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Java javax.swing Class JPopupMenu（JDK8）

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Java™ Platform
Standard Ed. 8
javax.swing

Class JPopupMenu

  • All Implemented Interfaces:
    ImageObserver, MenuContainer, Serializable, Accessible, MenuElement
    Direct Known Subclasses:
    BasicComboPopup 

    public class JPopupMenu
extends JComponent
implements Accessible, MenuElement
    An implementation of a popup menu -- a small window that pops up and displays a series of choices. A JPopupMenu is used for the menu that appears when the user selects an item on the menu bar. It is also used for "pull-right" menu that appears when the selects a menu item that activates it. Finally, a JPopupMenu can also be used anywhere else you want a menu to appear. For example, when the user right-clicks in a specified area.

    For information and examples of using popup menus, see How to Use Menus in The Java Tutorial.

    Warning: Swing is not thread safe. For more information see Swing's Threading Policy.

    Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans™ has been added to the java.beans package. Please see XMLEncoder.

    • Constructor Detail

      • JPopupMenu

        public JPopupMenu()
        Constructs a JPopupMenu without an "invoker".

      • JPopupMenu

        public JPopupMenu(String label)
        Constructs a JPopupMenu with the specified title.
        Parameters:
        label - the string that a UI may use to display as a title for the popup menu.

    • Method Detail

      • getDefaultLightWeightPopupEnabled

        public static boolean getDefaultLightWeightPopupEnabled()
        Gets the defaultLightWeightPopupEnabled property, which by default is true.
        Returns:
        the value of the defaultLightWeightPopupEnabled property
        See Also:
        setDefaultLightWeightPopupEnabled(boolean)

      • getUI

        public PopupMenuUI getUI()
        Returns the look and feel (L&F) object that renders this component.
        Returns:
        the PopupMenuUI object that renders this component

      • processFocusEvent

        protected void processFocusEvent(FocusEvent evt)
        Description copied from class: Component
        Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.

        This method is not called unless focus events are enabled for this component. Focus events are enabled when one of the following occurs:

        • A FocusListener object is registered via addFocusListener.
        • Focus events are enabled via enableEvents.

        If focus events are enabled for a Component, the current KeyboardFocusManager determines whether or not a focus event should be dispatched to registered FocusListener objects. If the events are to be dispatched, the KeyboardFocusManager calls the Component's dispatchEvent method, which results in a call to the Component's processFocusEvent method.

        If focus events are enabled for a Component, calling the Component's dispatchEvent method with a FocusEvent as the argument will result in a call to the Component's processFocusEvent method regardless of the current KeyboardFocusManager.

        Note that if the event parameter is null the behavior is unspecified and may result in an exception.

        Overrides:
        processFocusEvent in class Component
        Parameters:
        evt - the focus event
        See Also:
        FocusEvent, FocusListener, KeyboardFocusManager, Component.addFocusListener(java.awt.event.FocusListener), Component.enableEvents(long), Component.dispatchEvent(java.awt.AWTEvent)

      • setSelectionModel

        public void setSelectionModel(SingleSelectionModel model)
        Sets the model object to handle single selections.
        Parameters:
        model - the new SingleSelectionModel
        See Also:
        SingleSelectionModel

      • add

        public JMenuItem add(JMenuItem menuItem)
        Appends the specified menu item to the end of this menu.
        Parameters:
        menuItem - the JMenuItem to add
        Returns:
        the JMenuItem added

      • add

        public JMenuItem add(String s)
        Creates a new menu item with the specified text and appends it to the end of this menu.
        Parameters:
        s - the string for the menu item to be added

      • add

        public JMenuItem add(Action a)
        Appends a new menu item to the end of the menu which dispatches the specified Action object.
        Parameters:
        a - the Action to add to the menu
        Returns:
        the new menu item
        See Also:
        Action

      • createActionComponent

        protected JMenuItem createActionComponent(Action a)
        Factory method which creates the JMenuItem for Actions added to the JPopupMenu.
        Parameters:
        a - the Action for the menu item to be added
        Returns:
        the new menu item
        Since:
        1.3
        See Also:
        Action

      • createActionChangeListener

        protected PropertyChangeListener createActionChangeListener(JMenuItem b)
        Returns a properly configured PropertyChangeListener which updates the control as changes to the Action occur.

      • setLightWeightPopupEnabled

        public void setLightWeightPopupEnabled(boolean aFlag)
        Sets the value of the lightWeightPopupEnabled property, which by default is true. By default, when a look and feel displays a popup, it can choose to use a lightweight (all-Java) popup. Lightweight popup windows are more efficient than heavyweight (native peer) windows, but lightweight and heavyweight components do not mix well in a GUI. If your application mixes lightweight and heavyweight components, you should disable lightweight popups. Some look and feels might always use heavyweight popups, no matter what the value of this property.
        Parameters:
        aFlag - false to disable lightweight popups
        See Also:
        isLightWeightPopupEnabled()

      • isLightWeightPopupEnabled

        public boolean isLightWeightPopupEnabled()
        Gets the lightWeightPopupEnabled property.
        Returns:
        the value of the lightWeightPopupEnabled property
        See Also:
        setLightWeightPopupEnabled(boolean)

      • setLabel

        public void setLabel(String label)
        Sets the popup menu's label. Different look and feels may choose to display or not display this.
        Parameters:
        label - a string specifying the label for the popup menu
        See Also:
        setLabel(java.lang.String)

      • addSeparator

        public void addSeparator()
        Appends a new separator at the end of the menu.

      • insert

        public void insert(Action a,
                   int index)
        Inserts a menu item for the specified Action object at a given position.
        Parameters:
        a - the Action object to insert
        index - specifies the position at which to insert the Action, where 0 is the first
        Throws:
        IllegalArgumentException - if index < 0
        See Also:
        Action

      • insert

        public void insert(Component component,
                   int index)
        Inserts the specified component into the menu at a given position.
        Parameters:
        component - the Component to insert
        index - specifies the position at which to insert the component, where 0 is the first
        Throws:
        IllegalArgumentException - if index < 0

      • addPopupMenuListener

        public void addPopupMenuListener(PopupMenuListener l)
        Adds a PopupMenu listener.
        Parameters:
        l - the PopupMenuListener to add

      • removePopupMenuListener

        public void removePopupMenuListener(PopupMenuListener l)
        Removes a PopupMenu listener.
        Parameters:
        l - the PopupMenuListener to remove

      • getPopupMenuListeners

        public PopupMenuListener[] getPopupMenuListeners()
        Returns an array of all the PopupMenuListeners added to this JMenuItem with addPopupMenuListener().
        Returns:
        all of the PopupMenuListeners added or an empty array if no listeners have been added
        Since:
        1.4

      • addMenuKeyListener

        public void addMenuKeyListener(MenuKeyListener l)
        Adds a MenuKeyListener to the popup menu.
        Parameters:
        l - the MenuKeyListener to be added
        Since:
        1.5

      • removeMenuKeyListener

        public void removeMenuKeyListener(MenuKeyListener l)
        Removes a MenuKeyListener from the popup menu.
        Parameters:
        l - the MenuKeyListener to be removed
        Since:
        1.5

      • getMenuKeyListeners

        public MenuKeyListener[] getMenuKeyListeners()
        Returns an array of all the MenuKeyListeners added to this JPopupMenu with addMenuKeyListener().
        Returns:
        all of the MenuKeyListeners added or an empty array if no listeners have been added
        Since:
        1.5

      • firePopupMenuWillBecomeVisible

        protected void firePopupMenuWillBecomeVisible()
        Notifies PopupMenuListeners that this popup menu will become visible.

      • firePopupMenuWillBecomeInvisible

        protected void firePopupMenuWillBecomeInvisible()
        Notifies PopupMenuListeners that this popup menu will become invisible.

      • firePopupMenuCanceled

        protected void firePopupMenuCanceled()
        Notifies PopupMenuListeners that this popup menu is cancelled.

      • pack

        public void pack()
        Lays out the container so that it uses the minimum space needed to display its contents.

      • isVisible

        public boolean isVisible()
        Returns true if the popup menu is visible (currently being displayed).
        Overrides:
        isVisible in class Component
        Returns:
        true if the component is visible, false otherwise
        See Also:
        Component.setVisible(boolean)

      • setLocation

        public void setLocation(int x,
                        int y)
        Sets the location of the upper left corner of the popup menu using x, y coordinates.

        The method changes the geometry-related data. Therefore, the native windowing system may ignore such requests, or it may modify the requested data, so that the JPopupMenu object is placed and sized in a way that corresponds closely to the desktop settings.

        Overrides:
        setLocation in class Component
        Parameters:
        x - the x coordinate of the popup's new position in the screen's coordinate space
        y - the y coordinate of the popup's new position in the screen's coordinate space
        See Also:
        Component.getLocation(), Component.setBounds(int, int, int, int), Component.invalidate()

      • getInvoker

        public Component getInvoker()
        Returns the component which is the 'invoker' of this popup menu.
        Returns:
        the Component in which the popup menu is displayed

      • setInvoker

        public void setInvoker(Component invoker)
        Sets the invoker of this popup menu -- the component in which the popup menu menu is to be displayed.
        Parameters:
        invoker - the Component in which the popup menu is displayed

      • show

        public void show(Component invoker,
                 int x,
                 int y)
        Displays the popup menu at the position x,y in the coordinate space of the component invoker.
        Parameters:
        invoker - the component in whose space the popup menu is to appear
        x - the x coordinate in invoker's coordinate space at which the popup menu is to be displayed
        y - the y coordinate in invoker's coordinate space at which the popup menu is to be displayed

      • getComponentAtIndex

        @Deprecated
public Component getComponentAtIndex(int i)
        Deprecated. replaced by Container.getComponent(int)
        Returns the component at the specified index.
        Parameters:
        i - the index of the component, where 0 is the first
        Returns:
        the Component at that index

      • getComponentIndex

        public int getComponentIndex(Component c)
        Returns the index of the specified component.
        Parameters:
        c - the Component to find
        Returns:
        the index of the component, where 0 is the first; or -1 if the component is not found

      • setPopupSize

        public void setPopupSize(Dimension d)
        Sets the size of the Popup window using a Dimension object. This is equivalent to setPreferredSize(d).
        Parameters:
        d - the Dimension specifying the new size of this component.

      • setPopupSize

        public void setPopupSize(int width,
                         int height)
        Sets the size of the Popup window to the specified width and height. This is equivalent to setPreferredSize(new Dimension(width, height)).
        Parameters:
        width - the new width of the Popup in pixels
        height - the new height of the Popup in pixels

      • setSelected

        public void setSelected(Component sel)
        Sets the currently selected component, This will result in a change to the selection model.
        Parameters:
        sel - the Component to select

      • isBorderPainted

        public boolean isBorderPainted()
        Checks whether the border should be painted.
        Returns:
        true if the border is painted, false otherwise
        See Also:
        setBorderPainted(boolean)

      • setBorderPainted

        public void setBorderPainted(boolean b)
        Sets whether the border should be painted.
        Parameters:
        b - if true, the border is painted.
        See Also:
        isBorderPainted()

      • getMargin

        public Insets getMargin()
        Returns the margin, in pixels, between the popup menu's border and its containers.
        Returns:
        an Insets object containing the margin values.

      • paramString

        protected String paramString()
        Returns a string representation of this JPopupMenu. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.
        Overrides:
        paramString in class JComponent
        Returns:
        a string representation of this JPopupMenu.

      • getAccessibleContext

        public AccessibleContext getAccessibleContext()
        Gets the AccessibleContext associated with this JPopupMenu. For JPopupMenus, the AccessibleContext takes the form of an AccessibleJPopupMenu. A new AccessibleJPopupMenu instance is created if necessary.
        Specified by:
        getAccessibleContext in interface Accessible
        Overrides:
        getAccessibleContext in class Component
        Returns:
        an AccessibleJPopupMenu that serves as the AccessibleContext of this JPopupMenu

      • processKeyEvent

        public void processKeyEvent(KeyEvent e,
                            MenuElement[] path,
                            MenuSelectionManager manager)
        Processes a key event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using MenuSelectionManager's API.

        Note: you do not have to forward the event to sub-components. This is done automatically by the MenuSelectionManager.

        Specified by:
        processKeyEvent in interface MenuElement
        Parameters:
        e - a KeyEvent
        path - the MenuElement path array
        manager - the MenuSelectionManager

      • menuSelectionChanged

        public void menuSelectionChanged(boolean isIncluded)
        Messaged when the menubar selection changes to activate or deactivate this menu. This implements the javax.swing.MenuElement interface. Overrides MenuElement.menuSelectionChanged.
        Specified by:
        menuSelectionChanged in interface MenuElement
        Parameters:
        isIncluded - true if this menu is active, false if it is not
        See Also:
        MenuElement.menuSelectionChanged(boolean)

      • getSubElements

        public MenuElement[] getSubElements()
        Returns an array of MenuElements containing the submenu for this menu component. It will only return items conforming to the JMenuElement interface. If popup menu is null returns an empty array. This method is required to conform to the MenuElement interface.
        Specified by:
        getSubElements in interface MenuElement
        Returns:
        an array of MenuElement objects
        See Also:
        MenuElement.getSubElements()

      • isPopupTrigger

        public boolean isPopupTrigger(MouseEvent e)
        Returns true if the MouseEvent is considered a popup trigger by the JPopupMenu's currently installed UI.
        Returns:
        true if the mouse event is a popup trigger
        Since:
        1.3
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Java™ Platform
Standard Ed. 8

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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2022, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.

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