.LEFT";
			break;
		case SWT.END:
			hAlign = "SWT.END";
			break;
		case END:
			hAlign = "GridData.END";
			break;
		case SWT.RIGHT:
			hAlign = "SWT.RIGHT";
			break;
		case SWT.CENTER:
			hAlign = "SWT.CENTER";
			break;
		case CENTER:
			hAlign = "GridData.CENTER";
			break;
		default:
			hAlign = "Undefined " + horizontalAlignment;
			break;
	}//switch//
	
	switch(verticalAlignment) {
		case SWT.FILL:
			vAlign = "SWT.FILL";
			break;
		case SWT.BEGINNING:
			vAlign = "SWT.BEGINNING";
			break;
		case SWT.TOP:
			vAlign = "SWT.TOP";
			break;
		case SWT.END:
			vAlign = "SWT.END";
			break;
		case END:
			vAlign = "GridData.END";
			break;
		case SWT.BOTTOM:
			vAlign = "SWT.BOTTOM";
			break;
		case SWT.CENTER:
			vAlign = "SWT.CENTER";
			break;
		case CENTER:
			vAlign = "GridData.CENTER";
			break;
		default:
			vAlign = "Undefined " + verticalAlignment;
			break;
	}//switch//
	
	string = "GridData {horizontalAlignment: " + hAlign + " ";
	
	if(horizontalIndent != 0)
		string += "horizontalIndent=" + horizontalIndent + " ";
	if(horizontalSpan != 1)
		string += "horizontalSpan=" + horizontalSpan + " ";
	if(grabExcessHorizontalSpace)
		string += "grabExcessHorizontalSpace=" + grabExcessHorizontalSpace + " ";
	if(widthHint != SWT.DEFAULT)
		string += "widthHint=" + widthHint + " ";
	if(minimumWidth != 0)
		string += "minimumWidth=" + minimumWidth + " ";
	string += "verticalAlignment=" + vAlign + " ";
	if(verticalIndent != 0)
		string += "verticalIndent=" + verticalIndent + " ";
	if(verticalSpan != 1)
		string += "verticalSpan=" + verticalSpan + " ";
	if(grabExcessVerticalSpace)
		string += "grabExcessVerticalSpace=" + grabExcessVerticalSpace + " ";
	if(heightHint != SWT.DEFAULT)
		string += "heightHint=" + heightHint + " ";
	if(minimumHeight != 0)
		string += "minimumHeight=" + minimumHeight + " ";
	if(exclude)
		string += "exclude=" + exclude + " ";
	
	string = string.trim();
	string += "}";
	
	return string;
}//toString()//
}//GridData//