/*******************************************************************************
 * Copyright (c) 2000, 2007 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.swt.widgets;

import org.eclipse.swt.internal.cocoa.*;

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

/**
 * Instances of the receiver represent a selectable user interface object
 * that allows the user to drag a rubber banded outline of the sash within
 * the parent control.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>HORIZONTAL, VERTICAL, SMOOTH</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.
 * </p><p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the SWT implementation.
 * </p>
 */
public class Sash extends Control {
	Cursor sizeCursor;
	boolean dragging;
	int lastX, lastY, startX, startY;
	private final static int INCREMENT = 1;
	private final static int PAGE_INCREMENT = 9;

/**
 * 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 composite control which will be the parent of the new instance (cannot be null)
 * @param style the style of control 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>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#HORIZONTAL
 * @see SWT#VERTICAL
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Sash (Composite parent, int style) {
	super (parent, checkStyle (style));
	int cursorStyle = (style & SWT.VERTICAL) != 0 ? SWT.CURSOR_SIZEWE : SWT.CURSOR_SIZENS;
	sizeCursor = new Cursor (display, cursorStyle);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the control is selected by the user, by sending
 * it one of the messages defined in the <code>SelectionListener</code>
 * interface.
 * <p>
 * When <code>widgetSelected</code> is called, the x, y, width, and height fields of the event object are valid.
 * If the receiver is being dragged, the event object detail field contains the value <code>SWT.DRAG</code>.
 * <code>widgetDefaultSelected</code> is not called.
 * </p>
 *
 * @param listener the listener which should be notified when the control is selected by the user
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @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>
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener(SelectionListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener(listener);
	addListener(SWT.Selection,typedListener);
	addListener(SWT.DefaultSelection,typedListener);
}

static int checkStyle (int style) {
	/*
	* Macintosh only supports smooth dragging.
	*/
	style |= SWT.SMOOTH;
	return checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0);
}

boolean becomeFirstResponder () {
	boolean result = super.becomeFirstResponder();
	NSRect frame = view.frame();
	lastX = (int)frame.x;
	lastY = (int)frame.y;
	return result;
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget();
	int width = 0, height = 0;
	if ((style & SWT.HORIZONTAL) != 0) {
		width += DEFAULT_WIDTH;  height += 5;
	} else {
		width += 5; height += DEFAULT_HEIGHT;
	}
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	return new Point (width, height);
}

void createHandle () {
	SWTView widget = (SWTView)new SWTView().alloc();
	widget.initWithFrame (new NSRect());
	widget.setTag(jniRef);
	view = widget;
	parent.contentView().addSubview_(view);
}

boolean sendKeyEvent(NSEvent nsEvent, int type) {
	//TODO consumed
	int keyCode = nsEvent.keyCode();
	switch (keyCode) {
		case 126: /* Up arrow */
		case 123: /* Left arrow */
		case 125: /* Down arrow */
		case 124: /* Right arrow */ {
			int xChange = 0, yChange = 0;
			int stepSize = PAGE_INCREMENT;
			int modifiers = nsEvent.modifierFlags();
			if ((modifiers & OS.NSControlKeyMask) != 0) stepSize = INCREMENT;
			if ((style & SWT.VERTICAL) != 0) {
				if (keyCode == 126 || keyCode == 125) break;
				xChange = keyCode == 123 ? -stepSize : stepSize;
			} else {
				if (keyCode == 123 || keyCode  == 124) break;
				yChange = keyCode == 126 ? -stepSize : stepSize;
			}
			
			Rectangle bounds = getBounds ();
			int width = bounds.width, height = bounds.height;
			Rectangle parentBounds = parent.getBounds ();
			int parentWidth = parentBounds.width;
			int parentHeight = parentBounds.height;
			int newX = lastX, newY = lastY;
			if ((style & SWT.VERTICAL) != 0) {
				newX = Math.min (Math.max (0, lastX + xChange), parentWidth - width);
			} else {
				newY = Math.min (Math.max (0, lastY + yChange), parentHeight - height);
			}
			if (newX == lastX && newY == lastY) return true;
			Event event = new Event ();
			event.x = newX;
			event.y = newY;
			event.width = width;
			event.height = height;
			sendEvent (SWT.Selection, event);
			if (isDisposed ()) break;
			if (event.doit) {
				setBounds (event.x, event.y, width, height);
				if (isDisposed ()) break;
				lastX = event.x;
				lastY = event.y;
				if (isDisposed ()) return false;
				int cursorX = event.x, cursorY = event.y;
				if ((style & SWT.VERTICAL) != 0) {
					cursorY += height / 2;
				} else {
					cursorX += width / 2;
				}
				display.setCursorLocation (parent.toDisplay (cursorX, cursorY));
			}
			break;
		}
	}
	return true;
}

void mouseDown(int theEvent) {
	super.mouseDown(theEvent);
	NSEvent nsEvent = new NSEvent(theEvent);
	if (nsEvent.clickCount() != 1) return;
	NSPoint location = nsEvent.locationInWindow();
	NSPoint point = view.convertPoint_fromView_(location, null);
	startX = (int)point.x;
	startY = (int)point.y;
	NSRect frame = view.frame();
	Event event = new Event ();
	event.x = (int)frame.x;
	event.y = (int)frame.y;
	event.width = (int)frame.width;
	event.height = (int)frame.height;
	sendEvent (SWT.Selection, event);
	if (isDisposed ()) return;
	if (event.doit) {
		lastX = event.x;
		lastY = event.y;
		dragging = true;
		setLocation(event.x, event.y);
	}
}

void mouseDragged(int theEvent) {
	super.mouseDragged(theEvent);
	if (!dragging) return;
	NSEvent nsEvent = new NSEvent(theEvent);
	NSPoint location = nsEvent.locationInWindow();
	NSPoint point = view.convertPoint_fromView_(location, null);
	NSRect frame = view.frame();
	NSRect parentFrame = parent.topView().frame();
	int newX = lastX, newY = lastY;
	if ((style & SWT.VERTICAL) != 0) {
		newX = Math.min (Math.max (0, (int)(point.x + frame.x - startX)), (int)(parentFrame.width - frame.width));
	} else {
		newY = Math.min (Math.max (0, (int)(point.y + frame.y - startY)), (int)(parentFrame.height - frame.height));
	}
	if (newX == lastX && newY == lastY) return;
	Event event = new Event ();
	event.x = newX;
	event.y = newY;
	event.width = (int)frame.width;
	event.height = (int)frame.height;
	sendEvent (SWT.Selection, event);
	if (isDisposed ()) return;
	if (event.doit) {
		lastX = event.x;
		lastY = event.y;
		setBounds (event.x, event.y, (int)frame.width, (int)frame.height);
	}
}

void mouseEntered(int theEvent) {
	//TODO need to add tracking area
	super.mouseEntered(theEvent);
	sizeCursor.handle.set();
}

void mouseUp(int theEvent) {
	super.mouseUp(theEvent);
	if (!dragging) return;
	dragging = false;
	NSRect frame = view.frame();
	Event event = new Event ();
	event.x = lastX;
	event.y = lastY;
	event.width = (int)frame.width;
	event.height = (int)frame.height;
	sendEvent (SWT.Selection, event);
	if (isDisposed ()) return;
	if (event.doit) {
		setBounds (event.x, event.y, (int)frame.width, (int)frame.height);
	}
}

void releaseWidget () {
	super.releaseWidget ();
	if (sizeCursor != null) sizeCursor.dispose ();
	sizeCursor = null;
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the control is selected by the user.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @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>
 *
 * @see SelectionListener
 * @see #addSelectionListener
 */
public void removeSelectionListener(SelectionListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook(SWT.Selection, listener);
	eventTable.unhook(SWT.DefaultSelection,listener);
}

void resetCursorRects (int id, int sel) {
	super.resetCursorRects (id, sel);
	Cursor cursor = findCursor();
	if (cursor == null)	{
		cursor = display.getSystemCursor((style & SWT.HORIZONTAL) != 0 ? SWT.CURSOR_SIZENS : SWT.CURSOR_SIZEWE);
		view.addCursorRect(view.visibleRect(), cursor.handle);
	}
}

int traversalCode (int key, NSEvent theEvent) {
	return 0;
}

}