public JPopupMenu() 
{
        this(null);
}

Constructs a JPopupMenu without an "invoker".

 public JPopupMenu(String label) 
{
        this.label = label;
        lightWeightPopup = getDefaultLightWeightPopupEnabled();
        setSelectionModel(new DefaultSingleSelectionModel());
        enableEvents(AWTEvent.MOUSE_EVENT_MASK);
        setFocusTraversalKeysEnabled(false);
        updateUI();
}

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.

 public JMenuItem add(JMenuItem menuItem) 
{
        super.add(menuItem);
        return menuItem;
}

Appends the specified menu item to the end of this menu.

 public JMenuItem add(String s) 
{
        return add(new JMenuItem(s));
}

Creates a new menu item with the specified text and appends it to the end of this menu.

 public JMenuItem add(Action a) 
{
        JMenuItem mi = createActionComponent(a);
        mi.setAction(a);
        add(mi);
        return mi;
}

Appends a new menu item to the end of the menu which dispatches the specified Action object.

 public  void addMenuKeyListener(MenuKeyListener l) 
{
        listenerList.add(MenuKeyListener.class, l);
}

Adds a MenuKeyListener to the popup menu.

 public  void addPopupMenuListener(PopupMenuListener l) 
{
        listenerList.add(PopupMenuListener.class,l);
}

Adds a PopupMenu listener.

 public  void addSeparator() 
{
        add( new JPopupMenu.Separator() );
}

Appends a new separator at the end of the menu.

 Point adjustPopupLocationToFitScreen(int xPosition,
    int yPosition) 
{
        Point popupLocation = new Point(xPosition, yPosition);
        if(popupPostionFixDisabled == true || GraphicsEnvironment.isHeadless()) {
            return popupLocation;
        }
        // Get screen bounds
        Rectangle scrBounds;
        GraphicsConfiguration gc = getCurrentGraphicsConfiguration(popupLocation);
        Toolkit toolkit = Toolkit.getDefaultToolkit();
        if(gc != null) {
            // If we have GraphicsConfiguration use it to get screen bounds
            scrBounds = gc.getBounds();
        } else {
            // If we don't have GraphicsConfiguration use primary screen
            scrBounds = new Rectangle(toolkit.getScreenSize());
        }
        // Calculate the screen size that popup should fit
        Dimension popupSize = JPopupMenu.this.getPreferredSize();
        long popupRightX = (long)popupLocation.x + (long)popupSize.width;
        long popupBottomY = (long)popupLocation.y + (long)popupSize.height;
        int scrWidth = scrBounds.width;
        int scrHeight = scrBounds.height;
        if (!canPopupOverlapTaskBar()) {
            // Insets include the task bar. Take them into account.
            Insets scrInsets = toolkit.getScreenInsets(gc);
            scrBounds.x += scrInsets.left;
            scrBounds.y += scrInsets.top;
            scrWidth -= scrInsets.left + scrInsets.right;
            scrHeight -= scrInsets.top + scrInsets.bottom;
        }
        int scrRightX = scrBounds.x + scrWidth;
        int scrBottomY = scrBounds.y + scrHeight;
        // Ensure that popup menu fits the screen
        if (popupRightX  > (long)scrRightX) {
            popupLocation.x = scrRightX - popupSize.width;
            if( popupLocation.x <  scrBounds.x ) {
                popupLocation.x = scrBounds.x ;
            }
        }
        if (popupBottomY  > (long)scrBottomY) {
            popupLocation.y = scrBottomY - popupSize.height;
            if( popupLocation.y <  scrBounds.y ) {
                popupLocation.y = scrBounds.y;
            }
        }
        return popupLocation;
}

Returns an point which has been adjusted to take into account of the desktop bounds, taskbar and multi-monitor configuration.

This adustment may be cancelled by invoking the application with -Djavax.swing.adjustPopupLocationToFit=false

 boolean alwaysOnTop() 
{
        return true;
}

Always returns true since popups, by definition, should always be on top of all other windows.

 static boolean canPopupOverlapTaskBar() 
{
        boolean result = true;
        try {
            SecurityManager sm = System.getSecurityManager();
            if (sm != null) {
                sm.checkPermission(
                    SecurityConstants.AWT.SET_WINDOW_ALWAYS_ON_TOP_PERMISSION);
            }
        } catch (SecurityException se) {
            // There is no permission to show popups over the task bar
            result = false;
        }
        return result;
}

Checks that there are enough security permissions to make popup "always on top", which allows to show it above the task bar.

 protected PropertyChangeListener createActionChangeListener(JMenuItem b) 
{
        return b.createActionPropertyChangeListener0(b.getAction());
}

Returns a properly configured PropertyChangeListener which updates the control as changes to the Action occur.

 protected JMenuItem createActionComponent(Action a) 
{
        JMenuItem mi = new JMenuItem() {
            protected PropertyChangeListener createActionPropertyChangeListener(Action a) {
                PropertyChangeListener pcl = createActionChangeListener(this);
                if (pcl == null) {
                    pcl = super.createActionPropertyChangeListener(a);
                }
                return pcl;
            }
        };
        mi.setHorizontalTextPosition(JButton.TRAILING);
        mi.setVerticalTextPosition(JButton.CENTER);
        return mi;
}

Factory method which creates the JMenuItem for Actions added to the JPopupMenu.

 protected  void firePopupMenuCanceled() 
{
        Object[] listeners = listenerList.getListenerList();
        PopupMenuEvent e=null;
        for (int i = listeners.length-2; i >=0; i-=2) {
            if (listeners[i]==PopupMenuListener.class) {
                if (e == null)
                    e = new PopupMenuEvent(this);
                ((PopupMenuListener)listeners[i+1]).popupMenuCanceled(e);
            }
        }
}

Notifies PopupMenuListeners that this popup menu is cancelled.

 protected  void firePopupMenuWillBecomeInvisible() 
{
        Object[] listeners = listenerList.getListenerList();
        PopupMenuEvent e=null;
        for (int i = listeners.length-2; i >=0; i-=2) {
            if (listeners[i]==PopupMenuListener.class) {
                if (e == null)
                    e = new PopupMenuEvent(this);
                ((PopupMenuListener)listeners[i+1]).popupMenuWillBecomeInvisible(e);
            }
        }
}

Notifies PopupMenuListeners that this popup menu will become invisible.

 protected  void firePopupMenuWillBecomeVisible() 
{
        Object[] listeners = listenerList.getListenerList();
        PopupMenuEvent e=null;
        for (int i = listeners.length-2; i >=0; i-=2) {
            if (listeners[i]==PopupMenuListener.class) {
                if (e == null)
                    e = new PopupMenuEvent(this);
                ((PopupMenuListener)listeners[i+1]).popupMenuWillBecomeVisible(e);
            }
        }
}

Notifies PopupMenuListeners that this popup menu will become visible.

 public AccessibleContext getAccessibleContext() 
{
        if (accessibleContext == null) {
            accessibleContext = new AccessibleJPopupMenu();
        }
        return accessibleContext;
}

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.

 public Component getComponent() 
{
        return this;
}

Returns this JPopupMenu component.

 public Component getComponentAtIndex(int i) 
{
        return getComponent(i);
}

Returns the component at the specified index.

 public int getComponentIndex(Component c) 
{
        int ncomponents = this.getComponentCount();
        Component[] component = this.getComponents();
        for (int i = 0 ; i <  ncomponents ; i++) {
            Component comp = component[i];
            if (comp == c)
                return i;
        }
        return -1;
}

Returns the index of the specified component.

 public static boolean getDefaultLightWeightPopupEnabled() 
{
        Boolean b = (Boolean)
            SwingUtilities.appContextGet(defaultLWPopupEnabledKey);
        if (b == null) {
            SwingUtilities.appContextPut(defaultLWPopupEnabledKey,
                                         Boolean.TRUE);
            return true;
        }
        return b.booleanValue();
}

Gets the defaultLightWeightPopupEnabled property, which by default is true.

 public Component getInvoker() 
{
        return this.invoker;
}

Returns the component which is the 'invoker' of this popup menu.

 public String getLabel() 
{
        return label;
}

Returns the popup menu's label

 public Insets getMargin() 
{
        if(margin == null) {
            return new Insets(0,0,0,0);
        } else {
            return margin;
        }
}

Returns the margin, in pixels, between the popup menu's border and its containees.

 public MenuKeyListener[] getMenuKeyListeners() 
{
        return listenerList.getListeners(MenuKeyListener.class);
}

Returns an array of all the MenuKeyListeners added to this JPopupMenu with addMenuKeyListener().

 public PopupMenuListener[] getPopupMenuListeners() 
{
        return listenerList.getListeners(PopupMenuListener.class);
}

Returns an array of all the PopupMenuListeners added to this JMenuItem with addPopupMenuListener().

 JPopupMenu getRootPopupMenu() 
{
        JPopupMenu mp = this;
        while((mp!=null) && (mp.isPopupMenu()!=true) &&
              (mp.getInvoker() != null) &&
              (mp.getInvoker().getParent() != null) &&
              (mp.getInvoker().getParent() instanceof JPopupMenu)
              ) {
            mp = (JPopupMenu) mp.getInvoker().getParent();
        }
        return mp;
}

Returns the popup menu which is at the root of the menu system for this popup menu.

 public SingleSelectionModel getSelectionModel() 
{
        return selectionModel;
}

Returns the model object that handles single selections.

 public MenuElement[] getSubElements() 
{
        MenuElement result[];
        Vector< MenuElement > tmp = new Vector< MenuElement >();
        int c = getComponentCount();
        int i;
        Component m;
        for(i=0 ; i <  c ; i++) {
            m = getComponent(i);
            if(m instanceof MenuElement)
                tmp.addElement((MenuElement) m);
        }
        result = new MenuElement[tmp.size()];
        for(i=0,c=tmp.size() ; i <  c ; i++)
            result[i] = tmp.elementAt(i);
        return result;
}

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.

 public PopupMenuUI getUI() 
{
        return (PopupMenuUI)ui;
}

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

 public String getUIClassID() 
{
        return uiClassID;
}

Returns the name of the L&F class that renders this component.

 public  void insert(Action a,
    int index) 
{
        JMenuItem mi = createActionComponent(a);
        mi.setAction(a);
        insert(mi, index);
}

Inserts a menu item for the specified Action object at a given position.

 public  void insert(Component component,
    int index) 
{
        if (index <  0) {
            throw new IllegalArgumentException("index less than zero.");
        }
        int nitems = getComponentCount();
        // PENDING(ges): Why not use an array?
        Vector< Component > tempItems = new Vector< Component >();
        /* Remove the item at index, nitems-index times
           storing them in a temporary vector in the
           order they appear on the menu.
           */
        for (int i = index ; i <  nitems; i++) {
            tempItems.addElement(getComponent(index));
            remove(index);
        }
        add(component);
        /* Add the removed items back to the menu, they are
           already in the correct order in the temp vector.
           */
        for (Component tempItem : tempItems) {
            add(tempItem);
        }
}

Inserts the specified component into the menu at a given position.

 public boolean isBorderPainted() 
{
        return paintBorder;
}

Checks whether the border should be painted.

 public boolean isLightWeightPopupEnabled() 
{
        return lightWeightPopup;
}

Gets the lightWeightPopupEnabled property.

 public boolean isPopupTrigger(MouseEvent e) 
{
        return getUI().isPopupTrigger(e);
}

Returns true if the MouseEvent is considered a popup trigger by the JPopupMenu's currently installed UI.

 boolean isSubPopupMenu(JPopupMenu popup) 
{
        int ncomponents = this.getComponentCount();
        Component[] component = this.getComponents();
        for (int i = 0 ; i <  ncomponents ; i++) {
            Component comp = component[i];
            if (comp instanceof JMenu) {
                JMenu menu = (JMenu)comp;
                JPopupMenu subPopup = menu.getPopupMenu();
                if (subPopup == popup)
                    return true;
                if (subPopup.isSubPopupMenu(popup))
                    return true;
            }
        }
        return false;
}

Examines the list of menu items to determine whether popup is a popup menu.

 public boolean isVisible() 
{
        return popup != null;
}

Returns true if the popup menu is visible (currently being displayed).

 public  void menuSelectionChanged(boolean isIncluded) 
{
        if (DEBUG) {
            System.out.println("In JPopupMenu.menuSelectionChanged " + isIncluded);
        }
        if(invoker instanceof JMenu) {
            JMenu m = (JMenu) invoker;
            if(isIncluded)
                m.setPopupMenuVisible(true);
            else
                m.setPopupMenuVisible(false);
        }
        if (isPopupMenu() && !isIncluded)
          setVisible(false);
}

Messaged when the menubar selection changes to activate or deactivate this menu. This implements the javax.swing.MenuElement interface. Overrides MenuElement.menuSelectionChanged.

 public  void pack() 
{
        if(popup != null) {
            Dimension pref = getPreferredSize();
            if (pref == null || pref.width != getWidth() ||
                                pref.height != getHeight()) {
                popup = getPopup();
            } else {
                validate();
            }
        }
}

Lays out the container so that it uses the minimum space needed to display its contents.

 protected  void paintBorder(Graphics g) 
{
        if (isBorderPainted()) {
            super.paintBorder(g);
        }
}

Paints the popup menu's border if the borderPainted property is true.

 protected String paramString() 
{
        String labelString = (label != null ?
                              label : "");
        String paintBorderString = (paintBorder ?
                                    "true" : "false");
        String marginString = (margin != null ?
                              margin.toString() : "");
        String lightWeightPopupEnabledString = (isLightWeightPopupEnabled() ?
                                                "true" : "false");
        return super.paramString() +
            ",desiredLocationX=" + desiredLocationX +
            ",desiredLocationY=" + desiredLocationY +
        ",label=" + labelString +
        ",lightWeightPopupEnabled=" + lightWeightPopupEnabledString +
        ",margin=" + marginString +
        ",paintBorder=" + paintBorderString;
}

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.

 protected  void processFocusEvent(FocusEvent evt) 
{
        super.processFocusEvent(evt);
}

 protected  void processKeyEvent(KeyEvent evt) 
{
        MenuSelectionManager.defaultManager().processKeyEvent(evt);
        if (evt.isConsumed()) {
            return;
        }
        super.processKeyEvent(evt);
}

Processes key stroke events such as mnemonics and accelerators.

 public  void processKeyEvent(KeyEvent e,
    MenuElement[] path,
    MenuSelectionManager manager) 
{
        MenuKeyEvent mke = new MenuKeyEvent(e.getComponent(), e.getID(),
                                             e.getWhen(), e.getModifiers(),
                                             e.getKeyCode(), e.getKeyChar(),
                                             path, manager);
        processMenuKeyEvent(mke);
        if (mke.isConsumed())  {
            e.consume();
    }
}

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.

 public  void processMouseEvent(MouseEvent event,
    MenuElement[] path,
    MenuSelectionManager manager) 
{

}

This method is required to conform to the MenuElement interface, but it not implemented.

 public  void remove(int pos) 
{
        if (pos <  0) {
            throw new IllegalArgumentException("index less than zero.");
        }
        if (pos  > getComponentCount() -1) {
            throw new IllegalArgumentException("index greater than the number of items.");
        }
        super.remove(pos);
}

Removes the component at the specified index from this popup menu.

 public  void removeMenuKeyListener(MenuKeyListener l) 
{
        listenerList.remove(MenuKeyListener.class, l);
}

Removes a MenuKeyListener from the popup menu.

 public  void removePopupMenuListener(PopupMenuListener l) 
{
        listenerList.remove(PopupMenuListener.class,l);
}

Removes a PopupMenu listener.

 public  void setBorderPainted(boolean b) 
{
        paintBorder = b;
        repaint();
}

Sets whether the border should be painted.

 public static  void setDefaultLightWeightPopupEnabled(boolean aFlag) 
{
        SwingUtilities.appContextPut(defaultLWPopupEnabledKey,
                                     Boolean.valueOf(aFlag));
}

Sets the default value of the lightWeightPopupEnabled property.

 public  void setInvoker(Component invoker) 
{
        Component oldInvoker = this.invoker;
        this.invoker = invoker;
        if ((oldInvoker != this.invoker) && (ui != null)) {
            ui.uninstallUI(this);
            ui.installUI(this);
        }
        invalidate();
}

Sets the invoker of this popup menu -- the component in which the popup menu menu is to be displayed.

 public  void setLabel(String label) 
{
        String oldValue = this.label;
        this.label = label;
        firePropertyChange("label", oldValue, label);
        if (accessibleContext != null) {
            accessibleContext.firePropertyChange(
                AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY,
                oldValue, label);
        }
        invalidate();
        repaint();
}

Sets the popup menu's label. Different look and feels may choose to display or not display this.

 public  void setLightWeightPopupEnabled(boolean aFlag) 
{
        // NOTE: this use to set the flag on a shared JPopupMenu, which meant
        // this effected ALL JPopupMenus.
        lightWeightPopup = 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.

 public  void setLocation(int x,
    int y) 
{
        int oldX = desiredLocationX;
        int oldY = desiredLocationY;
        desiredLocationX = x;
        desiredLocationY = y;
        if(popup != null && (x != oldX || y != oldY)) {
            popup = getPopup();
        }
}

Sets the location of the upper left corner of the popup menu using x, y coordinates.

 public  void setPopupSize(Dimension d) 
{
        Dimension oldSize = getPreferredSize();
        setPreferredSize(d);
        if (popup != null) {
            Dimension newSize = getPreferredSize();
            if (!oldSize.equals(newSize)) {
                popup = getPopup();
            }
        }
}

Sets the size of the Popup window using a Dimension object. This is equivalent to setPreferredSize(d).

 public  void setPopupSize(int width,
    int height) 
{
        setPopupSize(new Dimension(width, height));
}

Sets the size of the Popup window to the specified width and height. This is equivalent to setPreferredSize(new Dimension(width, height)).

 public  void setSelected(Component sel) 
{
        SingleSelectionModel model = getSelectionModel();
        int index = getComponentIndex(sel);
        model.setSelectedIndex(index);
}

Sets the currently selected component, This will result in a change to the selection model.

 public  void setSelectionModel(SingleSelectionModel model) 
{
        selectionModel = model;
}

Sets the model object to handle single selections.

 public  void setUI(PopupMenuUI ui) 
{
        super.setUI(ui);
}

Sets the L&F object that renders this component.

 public  void setVisible(boolean b) 
{
        if (DEBUG) {
            System.out.println("JPopupMenu.setVisible " + b);
        }
        // Is it a no-op?
        if (b == isVisible())
            return;
        // if closing, first close all Submenus
        if (b == false) {
            // 4234793: This is a workaround because JPopupMenu.firePopupMenuCanceled is
            // a protected method and cannot be called from BasicPopupMenuUI directly
            // The real solution could be to make
            // firePopupMenuCanceled public and call it directly.
            Boolean doCanceled = (Boolean)getClientProperty("JPopupMenu.firePopupMenuCanceled");
            if (doCanceled != null && doCanceled == Boolean.TRUE) {
                putClientProperty("JPopupMenu.firePopupMenuCanceled", Boolean.FALSE);
                firePopupMenuCanceled();
            }
            getSelectionModel().clearSelection();
        } else {
            // This is a popup menu with MenuElement children,
            // set selection path before popping up!
            if (isPopupMenu()) {
                MenuElement me[] = new MenuElement[1];
                me[0] = this;
                MenuSelectionManager.defaultManager().setSelectedPath(me);
            }
        }
        if(b) {
            firePopupMenuWillBecomeVisible();
            popup = getPopup();
            firePropertyChange("visible", Boolean.FALSE, Boolean.TRUE);
        } else if(popup != null) {
            firePopupMenuWillBecomeInvisible();
            popup.hide();
            popup = null;
            firePropertyChange("visible", Boolean.TRUE, Boolean.FALSE);
            // 4694797: When popup menu is made invisible, selected path
            // should be cleared
            if (isPopupMenu()) {
                MenuSelectionManager.defaultManager().clearSelectedPath();
            }
        }
}

Sets the visibility of the popup menu.

 public  void show(Component invoker,
    int x,
    int y) 
{
        if (DEBUG) {
            System.out.println("in JPopupMenu.show " );
        }
        setInvoker(invoker);
        Frame newFrame = getFrame(invoker);
        if (newFrame != frame) {
            // Use the invoker's frame so that events
            // are propagated properly
            if (newFrame!=null) {
                this.frame = newFrame;
                if(popup != null) {
                    setVisible(false);
                }
            }
        }
        Point invokerOrigin;
        if (invoker != null) {
            invokerOrigin = invoker.getLocationOnScreen();
            // To avoid integer overflow
            long lx, ly;
            lx = ((long) invokerOrigin.x) +
                 ((long) x);
            ly = ((long) invokerOrigin.y) +
                 ((long) y);
            if(lx  > Integer.MAX_VALUE) lx = Integer.MAX_VALUE;
            if(lx <  Integer.MIN_VALUE) lx = Integer.MIN_VALUE;
            if(ly  > Integer.MAX_VALUE) ly = Integer.MAX_VALUE;
            if(ly <  Integer.MIN_VALUE) ly = Integer.MIN_VALUE;
            setLocation((int) lx, (int) ly);
        } else {
            setLocation(x, y);
        }
        setVisible(true);
}

Displays the popup menu at the position x,y in the coordinate space of the component invoker.

 public  void updateUI() 
{
        setUI((PopupMenuUI)UIManager.getUI(this));
}

Resets the UI property to a value from the current look and feel.