/*******************************************************************************
 * 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
 *******************************************************************************/
module dwt.widgets.Sash;

import dwt.dwthelper.utils;

import dwt.DWT;
import dwt.DWTException;
import dwt.events.SelectionEvent;
import dwt.events.SelectionListener;
import dwt.graphics.Cursor;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.internal.cocoa.NSEvent;
import dwt.internal.cocoa.NSPoint;
import dwt.internal.cocoa.NSRect;
import dwt.internal.cocoa.OS;
import dwt.internal.cocoa.SWTView;

/**
 * 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 DWT implementation.
 * </p>
 */
public class Sash : Control {
    Cursor sizeCursor;
    bool 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>DWT</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>DWT</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 DWTException <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 DWT#HORIZONTAL
 * @see DWT#VERTICAL
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Sash (Composite parent, int style) {
    super (parent, checkStyle (style));
    int cursorStyle = (style & DWT.VERTICAL) !is 0 ? DWT.CURSOR_SIZEWE : DWT.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>DWT.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 DWTException <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 is null) error (DWT.ERROR_NULL_ARGUMENT);
    TypedListener typedListener = new TypedListener(listener);
    addListener(DWT.Selection,typedListener);
    addListener(DWT.DefaultSelection,typedListener);
}

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

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

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

bool 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) !is 0) stepSize = INCREMENT;
            if ((style & DWT.VERTICAL) !is 0) {
                if (keyCode is 126 || keyCode is 125) break;
                xChange = keyCode is 123 ? -stepSize : stepSize;
            } else {
                if (keyCode is 123 || keyCode  is 124) break;
                yChange = keyCode is 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 & DWT.VERTICAL) !is 0) {
                newX = Math.min (Math.max (0, lastX + xChange), parentWidth - width);
            } else {
                newY = Math.min (Math.max (0, lastY + yChange), parentHeight - height);
            }
            if (newX is lastX && newY is lastY) return true;
            Event event = new Event ();
            event.x = newX;
            event.y = newY;
            event.width = width;
            event.height = height;
            sendEvent (DWT.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 & DWT.VERTICAL) !is 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() !is 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 (DWT.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 & DWT.VERTICAL) !is 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 is lastX && newY is lastY) return;
    Event event = new Event ();
    event.x = newX;
    event.y = newY;
    event.width = (int)frame.width;
    event.height = (int)frame.height;
    sendEvent (DWT.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 (DWT.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 !is 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 DWTException <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 is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (eventTable is null) return;
    eventTable.unhook(DWT.Selection, listener);
    eventTable.unhook(DWT.DefaultSelection,listener);
}

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

}