/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.custom;

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

/**
 * The SashForm lays out its children in a Row or Column arrangement (as specified
 * by the orientation) and places a Sash between the children.
 * One child may be maximized to occupy the entire size of the SashForm.
 * The relative sizes of the children may be specfied using weights.
 *
 * <p>
 * <dl>
 * <dt><b>Styles:</b><dd>HORIZONTAL, VERTICAL
 * </dl>
 */
public class SashForm extends Composite {

	public int SASH_WIDTH = 2;

	private static final int DRAG_MINIMUM = 20;
	
	private int orientation = SWT.HORIZONTAL;
	private Sash[] sashes = new Sash[0];
	private Control[] controls = new Control[0];
	private Control maxControl = null;
	private Listener sashListener;
	private final static String LAYOUT_RATIO = "layout ratio"; 				//$NON-NLS-1$
	
	//	DWC
	private final static String LAYOUT_CONSTRAINTS = "layout constraints"; 	//$NON-NLS-1$

	public void setFixed(Control control) {
		control.setData(LAYOUT_CONSTRAINTS, new SashForm.Constraints(control));
	}
	

	private class Constraints extends Object {
		private	Control _control;
		
		//	Defaults to TRUE
		//	If set, the contained control determines the size
		//
		boolean		bSizeToContent;
		
		//	If set, the user has resized the sash area and the sash should remain fixed across resizes
		//
		long		fixedSize;	
		
		public Constraints(Control control) {
			_control = control;
			bSizeToContent = true;
			fixedSize = 0;
		}
			
		long	getSize() {
			long	retSize;
			
			//	NOTE:	Default is not passed into both compute sizes
			//				so that specific value is what gets calculated
			//				If default is sent in for both, the size is
			//				always a single line even if there is
			//				multiple lines of data.
			//
			if (bSizeToContent) {
				if (orientation == SWT.HORIZONTAL) {
					retSize = _control.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x;
				} else {
					retSize = _control.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).y;
				}
			} else {
				retSize = fixedSize;
			}
						
		return retSize;
		}
	}

/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>SWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>SWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a widget which will be the parent of the new instance (cannot be null)
 * @param style the style of widget to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 * </ul>
 *
 * @see SWT#HORIZONTAL
 * @see SWT#VERTICAL
 * @see #getStyle
 */
public SashForm(Composite parent, int style) {
	super(parent, checkStyle(style));
	if ((style & SWT.VERTICAL) != 0){
		orientation = SWT.VERTICAL;
	}
	
	this.addListener(SWT.Resize, new Listener() {
		public void handleEvent(Event e) {
			layout(true);
		}
	});
	
	sashListener = new Listener() {
		public void handleEvent(Event e) {
			onDragSash(e);
		}
	};
}
private static int checkStyle (int style) {
	int mask = SWT.BORDER | SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
	return style & mask;
}
public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget();
	Control[] controls = getControls(true);
	if (controls.length == 0) return new Point(wHint, hHint);
	
	int width = 0;
	int height = 0;
	boolean vertical = (orientation == SWT.VERTICAL);
	if (vertical) {
		height += (controls.length - 1) * SASH_WIDTH;
	} else {
		width += (controls.length - 1) * SASH_WIDTH;
	}
	for (int i = 0; i < controls.length; i++) {
		if (vertical) {
			Point size = controls[i].computeSize(wHint, SWT.DEFAULT);
			height += size.y;	
			width = Math.max(width, size.x);
		} else {
			Point size = controls[i].computeSize(SWT.DEFAULT, hHint);
			width += size.x;
			height = Math.max(height, size.y);
		}
	}
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	
	return new Point(width, height);
}
/**
 * Returns SWT.HORIZONTAL if the controls in the SashForm are laid out side by side
 * or SWT.VERTICAL   if the controls in the SashForm are laid out top to bottom.
 * 
 * @return SWT.HORIZONTAL or SWT.VERTICAL
 */
public int getOrientation() {
	//checkWidget();
	return orientation;
}
/**
 * Answer the control that currently is maximized in the SashForm.  
 * This value may be null.
 * 
 * @return the control that currently is maximized or null
 */
public Control getMaximizedControl(){
	//checkWidget();
	return this.maxControl;
}
/**
 * Answer the relative weight of each child in the SashForm.  The weight represents the
 * percent of the total width (if SashForm has Horizontal orientation) or 
 * total height (if SashForm has Vertical orientation) each control occupies.
 * The weights are returned in order of the creation of the widgets (weight[0]
 * corresponds to the weight of the first child created).
 * 
 * @return the relative weight of each child
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */

public int[] getWeights() {
	checkWidget();
	Control[] cArray = getControls(false);
	int[] ratios = new int[cArray.length];
	for (int i = 0; i < cArray.length; i++) {
		Long ratio = (Long)cArray[i].getData(LAYOUT_RATIO);
		if (ratio != null) {
			ratios[i] = (int)(ratio.longValue() * 1000 >> 16);
		} else {
			ratios[i] = 200;
		}
	}
	return ratios;
}
private Control[] getControls(boolean onlyVisible) {
	Control[] children = getChildren();
	Control[] controls = new Control[0];
	for (int i = 0; i < children.length; i++) {
		if (children[i] instanceof Sash) continue;
		if (onlyVisible && !children[i].getVisible()) continue;

		Control[] newControls = new Control[controls.length + 1];
		System.arraycopy(controls, 0, newControls, 0, controls.length);
		newControls[controls.length] = children[i];
		controls = newControls;
	}
	return controls;
}
public void layout(boolean changed) {
	checkWidget();
	Rectangle area = getClientArea();
	if (area.width == 0 || area.height == 0) return;
	
	Control[] newControls = getControls(true);
	if (controls.length == 0 && newControls.length == 0) return;
	controls = newControls;
	
	if (maxControl != null && !maxControl.isDisposed()) {
		for (int i= 0; i < controls.length; i++){
			if (controls[i] != maxControl) {
				controls[i].setBounds(-200, -200, 0, 0);
			} else {
				controls[i].setBounds(area);
			}
		}
		return;
	}
	
	// keep just the right number of sashes
	if (sashes.length < controls.length - 1) {
		Sash[] newSashes = new Sash[controls.length - 1];
		System.arraycopy(sashes, 0, newSashes, 0, sashes.length);
		int sashOrientation = (orientation == SWT.HORIZONTAL) ? SWT.VERTICAL : SWT.HORIZONTAL;
		for (int i = sashes.length; i < newSashes.length; i++) {
			newSashes[i] = new Sash(this, sashOrientation);
			newSashes[i].addListener(SWT.Selection, sashListener);
			newSashes[i].setBackground(new Color(getDisplay(), 201, 196, 179));
		}
		sashes = newSashes;
	}
	if (sashes.length > controls.length - 1) {
		if (controls.length == 0) {
			for (int i = 0; i < sashes.length; i++) {
				sashes[i].dispose();
			}
			sashes = new Sash[0];
		} else {
			Sash[] newSashes = new Sash[controls.length - 1];
			System.arraycopy(sashes, 0, newSashes, 0, newSashes.length);
			for (int i = controls.length - 1; i < sashes.length; i++) {
				sashes[i].dispose();
			}
			sashes = newSashes;
		}
	}
	
	if (controls.length == 0) return;
	
	// get the ratios
	long[] ratios = new long[controls.length];
	long[] fixed = new long[controls.length];
	long totalRatios = 0;
	long totalFixed = 0;
	
	for (int i = 0; i < controls.length; i++) {
		Long 		ratio = (Long)controls[i].getData(LAYOUT_RATIO);
		Constraints	constraints =  (Constraints )controls[i].getData(LAYOUT_CONSTRAINTS);

		if (constraints != null) {
			fixed[i] = constraints.getSize();
			totalFixed += fixed[i];
		} else {
			if (ratio != null) {
				ratios[i] = ratio.longValue();
			} else {
				ratios[i] = ((200 << 16) + 999) / 1000;
			}
			totalRatios += ratios[i];
		}
	}
	
	//	There is a fixed cost for the width/height of the sashes
	totalFixed += (long )sashes.length*SASH_WIDTH;
	
	if (orientation == SWT.HORIZONTAL) {
		long totalToAllocate = Math.max(area.width - totalFixed, 1);
		int width = (fixed[0] > 0 ? (int )fixed[0] : ( int)(ratios[0] * totalToAllocate / totalRatios));
		int x = area.x;

		controls[0].setBounds(x, area.y, width, area.height);
		x += width;
		for (int i = 1; i < controls.length - 1; i++) {
			sashes[i - 1].setBounds(x, area.y, SASH_WIDTH, area.height);
			x += SASH_WIDTH;
			width = (fixed[i] > 0 ? (int )fixed[i]: ( int)(ratios[i] * totalToAllocate / totalRatios));
			controls[i].setBounds(x, area.y, width, area.height);
			x += width;
		}
		if (controls.length > 1) {
			sashes[sashes.length - 1].setBounds(x, area.y, SASH_WIDTH, area.height);
			x += SASH_WIDTH;
			width = area.width - x;
			controls[controls.length - 1].setBounds(x, area.y, width, area.height);
		}
	} else {
		long totalToAllocate = Math.max(area.height - totalFixed, 1);
		int height = (fixed[0] > 0 ? (int )fixed[0] : (int)(ratios[0] * totalToAllocate / totalRatios));
		int y = area.y;
		controls[0].setBounds(area.x, y, area.width, height);
		y += height;
		for (int i = 1; i < controls.length - 1; i++) {
			sashes[i - 1].setBounds(area.x, y, area.width, SASH_WIDTH);
			y += SASH_WIDTH;
			height = (fixed[i] > 0 ? (int )fixed[i] : (int)(ratios[i] * totalToAllocate / totalRatios));
			controls[i].setBounds(area.x, y, area.width, height);
			y += height;
		}
		if (controls.length > 1) {
			sashes[sashes.length - 1].setBounds(area.x, y, area.width, SASH_WIDTH);
			y += SASH_WIDTH;
			height = area.height - y;
			controls[controls.length - 1].setBounds(area.x, y, area.width, height);
		}

	}
}
private void onDragSash(Event event) {
	if (event.detail == SWT.DRAG) {
		// constrain feedback
		Rectangle area = getClientArea();
		if (orientation == SWT.HORIZONTAL) {
			event.x = Math.min(Math.max(DRAG_MINIMUM, event.x), area.width - DRAG_MINIMUM);
		} else {
			event.y = Math.min(Math.max(DRAG_MINIMUM, event.y), area.height - DRAG_MINIMUM -100);
		}
		
/*
		//	Don't constrain the manual resizing/TESTING.   DO NOT SUBMIT - DWC
		
		//	See if any controls wish to be constrained and impose the restrictions
		//	NOTE:	This only works if the 1st control is constrained - TBD
		Control[] controls = getControls(true);
		for (int i = 0; i < controls.length; i++) {
			Constraints	constraints =  (Constraints )controls[i].getData(LAYOUT_CONSTRAINTS);

			if (constraints != null) {
				if (orientation == SWT.HORIZONTAL) {
					System.out.println(event.x + " would be constrained to " +
						( int) Math.min(event.x, constraints.getSize()));	
					event.x = (int) Math.min(event.x, constraints.getSize());	
				} else {
					System.out.println(event.y + " would be constrained to " +
						( int) Math.min(event.y, constraints.getSize()));	
					event.y = (int) Math.min(event.y, constraints.getSize());	
	
				}
			}
		}		
*/
				
		return;
	}

	Sash sash = (Sash)event.widget;
	int sashIndex = -1;
	for (int i= 0; i < sashes.length; i++) {
		if (sashes[i] == sash) {
			sashIndex = i;
			break;
		}
	}
	if (sashIndex == -1) return;

	Control c1 = controls[sashIndex];
	Control c2 = controls[sashIndex + 1];
	Rectangle b1 = c1.getBounds();
	Rectangle b2 = c2.getBounds();
	
	Rectangle sashBounds = sash.getBounds();
	Rectangle area = getClientArea();
	if (orientation == SWT.HORIZONTAL) {
		int shift = event.x - sashBounds.x;
		b1.width += shift;
		b2.x += shift;
		b2.width -= shift;
		if (b1.width < DRAG_MINIMUM || b2.width < DRAG_MINIMUM) {
			return;
		}
		c1.setData(LAYOUT_RATIO, new Long((((long)b1.width << 16) + area.width - 1) / area.width));
		c2.setData(LAYOUT_RATIO, new Long((((long)b2.width << 16) + area.width - 1) / area.width));		
	} else {
		int shift = event.y - sashBounds.y;
		b1.height += shift;
		b2.y += shift;
		b2.height -= shift;
		if (b1.height < DRAG_MINIMUM || b2.height < DRAG_MINIMUM) {
			return;
		}
		c1.setData(LAYOUT_RATIO, new Long((((long)b1.height << 16) + area.height - 1) / area.height));
		c2.setData(LAYOUT_RATIO, new Long((((long)b2.height << 16) + area.height - 1) / area.height));
	}
	
	c1.setBounds(b1);
	sash.setBounds(event.x, event.y, event.width, event.height);
	c2.setBounds(b2);
}
/**
 * If orientation is SWT.HORIZONTAL, lay the controls in the SashForm 
 * out side by side.  If orientation is SWT.VERTICAL, lay the 
 * controls in the SashForm out top to bottom.
 * 
 * @param orientation SWT.HORIZONTAL or SWT.VERTICAL
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the value of orientation is not SWT.HORIZONTAL or SWT.VERTICAL
 * </ul>
 */
public void setOrientation(int orientation) {
	checkWidget();
	if (this.orientation == orientation) return;
	if (orientation != SWT.HORIZONTAL && orientation != SWT.VERTICAL) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	this.orientation = orientation;
	
	int sashOrientation = (orientation == SWT.HORIZONTAL) ? SWT.VERTICAL : SWT.HORIZONTAL;
	for (int i = 0; i < sashes.length; i++) {
		sashes[i].dispose();
		sashes[i] = new Sash(this, sashOrientation);
		sashes[i].addListener(SWT.Selection, sashListener);
	}
	layout();
}
public void setLayout (Layout layout) {
	checkWidget();
}
/**
 * Specify the control that should take up the entire client area of the SashForm.  
 * If one control has been maximized, and this method is called with a different control, 
 * the previous control will be minimized and the new control will be maximized..
 * if the value of control is null, the SashForm will minimize all controls and return to
 * the default layout where all controls are laid out separated by sashes.
 * 
 * @param control the control to be maximized or null
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setMaximizedControl(Control control){
	checkWidget();
	if (control == null) {
		if (maxControl != null) {
			this.maxControl = null;
			layout();
			for (int i= 0; i < sashes.length; i++){
				sashes[i].setVisible(true);
			}
		}
		return;
	}
	
	for (int i= 0; i < sashes.length; i++){
		sashes[i].setVisible(false);
	}
	maxControl = control;
	layout();
}

/**
 * Specify the relative weight of each child in the SashForm.  This will determine
 * what percent of the total width (if SashForm has Horizontal orientation) or 
 * total height (if SashForm has Vertical orientation) each control will occupy.
 * The weights must be positive values and there must be an entry for each
 * non-sash child of the SashForm.
 * 
 * @param weights the relative weight of each child
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the weights value is null or of incorrect length (must match the number of children)</li>
 * </ul>
 */
public void setWeights(int[] weights) {
	checkWidget();
	Control[] cArray = getControls(false);
	if (weights == null || weights.length != cArray.length) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	
	int total = 0;
	for (int i = 0; i < weights.length; i++) {
		if (weights[i] < 0) {
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		}
		total += weights[i];
	}
	if (total == 0) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	for (int i = 0; i < cArray.length; i++) {
		cArray[i].setData(LAYOUT_RATIO, new Long((((long)weights[i] << 16) + total - 1) / total));
	}

	layout();
}
}