javauis/eswt_qt/org.eclipse.swt/Eclipse SWT/qt/org/eclipse/swt/widgets/Menu.java
author hgs
Fri, 29 Oct 2010 11:49:32 +0300
changeset 87 1627c337e51e
parent 35 85266cc22c7f
permissions -rw-r--r--
v2.2.21_1

/*******************************************************************************
 * 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.internal.qt.OS;
import org.eclipse.swt.internal.qt.WidgetState;
import org.eclipse.swt.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;

/**
 * Instances of this class are user interface objects that contain
 * menu items.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>BAR, DROP_DOWN, POP_UP, NO_RADIO_GROUP</dd>
 * <dd>LEFT_TO_RIGHT, RIGHT_TO_LEFT</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Hide, Show </dd>
 * </dl>
 * <p>
 * Note: Only one of BAR, DROP_DOWN and POP_UP may be specified.
 * Only one of LEFT_TO_RIGHT or RIGHT_TO_LEFT may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */
public class Menu extends Widget {

    //Handle for the QActionGroup used for SWT.RADIO style menus.
    int actionGroupHandle;
    int x, y;
    int itemCount;
    boolean hasLocation;
    MenuItem cascade;
    Decorations parent;

/**
 * Constructs a new instance of this class given its parent,
 * and sets the style for the instance so that the instance
 * will be a popup menu on the given parent's shell.
 *
 * @param parent a control which will be the parent of the new instance (cannot be null)
 *
 * @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#POP_UP
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (Control parent) {
    this (checkNull (parent).menuShell (), SWT.POP_UP);
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a <code>Decorations</code>) and a style value
 * describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>SWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>SWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a decorations control which will be the parent of the new instance (cannot be null)
 * @param style the style of menu 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#BAR
 * @see SWT#DROP_DOWN
 * @see SWT#POP_UP
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (Decorations parent, int style) {
    super (parent, checkStyle (style));
    this.parent = parent;
    createWidget (0);
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a <code>Menu</code>) and sets the style
 * for the instance so that the instance will be a drop-down
 * menu on the given parent's parent.
 *
 * @param parentMenu a menu which will be the parent of the new instance (cannot be null)
 *
 * @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#DROP_DOWN
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (Menu parentMenu) {
    this (checkNull (parentMenu).parent, SWT.DROP_DOWN);
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a <code>MenuItem</code>) and sets the style
 * for the instance so that the instance will be a drop-down
 * menu on the given parent's parent menu.
 *
 * @param parentItem a menu item which will be the parent of the new instance (cannot be null)
 *
 * @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#DROP_DOWN
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (MenuItem parentItem) {
    this (checkNull (parentItem).parent);
}

static Control checkNull (Control control) {
    if (control == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
    return control;
}

static Menu checkNull (Menu menu) {
    if (menu == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
    return menu;
}

static MenuItem checkNull (MenuItem item) {
    if (item == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
    return item;
}

static int checkStyle (int style) {
    return checkBits (style, SWT.POP_UP, SWT.BAR, SWT.DROP_DOWN, 0, 0, 0);
}


/**
 * Adds the listener to the collection of listeners who will
 * be notified when menus are hidden or shown, by sending it
 * one of the messages defined in the <code>MenuListener</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 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 MenuListener
 * @see #removeMenuListener
 */
public void addMenuListener (MenuListener listener) {
    checkWidget();
    if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
    TypedListener typedListener = new TypedListener (listener);
    addListener (SWT.Hide,typedListener);
    addListener (SWT.Show,typedListener);
}

void createHandle_pp (int index) {

    if ((style & SWT.BAR) != 0) {
        handle = OS.QMenuBar_new( parent.topHandle );
    } else {
        handle = OS.QMenu_new( parent.handle );
    }
    if((style & SWT.RIGHT_TO_LEFT) != 0) {
        OS.QWidget_setLayoutDirection(handle, OS.QT_RIGHTTOLEFT);
    } else {
        OS.QWidget_setLayoutDirection(handle, OS.QT_LEFTTORIGHT);
    }
    topHandle = handle;
    state |= WidgetState.HANDLE;
}

void createWidget (int index) {
    checkOrientation (parent);
    super.createWidget (index);
    parent.addMenu (this);
}

void fixMenus (Decorations newParent) {
// Commented for now, needed for the reparenting of the Controls.
//
//  MenuItem [] items = getItems ();
//  for (int i=0; i<items.length; i++) {
//      items [i].fixMenus (newParent);
//  }
//  parent.removeMenu (this);
//  newParent.addMenu (this);
//  this.parent = newParent;
}

/**
 * Returns the default menu item or null if none has
 * been previously set.
 *
 * @return the default menu item.
 *
 * </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 MenuItem getDefaultItem () {
    checkWidget();
    int actionHandle = OS.QMenu_defaultAction( handle );
    Widget widget = Display.getWidget( actionHandle );
    if( widget != null){
        if (MenuItem.class.isInstance( widget ))
            return (MenuItem)widget;
    }
    return null;
}

/**
 * Returns <code>true</code> if the receiver is enabled, and
 * <code>false</code> otherwise. A disabled menu 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.QWidget_isEnabled( handle );
}

/**
 * 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 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 MenuItem getItem (int index) {
    checkWidget();
    if(index < 0) error (SWT.ERROR_INVALID_RANGE);
    int[] actions = OS.QWidget_actions(handle);
    int indexOfLastMenuItem = -1;
    MenuItem itemAtIndex = null;
    for(int i = 0; i < actions.length; ++i) {
    	Widget widget = Display.getWidget(actions[i]);
    	if(widget != null && widget instanceof MenuItem) {
    		if(++indexOfLastMenuItem == index) {
    			itemAtIndex = (MenuItem)widget;
    			break;
    		}
    	}
    }
    if(index > indexOfLastMenuItem) {
    	error (SWT.ERROR_INVALID_RANGE);
    }
   	return itemAtIndex;
}

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

/**
 * Returns a (possibly empty) array of <code>MenuItem</code>s which
 * are the items in the receiver.
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver.
 * </p>
 *
 * @return the items in the receiver
 *
 * @exception 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 MenuItem [] getItems () {
    checkWidget();
    int[] handles = OS.QWidget_actions( handle );
    int count = handles.length;
    if (count == 0) return new MenuItem [0];
    MenuItem [] children = new MenuItem [count];
    int items = 0;
    for( int i = 0; i < count; ++i) {
        int handle = handles[i];
        if (handle != 0) {
            Widget widget = Display.getWidget (handle);
            if (widget != null && widget != this) {
                if (widget instanceof MenuItem) {
                    children [items++] = (MenuItem) widget;
                }
            }
        }
    }
    if (items == count) return children;
    MenuItem [] newChildren = new MenuItem [items];
    System.arraycopy (children, 0, newChildren, 0, items);
    return newChildren;
}

String getNameText () {
    String result = "";
    MenuItem [] items = getItems ();
    int length = items.length;
    if (length > 0) {
        for (int i=0; i<length-1; i++) {
            result = result + items [i].getNameText() + ", ";
        }
        result = result + items [length-1].getNameText ();
    }
    return result;
}

/**
 * Returns the receiver's parent, which must be a <code>Decorations</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 Decorations getParent () {
    checkWidget();
    return parent;
}

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

/**
 * Returns the receiver's parent item, which must be a
 * <code>Menu</code> or null when the receiver is a
 * root.
 *
 * @return the receiver's parent item
 *
 * @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 getParentMenu () {
    checkWidget();
    if (cascade == null) return null;
    return cascade.getParent ();
}

/**
 * Returns the receiver's shell. For all controls other than
 * shells, this simply returns the control's nearest ancestor
 * shell. Shells return themselves, even if they are children
 * of other shells.
 *
 * @return the receiver's shell
 *
 * @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 #getParent
 */
public Shell getShell () {
    checkWidget();
    return parent.getShell ();
}

/**
 * Returns <code>true</code> if the receiver 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 visibility 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 getVisible () {
    checkWidget();
    return (!OS.QWidget_isHidden( handle ));

}

void qt_signal_aboutToHide() {
    sendEvent (SWT.Hide);
}

void qt_signal_aboutToShow() {
    sendEvent (SWT.Show);
}


void hookEvents_pp () {
    super.hookEvents_pp ();
    if ((style & SWT.BAR) == 0) {
        int aboutToHideProxy = OS.SignalHandler_new(handle, OS.QSIGNAL_ABOUTTOHIDE);
        OS.QObject_connectOrThrow(handle, "aboutToHide()", aboutToHideProxy, "widgetSignal()", OS.QT_AUTOCONNECTION);
        int aboutToShowProxy = OS.SignalHandler_new(handle, OS.QSIGNAL_ABOUTTOSHOW);
        OS.QObject_connectOrThrow(handle, "aboutToShow()", aboutToShowProxy, "widgetSignal()", OS.QT_AUTOCONNECTION);
    }
}

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

/**
 * 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 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 () {
    checkWidget();
    Menu parentMenu = getParentMenu ();
    if (parentMenu == null) {
        return getEnabled () && parent.isEnabled ();
    }
    return getEnabled () && parentMenu.isEnabled ();
}

/**
 * Returns <code>true</code> if the receiver is visible and all
 * of the receiver's ancestors are visible and <code>false</code>
 * otherwise.
 *
 * @return the receiver's visibility 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 #getVisible
 */
public boolean isVisible () {
    checkWidget();
    return OS.QWidget_isVisible( handle );
}

void menuItemAdded() {
	itemCount++;
}

void menuItemRemoved() {
	itemCount = Math.max(--itemCount, 0);
}

void releaseChildren_pp (boolean destroy) {
    MenuItem [] items = getItems ();
    for (int i=0; i<items.length; i++) {
        MenuItem item = items [i];
        if (item != null && !item.isDisposed ()) {
            item.release (false);
        }
    }
    super.releaseChildren_pp (destroy);
}

void releaseParent_pp () {
    super.releaseParent_pp ();
    if (cascade != null) cascade.setMenu (null);
    if ((style & SWT.BAR) != 0 && this == parent.menuBar) {
        parent.setMenuBar (null);
    }
}

void releaseWidget_pp () {
    super.releaseWidget_pp ();
    if (parent != null) parent.removeMenu (this);
    parent = null;
    cascade = null;
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the menu events are generated for the control.
 *
 * @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 MenuListener
 * @see #addMenuListener
 */
public void removeMenuListener (MenuListener listener) {
    checkWidget();
    if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
    if (eventTable == null) return;
    eventTable.unhook (SWT.Hide, listener);
    eventTable.unhook (SWT.Show, listener);
}

/**
 * Sets the default menu item to the argument or removes
 * the default emphasis when the argument is <code>null</code>.
 *
 * @param item the default menu item or null
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the menu item has been disposed</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 setDefaultItem (MenuItem item) {
    checkWidget();
    if (item != null) {
        if (item.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
        if (item.parent != this) return;
        OS.QMenu_setDefaultAction( handle, item.handle);
    }
    else{
        OS.QMenu_setDefaultAction(handle, 0);
    }

}

/**
 * Enables the receiver if the argument is <code>true</code>,
 * and disables it otherwise. A disabled menu 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.QWidget_setEnabled( handle, enabled );
}

/**
 * Sets the location of the receiver, which must be a popup,
 * to the point specified by the arguments which are relative
 * to the display.
 * <p>
 * Note that this is different from most widgets where the
 * location of the widget is relative to the parent.
 * </p><p>
 * Note that the platform window manager ultimately has control
 * over the location of popup menus.
 * </p>
 *
 * @param x the new x coordinate for the receiver
 * @param y the new y coordinate for the receiver
 *
 * @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 setLocation (int x, int y) {
    checkWidget();
    if ((style & (SWT.BAR | SWT.DROP_DOWN)) != 0) return;
    this.x = x;
    this.y = y;
    hasLocation = true;
}

/**
 * Sets the location of the receiver, which must be a popup,
 * to the point specified by the argument which is relative
 * to the display.
 * <p>
 * Note that this is different from most widgets where the
 * location of the widget is relative to the parent.
 * </p><p>
 * Note that the platform window manager ultimately has control
 * over the location of popup menus.
 * </p>
 *
 * @param location the new location for the receiver
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point 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>
 *
 * @since 2.1
 */
public void setLocation (Point location) {
    checkWidget();
    if (location == null) error (SWT.ERROR_NULL_ARGUMENT);
    setLocation (location.x, location.y);
}

/**
 * Marks the receiver 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 visible the new visibility 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 setVisible (boolean visible) {
    checkWidget();
    if ((style & (SWT.BAR | SWT.DROP_DOWN)) != 0) return;
    if (visible) {
        OS.QMenu_popup(handle, x, y, 0);
    } else {
        OS.QWidget_setVisible(handle, visible);
    }
}
}