File	Doc	Category	Size	Date	Package
BasicComboPopup.java	API Doc	Java SE 6 API	42924	Tue Jun 10 00:26:46 BST 2008	javax.swing.plaf.basic

BasicComboPopup

• java.lang.Object
  • java.awt.Component
    • java.awt.Container
      • javax.swing.JComponent
        • javax.swing.JPopupMenu

Fields Summary
static final ListModel	EmptyListModel
private static Border	LIST_BORDER
protected JComboBox	comboBox
protected JList	list This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
protected JScrollPane	scroller This protected field is implementation specific. Do not access directly or override. Use the create method instead
protected boolean	valueIsAdjusting As of Java 2 platform v1.4 this previously undocumented field is no longer used.
private Handler	handler Implementation of all the listener classes.
protected MouseMotionListener	mouseMotionListener This protected field is implementation specific. Do not access directly or override. Use the accessor or create methods instead.
protected MouseListener	mouseListener This protected field is implementation specific. Do not access directly or override. Use the accessor or create methods instead.
protected KeyListener	keyListener This protected field is implementation specific. Do not access directly or override. Use the accessor or create methods instead.
protected ListSelectionListener	listSelectionListener This protected field is implementation specific. Do not access directly or override. Use the create method instead.
protected MouseListener	listMouseListener This protected field is implementation specific. Do not access directly or override. Use the create method instead.
protected MouseMotionListener	listMouseMotionListener This protected field is implementation specific. Do not access directly or override. Use the create method instead
protected PropertyChangeListener	propertyChangeListener This protected field is implementation specific. Do not access directly or override. Use the create method instead
protected ListDataListener	listDataListener This protected field is implementation specific. Do not access directly or override. Use the create method instead
protected ItemListener	itemListener This protected field is implementation specific. Do not access directly or override. Use the create method instead
protected Timer	autoscrollTimer This protected field is implementation specific. Do not access directly or override.
protected boolean	hasEntered
protected boolean	isAutoScrolling
protected int	scrollDirection
protected static final int	SCROLL_UP
protected static final int	SCROLL_DOWN

Constructors Summary

public BasicComboPopup(JComboBox combo) super(); setName("ComboPopup.popup"); comboBox = combo; setLightWeightPopupEnabled( comboBox.isLightWeightPopupEnabled() ); // UI construction of the popup. list = createList(); list.setName("ComboBox.list"); configureList(); scroller = createScroller(); scroller.setName("ComboBox.scrollPane"); configureScroller(); configurePopup(); installComboBoxListeners(); installKeyboardActions();

Methods Summary
protected void	autoScrollDown() This protected method is implementation specific and should be private. do not call or override. int index = list.getSelectedIndex(); int lastItem = list.getModel().getSize() - 1; if ( index < lastItem ) { list.setSelectedIndex( index + 1 ); list.ensureIndexIsVisible( index + 1 ); }
protected void	autoScrollUp() This protected method is implementation specific and should be private. do not call or override. int index = list.getSelectedIndex(); if ( index > 0 ) { list.setSelectedIndex( index - 1 ); list.ensureIndexIsVisible( index - 1 ); }
protected java.awt.Rectangle	computePopupBounds(int px, int py, int pw, int ph) Calculate the placement and size of the popup portion of the combo box based on the combo box location and the enclosing screen bounds. If no transformations are required, then the returned rectangle will have the same values as the parameters. param px starting x location param py starting y location param pw starting width param ph starting height return a rectangle which represents the placement and size of the popup Toolkit toolkit = Toolkit.getDefaultToolkit(); Rectangle screenBounds; // Calculate the desktop dimensions relative to the combo box. GraphicsConfiguration gc = comboBox.getGraphicsConfiguration(); Point p = new Point(); SwingUtilities.convertPointFromScreen(p, comboBox); if (gc != null) { Insets screenInsets = toolkit.getScreenInsets(gc); screenBounds = gc.getBounds(); screenBounds.width -= (screenInsets.left + screenInsets.right); screenBounds.height -= (screenInsets.top + screenInsets.bottom); screenBounds.x += (p.x + screenInsets.left); screenBounds.y += (p.y + screenInsets.top); } else { screenBounds = new Rectangle(p, toolkit.getScreenSize()); } Rectangle rect = new Rectangle(px,py,pw,ph); if (py+ph > screenBounds.y+screenBounds.height && ph < screenBounds.height) { rect.y = -rect.height; } return rect;
protected void	configureList() Configures the list which is used to hold the combo box items in the popup. This method is called when the UI class is created. see #createList list.setFont( comboBox.getFont() ); list.setForeground( comboBox.getForeground() ); list.setBackground( comboBox.getBackground() ); list.setSelectionForeground( UIManager.getColor( "ComboBox.selectionForeground" ) ); list.setSelectionBackground( UIManager.getColor( "ComboBox.selectionBackground" ) ); list.setBorder( null ); list.setCellRenderer( comboBox.getRenderer() ); list.setFocusable( false ); list.setSelectionMode( ListSelectionModel.SINGLE_SELECTION ); setListSelection( comboBox.getSelectedIndex() ); installListListeners();
protected void	configurePopup() Configures the popup portion of the combo box. This method is called when the UI class is created. setLayout( new BoxLayout( this, BoxLayout.Y_AXIS ) ); setBorderPainted( true ); setBorder(LIST_BORDER); setOpaque( false ); add( scroller ); setDoubleBuffered( true ); setFocusable( false );
protected void	configureScroller() Configures the scrollable portion which holds the list within the combo box popup. This method is called when the UI class is created. scroller.setFocusable( false ); scroller.getVerticalScrollBar().setFocusable( false ); scroller.setBorder( null );
protected java.awt.event.MouseEvent	convertMouseEvent(java.awt.event.MouseEvent e) Point convertedPoint = SwingUtilities.convertPoint( (Component)e.getSource(), e.getPoint(), list ); MouseEvent newEvent = new MouseEvent( (Component)e.getSource(), e.getID(), e.getWhen(), e.getModifiers(), convertedPoint.x, convertedPoint.y, e.getXOnScreen(), e.getYOnScreen(), e.getClickCount(), e.isPopupTrigger(), MouseEvent.NOBUTTON ); return newEvent;
protected java.awt.event.ItemListener	createItemListener() Creates an ItemListener which will be added to the combo box. If this method returns null then it will not be added to the combo box. Subclasses may override this method to return instances of their own ItemEvent handlers. return an instance of an ItemListener or null return getHandler();
protected java.awt.event.KeyListener	createKeyListener() Creates the key listener that will be added to the combo box. If this method returns null then it will not be added to the combo box. return a KeyListener or null return null;
protected javax.swing.JList	createList() Creates the JList used in the popup to display the items in the combo box model. This method is called when the UI class is created. return a JList used to display the combo box items return new JList( comboBox.getModel() ) { public void processMouseEvent(MouseEvent e) { if (e.isControlDown()) { // Fix for 4234053. Filter out the Control Key from the list. // ie., don't allow CTRL key deselection. e = new MouseEvent((Component)e.getSource(), e.getID(), e.getWhen(), e.getModifiers() ^ InputEvent.CTRL_MASK, e.getX(), e.getY(), e.getXOnScreen(), e.getYOnScreen(), e.getClickCount(), e.isPopupTrigger(), MouseEvent.NOBUTTON); } super.processMouseEvent(e); } };
protected javax.swing.event.ListDataListener	createListDataListener() Creates a list data listener which will be added to the ComboBoxModel. If this method returns null then it will not be added to the combo box model. return an instance of a ListDataListener or null return null;
protected java.awt.event.MouseListener	createListMouseListener() Creates a mouse listener that watches for mouse events in the popup's list. If this method returns null then it will not be added to the combo box. return an instance of a MouseListener or null return getHandler();
protected java.awt.event.MouseMotionListener	createListMouseMotionListener() Creates a mouse motion listener that watches for mouse motion events in the popup's list. If this method returns null then it will not be added to the combo box. return an instance of a MouseMotionListener or null return getHandler();
protected javax.swing.event.ListSelectionListener	createListSelectionListener() Creates a list selection listener that watches for selection changes in the popup's list. If this method returns null then it will not be added to the popup list. return an instance of a ListSelectionListener or null return null;
protected java.awt.event.MouseListener	createMouseListener() Creates a listener that will watch for mouse-press and release events on the combo box. Warning: When overriding this method, make sure to maintain the existing behavior. return a MouseListener which will be added to the combo box or null return getHandler();
protected java.awt.event.MouseMotionListener	createMouseMotionListener() Creates the mouse motion listener which will be added to the combo box. Warning: When overriding this method, make sure to maintain the existing behavior. return a MouseMotionListener which will be added to the combo box or null return getHandler();
protected java.beans.PropertyChangeListener	createPropertyChangeListener() Creates a PropertyChangeListener which will be added to the combo box. If this method returns null then it will not be added to the combo box. return an instance of a PropertyChangeListener or null return getHandler();
protected javax.swing.JScrollPane	createScroller() Creates the scroll pane which houses the scrollable list. JScrollPane sp = new JScrollPane( list, ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER ); sp.setHorizontalScrollBar(null); return sp;
protected void	delegateFocus(java.awt.event.MouseEvent e) This is is a utility method that helps event handlers figure out where to send the focus when the popup is brought up. The standard implementation delegates the focus to the editor (if the combo box is editable) or to the JComboBox if it is not editable. if ( comboBox.isEditable() ) { Component comp = comboBox.getEditor().getEditorComponent(); if ((!(comp instanceof JComponent)) || ((JComponent)comp).isRequestFocusEnabled()) { comp.requestFocus(); } } else if (comboBox.isRequestFocusEnabled()) { comboBox.requestFocus(); }
protected void	firePopupMenuCanceled() super.firePopupMenuCanceled(); comboBox.firePopupMenuCanceled();
protected void	firePopupMenuWillBecomeInvisible() super.firePopupMenuWillBecomeInvisible(); comboBox.firePopupMenuWillBecomeInvisible();
protected void	firePopupMenuWillBecomeVisible() super.firePopupMenuWillBecomeVisible(); comboBox.firePopupMenuWillBecomeVisible();
public javax.accessibility.AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this BasicComboPopup. The AccessibleContext will have its parent set to the ComboBox. return an AccessibleContext for the BasicComboPopup since 1.5 AccessibleContext context = super.getAccessibleContext(); context.setAccessibleParent(comboBox); return context;
private javax.swing.plaf.basic.BasicComboPopup$Handler	getHandler() if (handler == null) { handler = new Handler(); } return handler;
public java.awt.event.KeyListener	getKeyListener() Implementation of ComboPopup.getKeyListener(). return a KeyListener or null see ComboPopup#getKeyListener if (keyListener == null) { keyListener = createKeyListener(); } return keyListener;
public javax.swing.JList	getList() Implementation of ComboPopup.getList(). return list;
public java.awt.event.MouseListener	getMouseListener() Implementation of ComboPopup.getMouseListener(). return a MouseListener or null see ComboPopup#getMouseListener if (mouseListener == null) { mouseListener = createMouseListener(); } return mouseListener;
public java.awt.event.MouseMotionListener	getMouseMotionListener() Implementation of ComboPopup.getMouseMotionListener(). return a MouseMotionListener or null see ComboPopup#getMouseMotionListener if (mouseMotionListener == null) { mouseMotionListener = createMouseMotionListener(); } return mouseMotionListener;
protected int	getPopupHeightForRowCount(int maxRowCount) Retrieves the height of the popup based on the current ListCellRenderer and the maximum row count. // Set the cached value of the minimum row count int minRowCount = Math.min( maxRowCount, comboBox.getItemCount() ); int height = 0; ListCellRenderer renderer = list.getCellRenderer(); Object value = null; for ( int i = 0; i < minRowCount; ++i ) { value = list.getModel().getElementAt( i ); Component c = renderer.getListCellRendererComponent( list, value, i, false, false ); height += c.getPreferredSize().height; } if (height == 0) { height = comboBox.getHeight(); } Border border = scroller.getViewportBorder(); if (border != null) { Insets insets = border.getBorderInsets(null); height += insets.top + insets.bottom; } border = scroller.getBorder(); if (border != null) { Insets insets = border.getBorderInsets(null); height += insets.top + insets.bottom; } return height;
private java.awt.Point	getPopupLocation() Calculates the upper left location of the Popup. Dimension popupSize = comboBox.getSize(); Insets insets = getInsets(); // reduce the width of the scrollpane by the insets so that the popup // is the same width as the combo box. popupSize.setSize(popupSize.width - (insets.right + insets.left), getPopupHeightForRowCount( comboBox.getMaximumRowCount())); Rectangle popupBounds = computePopupBounds( 0, comboBox.getBounds().height, popupSize.width, popupSize.height); Dimension scrollSize = popupBounds.getSize(); Point popupLocation = popupBounds.getLocation(); scroller.setMaximumSize( scrollSize ); scroller.setPreferredSize( scrollSize ); scroller.setMinimumSize( scrollSize ); list.revalidate(); return popupLocation;
public void	hide() Implementation of ComboPopup.hide(). MenuSelectionManager manager = MenuSelectionManager.defaultManager(); MenuElement [] selection = manager.getSelectedPath(); for ( int i = 0 ; i < selection.length ; i++ ) { if ( selection[i] == this ) { manager.clearSelectedPath(); break; } } if (selection.length > 0) { comboBox.repaint(); }
protected void	installComboBoxListeners() This method adds the necessary listeners to the JComboBox. if ((propertyChangeListener = createPropertyChangeListener()) != null) { comboBox.addPropertyChangeListener(propertyChangeListener); } if ((itemListener = createItemListener()) != null) { comboBox.addItemListener(itemListener); } installComboBoxModelListeners(comboBox.getModel());
protected void	installComboBoxModelListeners(javax.swing.ComboBoxModel model) Installs the listeners on the combo box model. Any listeners installed on the combo box model should be removed in uninstallComboBoxModelListeners. param model The combo box model to install listeners see #uninstallComboBoxModelListeners if (model != null && (listDataListener = createListDataListener()) != null) { model.addListDataListener(listDataListener); }
protected void	installKeyboardActions() /* XXX - shouldn't call this method. take it out for testing. ActionListener action = new ActionListener() { public void actionPerformed(ActionEvent e){ } }; comboBox.registerKeyboardAction( action, KeyStroke.getKeyStroke( KeyEvent.VK_ENTER, 0 ), JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT ); */
protected void	installListListeners() Adds the listeners to the list control. if ((listMouseListener = createListMouseListener()) != null) { list.addMouseListener( listMouseListener ); } if ((listMouseMotionListener = createListMouseMotionListener()) != null) { list.addMouseMotionListener( listMouseMotionListener ); } if ((listSelectionListener = createListSelectionListener()) != null) { list.addListSelectionListener( listSelectionListener ); }
public boolean	isFocusTraversable() Overridden to unconditionally return false. return false;
private void	setListSelection(int selectedIndex) Sets the list selection index to the selectedIndex. This method is used to synchronize the list selection with the combo box selection. param selectedIndex the index to set the list if ( selectedIndex == -1 ) { list.clearSelection(); } else { list.setSelectedIndex( selectedIndex ); list.ensureIndexIsVisible( selectedIndex ); }
public void	show() Implementation of ComboPopup.show(). //======================================== // begin ComboPopup method implementations // setListSelection(comboBox.getSelectedIndex()); Point location = getPopupLocation(); show( comboBox, location.x, location.y );
protected void	startAutoScrolling(int direction) This protected method is implementation specific and should be private. do not call or override. // XXX - should be a private method within InvocationMouseMotionHandler // if possible. if ( isAutoScrolling ) { autoscrollTimer.stop(); } isAutoScrolling = true; if ( direction == SCROLL_UP ) { scrollDirection = SCROLL_UP; Point convertedPoint = SwingUtilities.convertPoint( scroller, new Point( 1, 1 ), list ); int top = list.locationToIndex( convertedPoint ); list.setSelectedIndex( top ); autoscrollTimer = new Timer( 100, new AutoScrollActionHandler( SCROLL_UP) ); } else if ( direction == SCROLL_DOWN ) { scrollDirection = SCROLL_DOWN; Dimension size = scroller.getSize(); Point convertedPoint = SwingUtilities.convertPoint( scroller, new Point( 1, (size.height - 1) - 2 ), list ); int bottom = list.locationToIndex( convertedPoint ); list.setSelectedIndex( bottom ); autoscrollTimer = new Timer(100, new AutoScrollActionHandler( SCROLL_DOWN)); } autoscrollTimer.start();
protected void	stopAutoScrolling() This protected method is implementation specific and should be private. do not call or override. isAutoScrolling = false; if ( autoscrollTimer != null ) { autoscrollTimer.stop(); autoscrollTimer = null; }
protected void	togglePopup() Makes the popup visible if it is hidden and makes it hidden if it is visible. if ( isVisible() ) { hide(); } else { show(); }
protected void	uninstallComboBoxModelListeners(javax.swing.ComboBoxModel model) Removes the listeners from the combo box model param model The combo box model to install listeners see #installComboBoxModelListeners if (model != null && listDataListener != null) { model.removeListDataListener(listDataListener); }
protected void	uninstallKeyboardActions() // XXX - shouldn't call this method // comboBox.unregisterKeyboardAction( KeyStroke.getKeyStroke( KeyEvent.VK_ENTER, 0 ) );
void	uninstallListListeners() if (listMouseListener != null) { list.removeMouseListener(listMouseListener); listMouseListener = null; } if (listMouseMotionListener != null) { list.removeMouseMotionListener(listMouseMotionListener); listMouseMotionListener = null; } if (listSelectionListener != null) { list.removeListSelectionListener(listSelectionListener); listSelectionListener = null; } handler = null;
public void	uninstallingUI() Called when the UI is uninstalling. Since this popup isn't in the component tree, it won't get it's uninstallUI() called. It removes the listeners that were added in addComboBoxListeners(). if (propertyChangeListener != null) { comboBox.removePropertyChangeListener( propertyChangeListener ); } if (itemListener != null) { comboBox.removeItemListener( itemListener ); } uninstallComboBoxModelListeners(comboBox.getModel()); uninstallKeyboardActions(); uninstallListListeners(); // We do this, otherwise the listener the ui installs on // the model (the combobox model in this case) will keep a // reference to the list, causing the list (and us) to never get gced. list.setModel(EmptyListModel);
protected void	updateListBoxSelectionForEvent(java.awt.event.MouseEvent anEvent, boolean shouldScroll) A utility method used by the event listeners. Given a mouse event, it changes the list selection to the list item below the mouse. // XXX - only seems to be called from this class. shouldScroll flag is // never true Point location = anEvent.getPoint(); if ( list == null ) return; int index = list.locationToIndex(location); if ( index == -1 ) { if ( location.y < 0 ) index = 0; else index = comboBox.getModel().getSize() - 1; } if ( list.getSelectedIndex() != index ) { list.setSelectedIndex(index); if ( shouldScroll ) list.ensureIndexIsVisible(index); }