org.eclipse.swt.widgets.MenuItem Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.swt.gtk.linux.aarch64 Show documentation
Standard Widget Toolkit for GTK on aarch64
The newest version!
/*******************************************************************************
 * Copyright (c) 2000, 2023 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.internal.gtk3.*;
import org.eclipse.swt.internal.gtk4.*;
import org.eclipse.swt.widgets.Menu.*;

/**
 * Instances of this class represent a selectable user interface object
 * that issues notification when pressed and released.
 * 
 * Styles:
 * CHECK, CASCADE, PUSH, RADIO, SEPARATOR
 * Events:
 * Arm, Help, Selection
 * 
 * 
 * Note: Only one of the styles CHECK, CASCADE, PUSH, RADIO and SEPARATOR
 * may be specified.
 * 

 * IMPORTANT: This class is not intended to be subclassed.
 * 
 *
 * @see Sample code and further information
 * @noextend This class is not intended to be subclassed by clients.
 */
public class MenuItem extends Item {
	Menu parent, menu;
	long groupHandle, labelHandle, imageHandle;

	/** Feature in Gtk: as of Gtk version 3.10 GtkImageMenuItem is deprecated,
	 * meaning that MenuItems in SWT with images can no longer be GtkImageMenuItems
	 * after Gtk3.10. The solution to this is to create a GtkMenuItem, add a GtkBox
	 * as its child, and pack that box with a GtkLabel and GtkImage. This reproduces
	 * the functionality of a GtkImageMenuItem and allows SWT to retain image support
	 * for MenuItems.
	 *
	 * For more information see:
	 * https://developer.gnome.org/gtk3/stable/GtkImageMenuItem.html#GtkImageMenuItem.description
	 * Bug 470298
	 */
	long boxHandle;

	int accelerator, userId;
	String toolTipText;

	Image defaultDisableImage;
	boolean enabled = true;

	/** GTK4 only fields */
	long modelHandle, actionHandle, shortcutHandle;
	Section section;
	String actionName;

/**
 * Constructs a new instance of this class given its parent
 * (which must be a Menu) and a style value
 * describing its behavior and appearance. The item is added
 * to the end of the items maintained by its parent.
 * 
 * The style value is either one of the style constants defined in
 * class SWT which is applicable to instances of this
 * class, or must be built by bitwise OR'ing together
 * (that is, using the int "|" operator) two or more
 * of those SWT style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * 
 *
 * @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 
 *    ERROR_NULL_ARGUMENT - if the parent is null
 * 
 * @exception SWTException 
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
 *    ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
 * 
 *
 * @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 ());
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a Menu), a style value
 * describing its behavior and appearance, and the index
 * at which to place it in the items maintained by its parent.
 * 
 * The style value is either one of the style constants defined in
 * class SWT which is applicable to instances of this
 * class, or must be built by bitwise OR'ing together
 * (that is, using the int "|" operator) two or more
 * of those SWT style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * 
 *
 * @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 
 *    ERROR_NULL_ARGUMENT - if the parent is null
 *    ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the parent (inclusive)
 * 
 * @exception SWTException 
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
 *    ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
 * 
 *
 * @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);
}

void addAccelerator (long accelGroup) {
	updateAccelerator (accelGroup, true);
}

void addAccelerators (long accelGroup) {
	addAccelerator(accelGroup);
	if (menu != null) menu.addAccelerators(accelGroup);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the arm events are generated for the control, by sending
 * it one of the messages defined in the ArmListener
 * interface.
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see ArmListener
 * @see #removeArmListener
 */
public void addArmListener (ArmListener listener) {
	addTypedListener(listener, SWT.Arm);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the help events are generated for the control, by sending
 * it one of the messages defined in the HelpListener
 * interface.
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see HelpListener
 * @see #removeHelpListener
 */
public void addHelpListener (HelpListener listener) {
	addTypedListener(listener, SWT.Help);
}

/**
 * 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 SelectionListener
 * interface.
 * 
 * When widgetSelected is called, the stateMask field of the event object is valid.
 * widgetDefaultSelected is not called.
 * 
 * 
 * When the SWT.RADIO style bit is set, the widgetSelected method is
 * also called when the receiver loses selection because another item in the same radio group
 * was selected by the user. During widgetSelected the application can use
 * getSelection() to determine the current selected state of the receiver.
 * 
 *
 * @param listener the listener which should be notified when the menu item is selected by the user
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener (SelectionListener listener) {
	addTypedListener(listener, SWT.Selection, SWT.DefaultSelection);
}

static int checkStyle (int style) {
	return checkBits (style, SWT.PUSH, SWT.CHECK, SWT.RADIO, SWT.SEPARATOR, SWT.CASCADE, 0);
}

@Override
protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

@Override
void createHandle(int index) {
	state |= HANDLE;
	int bits = SWT.CHECK | SWT.RADIO | SWT.PUSH | SWT.SEPARATOR | SWT.CASCADE;

	if (GTK.GTK4) {
		switch (style & bits) {
			case SWT.SEPARATOR:
				modelHandle = OS.g_menu_new();
				handle = OS.g_menu_item_new_section(null, modelHandle);
				break;
			case SWT.RADIO:
				long stringVariantType = OS.g_variant_type_new(OS.G_VARIANT_TYPE_STRING);
				actionHandle = OS.g_simple_action_new_stateful(
					Converter.javaStringToCString(String.valueOf(this.hashCode())),
					stringVariantType,
					OS.g_variant_new_string(Converter.javaStringToCString("untoggled")));
				OS.g_action_map_add_action(parent.actionGroup, actionHandle);
				actionName = String.valueOf(parent.hashCode()) + "." + String.valueOf(this.hashCode()) + "::toggled";
				handle = OS.g_menu_item_new(null, Converter.javaStringToCString(actionName));
				OS.g_variant_type_free(stringVariantType);
				break;
			case SWT.CHECK:
				long boolVariantType = OS.g_variant_type_new(OS.G_VARIANT_TYPE_BOOLEAN);
				actionHandle = OS.g_simple_action_new_stateful(
					Converter.javaStringToCString(String.valueOf(this.hashCode())),
					0,
					OS.g_variant_new_boolean(false));
				OS.g_action_map_add_action(parent.actionGroup, actionHandle);
				actionName = String.valueOf(parent.hashCode()) + "." + String.valueOf(this.hashCode());
				handle = OS.g_menu_item_new(null, Converter.javaStringToCString(actionName));
				OS.g_variant_type_free(boolVariantType);
				break;
			case SWT.CASCADE:
				modelHandle = OS.g_menu_new();
				handle = OS.g_menu_item_new_submenu(Converter.javaStringToCString(""), modelHandle);
				break;
			case SWT.PUSH:
			default:
				actionHandle = OS.g_simple_action_new(Converter.javaStringToCString(String.valueOf(this.hashCode())), 0);
				OS.g_action_map_add_action(parent.actionGroup, actionHandle);
				actionName = String.valueOf(parent.hashCode()) + "." + String.valueOf(this.hashCode());
				handle = OS.g_menu_item_new(null, Converter.javaStringToCString(actionName));
				break;
		}


		Section selectedSection = parent.sections.getLast();
		for (Section section : parent.sections) {
			int sectionPosition = section.getSectionPosition();
			int sectionLength = section.getSectionSize();

			if (index > sectionPosition && index <= sectionPosition + sectionLength + 1) {
				selectedSection = section;
				break;
			}
		}

		int sectionRelativeIndex = index - (selectedSection.getSectionPosition() + 1);
		if ((style & SWT.SEPARATOR) != 0) {
			section = parent.new Section(this);

			int itemsToMove = selectedSection.sectionItems.size() - sectionRelativeIndex;
			for (int i = 0; i < itemsToMove; i++) {
				MenuItem removedItem = selectedSection.sectionItems.remove(sectionRelativeIndex);
				section.sectionItems.add(removedItem);

				OS.g_menu_remove(selectedSection.getSectionHandle(), sectionRelativeIndex);
				OS.g_menu_insert_item(modelHandle, section.sectionItems.indexOf(removedItem), removedItem.handle);
				removedItem.section = section;
			}

			int sectionInsertIndex = parent.sections.indexOf(selectedSection) + 1;
			parent.sections.add(sectionInsertIndex, section);
			OS.g_menu_insert_item(parent.modelHandle, sectionInsertIndex, handle);
		} else {
			section = selectedSection;
			selectedSection.sectionItems.add(sectionRelativeIndex, this);
			OS.g_menu_insert_item(selectedSection.getSectionHandle(), sectionRelativeIndex, handle);
		}

		parent.items.add(index, this);
	} else {
		byte[] buffer = new byte[1];

		switch (style & bits) {
			case SWT.SEPARATOR:
				handle = GTK3.gtk_separator_menu_item_new ();
				if (handle == 0) error (SWT.ERROR_NO_HANDLES);
				break;
			case SWT.RADIO:
				/*
				* Feature in GTK.  In GTK, radio button must always be part of
				* a radio button group.  In a GTK radio group, one button is always
				* selected.  This means that it is not possible to have a single
				* radio button that is unselected.  This is necessary to allow
				* applications to implement their own radio behavior or use radio
				* buttons outside of radio groups.  The fix is to create a hidden
				* radio button for each radio button we create and add them
				* to the same group.  This allows the visible button to be
				* unselected.
				*/
				groupHandle = GTK3.gtk_radio_menu_item_new (0);
				if (groupHandle == 0) error (SWT.ERROR_NO_HANDLES);
				OS.g_object_ref_sink (groupHandle);
				long group = GTK3.gtk_radio_menu_item_get_group (groupHandle);
				handle = GTK3.gtk_radio_menu_item_new (group);
				if (handle == 0) error (SWT.ERROR_NO_HANDLES);

				labelHandle = GTK3.gtk_accel_label_new (buffer);
				if (labelHandle == 0) error (SWT.ERROR_NO_HANDLES);

				boxHandle = gtk_box_new (GTK.GTK_ORIENTATION_HORIZONTAL, false, 6);
				if (boxHandle == 0) error (SWT.ERROR_NO_HANDLES);

				if (OS.SWT_PADDED_MENU_ITEMS) {
					imageHandle = GTK.gtk_image_new ();
					if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
				}
				break;
			case SWT.CHECK:
				handle = GTK3.gtk_check_menu_item_new ();
				if (handle == 0) error (SWT.ERROR_NO_HANDLES);

				labelHandle = GTK3.gtk_accel_label_new (buffer);
				if (labelHandle == 0) error (SWT.ERROR_NO_HANDLES);

				boxHandle = gtk_box_new (GTK.GTK_ORIENTATION_HORIZONTAL, false, 6);
				if (boxHandle == 0) error (SWT.ERROR_NO_HANDLES);

				if (OS.SWT_PADDED_MENU_ITEMS) {
					imageHandle = GTK.gtk_image_new ();
					if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
				}
				break;
			// This case now needs to be handled due to double padding. When double padded
			// menus are used, the "head" menu item (such as File, Edit, Help, etc.) should
			// not be padded. We only care about this in Gtk3.
			case SWT.CASCADE:
				handle = GTK3.gtk_menu_item_new ();
				if (handle == 0) error (SWT.ERROR_NO_HANDLES);

				labelHandle = GTK3.gtk_accel_label_new (buffer);
				if (labelHandle == 0) error (SWT.ERROR_NO_HANDLES);

				boxHandle = gtk_box_new (GTK.GTK_ORIENTATION_HORIZONTAL, false, 6);
				if (boxHandle == 0) error (SWT.ERROR_NO_HANDLES);
				if ((parent.style & bits) == SWT.BAR) {
					break;
				}
				if (OS.SWT_PADDED_MENU_ITEMS) {
					imageHandle = GTK.gtk_image_new ();
					if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
				}
				break;
			case SWT.PUSH:
			default:
				handle = GTK3.gtk_menu_item_new ();
				if (handle == 0) error (SWT.ERROR_NO_HANDLES);

				labelHandle = GTK3.gtk_accel_label_new (buffer);
				if (labelHandle == 0) error (SWT.ERROR_NO_HANDLES);

				boxHandle = gtk_box_new (GTK.GTK_ORIENTATION_HORIZONTAL, false, 6);
				if (boxHandle == 0) error (SWT.ERROR_NO_HANDLES);

				if (OS.SWT_PADDED_MENU_ITEMS) {
					imageHandle = GTK.gtk_image_new ();
					if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
				}
				break;
		}

		if (imageHandle != 0) {
			if (OS.SWT_PADDED_MENU_ITEMS) {
				GTK.gtk_image_set_pixel_size (imageHandle, 16);
			}

			GTK3.gtk_container_add (boxHandle, imageHandle);
			GTK.gtk_widget_show (imageHandle);
		}

		if (labelHandle != 0) {
			GTK.gtk_label_set_xalign (labelHandle, 0);
			GTK.gtk_widget_set_halign (labelHandle, GTK.GTK_ALIGN_FILL);
			gtk_box_pack_end (boxHandle, labelHandle, true, true, 0);
			GTK.gtk_widget_show (labelHandle);
		}

		if (boxHandle != 0) {
			GTK3.gtk_container_add (handle, boxHandle);
			GTK.gtk_widget_show (boxHandle);
		}

		if ((style & SWT.SEPARATOR) == 0) {
			if (boxHandle == 0) {
				labelHandle = GTK3.gtk_bin_get_child (handle);
			}
			GTK3.gtk_accel_label_set_accel_widget (labelHandle, 0);
		}

		long parentHandle = parent.handle;
		boolean enabled = GTK.gtk_widget_get_sensitive (parentHandle);
		if (!enabled) GTK.gtk_widget_set_sensitive (parentHandle, true);
		GTK3.gtk_menu_shell_insert (parentHandle, handle, index);
		if (!enabled) GTK.gtk_widget_set_sensitive (parentHandle, false);
		GTK.gtk_widget_show (handle);
	}
}

void fixMenus (Decorations newParent) {
	if (menu != null && !menu.isDisposed() && !newParent.isDisposed()) menu.fixMenus (newParent);
}

/**
 * Returns the widget accelerator.  An accelerator is the bit-wise
 * OR of zero or more modifier masks and a key. Examples:
 * SWT.CONTROL | SWT.SHIFT | 'T', SWT.ALT | SWT.F2.
 * The default value is zero, indicating that the menu item does
 * not have an accelerator.
 *
 * @return the accelerator or 0
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getAccelerator () {
	checkWidget();
	return accelerator;
}

long getAccelGroup () {
	Menu menu = parent;
	while (menu != null && menu.cascade != null) {
		menu = menu.cascade.parent;
	}
	if (menu == null) return 0;
	Decorations shell = menu.parent;
	if (shell == null) return 0;
	return shell.menuBar == menu ? shell.accelGroup : 0;
}

/**
 * Returns true if the receiver is enabled, and
 * false 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 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #isEnabled
 */
public boolean getEnabled () {
	checkWidget();

	if (GTK.GTK4) {
		if ((style & SWT.CASCADE) != 0) {
			return true;
		}

		return OS.g_action_get_enabled(actionHandle);
	} else {
		return GTK.gtk_widget_get_sensitive(handle);
	}
}

/**
 * Gets the identifier associated with the receiver.
 *
 * @return the receiver's identifier
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.7
 */
public int getID () {
	checkWidget();
	return userId;
}

/**
 * Returns the receiver's cascade menu if it has one or null
 * if it does not. Only CASCADE 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 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public Menu getMenu () {
	checkWidget();
	return menu;
}

@Override
String getNameText () {
	if ((style & SWT.SEPARATOR) != 0) return "|";
	return super.getNameText ();
}

/**
 * Returns the receiver's parent, which must be a Menu.
 *
 * @return the receiver's parent
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public Menu getParent () {
	checkWidget();
	return parent;
}

/**
 * Returns true if the receiver is selected,
 * and false otherwise.
 * 
 * When the receiver is of type CHECK or RADIO,
 * it is selected when it is checked.
 *
 * @return the selection state
 *
 * @exception SWTException 

 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public boolean getSelection () {
	checkWidget();
	if ((style & (SWT.CHECK | SWT.RADIO)) == 0) return false;

	if (GTK.GTK4) {
		long gVariantState = OS.g_action_get_state(actionHandle);
		if ((style & SWT.CHECK) != 0) {
			return OS.g_variant_get_boolean(gVariantState);
		} else {
			String stateString = Converter.cCharPtrToJavaString(OS.g_variant_get_string(gVariantState, null), false);
			return stateString.equals("toggled");
		}
	} else {
		return GTK3.gtk_check_menu_item_get_active(handle);
	}
}

/**
 * Returns the receiver's tool tip text, or null if it has not been set.
 *
 * @return the receiver's tool tip text
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.104
 */
public String getToolTipText () {
	checkWidget();
	return toolTipText;
}

@Override
long gtk_activate (long widget) {
	if ((style & SWT.CASCADE) != 0 && menu != null) return 0;

	if (!GTK.GTK4) {
		/*
		* Bug in GTK.  When an ancestor menu is disabled and
		* the user types an accelerator key, GTK delivers the
		* the activate signal even though the menu item cannot
		* be invoked using the mouse.  The fix is to ignore
		* activate signals when an ancestor menu is disabled.
		*/
		if (!isEnabled()) return 0;
	}

	if ((style & SWT.RADIO) != 0) {
		if ((parent.getStyle () & SWT.NO_RADIO_GROUP) == 0) {
			selectRadio ();
		}
	}

	sendSelectionEvent (SWT.Selection);
	return 0;
}

@Override
long gtk_select (long item) {
	parent.selectedItem = this;
	sendEvent (SWT.Arm);
	return 0;
}

@Override
long gtk3_show_help (long widget, long helpType) {
	boolean handled = hooks (SWT.Help);
	if (handled) {
		postEvent (SWT.Help);
	} else {
		handled = parent.sendHelpEvent (helpType);
	}
	if (handled) {
		GTK3.gtk_menu_shell_deactivate (parent.handle);
		return 1;
	}
	return 0;
}

@Override
void hookEvents() {
	super.hookEvents();

	if (GTK.GTK4) {
		if ((style & SWT.PUSH) != 0 || (style & SWT.RADIO) != 0) {
			OS.g_signal_connect(actionHandle, OS.activate, display.activateProc, handle);
		}
	} else {
		OS.g_signal_connect_closure(handle, OS.activate, display.getClosure (ACTIVATE), false);
		OS.g_signal_connect_closure(handle, OS.select, display.getClosure (SELECT), false);
		OS.g_signal_connect_closure_by_id(handle, display.signalIds[SHOW_HELP], 0, display.getClosure(SHOW_HELP), false);
	}
}

/**
 * Returns true if the receiver is enabled and all
 * of the receiver's ancestors are enabled, and false
 * 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 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #getEnabled
 */
public boolean isEnabled () {
	return getEnabled () && parent.isEnabled ();
}

@Override
void releaseChildren (boolean destroy) {
	if (menu != null) {
		menu.release (false);
		menu = null;
	}
	super.releaseChildren (destroy);
}

@Override
void releaseParent() {
	super.releaseParent();

	if (menu != null) {
		if (menu.selectedItem == this) menu.selectedItem = null;
		menu.dispose();

		menu = null;
	}
}

@Override
void releaseWidget() {
	super.releaseWidget();

	if (GTK.GTK4) {
		if (parent.actionGroup != 0 && actionName != null) OS.g_action_map_remove_action(parent.actionGroup, Converter.javaStringToCString(actionName));
	} else {
		long accelGroup = getAccelGroup();
		if (accelGroup != 0) removeAccelerator(accelGroup);

		if (groupHandle != 0) OS.g_object_unref(groupHandle);
		groupHandle = 0;
		parent = null;
	}

	accelerator = 0;

	disposeDefaultDisabledImage();
}

@Override
void destroyWidget() {
	if (GTK.GTK4) {
		if ((style & SWT.SEPARATOR) != 0) {
			Section aboveSection = parent.sections.get(parent.sections.indexOf(section) - 1);
			aboveSection.sectionItems.addAll(section.sectionItems);

			for (MenuItem item : section.sectionItems) {
				OS.g_menu_insert_item(aboveSection.getSectionHandle(), aboveSection.sectionItems.indexOf(item), item.handle);
			}

			OS.g_menu_remove(parent.modelHandle, parent.sections.indexOf(section));

			parent.sections.remove(section);
		} else {
			OS.g_menu_remove(section.getSectionHandle(), section.sectionItems.indexOf(this));
			section.sectionItems.remove(this);
		}

		parent.items.remove(this);
		parent = null;

		if (modelHandle != 0) OS.g_object_unref(modelHandle);
		OS.g_object_unref(handle);

		releaseHandle();
	} else {
		super.destroyWidget();
	}
}

void removeAccelerator (long accelGroup) {
	updateAccelerator (accelGroup, false);
}

void removeAccelerators (long accelGroup) {
	removeAccelerator (accelGroup);
	if (menu != null) menu.removeAccelerators (accelGroup);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the arm events are generated for the control.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see ArmListener
 * @see #addArmListener
 */
public void removeArmListener (ArmListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Arm, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the help events are generated for the control.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see HelpListener
 * @see #addHelpListener
 */
public void removeHelpListener (HelpListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Help, listener);
}

/**
 * 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 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @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);
}
@Override
void reskinChildren (int flags) {
	if (menu != null) {
		menu.reskin (flags);
	}
	super.reskinChildren (flags);
}
void selectRadio () {
	int index = 0;
	MenuItem [] items = parent.getItems ();
	while (index < items.length && items [index] != this) index++;
	int i = index - 1;
	while (i >= 0 && items [i].setRadioSelection (false)) --i;
	int j = index + 1;
	while (j < items.length && items [j].setRadioSelection (false)) j++;
	setSelection (true);
}
/**
 * Sets the widget accelerator.  An accelerator is the bit-wise
 * OR of zero or more modifier masks and a key. Examples:
 * SWT.MOD1 | SWT.MOD2 | 'T', SWT.MOD3 | SWT.F2.
 * SWT.CONTROL | SWT.SHIFT | 'T', SWT.ALT | SWT.F2.
 * 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
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setAccelerator (int accelerator) {
	checkWidget();
	if (this.accelerator == accelerator) return;

	if (GTK.GTK4) {
		if (shortcutHandle != 0) {
			GTK4.gtk_shortcut_controller_remove_shortcut(parent.shortcutController, shortcutHandle);
			shortcutHandle = 0;
		}

		this.accelerator = accelerator;
		addShortcut(accelerator);
	} else {
		long accelGroup = getAccelGroup();
		if (accelGroup != 0) removeAccelerator(accelGroup);
		this.accelerator = accelerator;
		if (accelGroup != 0) addAccelerator(accelGroup);
	}
}

void addShortcut(int accelerator) {
	if (accelerator == 0 || !getEnabled()) return;
	if ((accelerator & SWT.COMMAND) != 0) return;

	int mask = 0;
	if ((accelerator & SWT.ALT) != 0) mask |= GDK.GDK_MOD1_MASK;
	if ((accelerator & SWT.SHIFT) != 0) mask |= GDK.GDK_SHIFT_MASK;
	if ((accelerator & SWT.CONTROL) != 0) mask |= GDK.GDK_CONTROL_MASK;

	int keyval = accelerator & SWT.KEY_MASK;
	int newKey = Display.untranslateKey (keyval);
	if (newKey != 0) {
		keyval = newKey;
	} else {
		switch (keyval) {
			case '\r': keyval = GDK.GDK_Return; break;
			default: keyval = Converter.wcsToMbcs ((char) keyval);
		}
	}

	if (keyval != 0) {
		shortcutHandle = GTK4.gtk_shortcut_new(
				GTK4.gtk_keyval_trigger_new(keyval, mask),
				GTK4.gtk_named_action_new(Converter.javaStringToCString(actionName))
			);
		if (shortcutHandle == 0) error(SWT.ERROR_NO_HANDLES);
		GTK4.gtk_shortcut_controller_add_shortcut(parent.shortcutController, shortcutHandle);
	}
}

/**
 * Enables the receiver if the argument is true,
 * 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 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setEnabled (boolean enabled) {
	checkWidget();

	if (GTK.GTK4) {
		if (actionHandle != 0) OS.g_simple_action_set_enabled(actionHandle, enabled);
	} else {
		if (GTK.gtk_widget_get_sensitive(handle) == enabled) return;
		long accelGroup = getAccelGroup();
		if (accelGroup != 0) removeAccelerator(accelGroup);
		GTK.gtk_widget_set_sensitive(handle, enabled);
		if (accelGroup != 0) addAccelerator(accelGroup);
	}

	if (this.enabled == enabled) return;
	this.enabled = enabled;

	_setEnabledOrDisabledImage();
}

private void _setEnabledOrDisabledImage() {
	if (!enabled) {
		if (defaultDisableImage == null && image != null) {
			defaultDisableImage = new Image(getDisplay(), image, SWT.IMAGE_DISABLE);
		}
		_setImage(defaultDisableImage);
	}
	if (enabled && image != null) _setImage(image);
}

/**
 * Sets the identifier associated with the receiver to the argument.
 *
 * @param id the new identifier. This must be a non-negative value. System-defined identifiers are negative values.
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 *    ERROR_INVALID_ARGUMENT - if called with an negative-valued argument.
 * 
 *
 * @since 3.7
 */
public void setID (int id) {
	checkWidget();
	if (id < 0) error(SWT.ERROR_INVALID_ARGUMENT);
	userId = id;
}

/**
 * Sets the receiver's image to the argument, which may be
 * null indicating that no image should be displayed.
 * 
 * Note: This operation is a HINT and is not supported on
 * platforms that do not have this concept (for example, Windows NT).
 * Some platforms (such as GTK3) support images alongside check boxes.
 * 
 *
 * @param image the image to display on the receiver (may be null)
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
@Override
public void setImage (Image image) {
	//TODO: GTK4 Menu images with text are no longer supported
	if (GTK.GTK4) return;

	checkWidget();
	if (this.image == image) return;
	if ((style & SWT.SEPARATOR) != 0) return;
	disposeDefaultDisabledImage();
	super.setImage (image);

	_setEnabledOrDisabledImage();
}

private void _setImage (Image image) {
	if (image != null) {
		ImageList imageList = parent.imageList;
		if (imageList == null) imageList = parent.imageList = new ImageList ();
		int imageIndex = imageList.indexOf (image);
		long surface = 0;
		if (imageIndex == -1) {
			imageIndex = imageList.add (image);
			surface = imageList.getSurface (imageIndex);
		} else {
			imageList.put (imageIndex, image);
			surface = imageList.getSurface (imageIndex);
		}

		if (!GTK3.GTK_IS_MENU_ITEM (handle)) return;
		if (OS.SWT_PADDED_MENU_ITEMS && imageHandle != 0) {
			GTK3.gtk_image_set_from_surface(imageHandle, surface);
		} else {
			if (imageHandle == 0) {
				imageHandle = GTK3.gtk_image_new_from_surface(surface);
				if (imageHandle == 0) error(SWT.ERROR_NO_HANDLES);

				GTK3.gtk_container_add(boxHandle, imageHandle);
				GTK3.gtk_box_reorder_child(boxHandle, imageHandle, 0);
			} else {
				GTK3.gtk_image_set_from_surface(imageHandle, surface);
			}
		}
		GTK.gtk_widget_show(imageHandle);
	} else {
		if (imageHandle != 0) {
			if (OS.SWT_PADDED_MENU_ITEMS) {
				GTK3.gtk_container_remove(boxHandle, imageHandle);
				imageHandle = GTK.gtk_image_new ();
				if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
				GTK.gtk_image_set_pixel_size (imageHandle, 16);
				GTK3.gtk_container_add (boxHandle, imageHandle);
				GTK.gtk_widget_show (imageHandle);
			} else {
				GTK3.gtk_container_remove(boxHandle, imageHandle);
				imageHandle = 0;
			}
		}
	}
}

/**
 * Sets the receiver's pull down menu to the argument.
 * Only CASCADE 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.
 * 
 * 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.
 * 
 *
 * @param menu the new pull down menu
 *
 * @exception IllegalArgumentException 
 *    ERROR_MENU_NOT_DROP_DOWN - if the menu is not a drop down menu
 *    ERROR_MENUITEM_NOT_CASCADE - if the menu item is not a CASCADE
 *    ERROR_INVALID_ARGUMENT - if the menu has been disposed
 *    ERROR_INVALID_PARENT - if the menu is not in the same widget tree
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
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);
	}
	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);
		}
	}

	/* Assign the new menu */
	Menu oldMenu = this.menu;
	if (oldMenu == menu) return;

	if (GTK.GTK4) {
		this.menu = menu;
		if (menu != null) {
			menu.cascade = this;
			OS.g_menu_item_set_submenu(handle, menu.modelHandle);
		} else {
			oldMenu.cascade = null;
			OS.g_menu_item_set_submenu(handle, 0);
		}

		OS.g_menu_remove(section.getSectionHandle(), section.getItemPosition(this));
		OS.g_menu_insert_item(section.getSectionHandle(), section.getItemPosition(this), handle);
	} else {
		long accelGroup = getAccelGroup ();
		if (accelGroup != 0) removeAccelerators (accelGroup);
		if (oldMenu != null) {
			oldMenu.cascade = null;
			/*
			* Add a reference to the menu we are about
			* to replace or GTK will destroy it.
			*/
			OS.g_object_ref (oldMenu.handle);
			GTK3.gtk_menu_item_set_submenu (handle, 0);
		}
		if ((this.menu = menu) != null) {
			menu.cascade = this;
			GTK3.gtk_menu_item_set_submenu (handle, menu.handle);
		}
		if (accelGroup != 0) addAccelerators (accelGroup);
	}
}

@Override
void setOrientation (boolean create) {
	super.setOrientation (create);
	if ((parent.style & SWT.RIGHT_TO_LEFT) != 0 || !create) {
		int dir = (parent.style & SWT.RIGHT_TO_LEFT) != 0 ? GTK.GTK_TEXT_DIR_RTL : GTK.GTK_TEXT_DIR_LTR;
		GTK.gtk_widget_set_direction (handle, dir);
		GTK3.gtk_container_forall (handle, display.setDirectionProc, dir);
		if (menu != null) menu._setOrientation (parent.style & (SWT.RIGHT_TO_LEFT | SWT.LEFT_TO_RIGHT));
	}
}

boolean setRadioSelection (boolean value) {
	if ((style & SWT.RADIO) == 0) return false;
	if (getSelection () != value) {
		setSelection (value);
		sendSelectionEvent (SWT.Selection);
	}
	return true;
}

/**
 * Sets the selection state of the receiver.
 * 
 * When the receiver is of type CHECK or RADIO,
 * it is selected when it is checked.
 *
 * @param selected the new selection state
 *
 * @exception SWTException 

 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setSelection (boolean selected) {
	checkWidget();
	if ((style & (SWT.CHECK | SWT.RADIO)) == 0) return;

	if (GTK.GTK4) {
		if ((style & SWT.CHECK) != 0) {
			OS.g_simple_action_set_state(actionHandle, OS.g_variant_new_boolean(selected));
		} else {
			OS.g_simple_action_set_state(actionHandle, OS.g_variant_new_string(Converter.javaStringToCString(selected ? "toggled" : "untoggled")));
		}
	} else {
		OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, ACTIVATE);
		GTK3.gtk_check_menu_item_set_active (handle, selected);
		if ((style & SWT.RADIO) != 0) GTK3.gtk_check_menu_item_set_active (groupHandle, !selected);
		OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, ACTIVATE);
	}
}

/**
 * Sets the receiver's text. The string may include
 * the mnemonic character and accelerator text.
 * 
 * Mnemonics are indicated by an '&' that causes the next
 * character to be the mnemonic.  When the user presses a
 * key sequence that matches the mnemonic, a selection
 * event occurs. On most platforms, the mnemonic appears
 * underlined but may be emphasised in a platform specific
 * manner.  The mnemonic indicator character '&' can be
 * escaped by doubling it in the string, causing a single
 * '&' to be displayed.
 * 
 * 
 * Accelerator text is indicated by the '\t' character.
 * On platforms that support accelerator text, the text
 * that follows the '\t' character is displayed to the user,
 * typically indicating the key stroke that will cause
 * the item to become selected.  On most platforms, the
 * accelerator text appears right aligned in the menu.
 * Setting the accelerator text does not install the
 * accelerator key sequence. The accelerator key sequence
 * is installed using #setAccelerator.
 * 
 *
 * @param string the new text
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the text is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #setAccelerator
 */
@Override
public void setText (String string) {
	checkWidget();
	if (string == null) error(SWT.ERROR_NULL_ARGUMENT);
	if ((style & SWT.SEPARATOR) != 0) return;
	if (text.equals(string)) return;
	super.setText(string);

	int index = string.indexOf('\t');
	if (index != -1) {
		string = string.substring(0, index);
	}
	char[] chars = fixMnemonic(string);
	byte[] buffer = Converter.wcsToMbcs(chars, true);

	if (GTK.GTK4) {
		OS.g_menu_item_set_label(handle, buffer);
		MaskKeysym maskKeysym = getMaskKeysym();
		if (maskKeysym != null) {
			OS.g_menu_item_set_attribute(handle,
					Converter.javaStringToCString("accel"),
					Converter.javaStringToCString("s"),
					GTK.gtk_accelerator_name(maskKeysym.keysym, maskKeysym.mask)
				);
		}
		OS.g_menu_remove(section.getSectionHandle(), section.getItemPosition(this));
		OS.g_menu_insert_item(section.getSectionHandle(), section.getItemPosition(this), handle);
	} else {
		if (labelHandle != 0 && GTK.GTK_IS_LABEL (labelHandle)) {
			GTK.gtk_label_set_text_with_mnemonic (labelHandle, buffer);
			if (GTK.GTK_IS_ACCEL_LABEL (labelHandle)) {
				MaskKeysym maskKeysym = getMaskKeysym();
				if (maskKeysym != null) {
					GTK3.gtk_accel_label_set_accel_widget (labelHandle, handle);
					GTK3.gtk_accel_label_set_accel (labelHandle,
							maskKeysym.keysym, maskKeysym.mask);
				}
				// A workaround for Ubuntu Unity global menu
				OS.g_signal_emit_by_name(handle, OS.accel_closures_changed);
			}
		}
	}
}

/**
 * Sets the receiver's tool tip text to the argument, which
 * may be null indicating that the default tool tip for the
 * control will be shown. For a menu item that has a default
 * tool tip, setting
 * the tool tip text to an empty string replaces the default,
 * causing no tool tip text to be shown.
 * 
 * The mnemonic indicator (character '&') is not displayed in a tool tip.
 * To display a single '&' in the tool tip, the character '&' can be
 * escaped by doubling it in the string.
 * 
 * 
 * NOTE: Tooltips are currently not shown for top-level menu items in the
 * {@link Shell#setMenuBar(Menu) shell menubar} on Windows, Mac, and Ubuntu Unity desktop.
 * 
 * 
 * NOTE: This operation is a hint and behavior is platform specific, on Windows
 * for CJK-style mnemonics of the form " (&C)" at the end of the tooltip text
 * are not shown in tooltip.
 * 
 * @param toolTip the new tool tip text (or null)
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.104
 */
public void setToolTipText(String toolTip) {
	checkWidget();
	if (GTK.GTK4) return; // GTK4 does not support tooltips within menus

	if (toolTip != null && (toolTip.trim().length() == 0 || toolTip.equals(toolTipText))) return;

	toolTipText = toolTip;
	setToolTipText(handle, toolTip);
}

void updateAccelerator (long accelGroup, boolean add) {
	if (accelerator == 0 || !getEnabled ()) return;
	if ((accelerator & SWT.COMMAND) != 0) return;
	int mask = 0;
	if ((accelerator & SWT.ALT) != 0) mask |= GDK.GDK_MOD1_MASK;
	if ((accelerator & SWT.SHIFT) != 0) mask |= GDK.GDK_SHIFT_MASK;
	if ((accelerator & SWT.CONTROL) != 0) mask |= GDK.GDK_CONTROL_MASK;
	int keysym = accelerator & SWT.KEY_MASK;
	int newKey = Display.untranslateKey (keysym);
	if (newKey != 0) {
		keysym = newKey;
	} else {
		switch (keysym) {
			case '\r': keysym = GDK.GDK_Return; break;
			default: keysym = Converter.wcsToMbcs ((char) keysym);
		}
	}
	/* When accel_key is zero, it causes GTK warnings */
	if (keysym != 0) {
		if (add) {
			GTK3.gtk_widget_add_accelerator(handle, OS.activate, accelGroup, keysym, mask, GTK.GTK_ACCEL_VISIBLE);
		} else {
			GTK3.gtk_widget_remove_accelerator(handle, accelGroup, keysym, mask);
		}
	}
}

private static class MaskKeysym {
	int mask = 0;
	int keysym = 0;
}

private MaskKeysym getMaskKeysym() {
	if (text == null) return null;
	MaskKeysym maskKeysym = new MaskKeysym();
	int accelIndex = text.indexOf ('\t');
	if (accelIndex == -1) return null;
	int start = accelIndex + 1;
	int plusIndex = text.indexOf('+', start);
	while (plusIndex != -1) {
		String maskStr = text.substring(start, plusIndex);
		if (maskStr.equals("Ctrl")) maskKeysym.mask |= GDK.GDK_CONTROL_MASK;
		if (maskStr.equals("Shift")) maskKeysym.mask |= GDK.GDK_SHIFT_MASK;
		if (maskStr.equals("Alt")) maskKeysym.mask |= GDK.GDK_MOD1_MASK;
		start = plusIndex + 1;
		plusIndex = text.indexOf('+', start);
	}
	if ("Enter".equals(text.substring(start))) {
		maskKeysym.keysym = GDK.GDK_ISO_Enter;
	}
	switch (text.length() - start) {
		case 1:
			maskKeysym.keysym = text.charAt(start);
			maskKeysym.keysym = Converter.wcsToMbcs ((char) maskKeysym.keysym);
			break;
		case 2:
			if (text.charAt(start) == 'F') {
				switch (text.charAt(start + 1)) {
					case '1': maskKeysym.keysym = GDK.GDK_F1; break;
					case '2': maskKeysym.keysym = GDK.GDK_F2; break;
					case '3': maskKeysym.keysym = GDK.GDK_F3; break;
					case '4': maskKeysym.keysym = GDK.GDK_F4; break;
					case '5': maskKeysym.keysym = GDK.GDK_F5; break;
					case '6': maskKeysym.keysym = GDK.GDK_F6; break;
					case '7': maskKeysym.keysym = GDK.GDK_F7; break;
					case '8': maskKeysym.keysym = GDK.GDK_F8; break;
					case '9': maskKeysym.keysym = GDK.GDK_F9; break;
				}
			}
			break;
		case 3:
			if (text.charAt(start) == 'F' && text.charAt(start + 1) == '1') {
				switch (text.charAt(start + 2)) {
					case '0': maskKeysym.keysym = GDK.GDK_F10; break;
					case '1': maskKeysym.keysym = GDK.GDK_F11; break;
					case '2': maskKeysym.keysym = GDK.GDK_F12; break;
					case '3': maskKeysym.keysym = GDK.GDK_F13; break;
					case '4': maskKeysym.keysym = GDK.GDK_F14; break;
					case '5': maskKeysym.keysym = GDK.GDK_F15; break;
				}
			}
			break;
	}
	return maskKeysym;
}
boolean updateAcceleratorText (boolean show) {
	if (accelerator != 0) return false;
	MaskKeysym maskKeysym = null;
	if (show) {
		maskKeysym = getMaskKeysym();
	}
	if (maskKeysym == null) return true;
	if (maskKeysym.keysym != 0) {
		long accelGroup = getAccelGroup ();
		if (show) {
			GTK3.gtk_widget_add_accelerator (handle, OS.activate, accelGroup, maskKeysym.keysym, maskKeysym.mask, GTK.GTK_ACCEL_VISIBLE);
		} else {
			GTK3.gtk_widget_remove_accelerator (handle, accelGroup, maskKeysym.keysym, maskKeysym.mask);
		}
	}
	return maskKeysym.keysym != 0;
}

@Override
long dpiChanged(long object, long arg0) {
	super.dpiChanged(object, arg0);

	if (image != null) {
		image.internal_gtk_refreshImageForZoom();
		setImage(image);
	}

	return 0;
}

private void disposeDefaultDisabledImage() {
	if (defaultDisableImage != null) {
		defaultDisableImage.dispose();
		defaultDisableImage = null;
	}
}
}