/*******************************************************************************

 * Copyright (c) 2000, 2007 IBM Corporation and others.

 * Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

 * 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

 *     Nokia Corporation - Qt implementation

 *******************************************************************************/

package org.eclipse.swt.widgets;

import org.eclipse.swt.*;

import org.eclipse.swt.graphics.*;

import org.eclipse.swt.internal.qt.OS;

import org.eclipse.swt.internal.qt.WidgetState;

import org.eclipse.swt.events.*;

/**

 * Instances of this class represent a selectable user interface object

 * that issues notification when pressed and released. 

 * <dl>

 * <dt><b>Styles:</b></dt>

 * <dd>CHECK, CASCADE, PUSH, RADIO, SEPARATOR</dd>

 * <dt><b>Events:</b></dt>

 * <dd>Arm, Selection</dd>

 * </dl>

 * <p>

 * Note: Only one of the styles CHECK, CASCADE, PUSH, RADIO and SEPARATOR

 * may be specified.

 * </p><p>

 * IMPORTANT: This class is <em>not</em> intended to be subclassed.

 * </p>

 */

public class MenuItem extends Item {

    Menu parent, menu;

    int accelerator;

/**

 * Constructs a new instance of this class given its parent

 * (which must be a <code>Menu</code>) and a style value

 * describing its behavior and appearance. The item is added

 * to the end of the items maintained by its parent.

 * <p>

 * The style value is either one of the style constants defined in

 * class <code>SWT</code> which is applicable to instances of this

 * class, or must be built by <em>bitwise OR</em>'ing together 

 * (that is, using the <code>int</code> "|" operator) two or more

 * of those <code>SWT</code> style constants. The class description

 * lists the style constants that are applicable to the class.

 * Style bits are also inherited from superclasses.

 * </p>

 *

 * @param parent a menu control which will be the parent of the new instance (cannot be null)

 * @param style the style of control to construct

 *

 * @exception IllegalArgumentException <ul>

 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>

 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>

 * </ul>

 *

 * @see SWT#CHECK

 * @see SWT#CASCADE

 * @see SWT#PUSH

 * @see SWT#RADIO

 * @see SWT#SEPARATOR

 * @see Widget#checkSubclass

 * @see Widget#getStyle

 */

public MenuItem (Menu parent, int style) {

    super (parent, checkStyle (style));

    this.parent = parent;

    createWidget (parent.getItemCount ());

    parent.menuItemAdded();

}

/**

 * Constructs a new instance of this class given its parent

 * (which must be a <code>Menu</code>), a style value

 * describing its behavior and appearance, and the index

 * at which to place it in the items maintained by its parent.

 * <p>

 * The style value is either one of the style constants defined in

 * class <code>SWT</code> which is applicable to instances of this

 * class, or must be built by <em>bitwise OR</em>'ing together 

 * (that is, using the <code>int</code> "|" operator) two or more

 * of those <code>SWT</code> style constants. The class description

 * lists the style constants that are applicable to the class.

 * Style bits are also inherited from superclasses.

 * </p>

 *

 * @param parent a menu control which will be the parent of the new instance (cannot be null)

 * @param style the style of control to construct

 * @param index the zero-relative index to store the receiver in its parent

 *

 * @exception IllegalArgumentException <ul>

 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>

 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the parent (inclusive)</li>

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>

 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>

 * </ul>

 *

 * @see SWT#CHECK

 * @see SWT#CASCADE

 * @see SWT#PUSH

 * @see SWT#RADIO

 * @see SWT#SEPARATOR

 * @see Widget#checkSubclass

 * @see Widget#getStyle

 */

public MenuItem (Menu parent, int style, int index) {

    super (parent, checkStyle (style));

    this.parent = parent;

    int count = parent.getItemCount ();

    if (!(0 <= index && index <= count)) {

        error (SWT.ERROR_INVALID_RANGE);

    }

    createWidget (index);

    parent.menuItemAdded();

}

/**

 * Adds the listener to the collection of listeners who will

 * be notified when the menu item is selected by the user, by sending

 * it one of the messages defined in the <code>SelectionListener</code>

 * interface.

 * <p>

 * When <code>widgetSelected</code> is called, the stateMask field of the event object is valid.

 * <code>widgetDefaultSelected</code> is not called.

 * </p>

 *

 * @param listener the listener which should be notified when the menu item is selected by the user

 *

 * @exception IllegalArgumentException <ul>

 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 *

 * @see SelectionListener

 * @see #removeSelectionListener

 * @see SelectionEvent

 */

public void addSelectionListener (SelectionListener listener) {

    checkWidget();

    if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);

    TypedListener typedListener = new TypedListener(listener);

    addListener (SWT.Selection,typedListener);

    addListener (SWT.DefaultSelection,typedListener);

}

static int checkStyle (int style) {

    return checkBits (style, SWT.PUSH, SWT.CHECK, SWT.RADIO, SWT.SEPARATOR, SWT.CASCADE, 0);

}

protected void checkSubclass () {

    if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);

}

void createHandle_pp (int index) {

    topHandle = handle = OS.QAction_new( parent.handle );

    state |= WidgetState.HANDLE;

    if ((parent.style & SWT.BAR) != 0){

        OS.QMenuBar_addAction( parent.handle, handle );

    }

    else{

        int itemCount = parent.getItemCount();

        if( itemCount > 0 && index < itemCount ){

            int beforeHandle = parent.getItems()[index].handle;

            OS.QWidget_insertAction(parent.handle, beforeHandle, handle );

        }

        else{

            OS.QMenu_addAction(parent.handle, handle );

        }

    }

    int bits = SWT.CHECK | SWT.RADIO | SWT.PUSH | SWT.SEPARATOR ;

    switch (style & bits) {

        case SWT.SEPARATOR:

            OS.QAction_setSeparator( handle, true );

            break;

        case SWT.RADIO:

            if (parent.actionGroupHandle == 0){

                parent.actionGroupHandle = OS.QActionGroup_new( parent.handle );

                if ((parent.style & SWT.NO_RADIO_GROUP ) != 0 ){

                    OS.QActionGroup_setExclusive(parent.actionGroupHandle, false);

                }

            }

            OS.QAction_setCheckable( handle, true );

            OS.QActionGroup_addAction( parent.actionGroupHandle, handle );

            break;

        case SWT.CHECK:

            OS.QAction_setCheckable( handle, true );

            break;

        case SWT.PUSH:

        default:

            break;

    }

}

void fixMenus (Decorations newParent) {

//Commented for now. Needed for the reparenting of the Controls

//  if (menu != null) menu.fixMenus (newParent);

}

/**

 * Returns the widget accelerator.  An accelerator is the bit-wise

 * OR of zero or more modifier masks and a key. Examples:

 * <code>SWT.CONTROL | SWT.SHIFT | 'T', SWT.ALT | SWT.F2</code>.

 * The default value is zero, indicating that the menu item does

 * not have an accelerator.

 *

 * @return the accelerator or 0

 *

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public int getAccelerator () {

    checkWidget();

    return accelerator;

}

/**

 * Returns <code>true</code> if the receiver is enabled, and

 * <code>false</code> otherwise. A disabled menu item is typically

 * not selectable from the user interface and draws with an

 * inactive or "grayed" look.

 *

 * @return the receiver's enabled state

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 * 

 * @see #isEnabled

 */

public boolean getEnabled () {

    checkWidget();

    return OS.QAction_isEnabled( handle );

}

/**

 * Returns the receiver's cascade menu if it has one or null

 * if it does not. Only <code>CASCADE</code> menu items can have

 * a pull down menu. The sequence of key strokes, button presses 

 * and/or button releases that are used to request a pull down

 * menu is platform specific.

 *

 * @return the receiver's menu

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public Menu getMenu () {

    checkWidget();

    return menu;

}

String getNameText () {

    if ((style & SWT.SEPARATOR) != 0) return "|";

    return super.getNameText ();

}

/**

 * Returns the receiver's parent, which must be a <code>Menu</code>.

 *

 * @return the receiver's parent

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public Menu getParent () {

    checkWidget();

    return parent;

}

/**

 * Returns <code>true</code> if the receiver is selected,

 * and false otherwise.

 * <p>

 * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>,

 * it is selected when it is checked.

 *

 * @return the selection state

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public boolean getSelection () {

    checkWidget();

    if ((style & (SWT.CHECK | SWT.RADIO)) == 0) return false;

    return OS.QAction_isChecked( handle );

}

void qt_signal_triggered_pp( boolean checked ) {

    Event event = new Event ();

    sendEvent (SWT.Selection, event);

}

void qt_signal_hover() {

    sendEvent (SWT.Arm);

}

void hookEvents_pp () {

    super.hookEvents_pp ();

    if ((style & SWT.CASCADE) == 0 ){

        int triggeredProxy = OS.SignalHandler_new(handle, OS.QSIGNAL_TRIGGERED);

        OS.QObject_connectOrThrow(handle, "triggered(bool)", triggeredProxy, "widgetSignal(bool)", OS.QT_AUTOCONNECTION);

    }

    int hoveredProxy = OS.SignalHandler_new(handle, OS.QSIGNAL_HOVER );

    OS.QObject_connectOrThrow(handle, "hovered()", hoveredProxy, "widgetSignal()", OS.QT_AUTOCONNECTION);

}

/**

 * Returns <code>true</code> if the receiver is enabled and all

 * of the receiver's ancestors are enabled, and <code>false</code>

 * otherwise. A disabled menu item is typically not selectable from the

 * user interface and draws with an inactive or "grayed" look.

 *

 * @return the receiver's enabled state

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 * 

 * @see #getEnabled

 */

public boolean isEnabled () {

    return getEnabled () && parent.isEnabled ();

}

void releaseChildren_pp (boolean destroy) {

    if (menu != null) {

        menu.release (false);

        menu = null;

    }

    super.releaseChildren_pp (destroy);

}

void releaseParent_pp () {

    super.releaseParent_pp ();

    if (menu != null) {

        menu.dispose ();

    }

    menu = null;

    parent.menuItemRemoved();

}

void releaseWidget_pp () {

    if( (style & SWT.RADIO) != 0 ){

        if (parent.actionGroupHandle != 0){

            OS.QActionGroup_removeAction(parent.actionGroupHandle, handle);

        }

    }

    OS.QWidget_removeAction( parent.handle, handle );

    super.releaseWidget_pp ();

    accelerator = 0;

    parent = null;

}

/**

 * Removes the listener from the collection of listeners who will

 * be notified when the control is selected by the user.

 *

 * @param listener the listener which should no longer be notified

 *

 * @exception IllegalArgumentException <ul>

 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 *

 * @see SelectionListener

 * @see #addSelectionListener

 */

public void removeSelectionListener (SelectionListener listener) {

    checkWidget();

    if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);

    if (eventTable == null) return;

    eventTable.unhook (SWT.Selection, listener);

    eventTable.unhook (SWT.DefaultSelection,listener);  

}

/**

 * Sets the widget accelerator.  An accelerator is the bit-wise

 * OR of zero or more modifier masks and a key. Examples:

 * <code>SWT.MOD1 | SWT.MOD2 | 'T', SWT.MOD3 | SWT.F2</code>.

 * <code>SWT.CONTROL | SWT.SHIFT | 'T', SWT.ALT | SWT.F2</code>.

 * The default value is zero, indicating that the menu item does

 * not have an accelerator.

 *

 * @param accelerator an integer that is the bit-wise OR of masks and a key

 *

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public void setAccelerator (int accelerator) {

    checkWidget();

    if (this.accelerator == accelerator) return;

    int mask = 0;

    if ((accelerator & SWT.ALT) != 0) mask |= OS.QT_ALTMODIFIER;

    if ((accelerator & SWT.SHIFT) != 0) mask |= OS.QT_SHIFTMODIFIER;

    if ((accelerator & SWT.CONTROL) != 0) mask |= OS.QT_CONTROLMODIFIER;

    int keysym = accelerator & SWT.KEY_MASK;

    int newKey = Display.untranslateKey (keysym);

    if (newKey != 0) {

        keysym = newKey;

    }

    int keySequenceHandle = OS.QKeySequence_new( mask + keysym );

    OS.QAction_setShortcut( handle, keySequenceHandle );

    this.accelerator = accelerator;

    OS.QKeySequence_delete( keySequenceHandle );

}

/**

 * Enables the receiver if the argument is <code>true</code>,

 * and disables it otherwise. A disabled menu item is typically

 * not selectable from the user interface and draws with an

 * inactive or "grayed" look.

 *

 * @param enabled the new enabled state

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public void setEnabled (boolean enabled) {

    checkWidget();

    OS.QAction_setEnabled(handle, enabled);

}

/**

 * Sets the image the receiver will display to the argument.

 * <p>

 * Note: This operation is a hint and is not supported on

 * platforms that do not have this concept (for example, Windows NT).

 * </p>

 *

 * @param image the image to display

 *

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public void setImage (Image image) {

    checkWidget();

    if ((style & SWT.SEPARATOR) != 0) return;

    super.setImage (image);

    if (image != null ) {

        OS.QAction_setIcon(handle, Internal_GfxPackageSupport.getIconHandle(image));

    } else {

        OS.QAction_setIcon(handle, Internal_GfxPackageSupport.getNullIconHandle());

    }

}

/**

 * Sets the receiver's pull down menu to the argument.

 * Only <code>CASCADE</code> menu items can have a

 * pull down menu. The sequence of key strokes, button presses

 * and/or button releases that are used to request a pull down

 * menu is platform specific.

 * <p>

 * Note: Disposing of a menu item that has a pull down menu

 * will dispose of the menu.  To avoid this behavior, set the

 * menu to null before the menu item is disposed.

 * </p>

 *

 * @param menu the new pull down menu

 *

 * @exception IllegalArgumentException <ul>

 *    <li>ERROR_MENU_NOT_DROP_DOWN - if the menu is not a drop down menu</li>

 *    <li>ERROR_MENUITEM_NOT_CASCADE - if the menu item is not a <code>CASCADE</code></li>

 *    <li>ERROR_INVALID_ARGUMENT - if the menu has been disposed</li>

 *    <li>ERROR_INVALID_PARENT - if the menu is not in the same widget tree</li>

 * </ul>

 * @exception SWTException <ul>

 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>

 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>

 * </ul>

 */

public void setMenu (Menu menu) {

    checkWidget ();

    /* Check to make sure the new menu is valid */

    if ((style & SWT.CASCADE) == 0) {

        error (SWT.ERROR_MENUITEM_NOT_CASCADE);

    }

    int menuHandle = 0;

    if (menu != null) {

        if ((menu.style & SWT.DROP_DOWN) == 0) {

            error (SWT.ERROR_MENU_NOT_DROP_DOWN);

        }

        if (menu.parent != parent.parent) {

            error (SWT.ERROR_INVALID_PARENT);

        }

        menuHandle = menu.handle;

    }

    /* Assign the new menu */

    Menu oldMenu = this.menu;