Class MenuItem


  • public class MenuItem
    extends Item
    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 Also:
    Sample code and further information
    Restriction:
    This class is not intended to be subclassed by clients.
    • Constructor Summary

      Constructors 
      Constructor Description
      MenuItem​(Menu parent, int style)
      Constructs a new instance of this class given its parent (which must be a Menu) and a style value describing its behavior and appearance.
      MenuItem​(Menu parent, int style, int index)
      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.
    • Constructor Detail

      • MenuItem

        public MenuItem​(Menu parent,
                        int style)
        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.

        Parameters:
        parent - a menu control which will be the parent of the new instance (cannot be null)
        style - the style of control to construct
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the parent is null
        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 Also:
        SWT.CHECK, SWT.CASCADE, SWT.PUSH, SWT.RADIO, SWT.SEPARATOR, Widget.checkSubclass(), Widget.getStyle()
      • MenuItem

        public MenuItem​(Menu parent,
                        int style,
                        int index)
        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.

        Parameters:
        parent - a menu control which will be the parent of the new instance (cannot be null)
        style - the style of control to construct
        index - the zero-relative index to store the receiver in its parent
        Throws:
        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)
        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 Also:
        SWT.CHECK, SWT.CASCADE, SWT.PUSH, SWT.RADIO, SWT.SEPARATOR, Widget.checkSubclass(), Widget.getStyle()
    • Method Detail

      • addArmListener

        public void addArmListener​(ArmListener listener)
        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.
        Parameters:
        listener - the listener which should be notified
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the listener is null
        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 Also:
        ArmListener, removeArmListener(org.eclipse.swt.events.ArmListener)
      • addHelpListener

        public void addHelpListener​(HelpListener listener)
        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.
        Parameters:
        listener - the listener which should be notified
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the listener is null
        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 Also:
        HelpListener, removeHelpListener(org.eclipse.swt.events.HelpListener)
      • addSelectionListener

        public void addSelectionListener​(SelectionListener listener)
        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.

        Parameters:
        listener - the listener which should be notified when the menu item is selected by the user
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the listener is null
        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 Also:
        SelectionListener, removeSelectionListener(org.eclipse.swt.events.SelectionListener), SelectionEvent
      • checkSubclass

        protected void checkSubclass()
        Description copied from class: Widget
        Checks that this class can be subclassed.

        The SWT class library is intended to be subclassed only at specific, controlled points (most notably, Composite and Canvas when implementing new widgets). This method enforces this rule unless it is overridden.

        IMPORTANT: By providing an implementation of this method that allows a subclass of a class which does not normally allow subclassing to be created, the implementer agrees to be fully responsible for the fact that any such subclass will likely fail between SWT releases and will be strongly platform specific. No support is provided for user-written classes which are implemented in this fashion.

        The ability to subclass outside of the allowed SWT classes is intended purely to enable those not on the SWT development team to implement patches in order to get around specific limitations in advance of when those limitations can be addressed by the team. Subclassing should not be attempted without an intimate and detailed understanding of the hierarchy.

        Overrides:
        checkSubclass in class Item
      • getAccelerator

        public int getAccelerator()
        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.
        Returns:
        the accelerator or 0
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getEnabled

        public boolean getEnabled()
        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.
        Returns:
        the receiver's enabled state
        Throws:
        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 Also:
        isEnabled()
      • getID

        public int getID()
        Gets the identifier associated with the receiver.
        Returns:
        the receiver's identifier
        Throws:
        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
      • getMenu

        public Menu getMenu()
        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.
        Returns:
        the receiver's menu
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getParent

        public Menu getParent()
        Returns the receiver's parent, which must be a Menu.
        Returns:
        the receiver's parent
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getSelection

        public boolean getSelection()
        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.

        Returns:
        the selection state
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getToolTipText

        public String getToolTipText()
        Returns the receiver's tool tip text, or null if it has not been set.
        Returns:
        the receiver's tool tip text
        Throws:
        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
      • isEnabled

        public boolean isEnabled()
        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.
        Returns:
        the receiver's enabled state
        Throws:
        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 Also:
        getEnabled()
      • removeArmListener

        public void removeArmListener​(ArmListener listener)
        Removes the listener from the collection of listeners who will be notified when the arm events are generated for the control.
        Parameters:
        listener - the listener which should no longer be notified
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the listener is null
        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 Also:
        ArmListener, addArmListener(org.eclipse.swt.events.ArmListener)
      • removeHelpListener

        public void removeHelpListener​(HelpListener listener)
        Removes the listener from the collection of listeners who will be notified when the help events are generated for the control.
        Parameters:
        listener - the listener which should no longer be notified
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the listener is null
        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 Also:
        HelpListener, addHelpListener(org.eclipse.swt.events.HelpListener)
      • setAccelerator

        public void setAccelerator​(int accelerator)
        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.
        Parameters:
        accelerator - an integer that is the bit-wise OR of masks and a key
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setEnabled

        public void setEnabled​(boolean enabled)
        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.
        Parameters:
        enabled - the new enabled state
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setID

        public void setID​(int id)
        Sets the identifier associated with the receiver to the argument.
        Parameters:
        id - the new identifier. This must be a non-negative value. System-defined identifiers are negative values.
        Throws:
        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
      • setImage

        public void setImage​(Image image)
        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). Furthermore, some platforms (such as GTK2), cannot display both a check box and an image at the same time. Instead, they hide the image and display the check box. Some platforms (such as GTK3) support images alongside check boxes.

        Overrides:
        setImage in class Item
        Parameters:
        image - the image to display on the receiver (may be null)
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setMenu

        public void setMenu​(Menu menu)
        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.

        Parameters:
        menu - the new pull down menu
        Throws:
        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
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setSelection

        public void setSelection​(boolean selected)
        Sets the selection state of the receiver.

        When the receiver is of type CHECK or RADIO, it is selected when it is checked.

        Parameters:
        selected - the new selection state
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setText

        public void setText​(String string)
        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.

        Overrides:
        setText in class Item
        Parameters:
        string - the new text
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the text is null
        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 Also:
        setAccelerator(int)
      • setToolTipText

        public void setToolTipText​(String toolTip)
        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 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.

        Parameters:
        toolTip - the new tool tip text (or null)
        Throws:
        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