/*******************************************************************************
 * Copyright (c) 2000, 2008 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
 *     
 * Port to the D programming language:
 *     Jacob Carlborg <doob@me.com>
 *******************************************************************************/
module dwt.widgets.TabFolder;

import dwt.dwthelper.utils;


import dwt.DWT;
import dwt.DWTException;
import dwt.events.SelectionEvent;
import dwt.events.SelectionListener;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.internal.cocoa.NSFont;
import dwt.internal.cocoa.NSPoint;
import dwt.internal.cocoa.NSRect;
import dwt.internal.cocoa.NSSize;
import dwt.internal.cocoa.NSTabView;
import dwt.internal.cocoa.NSTabViewItem;
import dwt.internal.cocoa.NSView;
import dwt.internal.cocoa.OS;
import dwt.internal.cocoa.SWTTabView;

import objc = dwt.internal.objc.runtime;
import dwt.widgets.Composite;
import dwt.widgets.Control;
import dwt.widgets.Event;
import dwt.widgets.TabItem;
import dwt.widgets.TypedListener;

/**
 * Instances of this class implement the notebook user interface
 * metaphor.  It allows the user to select a notebook page from
 * set of pages.
 * <p>
 * The item children that may be added to instances of this class
 * must be of type <code>TabItem</code>.
 * <code>Control</code> children are created and then set into a
 * tab item using <code>TabItem#setControl</code>.
 * </p><p>
 * Note that although this class is a subclass of <code>Composite</code>,
 * it does not make sense to set a layout on it.
 * </p><p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>TOP, BOTTOM</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles TOP and BOTTOM may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 *
 * @see <a href="http://www.eclipse.org/swt/snippets/#tabfolder">TabFolder, TabItem snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">DWT Example: ControlExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */
public class TabFolder : Composite {
    TabItem [] items;
    int itemCount;
    bool ignoreSelect;
    
/**
 * 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
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public this (Composite parent, int style) {
    super (parent, checkStyle (style));
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the user changes the receiver's selection, by sending
 * it one of the messages defined in the <code>SelectionListener</code>
 * interface.
 * <p>
 * When <code>widgetSelected</code> is called, the item field of the event object is valid.
 * <code>widgetDefaultSelected</code> is not called.
 * </p>
 *
 * @param listener the listener which should be notified when the user changes the receiver's selection
 *
 * @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) {
    style = checkBits (style, DWT.TOP, DWT.BOTTOM, 0, 0, 0, 0);
    /*
     * Even though it is legal to create this widget
     * with scroll bars, they serve no useful purpose
     * because they do not automatically scroll the
     * widget's client area.  The fix is to clear
     * the DWT style.
     */
    return style & ~(DWT.H_SCROLL | DWT.V_SCROLL);
}

protected void checkSubclass () {
    if (!isValidSubclass ()) error (DWT.ERROR_INVALID_SUBCLASS);
}

public Point computeSize (int wHint, int hHint, bool changed) {
    Point size = super.computeSize (wHint, hHint, changed);
    if (wHint is DWT.DEFAULT && items.length > 0) {
        NSSize minSize = (cast(NSTabView)view).minimumSize();
        Rectangle trim = computeTrim (0, 0, cast(int)Math.ceil (minSize.width), 0);
        size.x = Math.max (trim.width, size.x);
    }
    return size;
}

public Rectangle computeTrim (int x, int y, int width, int height) {
    checkWidget ();
    NSTabView widget = cast(NSTabView)view;
    NSRect rect = widget.contentRect ();
    x -= rect.x; y -= rect.y;
    width += Math.ceil (rect.x); height += Math.ceil (rect.y);
    return super.computeTrim (x, y, width, height);
}

void createHandle () {
    NSTabView widget = cast(NSTabView)(new SWTTabView()).alloc();
    widget.initWithFrame (NSRect());
    widget.setDelegate(widget);
    if ((style & DWT.BOTTOM) !is 0) {
        widget.setTabViewType(OS.NSBottomTabsBezelBorder);
    }
    view = widget;
}

void createItem (TabItem item, int index) {
    int count = itemCount;
    if (!(0 <= index && index <= count)) error (DWT.ERROR_INVALID_RANGE);
    if (count is items.length) {
        TabItem [] newItems = new TabItem [items.length + 4];
        System.arraycopy (items, 0, newItems, 0, items.length);
        items = newItems;
    }
    System.arraycopy (items, index, items, index + 1, count - index);
    items [index] = item;
    itemCount++;
    NSTabViewItem nsItem = cast(NSTabViewItem)(new NSTabViewItem()).alloc().init();
    item.nsItem = nsItem;
    (cast(NSTabView)view).insertTabViewItem(nsItem, index);
}

void createWidget () {
    super.createWidget ();
    items = new TabItem [4];
}

void destroyItem (TabItem item) {
    int count = itemCount;
    int index = 0;
    while (index < count) {
        if (items [index] is item) break;
        index++;
    }
    if (index is count) return;
    --count;
    System.arraycopy (items, index + 1, items, index, count - index);
    items [count] = null;
    if (count is 0) {
        items = new TabItem [4];
    }
    itemCount = count;
    (cast(NSTabView)view).removeTabViewItem(item.nsItem);
}

public Rectangle getClientArea () {
    checkWidget ();
    NSRect rect = (cast(NSTabView)view).contentRect();
    int x = Math.max (0, cast(int)rect.x);
    int y = Math.max (0, cast(int)rect.y);
    int width = Math.max (0, cast(int)Math.ceil (rect.width));
    int height = Math.max (0, cast(int)Math.ceil (rect.height));
    return new Rectangle (x, y, width, height);
}

/**
 * Returns the item at the given, zero-relative index in the
 * receiver. Throws an exception if the index is out of range.
 *
 * @param index the index of the item to return
 * @return the item at the given index
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</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>
 */
public TabItem getItem (int index) {
    checkWidget ();
    int count = itemCount;
    if (!(0 <= index && index < count)) error (DWT.ERROR_INVALID_RANGE);
    return items [index];
}

/**
 * Returns the tab item at the given point in the receiver
 * or null if no such item exists. The point is in the
 * coordinate system of the receiver.
 *
 * @param point the point used to locate the item
 * @return the tab item at the given point, or null if the point is not in a tab item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point 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>
 * 
 * @since 3.4
 */
public TabItem getItem (Point point) {
    checkWidget ();
    if (point is null) error (DWT.ERROR_NULL_ARGUMENT);
    NSPoint nsPoint = NSPoint ();
    nsPoint.x = point.x;
    nsPoint.y = point.y;
    NSTabView tabView = cast(NSTabView) view;
    NSTabViewItem tabViewItem = tabView.tabViewItemAtPoint (nsPoint);
    for (int i = 0; i < itemCount; i++) {
        NSTabViewItem item = items[i].nsItem;
        if (item.isEqual (tabViewItem)) {
            return items [i];
        }
    }
    return null;
}

/**
 * Returns the number of items contained in the receiver.
 *
 * @return the number of items
 *
 * @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>
 */
public int getItemCount () {
    checkWidget ();
    return itemCount;
}

/**
 * Returns an array of <code>TabItem</code>s which are the items
 * in the receiver. 
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver. 
 * </p>
 *
 * @return the items in the receiver
 *
 * @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>
 */
public TabItem [] getItems () {
    checkWidget ();
    int count = itemCount;
    TabItem [] result = new TabItem [count];
    System.arraycopy (items, 0, result, 0, count);
    return result;
}

/**
 * Returns an array of <code>TabItem</code>s that are currently
 * selected in the receiver. An empty array indicates that no
 * items are selected.
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its selection, so modifying the array will
 * not affect the receiver. 
 * </p>
 * @return an array representing the selection
 *
 * @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>
 */
public TabItem [] getSelection () {
    checkWidget ();
    int index = getSelectionIndex ();
    if (index is -1) return new TabItem [0];
    return [items [index]];
}

/**
 * Returns the zero-relative index of the item which is currently
 * selected in the receiver, or -1 if no item is selected.
 *
 * @return the index of the selected item
 *
 * @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>
 */
public int getSelectionIndex () {
    checkWidget ();
    NSTabViewItem selected =  (cast(NSTabView)view).selectedTabViewItem();
    if (selected is null) return -1;
    for (int i = 0; i < itemCount; i++) {
        if (items[i].nsItem.id is selected.id) return i;
    }
    return -1;
}

float getThemeAlpha () {
    return 0.25f * parent.getThemeAlpha ();
}

/**
 * Searches the receiver's list starting at the first item
 * (index 0) until an item is found that is equal to the 
 * argument, and returns the index of that item. If no item
 * is found, returns -1.
 *
 * @param item the search item
 * @return the index of the item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item 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>
 */
public int indexOf (TabItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    int count = itemCount;
    for (int i=0; i<count; i++) {
        if (items [i] is item) return i;
    }
    return -1;
}

Point minimumSize (int wHint, int hHint, bool flushCache) {
    Control [] children = _getChildren ();
    int width = 0, height = 0;
    for (int i=0; i<children.length; i++) {
        Control child = children [i];
        int index = 0;
        int count = itemCount;
        while (index < count) {
            if (items [index].control is child) break;
            index++;
        }
        if (index is count) {
            Rectangle rect = child.getBounds ();
            width = Math.max (width, rect.x + rect.width);
            height = Math.max (height, rect.y + rect.height);
        } else {
            Point size = child.computeSize (wHint, hHint, flushCache);
            width = Math.max (width, size.x);
            height = Math.max (height, size.y);
        }
    }
    return new Point (width, height);
}

void releaseChildren (bool destroy) {
    if (items !is null) {
        for (int i=0; i<items.length; i++) {
            TabItem item = items [i];
            if (item !is null && !item.isDisposed ()) {
                item.release (false);
            }
        }
        items = null;
    }
    super.releaseChildren (destroy);
}

void removeControl (Control control) {
    super.removeControl (control);
    int count = itemCount;
    for (int i=0; i<count; i++) {
        TabItem item = items [i];
        if (item.control is control) item.setControl (null);
    }
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the user changes the receiver's selection.
 *
 * @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);  
}

void setFont (NSFont font) {
    (cast(NSTabView)view).setFont(font);
}

/**
 * Sets the receiver's selection to the given item.
 * The current selected is first cleared, then the new item is
 * selected.
 *
 * @param item the item to select
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item 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>
 * 
 * @since 3.2
 */
public void setSelection (TabItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    setSelection ([item]);
}

/**
 * Sets the receiver's selection to be the given array of items.
 * The current selected is first cleared, then the new items are
 * selected.
 *
 * @param items the array of items
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the items array 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>
 */
public void setSelection (TabItem [] items) {
    checkWidget ();
    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (items.length is 0) {
        setSelection (-1, false, false);
    } else {
        for (int i=items.length - 1; i>=0; --i) {
            int index = indexOf (items [i]);
            if (index !is -1) setSelection (index, false, false);
        }
    }
}

/**
 * Selects the item at the given zero-relative index in the receiver. 
 * If the item at the index was already selected, it remains selected.
 * The current selection is first cleared, then the new items are
 * selected. Indices that are out of range are ignored.
 *
 * @param index the index of the item to select
 *
 * @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>
 */
public void setSelection (int index) {
    checkWidget ();
    int count = itemCount;
    if (!(0 <= index && index < count)) return;
    setSelection (index, false, false);
}

void setSelection (int index, bool notify, bool force) {
    if (!(0 <= index && index < itemCount)) return;
    int currentIndex = getSelectionIndex ();
    if (!force && currentIndex is index) return;
    if (currentIndex !is -1) {
        TabItem item = items [currentIndex];
        if (item !is null) {
            Control control = item.control;
            if (control !is null && !control.isDisposed ()) {
                control.setVisible (false);
            }
        }
    }
    ignoreSelect = true;
    ignoreSelect = false;
    index = getSelectionIndex();
    if (index !is -1) {
        TabItem item = items [index];
        if (item !is null) {
            Control control = item.control;
            if (control !is null && !control.isDisposed ()) {
                control.setVisible (true);
            }
            if (notify) {
                Event event = new Event ();
                event.item = item;
                sendEvent (DWT.Selection, event);
            }
        }
    }
}

bool traversePage (bool next) {
    int count = getItemCount ();
    if (count is 0) return false;
    int index = getSelectionIndex ();
    if (index is -1) {
        index = 0;
    } else {
        int offset = (next) ? 1 : -1;
        index = (index + offset + count) % count;
    }
    setSelection (index, true, false);
    return index is getSelectionIndex ();
}

void tabView_willSelectTabViewItem(objc.id id, objc.SEL sel, objc.id tabView, objc.id tabViewItem) {
    if (tabViewItem is null) return;
    for (int i = 0; i < itemCount; i++) {
        TabItem item = items [i];
        if (item.nsItem.id is tabViewItem) {
            int currentIndex = getSelectionIndex ();
            if (currentIndex !is -1) {
                TabItem selected = items [currentIndex];
                if (selected !is null) {
                    Control control = selected.control;
                    if (control !is null && !control.isDisposed ()) {
                        control.setVisible (false);
                    }
                }
            }
            Control control = item.control;
            if (control !is null && !control.isDisposed ()) {
                control.setVisible (true);
            }
            break;
        }
    }
}

void tabView_didSelectTabViewItem(objc.id id, objc.SEL sel, objc.id tabView, objc.id tabViewItem) {
    if (tabViewItem is null) return;
    for (int i = 0; i < itemCount; i++) {
        TabItem item = items [i];
        /*
         * Feature in Cocoa.  For some reason the control on a tab being
         * deselected has its parent removed natively.  The fix is to
         * re-set the control's parent.
         */
        Control control = item.control;
        if (control !is null) {
            NSView topView = control.topView ();
            if (topView.superview () is null) {
                contentView ().addSubview (topView, OS.NSWindowBelow, null);
            }
        }
        if (item.nsItem.id is tabViewItem) {
            if (!ignoreSelect) {
                Event event = new Event ();
                event.item = item;
                postEvent (DWT.Selection, event);
            }
        }
    }
}

}