/*******************************************************************************
 * 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.Tree;

import dwt.dwthelper.utils;

 
import dwt.DWT;
import dwt.DWTException;
import dwt.events.SelectionEvent;
import dwt.events.SelectionListener;
import dwt.events.TreeListener;
import dwt.graphics.Color;
import dwt.graphics.Font;
import dwt.graphics.Image;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.internal.cocoa.NSBrowserCell;
import dwt.internal.cocoa.NSButtonCell;
import dwt.internal.cocoa.NSIndexSet;
import dwt.internal.cocoa.NSNumber;
import dwt.internal.cocoa.NSOutlineView;
import dwt.internal.cocoa.NSRect;
import dwt.internal.cocoa.NSString;
import dwt.internal.cocoa.NSTableColumn;
import dwt.internal.cocoa.NSTableHeaderView;
import dwt.internal.cocoa.NSTableView;
import dwt.internal.cocoa.OS;
import dwt.internal.cocoa.SWTOutlineView;
import dwt.internal.cocoa.SWTScrollView;
import dwt.internal.cocoa.SWTTreeItem;
import dwt.internal.cocoa.id;

/**
 * Instances of this class provide a selectable user interface object
 * that displays a hierarchy of items and issues notification when an
 * item in the hierarchy is selected.
 * <p>
 * The item children that may be added to instances of this class
 * must be of type <code>TreeItem</code>.
 * </p><p>
 * Style <code>VIRTUAL</code> is used to create a <code>Tree</code> whose
 * <code>TreeItem</code>s are to be populated by the client on an on-demand basis
 * instead of up-front.  This can provide significant performance improvements for
 * trees that are very large or for which <code>TreeItem</code> population is
 * expensive (for example, retrieving values from an external source).
 * </p><p>
 * Here is an example of using a <code>Tree</code> with style <code>VIRTUAL</code>:
 * <code><pre>
 *  final Tree tree = new Tree(parent, DWT.VIRTUAL | DWT.BORDER);
 *  tree.setItemCount(20);
 *  tree.addListener(DWT.SetData, new Listener() {
 *      public void handleEvent(Event event) {
 *          TreeItem item = (TreeItem)event.item;
 *          TreeItem parentItem = item.getParentItem();
 *          String text = null;
 *          if (parentItem is null) {
 *              text = "node " + tree.indexOf(item);
 *          } else {
 *              text = parentItem.getText() + " - " + parentItem.indexOf(item);
 *          }
 *          item.setText(text);
 *          System.out.println(text);
 *          item.setItemCount(10);
 *      }
 *  });
 * </pre></code>
 * </p><p>
 * Note that although this class is a subclass of <code>Composite</code>,
 * it does not make sense to add <code>Control</code> children to it,
 * or set a layout on it.
 * </p><p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SINGLE, MULTI, CHECK, FULL_SELECTION, VIRTUAL</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection, DefaultSelection, Collapse, Expand, SetData, MeasureItem, EraseItem, PaintItem</dd>
 * </dl>
 * </p><p>
 * Note: Only one of the styles SINGLE and MULTI may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */
public class Tree extends Composite {
    NSTableColumn firstColumn, checkColumn;
    NSTableHeaderView headerView;
    TreeItem [] items;
    int itemCount;
    TreeColumn [] columns;
    TreeColumn sortColumn;
    int columnCount;
    int sortDirection;
    bool ignoreExpand, 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#SINGLE
 * @see DWT#MULTI
 * @see DWT#CHECK
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Tree (Composite parent, int style) {
    super (parent, checkStyle (style));
}

void _addListener (int eventType, Listener listener) {
    super._addListener (eventType, listener);
    for (int i = 0; i < items.length; i++) {
        if (items [i] !is null) items [i].width = -1;        
    }
}

TreeItem _getItem (TreeItem parentItem, int index) {
    int count;
    TreeItem[] items;
    if (parentItem !is null) {
        count = parentItem.itemCount;
        items = parentItem.items;
    } else {
        count = this.itemCount;
        items = this.items;
    }
    if (index < 0 || index >= count) return null;
    TreeItem item = items [index]; 
    if (item !is null || (style & DWT.VIRTUAL) is 0) return item;
    item = new TreeItem (this, parentItem, DWT.NONE, index, false);
    items [index] = item;
    return item;
}

/**
 * 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.
 * If the receiver has the <code>DWT.CHECK</code> style and the check selection changes,
 * the event object detail field contains the value <code>DWT.CHECK</code>.
 * <code>widgetDefaultSelected</code> is typically called when an item is double-clicked.
 * The item field of the event object is valid for default selection, but the detail field is not used.
 * </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);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when an item in the receiver is expanded or collapsed
 * by sending it one of the messages defined in the <code>TreeListener</code>
 * interface.
 *
 * @param listener the listener which should 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 TreeListener
 * @see #removeTreeListener
 */
public void addTreeListener(TreeListener listener) {
    checkWidget ();
    if (listener is null) error (DWT.ERROR_NULL_ARGUMENT);
    TypedListener typedListener = new TypedListener (listener);
    addListener (DWT.Expand, typedListener);
    addListener (DWT.Collapse, typedListener);
}

bool checkData (TreeItem item, bool redraw) {
    if (item.cached) return true;
    if ((style & DWT.VIRTUAL) !is 0) {
        item.cached = true;
        Event event = new Event ();
        TreeItem parentItem = item.getParentItem ();
        event.item = item;
        event.index = parentItem is null ? indexOf (item) : parentItem.indexOf (item);
//      ignoreRedraw = true;
        sendEvent (DWT.SetData, event);
        //widget could be disposed at this point
//      ignoreRedraw = false;
        if (isDisposed () || item.isDisposed ()) return false;
        if (redraw) {
//          if (!setScrollWidth (item)) item.redraw (OS.kDataBrowserNoItem);
        }
    }
    return true;
}

static int checkStyle (int style) {
    /*
    * Feature in Windows.  Even when WS_HSCROLL or
    * WS_VSCROLL is not specified, Windows creates
    * trees and tables with scroll bars.  The fix
    * is to set H_SCROLL and V_SCROLL.
    * 
    * NOTE: This code appears on all platforms so that
    * applications have consistent scroll bar behavior.
    */
    if ((style & DWT.NO_SCROLL) is 0) {
        style |= DWT.H_SCROLL | DWT.V_SCROLL;
    }
    return checkBits (style, DWT.SINGLE, DWT.MULTI, 0, 0, 0, 0);
}

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

void clear (TreeItem parentItem, int index, bool all) {
//  int [] ids = parentItem is null ? childIds : parentItem.childIds;
//  TreeItem item = _getItem (ids [index], false);
//  if (item !is null) {
//      item.clear();
//      if (all) {
//          clearAll (item, true);
//      } else {
//          int container = parentItem is null ? OS.kDataBrowserNoItem : parentItem.id;
//          OS.UpdateDataBrowserItems (handle, container, 1, new int[] {item.id}, OS.kDataBrowserItemNoProperty, OS.kDataBrowserNoItem);
//      }
//  }
}

void clearAll (TreeItem parentItem, bool all) {
//  bool update = !inClearAll;
//  int count = getItemCount (parentItem);
//  if (count is 0) return;
//  inClearAll = true;
//  int [] ids = parentItem is null ? childIds : parentItem.childIds;
//  for (int i=0; i<count; i++) {
//      TreeItem item = _getItem (ids [i], false);
//      if (item !is null) {
//          item.clear ();
//          if (all) clearAll (item, true);
//      }
//  }
//  if (update) {
//      OS.UpdateDataBrowserItems (handle, 0, 0, null, OS.kDataBrowserItemNoProperty, OS.kDataBrowserNoItem);
//      inClearAll = false;
//  }
}

/**
 * Clears the item at the given zero-relative index in the receiver.
 * The text, icon and other attributes of the item are set to the default
 * value.  If the tree was created with the <code>DWT.VIRTUAL</code> style,
 * these attributes are requested again as needed.
 *
 * @param index the index of the item to clear
 * @param all <code>true</code> if all child items of the indexed item should be
 * cleared recursively, and <code>false</code> otherwise
 *
 * @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>
 * 
 * @see DWT#VIRTUAL
 * @see DWT#SetData
 * 
 * @since 3.2
 */
public void clear (int index, bool all) {
    checkWidget ();
    int count = getItemCount ();
    if (index < 0 || index >= count) error (DWT.ERROR_INVALID_RANGE);
    clear (null, index, all);
}

/**
 * Clears all the items in the receiver. The text, icon and other
 * attributes of the items are set to their default values. If the
 * tree was created with the <code>DWT.VIRTUAL</code> style, these
 * attributes are requested again as needed.
 * 
 * @param all <code>true</code> if all child items should be cleared
 * recursively, and <code>false</code> otherwise
 *
 * @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 DWT#VIRTUAL
 * @see DWT#SetData
 * 
 * @since 3.2
 */
public void clearAll (bool all) {
    checkWidget ();
    clearAll (null, all);
}

public Point computeSize (int wHint, int hHint, bool changed) {
    checkWidget ();
    int width = 0, height = 0;
    if (wHint is DWT.DEFAULT) {
        if (columnCount !is 0) {
            for (int i=0; i<columnCount; i++) {
                width += columns [i].getWidth ();
            }
        } else {
//          int levelIndent = DISCLOSURE_COLUMN_LEVEL_INDENT;
//          if (OS.VERSION >= 0x1040) {
//              float [] metric = new float [1];
//              OS.DataBrowserGetMetric (handle, OS.kDataBrowserMetricDisclosureColumnPerDepthGap, null, metric);
//              levelIndent = (int) metric [0];
//          }
//          GC gc = new GC (this);
//          width = calculateWidth (childIds, gc, true, 0, levelIndent);
//          gc.dispose ();
//          width += getInsetWidth (column_id, true);
        }
        if ((style & DWT.CHECK) !is 0) width += getCheckColumnWidth ();
    } else {
        width = wHint;
    }
    if (hHint is DWT.DEFAULT) {
        height = ((NSTableView)view).numberOfRows() * getItemHeight () + getHeaderHeight();
    } else {
        height = hHint;
    }
    if (width <= 0) width = DEFAULT_WIDTH;
    if (height <= 0) height = DEFAULT_HEIGHT;
    Rectangle rect = computeTrim (0, 0, width, height);
    return new Point (rect.width, rect.height);
}

void createHandle () {
    SWTScrollView scrollWidget = (SWTScrollView)new SWTScrollView().alloc();
    scrollWidget.initWithFrame(new NSRect ());
    scrollWidget.setHasHorizontalScroller(true);
    scrollWidget.setHasVerticalScroller(true);
    scrollWidget.setAutohidesScrollers(true);
    scrollWidget.setBorderType(hasBorder() ? OS.NSBezelBorder : OS.NSNoBorder);
    scrollWidget.setTag(jniRef);
    
    NSOutlineView widget = (NSOutlineView)new SWTOutlineView().alloc();
    widget.initWithFrame(new NSRect());
    widget.setAllowsMultipleSelection((style & DWT.MULTI) !is 0);
    widget.setAutoresizesOutlineColumn(false);
    widget.setAutosaveExpandedItems(true);
    widget.setDataSource(widget);
    widget.setDelegate(widget);
    widget.setDoubleAction(OS.sel_sendDoubleSelection);
    if (!hasBorder()) widget.setFocusRingType(OS.NSFocusRingTypeNone);
    widget.setTag(jniRef);
    
    headerView = widget.headerView();
    headerView.retain();
    widget.setHeaderView(null);
    
    NSString str = NSString.stringWith("");
    if ((style & DWT.CHECK) !is 0) {
        checkColumn = (NSTableColumn)new NSTableColumn().alloc();
        checkColumn.initWithIdentifier(str);
        checkColumn.headerCell().setTitle(str);
        widget.addTableColumn (checkColumn);
        widget.setOutlineTableColumn(checkColumn);
        NSButtonCell cell = (NSButtonCell)new NSButtonCell().alloc().init();
        checkColumn.setDataCell(cell);
        cell.setButtonType(OS.NSSwitchButton);
        cell.setImagePosition(OS.NSImageOnly);
        cell.setAllowsMixedState(true);
        checkColumn.setWidth(getCheckColumnWidth());
        checkColumn.setResizingMask(OS.NSTableColumnNoResizing);
        checkColumn.setEditable(false);
        cell.release();
    }
    
    firstColumn = (NSTableColumn)new NSTableColumn().alloc();
    firstColumn.initWithIdentifier(str);
    firstColumn.headerCell().setTitle(str);
    widget.addTableColumn (firstColumn);
    widget.setOutlineTableColumn(firstColumn);
    NSBrowserCell cell = (NSBrowserCell)new NSBrowserCell().alloc().init();
    cell.setLeaf(true);
    firstColumn.setDataCell(cell);
    cell.release();
    
    scrollView = scrollWidget;
    view = widget;
    scrollView.setDocumentView(widget);
    parent.contentView().addSubview_(scrollView);
}

void createItem (TreeColumn column, int index) {
    if (!(0 <= index && index <= columnCount)) error (DWT.ERROR_INVALID_RANGE);
    if (index is 0) {
        // first column must be left aligned
        column.style &= ~(DWT.LEFT | DWT.RIGHT | DWT.CENTER);
        column.style |= DWT.LEFT;
    }
    if (columnCount is columns.length) {
        TreeColumn [] newColumns = new TreeColumn [columnCount + 4];
        System.arraycopy (columns, 0, newColumns, 0, columns.length);
        columns = newColumns;
    }
    NSTableColumn nsColumn;
    if (columnCount is 0) {
        //TODO - clear attributes, alignment etc.
        nsColumn = firstColumn;
        firstColumn = null;
    } else {
        //TODO - set attributes, alignment etc.
        NSString str = NSString.stringWith("");
        nsColumn = (NSTableColumn)new NSTableColumn().alloc();
        nsColumn.initWithIdentifier(str);
        nsColumn.headerCell().setTitle(str);
        ((NSTableView)view).addTableColumn (nsColumn);
        int checkColumn = (style & DWT.CHECK) !is 0 ? 1 : 0;
        ((NSTableView)view).moveColumn (columnCount + checkColumn, index + checkColumn);
        NSBrowserCell cell = (NSBrowserCell)new NSBrowserCell().alloc().init();
        cell.setLeaf(true);
        nsColumn.setDataCell(cell);
        cell.release();
    }
    column.nsColumn = nsColumn;
    nsColumn.headerCell().setTitle(NSString.stringWith(""));
    nsColumn.setWidth(0);
    System.arraycopy (columns, index, columns, index + 1, columnCount++ - index);
    columns [index] = column;
    if (columnCount > 1) {
        for (int i=0; i<items.length; i++) {
            TreeItem item = items [i];
            if (item !is null) {
                String [] strings = item.strings;
                if (strings !is null) {
                    String [] temp = new String [columnCount];
                    System.arraycopy (strings, 0, temp, 0, index);
                    System.arraycopy (strings, index, temp, index+1, columnCount-index-1);
                    temp [index] = "";
                    item.strings = temp;
                }
                if (index is 0) item.text = "";
                Image [] images = item.images;
                if (images !is null) {
                    Image [] temp = new Image [columnCount];
                    System.arraycopy (images, 0, temp, 0, index);
                    System.arraycopy (images, index, temp, index+1, columnCount-index-1);
                    item.images = temp;
                }
                if (index is 0) item.image = null;
                Color [] cellBackground = item.cellBackground;
                if (cellBackground !is null) {
                    Color [] temp = new Color [columnCount];
                    System.arraycopy (cellBackground, 0, temp, 0, index);
                    System.arraycopy (cellBackground, index, temp, index+1, columnCount-index-1);
                    item.cellBackground = temp;
                }
                Color [] cellForeground = item.cellForeground;
                if (cellForeground !is null) {
                    Color [] temp = new Color [columnCount];
                    System.arraycopy (cellForeground, 0, temp, 0, index);
                    System.arraycopy (cellForeground, index, temp, index+1, columnCount-index-1);
                    item.cellForeground = temp;
                }
                Font [] cellFont = item.cellFont;
                if (cellFont !is null) {
                    Font [] temp = new Font [columnCount];
                    System.arraycopy (cellFont, 0, temp, 0, index);
                    System.arraycopy (cellFont, index, temp, index+1, columnCount-index-1);
                    item.cellFont = temp;
                }
            }
        }
    }
}

void createItem (TreeItem item, TreeItem parentItem, int index) {
    int count;
    TreeItem[] items;
    if (parentItem !is null) {
        count = parentItem.itemCount;
        items = parentItem.items;
    } else {
        count = this.itemCount;
        items = this.items;
    }
    if (index is -1) index = count;
    if (!(0 <= index && index <= count)) error (DWT.ERROR_INVALID_RANGE);
    if (count is items.length) {
        TreeItem [] newItems = new TreeItem [items.length + 4];
        System.arraycopy (items, 0, newItems, 0, items.length);
        items = newItems;
        if (parentItem !is null) {
            parentItem.items = items;
        } else {
            this.items = items;
        }
    }
    System.arraycopy (items, index, items, index + 1, count++ - index);
    items [index] = item;
    item.items = new TreeItem[4];
    item.createJNIRef();
    SWTTreeItem handle = (SWTTreeItem)new SWTTreeItem().alloc().init();
    handle.setTag(item.jniRef);
    item.handle = handle;
    if (parentItem !is null) {
        parentItem.itemCount = count;
    } else {
        this.itemCount = count;
    }
    //TODO ?
    ((NSTableView)view).reloadData();
}

void createWidget () {
    super.createWidget ();
    items = new TreeItem [4];
    columns = new TreeColumn [4];
}

Color defaultBackground () {
    return display.getSystemColor (DWT.COLOR_LIST_BACKGROUND);
}

Color defaultForeground () {
    return display.getSystemColor (DWT.COLOR_LIST_FOREGROUND);
}

/**
 * Deselects all selected 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 void deselectAll () {
    checkWidget ();
    NSTableView widget = (NSTableView)view;
    ignoreSelect = true;
    widget.deselectAll(null);
    ignoreSelect = false;
}

public void deselect (TreeItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (item.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
//  ignoreSelect = true;
//  /*
//  * Bug in the Macintosh.  When the DataBroswer selection flags includes
//  * both kDataBrowserNeverEmptySelectionSet and kDataBrowserSelectOnlyOne,
//  * two items are selected when SetDataBrowserSelectedItems() is called
//  * with kDataBrowserItemsAssign to assign a new seletion despite the fact
//  * that kDataBrowserSelectOnlyOne was specified.  The fix is to save and
//  * restore kDataBrowserNeverEmptySelectionSet around each call to
//  * SetDataBrowserSelectedItems().
//  */
//  int [] selectionFlags = null;
//  if ((style & DWT.SINGLE) !is 0) {
//      selectionFlags = new int [1];
//      OS.GetDataBrowserSelectionFlags (handle, selectionFlags);
//      OS.SetDataBrowserSelectionFlags (handle, selectionFlags [0] & ~OS.kDataBrowserNeverEmptySelectionSet);
//  }
//  OS.SetDataBrowserSelectedItems (handle, 1, new int [] {item.id}, OS.kDataBrowserItemsRemove);
//  if ((style & DWT.SINGLE) !is 0) {
//      OS.SetDataBrowserSelectionFlags (handle, selectionFlags [0]);
//  }
//  ignoreSelect = false;
}


void destroyItem (TreeColumn column) {
    int index = 0;
    while (index < columnCount) {
        if (columns [index] is column) break;
        index++;
    }
    for (int i=0; i<items.length; i++) {
        TreeItem item = items [i];
        if (item !is null) {
            if (columnCount <= 1) {
                item.strings = null;
                item.images = null;
                item.cellBackground = null;
                item.cellForeground = null;
                item.cellFont = null;
            } else {
                if (item.strings !is null) {
                    String [] strings = item.strings;
                    if (index is 0) {
                        item.text = strings [1] !is null ? strings [1] : "";
                    }
                    String [] temp = new String [columnCount - 1];
                    System.arraycopy (strings, 0, temp, 0, index);
                    System.arraycopy (strings, index + 1, temp, index, columnCount - 1 - index);
                    item.strings = temp;
                } else {
                    if (index is 0) item.text = "";
                }
                if (item.images !is null) {
                    Image [] images = item.images;
                    if (index is 0) item.image = images [1];
                    Image [] temp = new Image [columnCount - 1];
                    System.arraycopy (images, 0, temp, 0, index);
                    System.arraycopy (images, index + 1, temp, index, columnCount - 1 - index);
                    item.images = temp;
                } else {
                    if (index is 0) item.image = null;
                }
                if (item.cellBackground !is null) {
                    Color [] cellBackground = item.cellBackground;
                    Color [] temp = new Color [columnCount - 1];
                    System.arraycopy (cellBackground, 0, temp, 0, index);
                    System.arraycopy (cellBackground, index + 1, temp, index, columnCount - 1 - index);
                    item.cellBackground = temp;
                }
                if (item.cellForeground !is null) {
                    Color [] cellForeground = item.cellForeground;
                    Color [] temp = new Color [columnCount - 1];
                    System.arraycopy (cellForeground, 0, temp, 0, index);
                    System.arraycopy (cellForeground, index + 1, temp, index, columnCount - 1 - index);
                    item.cellForeground = temp;
                }
                if (item.cellFont !is null) {
                    Font [] cellFont = item.cellFont;
                    Font [] temp = new Font [columnCount - 1];
                    System.arraycopy (cellFont, 0, temp, 0, index);
                    System.arraycopy (cellFont, index + 1, temp, index, columnCount - 1 - index);
                    item.cellFont = temp;
                }
            }
        }
    }
//  if (columnCount is 1) {
//      column_id = column.id; idCount = 0;
//      DataBrowserListViewHeaderDesc desc = new DataBrowserListViewHeaderDesc ();
//      desc.version = OS.kDataBrowserListViewLatestHeaderDesc;
//      short [] width = new short [1];
//      OS.GetDataBrowserTableViewNamedColumnWidth (handle, column_id, width);
//      desc.minimumWidth = desc.maximumWidth = width [0];
//      int str = OS.CFStringCreateWithCharacters (OS.kCFAllocatorDefault, null, 0);
//      desc.titleString = str;
//      OS.SetDataBrowserListViewHeaderDesc (handle, column_id, desc);
//      OS.CFRelease (str);
//  } else {
//      int [] disclosure = new int [1];
//      bool [] expandableRows = new bool [1];
//      OS.GetDataBrowserListViewDisclosureColumn (handle, disclosure, expandableRows);
//      if (disclosure [0] is column.id) {
//          TreeColumn firstColumn = columns [1];
//          firstColumn.style &= ~(DWT.LEFT | DWT.RIGHT | DWT.CENTER);
//          firstColumn.style |= DWT.LEFT;
//          firstColumn.updateHeader();
//          OS.SetDataBrowserListViewDisclosureColumn (handle, firstColumn.id, expandableRows [0]);
//      }
//      if (OS.RemoveDataBrowserTableViewColumn (handle, column.id) !is OS.noErr) {
//          error (DWT.ERROR_ITEM_NOT_REMOVED);
//      }
//  }
    System.arraycopy (columns, index + 1, columns, index, --columnCount - index);
    columns [columnCount] = null;
    for (int i=index; i<columnCount; i++) {
        columns [i].sendEvent (DWT.Move);
    }
}

void destroyItem (TreeItem item) {
    int count;
    TreeItem[] items;
    TreeItem parentItem = item.parentItem;
    if (parentItem !is null) {
        count = parentItem.itemCount;
        items = parentItem.items;
    } else {
        count = this.itemCount;
        items = this.items;
    }
    int index = 0;
    while (index < count) {
        if (items [index] is item) break;
        index++;
    }
//  if (index !is itemCount - 1) fixSelection (index, false); 
    System.arraycopy (items, index + 1, items, index, --count - index);
    items [count] = null;
    if (parentItem !is null) {
        parentItem.itemCount = count;
        ((NSOutlineView)view).reloadItem_reloadChildren_(parentItem.handle, true);
    } else {
        this.itemCount = count;
        ((NSOutlineView)view).reloadItem_(null);
    }
    
    //noteNumberOfRowsChanged was causing crashes whenever
    //a TreeItem was disposed. 
    //Using reloadItem avoids the crashes.
    //Not sure that this NSTableView function 
    //makes sense in an NSOutlineView.
    
    //((NSTableView)view).noteNumberOfRowsChanged();
    
//  setScrollWidth (true);
//  fixScrollBar ();
}


void fixScrollBar () {
    /*
    * Bug in the Macintosh. For some reason, the data browser does not update
    * the vertical scrollbar when it is scrolled to the bottom and items are
    * removed.  The fix is to check if the scrollbar value is bigger the
    * maximum number of visible items and clamp it when needed.
    */
//  int [] top = new int [1], left = new int [1];
//  OS.GetDataBrowserScrollPosition (handle, top, left);
//  int maximum = Math.max (0, getItemHeight () * visibleCount - getClientArea ().height);
//  if (top [0] > maximum) {
//      OS.SetDataBrowserScrollPosition (handle, maximum, left [0]);
//  }
}

int getCheckColumnWidth () {
    return 20; //TODO - compute width
}

/**
 * Returns the column at the given, zero-relative index in the
 * receiver. Throws an exception if the index is out of range.
 * Columns are returned in the order that they were created.
 * If no <code>TreeColumn</code>s were created by the programmer,
 * this method will throw <code>ERROR_INVALID_RANGE</code> despite
 * the fact that a single column of data may be visible in the tree.
 * This occurs when the programmer uses the tree like a list, adding
 * items but never creating a column.
 *
 * @param index the index of the column to return
 * @return the column 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>
 * 
 * @see Tree#getColumnOrder()
 * @see Tree#setColumnOrder(int[])
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(bool)
 * @see DWT#Move
 * 
 * @since 3.1
 */
public TreeColumn getColumn (int index) {
    checkWidget ();
    if (!(0 <=index && index < columnCount)) error (DWT.ERROR_INVALID_RANGE);
    return columns [index];
}

/**
 * Returns the number of columns contained in the receiver.
 * If no <code>TreeColumn</code>s were created by the programmer,
 * this value is zero, despite the fact that visually, one column
 * of items may be visible. This occurs when the programmer uses
 * the tree like a list, adding items but never creating a column.
 *
 * @return the number of columns
 *
 * @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 3.1
 */
public int getColumnCount () {
    checkWidget ();
    return columnCount;
}

/**
 * Returns an array of zero-relative integers that map
 * the creation order of the receiver's items to the
 * order in which they are currently being displayed.
 * <p>
 * Specifically, the indices of the returned array represent
 * the current visual order of the items, and the contents
 * of the array represent the creation order of the items.
 * </p><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 current visual order of the receiver's 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>
 * 
 * @see Tree#setColumnOrder(int[])
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(bool)
 * @see DWT#Move
 * 
 * @since 3.2
 */
public int [] getColumnOrder () {
    checkWidget ();
    int [] order = new int [columnCount];
    int [] position = new int [1];
    for (int i=0; i<columnCount; i++) {
        TreeColumn column = columns [i];
//      OS.GetDataBrowserTableViewColumnPosition (handle, column.id, position);
//      if ((style & DWT.CHECK) !is 0) position [0] -= 1;
        order [position [0]] = i;
    }
    return order;
}

/**
 * Returns an array of <code>TreeColumn</code>s which are the
 * columns in the receiver. Columns are returned in the order
 * that they were created.  If no <code>TreeColumn</code>s were
 * created by the programmer, the array is empty, despite the fact
 * that visually, one column of items may be visible. This occurs
 * when the programmer uses the tree like a list, adding items but
 * never creating a column.
 * <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>
 * 
 * @see Tree#getColumnOrder()
 * @see Tree#setColumnOrder(int[])
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(bool)
 * @see DWT#Move
 * 
 * @since 3.1
 */
public TreeColumn [] getColumns () {
    checkWidget ();
    TreeColumn [] result = new TreeColumn [columnCount];
    System.arraycopy (columns, 0, result, 0, columnCount);
    return result;
}

/**
 * Returns the width in pixels of a grid line.
 *
 * @return the width of a grid line in pixels
 * 
 * @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 3.1
 */
public int getGridLineWidth () {
    checkWidget ();
    return 0;
}

/**
 * Returns the height of the receiver's header 
 *
 * @return the height of the header or zero if the header is not visible
 *
 * @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 3.1 
 */
public int getHeaderHeight () {
    checkWidget ();
    NSTableHeaderView headerView = ((NSTableView)view).headerView();
    if (headerView is null) return 0;
    return (int)headerView.bounds().height;
}

/**
 * Returns <code>true</code> if the receiver's header is visible,
 * and <code>false</code> otherwise.
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, this method
 * may still indicate that it is considered visible even though
 * it may not actually be showing.
 * </p>
 *
 * @return the receiver's header's visibility state
 *
 * @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 3.1
 */
public bool getHeaderVisible () {
    checkWidget ();
    return ((NSTableView)view).headerView() !is null;
}

/**
 * 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>
 * 
 * @since 3.1
 */
public TreeItem getItem (int index) {
    checkWidget ();
    int count = getItemCount ();
    if (index < 0 || index >= count) error (DWT.ERROR_INVALID_RANGE);
    return _getItem (null, index);
}

/**
 * Returns the 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.
 * <p>
 * The item that is returned represents an item that could be selected by the user.
 * For example, if selection only occurs in items in the first column, then null is 
 * returned if the point is outside of the item. 
 * Note that the DWT.FULL_SELECTION style hint, which specifies the selection policy,
 * determines the extent of the selection.
 * </p>
 *
 * @param point the point used to locate the item
 * @return the item at the given point, or null if the point is not in a selectable 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>
 */
public TreeItem getItem (Point point) {
    checkWidget ();
    if (point is null) error (DWT.ERROR_NULL_ARGUMENT);
//  Rect rect = new Rect ();
//  dwt.internal.carbon.Point pt = new dwt.internal.carbon.Point ();
//  OS.SetPt (pt, (short) point.x, (short) point.y);
//  if (0 < lastHittest && lastHittest <= items.length && lastHittestColumn !is 0) {
//      TreeItem item = _getItem (lastHittest, false);
//      if (item !is null) {
//          if (OS.GetDataBrowserItemPartBounds (handle, item.id, lastHittestColumn, OS.kDataBrowserPropertyDisclosurePart, rect) is OS.noErr) {
//              if (OS.PtInRect (pt, rect)) return null;
//          }
//          if (OS.GetDataBrowserItemPartBounds (handle, item.id, lastHittestColumn, OS.kDataBrowserPropertyEnclosingPart, rect) is OS.noErr) {
//              if (rect.top <= pt.v && pt.v <= rect.bottom) {
//                  if ((style & DWT.FULL_SELECTION) !is 0) {
//                      return item;
//                  } else {
//                      return OS.PtInRect (pt, rect) ? item : null;
//                  }
//              }
//          }
//      }
//  }
//  //TODO - optimize
//  for (int i=0; i<items.length; i++) {
//      TreeItem item = items [i];
//      if (item !is null) {
//          if (OS.GetDataBrowserItemPartBounds (handle, item.id, column_id, OS.kDataBrowserPropertyDisclosurePart, rect) is OS.noErr) {
//              if (OS.PtInRect (pt, rect)) return null;
//          }
//          if (columnCount is 0) {
//              if (OS.GetDataBrowserItemPartBounds (handle, item.id, column_id, OS.kDataBrowserPropertyEnclosingPart, rect) is OS.noErr) {
//                  if (rect.top <= pt.v && pt.v <= rect.bottom) {
//                      if ((style & DWT.FULL_SELECTION) !is 0) {
//                          return item;
//                      } else {
//                          return OS.PtInRect (pt, rect) ? item : null;
//                      }
//                  }
//              }
//          } else {
//              for (int j = 0; j < columnCount; j++) {
//                  if (OS.GetDataBrowserItemPartBounds (handle, item.id, columns [j].id, OS.kDataBrowserPropertyEnclosingPart, rect) is OS.noErr) {
//                      if (rect.top <= pt.v && pt.v <= rect.bottom) {
//                          if ((style & DWT.FULL_SELECTION) !is 0) {
//                              return item;
//                          } else {
//                              return OS.PtInRect (pt, rect) ? item : null;
//                          }
//                      }
//                  }
//              }
//          }
//      }
//  }
    return null;
}

/**
 * Returns the number of items contained in the receiver
 * that are direct item children of the receiver.  The
 * number that is returned is the number of roots in the
 * tree.
 *
 * @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 the height of the area which would be used to
 * display <em>one</em> of the items in the tree.
 *
 * @return the height of one 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 getItemHeight () {
    checkWidget ();
    return (int)((NSTableView)view).rowHeight();
}

/**
 * Returns a (possibly empty) array of items contained in the
 * receiver that are direct item children of the receiver.  These
 * are the roots of the tree.
 * <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
 *
 * @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 TreeItem [] getItems () {
    checkWidget ();
    TreeItem [] result = new TreeItem [itemCount];
    for (int i=0; i<itemCount; i++) {
        result [i] = _getItem (null, i);
    }
    return result;
}

/**
 * Returns <code>true</code> if the receiver's lines are visible,
 * and <code>false</code> otherwise.
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, this method
 * may still indicate that it is considered visible even though
 * it may not actually be showing.
 * </p>
 *
 * @return the visibility state of the lines
 *
 * @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 3.1
 */
public bool getLinesVisible () {
    checkWidget ();
//  if (OS.VERSION >= 0x1040) {
//      int [] attrib = new int [1];
//      OS.DataBrowserGetAttributes (handle, attrib);
//      return (attrib [0] & (OS.kDataBrowserAttributeListViewAlternatingRowColors | OS.kDataBrowserAttributeListViewDrawColumnDividers)) !is 0;
//  }
    return false;
}

/**
 * Returns the receiver's parent item, which must be a
 * <code>TreeItem</code> or null when the receiver is a
 * root.
 *
 * @return the receiver's parent 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 TreeItem getParentItem () {
    checkWidget ();
    return null;
}

/**
 * Returns an array of <code>TreeItem</code>s that are currently
 * selected in the receiver. The order of the items is unspecified.
 * 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 TreeItem [] getSelection () {
    checkWidget ();
    NSOutlineView widget = (NSOutlineView)view;
    if (widget.numberOfSelectedRows() is 0) {
        return new TreeItem [0];
    }
    NSIndexSet selection = widget.selectedRowIndexes();
    int count = selection.count();
    int [] indexBuffer = new int [count];
    selection.getIndexes(indexBuffer, count, 0);
    TreeItem [] result = new TreeItem  [count];
    for (int i=0; i<count; i++) {
        id item = widget.itemAtRow(indexBuffer [i]);
        int jniRef = OS.objc_msgSend(item.id, OS.sel_tag);
        if (jniRef !is -1 && jniRef !is 0) {
            //TODO virtual
            result[i] = (TreeItem)OS.JNIGetObject(jniRef);
        }
    }
    return result;
}

/**
 * Returns the number of selected items contained in the receiver.
 *
 * @return the number of selected 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 getSelectionCount () {
    checkWidget ();
    return ((NSTableView)view).numberOfSelectedRows();
}

/**
 * Returns the column which shows the sort indicator for
 * the receiver. The value may be null if no column shows
 * the sort indicator.
 *
 * @return the sort indicator 
 *
 * @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 #setSortColumn(TreeColumn)
 * 
 * @since 3.2
 */
public TreeColumn getSortColumn () {
    checkWidget ();
    return sortColumn;
}

/**
 * Returns the direction of the sort indicator for the receiver. 
 * The value will be one of <code>UP</code>, <code>DOWN</code> 
 * or <code>NONE</code>.
 *
 * @return the sort direction
 *
 * @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 #setSortDirection(int)
 * 
 * @since 3.2
 */
public int getSortDirection () {
    checkWidget ();
    return sortDirection;
}

/**
 * Returns the item which is currently at the top of the receiver.
 * This item can change when items are expanded, collapsed, scrolled
 * or new items are added or removed.
 *
 * @return the item at the top of 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>
 * 
 * @since 2.1
 */
public TreeItem getTopItem () {
    checkWidget();
//  //TODO - optimize
//  Rect rect = new Rect ();
//  int y = getBorder () + getHeaderHeight ();
//  for (int i=0; i<items.length; i++) {
//      TreeItem item = items [i];
//      if (item !is null) {
//          int columnId = (columnCount is 0) ? column_id : columns [0].id;
//          if (OS.GetDataBrowserItemPartBounds (handle, item.id, columnId, OS.kDataBrowserPropertyEnclosingPart, rect) is OS.noErr) {
//              if (rect.top <= y && y <= rect.bottom) return item;
//          }
//      }
//  }
    return null;
}

/**
 * Searches the receiver's list starting at the first column
 * (index 0) until a column is found that is equal to the 
 * argument, and returns the index of that column. If no column
 * is found, returns -1.
 *
 * @param column the search column
 * @return the index of the column
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the column 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 3.1
 */
public int indexOf (TreeColumn column) {
    checkWidget ();
    if (column is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (column.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
    for (int i=0; i<columnCount; i++) {
        if (columns [i] is column) return i;
    }
    return -1;
}

/**
 * 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>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</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 3.1
 */
public int indexOf (TreeItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (item.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
    if (item.parentItem !is null) return -1;
    for (int i = 0; i < itemCount; i++) {
        if (item is items[i]) return i;
    }
    return -1;
}

int outlineView_child_ofItem(int outlineView, int index, int ref) {
    TreeItem parent = null;
    if (ref !is 0) parent = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag));
    TreeItem item = _getItem(parent, index);
    return item.handle.id;
}

int outlineView_objectValueForTableColumn_byItem(int outlineView, int tableColumn, int ref) {
    TreeItem item = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag));
    if (checkColumn !is null && tableColumn is checkColumn.id) {
        NSNumber value;
        if (item.checked && item.grayed) {
            value = NSNumber.numberWithInt(OS.NSMixedState);
        } else {
            value = NSNumber.numberWithInt(item.checked ? OS.NSOnState : OS.NSOffState);
        }
        return value.id;
    }
    for (int i=0; i<columnCount; i++) {
        if (columns [i].nsColumn.id is tableColumn) {
            return item.createString(i).id;
        }
    }
    return item.createString(0).id;
}

bool outlineView_isItemExpandable(int outlineView, int ref) {
    if (ref is 0) return true;
    return ((TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag))).itemCount !is 0;
}

int outlineView_numberOfChildrenOfItem(int outlineView, int ref) {
    if (ref is 0) return itemCount;
    return ((TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag))).itemCount;
}

void outlineView_willDisplayCell_forTableColumn_item(int outlineView, int cell, int tableColumn, int ref) {
    if (checkColumn !is null && tableColumn is checkColumn.id) return;
    TreeItem item = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag));
    Image image = item.image;
    for (int i=0; i<columnCount; i++) {
        if (columns [i].nsColumn.id is tableColumn) {
            image = item.getImage(i);
        }
    }
    NSBrowserCell browserCell = new NSBrowserCell(cell);
    browserCell.setImage(image !is null ? image.handle : null);
}

void outlineViewSelectionDidChange(int notification) {
    if (ignoreSelect) return;
    NSOutlineView widget = (NSOutlineView)view;
    int row = widget.selectedRow();
    if(row is -1)
        postEvent(DWT.Selection);
    else {
        id _id = widget.itemAtRow(row);
        TreeItem item = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(_id.id, OS.sel_tag));
        Event event = new Event();
        event.item = item;
        event.index = row;
        postEvent(DWT.Selection, event);
    }
}

bool outlineView_shouldCollapseItem(int outlineView, int ref) {
    if (!ignoreExpand) {
        TreeItem item = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag));
        Event event = new Event();
        event.item = item;
        sendEvent(DWT.Collapse, event);
        item.expanded = false;
    }
    return true;
}

bool outlineView_shouldExpandItem(int outlineView, int ref) {
    if (!ignoreExpand) {
        TreeItem item = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag));
        Event event = new Event();
        event.item = item;
        sendEvent(DWT.Expand, event);
        item.expanded = true;
    }
    return true;
}

void outlineView_setObjectValue_forTableColumn_byItem(int outlineView, int object, int tableColumn, int ref) {
    TreeItem item = (TreeItem)OS.JNIGetObject(OS.objc_msgSend(ref, OS.sel_tag));
    if (checkColumn !is null && tableColumn is checkColumn.id)  {
        item.checked = !item.checked;
        Event event = new Event();
        event.detail = DWT.CHECK;
        event.item = item;
        postEvent(DWT.Selection, event);
    }
}

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

void releaseHandle () {
    super.releaseHandle ();
    if (headerView !is null) headerView.release();
    headerView = null;
    if (firstColumn !is null) firstColumn.release();
    firstColumn = null;
    if (checkColumn !is null) checkColumn.release();
    checkColumn = null;
}

void releaseWidget () {
    super.releaseWidget ();
    //release handle
    sortColumn = null;
}

/**
 * Removes all of the items from 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 void removeAll () {
    checkWidget ();
    for (int i=0; i<items.length; i++) {
        TreeItem item = items [i];
        if (item !is null && !item.isDisposed ()) item.release (false);
    }
    items = new TreeItem [4];
    itemCount = 0;
    ((NSOutlineView)view).reloadItem_(null);
    //((NSTableView)view).noteNumberOfRowsChanged();
//  setScrollWidth (true);
}

/**
 * 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);
    eventTable.unhook (DWT.Selection, listener);
    eventTable.unhook (DWT.DefaultSelection, listener); 
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when items in the receiver are expanded or collapsed.
 *
 * @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 TreeListener
 * @see #addTreeListener
 */
public void removeTreeListener(TreeListener listener) {
    checkWidget ();
    if (listener is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (eventTable is null) return;
    eventTable.unhook (DWT.Expand, listener);
    eventTable.unhook (DWT.Collapse, listener);
}

/**
 * Display a mark indicating the point at which an item will be inserted.
 * The drop insert item has a visual hint to show where a dragged item 
 * will be inserted when dropped on the tree.
 * 
 * @param item the insert item.  Null will clear the insertion mark.
 * @param before true places the insert mark above 'item'. false places 
 *  the insert mark below 'item'.
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</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 setInsertMark (TreeItem item, bool before) {
    checkWidget ();
    if (item !is null) {
        if (item.isDisposed()) error(DWT.ERROR_INVALID_ARGUMENT);
    }
}

/**
 * Selects all of the items in the receiver.
 * <p>
 * If the receiver is single-select, do nothing.
 * </p>
 *
 * @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 selectAll () {
    checkWidget ();
    if ((style & DWT.SINGLE) !is 0) return;
    NSTableView widget = (NSTableView)view;
    ignoreSelect = true;
    widget.selectAll(null);
    ignoreSelect = false;
}

public void select (TreeItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (item.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
//  showItem (item, false);
//  ignoreSelect = true;
//  /*
//  * Bug in the Macintosh.  When the DataBroswer selection flags includes
//  * both kDataBrowserNeverEmptySelectionSet and kDataBrowserSelectOnlyOne,
//    * two items are selected when SetDataBrowserSelectedItems() is called
//    * with kDataBrowserItemsAssign to assign a new seletion despite the fact
//  * that kDataBrowserSelectOnlyOne was specified.  The fix is to save and
//  * restore kDataBrowserNeverEmptySelectionSet around each call to
//  * SetDataBrowserSelectedItems().
//  */
//  int [] selectionFlags = null;
//  if ((style & DWT.SINGLE) !is 0) {
//      selectionFlags = new int [1];
//      OS.GetDataBrowserSelectionFlags (handle, selectionFlags);
//      OS.SetDataBrowserSelectionFlags (handle, selectionFlags [0] & ~OS.kDataBrowserNeverEmptySelectionSet);
//  }
//  OS.SetDataBrowserSelectedItems (handle, 1, new int [] {item.id}, OS.kDataBrowserItemsAssign);
//  if ((style & DWT.SINGLE) !is 0) {
//      OS.SetDataBrowserSelectionFlags (handle, selectionFlags [0]);
//  }
//  ignoreSelect = false;
}

void sendDoubleSelection() {
    postEvent (DWT.DefaultSelection);
}

/**
 * Sets the order that the items in the receiver should 
 * be displayed in to the given argument which is described
 * in terms of the zero-relative ordering of when the items
 * were added.
 *
 * @param order the new order to display the 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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item order is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item order is not the same length as the number of items</li>
 * </ul>
 * 
 * @see Tree#getColumnOrder()
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(bool)
 * @see DWT#Move
 * 
 * @since 3.2
 */
public void setColumnOrder (int [] order) {
    checkWidget ();
    if (order is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (columnCount is 0) {
        if (order.length !is 0) error (DWT.ERROR_INVALID_ARGUMENT);
        return;
    }
    if (order.length !is columnCount) error (DWT.ERROR_INVALID_ARGUMENT);
    int [] oldOrder = getColumnOrder ();
    bool reorder = false;
    bool [] seen = new bool [columnCount];
    for (int i=0; i<order.length; i++) {
        int index = order [i];
        if (index < 0 || index >= columnCount) error (DWT.ERROR_INVALID_ARGUMENT);
        if (seen [index]) error (DWT.ERROR_INVALID_ARGUMENT);
        seen [index] = true;
        if (order [i] !is oldOrder [i]) reorder = true;
    }
    if (reorder) {
        int [] disclosure = new int [1];
        bool [] expandableRows = new bool [1];
//      OS.GetDataBrowserListViewDisclosureColumn (handle, disclosure, expandableRows);
        TreeColumn firstColumn = columns [order [0]];
//      if (disclosure [0] !is firstColumn.id) {
//          OS.SetDataBrowserListViewDisclosureColumn (handle, firstColumn.id, expandableRows [0]);
//      }
        int x = 0;
        short [] width = new short [1];
        int [] oldX = new int [oldOrder.length];
        for (int i=0; i<oldOrder.length; i++) {
            int index = oldOrder [i];
            TreeColumn column = columns [index];
            oldX [index] =  x;
//          OS.GetDataBrowserTableViewNamedColumnWidth(handle, column.id, width);
            x += width [0];
        }
        x = 0;
        int [] newX = new int [order.length];
        for (int i=0; i<order.length; i++) {
            int index = order [i];
            TreeColumn column = columns [index];
            int position = (style & DWT.CHECK) !is 0 ? i + 1 : i;
//          OS.SetDataBrowserTableViewColumnPosition(handle, column.id, position);
//          column.lastPosition = position;
            newX [index] =  x;
//          OS.GetDataBrowserTableViewNamedColumnWidth(handle, column.id, width);
            x += width [0];
        }
        TreeColumn[] newColumns = new TreeColumn [columnCount];
        System.arraycopy (columns, 0, newColumns, 0, columnCount);
        for (int i=0; i<columnCount; i++) {
            TreeColumn column = newColumns [i];
            if (!column.isDisposed ()) {
                if (newX [i] !is oldX [i]) {
                    column.sendEvent (DWT.Move);
                }
            }
        }
    }
}

/**
 * Marks the receiver's header as visible if the argument is <code>true</code>,
 * and marks it invisible otherwise. 
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, marking
 * it visible may not actually cause it to be displayed.
 * </p>
 *
 * @param show the new visibility state
 *
 * @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 3.1
 */
public void setHeaderVisible (bool show) {
    checkWidget ();
    ((NSTableView)view).setHeaderView (show ? headerView : null);
}

/**
 * Sets the number of root-level items contained in the receiver.
 *
 * @param count 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>
 *
 * @since 3.2
 */
public void setItemCount (int count) {
    checkWidget ();
    count = Math.max (0, count);
    setItemCount (null, count);
}

void setItemCount (TreeItem parentItem, int count) {
//  int itemCount = getItemCount (parentItem);
//  if (count is itemCount) return;
//  setRedraw (false);
//  int [] top = new int [1], left = new int [1];
//    OS.GetDataBrowserScrollPosition (handle, top, left);
//    DataBrowserCallbacks callbacks = new DataBrowserCallbacks ();
//  OS.GetDataBrowserCallbacks (handle, callbacks);
//  callbacks.v1_itemNotificationCallback = 0;
//  callbacks.v1_itemCompareCallback = 0;
//  OS.SetDataBrowserCallbacks (handle, callbacks);
//  int[] ids = parentItem is null ? childIds : parentItem.childIds;
//  if (count < itemCount) {
//      for (int index = ids.length - 1; index >= count; index--) {
//          int id = ids [index];
//          if (id !is 0) {
//              TreeItem item = _getItem (id, false);
//              if (item !is null && !item.isDisposed ()) {
//                  item.dispose ();
//              } else {
//                  if (parentItem is null || parentItem.getExpanded ()) {
//                      if (OS.RemoveDataBrowserItems (handle, OS.kDataBrowserNoItem, 1, new int [] {id}, 0) !is OS.noErr) {
//                          error (DWT.ERROR_ITEM_NOT_REMOVED);
//                          break;
//                      }
//                      visibleCount--;
//                  }
//              }
//          }
//      }
//      //TODO - move shrink to paint event
//      // shrink items array
//      int lastIndex = items.length;
//      for (int i=items.length; i>0; i--) {
//          if (items [i-1] !is null) {
//              lastIndex = i;
//              break;
//          }
//      }
//      if (lastIndex < items.length - 4) {
//          int length = Math.max (4, (lastIndex + 3) / 4 * 4);
//          TreeItem [] newItems = new TreeItem [length];
//          System.arraycopy(items, 0, newItems, 0, Math.min(items.length, lastIndex));
//      }
//  }
//  
//  if (parentItem !is null) parentItem.itemCount = count;
//  int length = Math.max (4, (count + 3) / 4 * 4);
//  int [] newIds = new int [length];
//  if (ids !is null) {
//      System.arraycopy (ids, 0, newIds, 0, Math.min (count, itemCount));
//  }
//  ids = newIds;
//  if (parentItem is null) {
//      childIds = newIds;
//  } else {
//      parentItem.childIds = newIds;
//  }
//  
//  if (count > itemCount) {
//      if ((getStyle() & DWT.VIRTUAL) is 0) {
//          int delta = Math.max (4, (count - itemCount + 3) / 4 * 4);
//          TreeItem [] newItems = new TreeItem [items.length + delta];
//          System.arraycopy (items, 0, newItems, 0, items.length);
//          items = newItems;
//          for (int i=itemCount; i<count; i++) {
//              items [i] = new TreeItem (this, parentItem, DWT.NONE, i, true);
//          }
//      } else {
//          if (parentItem is null || parentItem.getExpanded ()) {
//              int parentID = parentItem is null ? OS.kDataBrowserNoItem : parentItem.id;
//              int [] addIds = _getIds (count - itemCount);
//              if (OS.AddDataBrowserItems (handle, parentID, addIds.length, addIds, OS.kDataBrowserItemNoProperty) !is OS.noErr) {
//                  error (DWT.ERROR_ITEM_NOT_ADDED);
//              }
//              visibleCount += (count - itemCount);
//              System.arraycopy (addIds, 0, ids, itemCount, addIds.length);
//          }
//      }
//  }
//  
//  callbacks.v1_itemNotificationCallback = display.itemNotificationProc;
//  callbacks.v1_itemCompareCallback = display.itemCompareProc;
//  OS.SetDataBrowserCallbacks (handle, callbacks);
//  setRedraw (true);
//  if (itemCount is 0 && parentItem !is null) parentItem.redraw (OS.kDataBrowserNoItem);
}

/*public*/ void setItemHeight (int itemHeight) {
    checkWidget ();
    if (itemHeight < -1) error (DWT.ERROR_INVALID_ARGUMENT);
    if (itemHeight is -1) {
        //TODO - reset item height, ensure other API's such as setFont don't do this
    } else {
//      OS.SetDataBrowserTableViewRowHeight (handle, (short) itemHeight);
    }
}

void setItemHeight (Image image) {
//  Rectangle bounds = image !is null ? image.getBounds () : imageBounds;
//  if (bounds is null) return;
//  imageBounds = bounds;
//  short [] height = new short [1];
//  if (OS.GetDataBrowserTableViewRowHeight (handle, height) is OS.noErr) {
//      if (height [0] < bounds.height) {
//          OS.SetDataBrowserTableViewRowHeight (handle, (short) bounds.height);
//      }
//  }
}

/**
 * Marks the receiver's lines as visible if the argument is <code>true</code>,
 * and marks it invisible otherwise. 
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, marking
 * it visible may not actually cause it to be displayed.
 * </p>
 *
 * @param show the new visibility state
 *
 * @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 3.1
 */
public void setLinesVisible (bool show) {
    checkWidget ();
    ((NSTableView)view).setUsesAlternatingRowBackgroundColors(show);
}

public void setRedraw (bool redraw) {
    checkWidget();
    super.setRedraw (redraw);
    if (redraw && drawCount is 0) {
        setScrollWidth (true);
    }
}

bool setScrollWidth (TreeItem item) {
//  if (ignoreRedraw || drawCount !is 0) return false;
    if (columnCount !is 0) return false;
//  TreeItem parentItem = item.parentItem;
//  if (parentItem !is null && !parentItem._getExpanded ()) return false;
//  GC gc = new GC (this);
//  int newWidth = item.calculateWidth (0, gc);
//  gc.dispose ();
//  newWidth += getInsetWidth (column_id, false);
//  short [] width = new short [1];
//  OS.GetDataBrowserTableViewNamedColumnWidth (handle, column_id, width);
//  if (width [0] < newWidth) {
//      OS.SetDataBrowserTableViewNamedColumnWidth (handle, column_id, (short) newWidth);
//      return true;
//  }
//  firstColumn.setWidth(400);
    return false;
}

bool setScrollWidth (bool set) {
//  return setScrollWidth(set, childIds, true);
    return false;
}

bool setScrollWidth (bool set, int[] childIds, bool recurse) {
//  if (ignoreRedraw || drawCount !is 0) return false;
//  if (columnCount !is 0 || childIds is null) return false;
//  GC gc = new GC (this);
//  int newWidth = calculateWidth (childIds, gc, recurse, 0, 0);
//  gc.dispose ();
//  newWidth += getInsetWidth (column_id, false);
//  if (!set) {
//      short [] width = new short [1];
//      OS.GetDataBrowserTableViewNamedColumnWidth (handle, column_id, width);
//      if (width [0] >= newWidth) return false;
//  }
//  OS.SetDataBrowserTableViewNamedColumnWidth (handle, column_id, (short) newWidth);
    return true;
}

/**
 * Sets the receiver's selection to the given item.
 * The current selection is cleared before the new item is selected.
 * <p>
 * If the item is not in the receiver, then it is ignored.
 * </p>
 *
 * @param item the item to select
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</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 (TreeItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    setSelection (new TreeItem [] {item});
}

/**
 * Sets the receiver's selection to be the given array of items.
 * The current selection is cleared before the new items are selected.
 * <p>
 * Items that are not in the receiver are ignored.
 * If the receiver is single-select and multiple items are specified,
 * then all items are ignored.
 * </p>
 *
 * @param items the array of items
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the array of items is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if one of the items has been disposed</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 Tree#deselectAll()
 */
public void setSelection (TreeItem [] items) {
    checkWidget ();
    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
    deselectAll ();
//  int length = items.length;
//  if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
//  int count = 0;
//  int[] ids = new int [length];
//  for (int i=0; i<length; i++) {
//      if (items [i] !is null) {
//          if (items [i].isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
//          ids [count++] = items [i].id;
//          showItem (items [i], false);
//      }
//  }
//  ignoreSelect = true;
//  /*
//  * Bug in the Macintosh.  When the DataBroswer selection flags includes
//  * both kDataBrowserNeverEmptySelectionSet and kDataBrowserSelectOnlyOne,
//    * two items are selected when SetDataBrowserSelectedItems() is called
//    * with kDataBrowserItemsAssign to assign a new seletion despite the fact
//  * that kDataBrowserSelectOnlyOne was specified.  The fix is to save and
//  * restore kDataBrowserNeverEmptySelectionSet around each call to
//  * SetDataBrowserSelectedItems().
//  */
//  int [] selectionFlags = null;
//  if ((style & DWT.SINGLE) !is 0) {
//      selectionFlags = new int [1];
//      OS.GetDataBrowserSelectionFlags (handle, selectionFlags);
//      OS.SetDataBrowserSelectionFlags (handle, selectionFlags [0] & ~OS.kDataBrowserNeverEmptySelectionSet);
//  }
//  OS.SetDataBrowserSelectedItems (handle, count, ids, OS.kDataBrowserItemsAssign);
//  if ((style & DWT.SINGLE) !is 0) {
//      OS.SetDataBrowserSelectionFlags (handle, selectionFlags [0]);
//  }
//  ignoreSelect = false;
//  if (length > 0) {
//      int index = -1;
//      for (int i=0; i<items.length; i++) {
//          if (items [i] !is null) {
//              index = i;
//              break;
//          }
//      }
//      if (index !is -1) showItem (items [index], true);
//  }
}

/**
 * Sets the column used by the sort indicator for the receiver. A null
 * value will clear the sort indicator.  The current sort column is cleared 
 * before the new column is set.
 *
 * @param column the column used by the sort indicator or <code>null</code>
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the column is disposed</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 setSortColumn (TreeColumn column) {
    checkWidget ();
    if (column !is null && column.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
    if (column is sortColumn) return;
//  if (column is null) {
//      if (sortColumn !is null  && !sortColumn.isDisposed ()  && sortDirection !is DWT.NONE) {
//          OS.SetDataBrowserSortOrder (handle, (short) OS.kDataBrowserOrderIncreasing);
//          sortColumn = null; 
//          OS.SetDataBrowserSortProperty (handle, 0);
//      }
//  }
//  sortColumn = column;
//  if (sortColumn !is null  && !sortColumn.isDisposed () && sortDirection !is DWT.NONE) {
//      OS.SetDataBrowserSortProperty (handle, sortColumn.id);
//      int order = sortDirection is DWT.DOWN ? OS.kDataBrowserOrderDecreasing : OS.kDataBrowserOrderIncreasing;
//      OS.SetDataBrowserSortOrder (handle, (short) order);
//  }
}

/**
 * Sets the direction of the sort indicator for the receiver. The value 
 * can be one of <code>UP</code>, <code>DOWN</code> or <code>NONE</code>.
 *
 * @param direction the direction of the sort indicator 
 *
 * @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 setSortDirection  (int direction) {
    checkWidget ();
    if (direction !is DWT.UP && direction !is DWT.DOWN && direction !is DWT.NONE) return;
//  if (direction is sortDirection) return;
//  sortDirection = direction;
//  if (sortColumn !is null && !sortColumn.isDisposed ()) {
//      if (sortDirection is DWT.NONE) {
//          OS.SetDataBrowserSortOrder (handle, (short) OS.kDataBrowserOrderIncreasing);
//          TreeColumn column = sortColumn;
//          sortColumn = null; 
//          OS.SetDataBrowserSortProperty (handle, 0);
//          sortColumn = column;
//      } else {
//          OS.SetDataBrowserSortProperty (handle, 0);
//          OS.SetDataBrowserSortProperty (handle, sortColumn.id);
//          int order = sortDirection is DWT.DOWN ? OS.kDataBrowserOrderDecreasing : OS.kDataBrowserOrderIncreasing;
//          OS.SetDataBrowserSortOrder (handle, (short) order);
//      }
//  }
}

/**
 * Sets the item which is currently at the top of the receiver.
 * This item can change when items are expanded, collapsed, scrolled
 * or new items are added or removed.
 *
 * @param item the item to be shown
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</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 Tree#getTopItem()
 * 
 * @since 2.1
 */
public void setTopItem (TreeItem item) {
    checkWidget();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (item.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
//  showItem (item, false);
//  int columnId = (columnCount is 0) ? column_id : columns [0].id;
//  OS.RevealDataBrowserItem (handle, item.id, columnId, (byte) OS.kDataBrowserRevealWithoutSelecting);
//  Rect rect = new Rect ();
//  if (OS.GetDataBrowserItemPartBounds (handle, item.id, column_id, OS.kDataBrowserPropertyEnclosingPart, rect) is OS.noErr) {
//      int border = getBorder ();
//      int [] top = new int [1], left = new int [1];
//      OS.GetDataBrowserScrollPosition (handle, top, left);
//      OS.SetDataBrowserScrollPosition (handle, Math.max (0, top [0] + rect.top - border - getHeaderHeight ()), left [0]);
//  }
}

/**
 * Shows the column.  If the column is already showing in the receiver,
 * this method simply returns.  Otherwise, the columns are scrolled until
 * the column is visible.
 *
 * @param column the column to be shown
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</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 3.1
 */
public void showColumn (TreeColumn column) {
    checkWidget ();
    if (column is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (column.isDisposed()) error(DWT.ERROR_INVALID_ARGUMENT);
    if (column.parent !is this) return;
    int index = indexOf (column);
    if (columnCount <= 1 || !(0 <= index && index < columnCount)) return;
    ((NSTableView)view).scrollColumnToVisible(index + ((style & DWT.CHECK) !is 0 ? 1 : 0));
}

/**
 * Shows the item.  If the item is already showing in the receiver,
 * this method simply returns.  Otherwise, the items are scrolled
 * and expanded until the item is visible.
 *
 * @param item the item to be shown
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</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 Tree#showSelection()
 */
public void showItem (TreeItem item) {
    checkWidget ();
    if (item is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (item.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
    showItem (item, true);
}

void showItem (TreeItem item, bool scroll) {
    int count = 0;
//  TreeItem parentItem = item.parentItem;
//  while (parentItem !is null && !parentItem._getExpanded ()) {
//      count++;
//      parentItem = parentItem.parentItem;
//  }
//  int index = 0;
//  parentItem = item.parentItem;
//  TreeItem [] path = new TreeItem [count];
//  while (parentItem !is null && !parentItem._getExpanded ()) {
//      path [index++] = parentItem;
//      parentItem = parentItem.parentItem;
//  }
//  for (int i=path.length-1; i>=0; --i) {
//      path [i].setExpanded (true);
//  }
//  if (scroll) {
//      /*
//      * Bug in the Macintosh.  When there is not room to show a
//      * single item in the data browser, RevealDataBrowserItem()
//      * scrolls the item such that it is above the top of the data
//      * browser.  The fix is to remember the index and scroll when
//      * the data browser is resized.
//      * 
//      * Bug in the Macintosh.  When items are added to the data
//      * browser after is has been hidden, RevealDataBrowserItem()
//      * when called before the controls behind the data browser
//      * are repainted causes a redraw.  This redraw happens right
//      * away causing pixel corruption.  The fix is to remember the
//      * index and scroll when the data browser is shown.
//      */
//      Rectangle rect = getClientArea ();
//      if (rect.height < getItemHeight () || !OS.IsControlVisible (handle)) {
//          showItem = item;
//          return;
//      }
//      showItem = null;
//      Rectangle itemRect = item.getBounds ();
//      if (!itemRect.isEmpty()) {
//          if (rect.contains (itemRect.x, itemRect.y)
//              && rect.contains (itemRect.x, itemRect.y + itemRect.height)) return;
//      }
//      int [] top = new int [1], left = new int [1];
//      OS.GetDataBrowserScrollPosition (handle, top, left);
//      int columnId = (columnCount is 0) ? column_id : columns [0].id;
//      int options = OS.kDataBrowserRevealWithoutSelecting;
//      /*
//      * This code is intentionally commented, since kDataBrowserRevealAndCenterInView
//      * does not scroll the item to the center always (it seems to scroll to the
//      * end in some cases).
//      */
//      //options |= OS.kDataBrowserRevealAndCenterInView;
//      OS.RevealDataBrowserItem (handle, item.id, columnId, (byte) options);
//      int [] newTop = new int [1], newLeft = new int [1];
//      if (columnCount is 0) {
//          bool fixScroll = false;
//          Rect content = new Rect ();
//          if (OS.GetDataBrowserItemPartBounds (handle, item.id, columnId, OS.kDataBrowserPropertyContentPart, content) is OS.noErr) {
//              fixScroll = content.left < rect.x || content.left >= rect.x + rect.width;
//              if (!fixScroll) {
//                  GC gc = new GC (this);
//                  int contentWidth = calculateWidth (new int[]{item.id}, gc, false, 0, 0);
//                  gc.dispose ();
//                  fixScroll =  content.left + contentWidth > rect.x + rect.width;
//              }
//          }
//          if (fixScroll) {
//              int leftScroll = getLeftDisclosureInset (columnId);
//              int levelIndent = DISCLOSURE_COLUMN_LEVEL_INDENT;
//              if (OS.VERSION >= 0x1040) {
//                  float [] metric = new float [1];
//                  OS.DataBrowserGetMetric (handle, OS.kDataBrowserMetricDisclosureColumnPerDepthGap, null, metric);
//                  levelIndent = (int) metric [0];
//              }
//              TreeItem temp = item;
//              while (temp.parentItem !is null) {
//                  leftScroll += levelIndent;
//                  temp = temp.parentItem;
//              }
//              OS.GetDataBrowserScrollPosition (handle, newTop, newLeft);
//              OS.SetDataBrowserScrollPosition (handle, newTop [0], leftScroll);
//          }
//      }
//
//      /*
//      * Bug in the Macintosh.  For some reason, when the DataBrowser is scrolled
//      * by RevealDataBrowserItem(), the scrollbars are not redrawn.  The fix is to
//      * force a redraw.
//      */
//      OS.GetDataBrowserScrollPosition (handle, newTop, newLeft);
//      if (horizontalBar !is null && newLeft [0] !is left [0]) horizontalBar.redraw ();
//      if (verticalBar !is null && newTop [0] !is top [0]) verticalBar.redraw ();
//  }
}

/**
 * Shows the selection.  If the selection is already showing in the receiver,
 * this method simply returns.  Otherwise, the items are scrolled until
 * the selection is visible.
 *
 * @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 Tree#showItem(TreeItem)
 */
public void showSelection () {
    checkWidget ();
    //checkItems (false);
    //TODO - optimize
    TreeItem [] selection = getSelection ();
    if (selection.length > 0) showItem (selection [0], true);
}

}