Module java.desktop
Package javax.swing.plaf.basic

Class BasicListUI

  • Direct Known Subclasses:
    SynthListUI
    public class BasicListUI
extends ListUI
    An extensible implementation of ListUI.

    BasicListUI instances cannot be shared between multiple lists.

    • Field Detail

      • list

        protected JList<Object> list
        The instance of JList.

      • rendererPane

        protected CellRendererPane rendererPane
        The instance of CellRendererPane.

      • focusListener

        protected FocusListener focusListener
        FocusListener that attached to JList.

      • mouseInputListener

        protected MouseInputListener mouseInputListener
        MouseInputListener that attached to JList.

      • listSelectionListener

        protected ListSelectionListener listSelectionListener
        ListSelectionListener that attached to JList.

      • listDataListener

        protected ListDataListener listDataListener
        ListDataListener that attached to JList.

      • propertyChangeListener

        protected PropertyChangeListener propertyChangeListener
        PropertyChangeListener that attached to JList.

      • cellHeights

        protected int[] cellHeights
        The array of cells' height

      • cellHeight

        protected int cellHeight
        The height of cell.

      • cellWidth

        protected int cellWidth
        The width of cell.

      • updateLayoutStateNeeded

        protected int updateLayoutStateNeeded
        The value represents changes to JList model.

      • modelChanged

        protected static final int modelChanged
        The bit relates to model changed property.
        See Also:
        Constant Field Values

      • selectionModelChanged

        protected static final int selectionModelChanged
        The bit relates to selection model changed property.
        See Also:
        Constant Field Values

      • fontChanged

        protected static final int fontChanged
        The bit relates to font changed property.
        See Also:
        Constant Field Values

      • fixedCellWidthChanged

        protected static final int fixedCellWidthChanged
        The bit relates to fixed cell width changed property.
        See Also:
        Constant Field Values

      • fixedCellHeightChanged

        protected static final int fixedCellHeightChanged
        The bit relates to fixed cell height changed property.
        See Also:
        Constant Field Values

      • prototypeCellValueChanged

        protected static final int prototypeCellValueChanged
        The bit relates to prototype cell value changed property.
        See Also:
        Constant Field Values

      • cellRendererChanged

        protected static final int cellRendererChanged
        The bit relates to cell renderer changed property.
        See Also:
        Constant Field Values

    • Constructor Detail

      • BasicListUI

        public BasicListUI()

    • Method Detail

      • paintCell

        protected void paintCell​(Graphics g,
                         int row,
                         Rectangle rowBounds,
                         ListCellRenderer<Object> cellRenderer,
                         ListModel<Object> dataModel,
                         ListSelectionModel selModel,
                         int leadIndex)
        Paint one List cell: compute the relevant state, get the "rubber stamp" cell renderer component, and then use the CellRendererPane to paint it. Subclasses may want to override this method rather than paint().
        Parameters:
        g - an instance of Graphics
        row - a row
        rowBounds - a bounding rectangle to render to
        cellRenderer - a list of ListCellRenderer
        dataModel - a list model
        selModel - a selection model
        leadIndex - a lead index
        See Also:
        paint(java.awt.Graphics, javax.swing.JComponent)

      • getPreferredSize

        public Dimension getPreferredSize​(JComponent c)
        The preferredSize of the list depends upon the layout orientation.
        Describes the preferred size for each layout orientation
        Layout Orientation Preferred Size
        JList.VERTICAL The preferredSize of the list is total height of the rows and the maximum width of the cells. If JList.fixedCellHeight is specified then the total height of the rows is just (cellVerticalMargins + fixedCellHeight) * model.getSize() where rowVerticalMargins is the space we allocate for drawing the yellow focus outline. Similarly if fixedCellWidth is specified then we just use that.
        JList.VERTICAL_WRAP If the visible row count is greater than zero, the preferredHeight is the maximum cell height * visibleRowCount. If the visible row count is <= 0, the preferred height is either the current height of the list, or the maximum cell height, whichever is bigger. The preferred width is than the maximum cell width * number of columns needed. Where the number of columns needs is list.height / max cell height. Max cell height is either the fixed cell height, or is determined by iterating through all the cells to find the maximum height from the ListCellRenderer.
        JList.HORIZONTAL_WRAP If the visible row count is greater than zero, the preferredHeight is the maximum cell height * adjustedRowCount. Where visibleRowCount is used to determine the number of columns. Because this lays out horizontally the number of rows is then determined from the column count. For example, lets say you have a model with 10 items and the visible row count is 8. The number of columns needed to display this is 2, but you no longer need 8 rows to display this, you only need 5, thus the adjustedRowCount is 5.

        If the visible row count is <= 0, the preferred height is dictated by the number of columns, which will be as many as can fit in the width of the JList (width / max cell width), with at least one column. The preferred height then becomes the model size / number of columns * maximum cell height. Max cell height is either the fixed cell height, or is determined by iterating through all the cells to find the maximum height from the ListCellRenderer.

        The above specifies the raw preferred width and height. The resulting preferred width is the above width + insets.left + insets.right and the resulting preferred height is the above height + insets.top + insets.bottom. Where the Insets are determined from list.getInsets().
        Overrides:
        getPreferredSize in class ComponentUI
        Parameters:
        c - The JList component.
        Returns:
        The total size of the list.
        See Also:
        JComponent.getPreferredSize(), LayoutManager.preferredLayoutSize(java.awt.Container)

      • selectPreviousIndex

        protected void selectPreviousIndex()
        Selected the previous row and force it to be visible.
        See Also:
        JList.ensureIndexIsVisible(int)

      • installKeyboardActions

        protected void installKeyboardActions()
        Registers the keyboard bindings on the JList that the BasicListUI is associated with. This method is called at installUI() time.
        See Also:
        installUI(javax.swing.JComponent)

      • uninstallKeyboardActions

        protected void uninstallKeyboardActions()
        Unregisters keyboard actions installed from installKeyboardActions. This method is called at uninstallUI() time - subclassess should ensure that all of the keyboard actions registered at installUI time are removed here.
        See Also:
        installUI(javax.swing.JComponent)

      • uninstallListeners

        protected void uninstallListeners()
        Removes the listeners from the JList, its model, and its selectionModel. All of the listener fields, are reset to null here. This method is called at uninstallUI() time, it should be kept in sync with installListeners.
        See Also:
        uninstallUI(javax.swing.JComponent), installListeners()

      • installDefaults

        protected void installDefaults()
        Initializes list properties such as font, foreground, and background, and adds the CellRendererPane. The font, foreground, and background properties are only set if their current value is either null or a UIResource, other properties are set if the current value is null.
        See Also:
        uninstallDefaults(), installUI(javax.swing.JComponent), CellRendererPane

      • uninstallUI

        public void uninstallUI​(JComponent c)
        Uninitializes this.list by calling uninstallListeners(), uninstallKeyboardActions(), and uninstallDefaults() in order. Sets this.list to null.
        Overrides:
        uninstallUI in class ComponentUI
        Parameters:
        c - the component from which this UI delegate is being removed; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components
        See Also:
        uninstallListeners(), uninstallKeyboardActions(), uninstallDefaults()

      • createUI

        public static ComponentUI createUI​(JComponent list)
        Returns a new instance of BasicListUI. BasicListUI delegates are allocated one per JList.
        Parameters:
        list - a component
        Returns:
        a new ListUI implementation for the Windows look and feel.

      • locationToIndex

        public int locationToIndex​(JList<?> list,
                           Point location)
        Returns the cell index in the specified JList closest to the given location in the list's coordinate system. To determine if the cell actually contains the specified location, compare the point against the cell's bounds, as provided by getCellBounds. This method returns -1 if the list's model is empty.
        Specified by:
        locationToIndex in class ListUI
        Parameters:
        list - the list
        location - the coordinates of the point
        Returns:
        the cell index closest to the given location, or -1
        Throws:
        NullPointerException - if location is null

      • getRowHeight

        protected int getRowHeight​(int row)
        Returns the height of the specified row based on the current layout.
        Parameters:
        row - a row
        Returns:
        the specified row height or -1 if row isn't valid
        See Also:
        convertYToRow(int), convertRowToY(int), updateLayoutState()

      • convertYToRow

        protected int convertYToRow​(int y0)
        Convert the JList relative coordinate to the row that contains it, based on the current layout. If y0 doesn't fall within any row, return -1.
        Parameters:
        y0 - a relative Y coordinate
        Returns:
        the row that contains y0, or -1
        See Also:
        getRowHeight(int), updateLayoutState()

      • convertRowToY

        protected int convertRowToY​(int row)
        Return the JList relative Y coordinate of the origin of the specified row or -1 if row isn't valid.
        Parameters:
        row - a row
        Returns:
        the Y coordinate of the origin of row, or -1
        See Also:
        getRowHeight(int), updateLayoutState()

      • maybeUpdateLayoutState

        protected void maybeUpdateLayoutState()
        If updateLayoutStateNeeded is non zero, call updateLayoutState() and reset updateLayoutStateNeeded. This method should be called by methods before doing any computation based on the geometry of the list. For example it's the first call in paint() and getPreferredSize().
        See Also:
        updateLayoutState()

      • updateLayoutState

        protected void updateLayoutState()
        Recompute the value of cellHeight or cellHeights based and cellWidth, based on the current font and the current values of fixedCellWidth, fixedCellHeight, and prototypeCellValue.
        See Also:
        maybeUpdateLayoutState()

      • createMouseInputListener

        protected MouseInputListener createMouseInputListener()
        Creates a delegate that implements MouseInputListener. The delegate is added to the corresponding java.awt.Component listener lists at installUI() time. Subclasses can override this method to return a custom MouseInputListener, e.g. 
         class MyListUI extends BasicListUI {
    protected MouseInputListener createMouseInputListener() {
        return new MyMouseInputHandler();
    }
    public class MyMouseInputHandler extends MouseInputHandler {
        public void mouseMoved(MouseEvent e) {
            // do some extra work when the mouse moves
            super.mouseMoved(e);
        }
    }
 }
        Returns:
        an instance of MouseInputListener
        See Also:
        BasicListUI.MouseInputHandler, installUI(javax.swing.JComponent)

      • createFocusListener

        protected FocusListener createFocusListener()
        Returns an instance of FocusListener.
        Returns:
        an instance of FocusListener

      • createListSelectionListener

        protected ListSelectionListener createListSelectionListener()
        Creates an instance of ListSelectionHandler that's added to the JLists by selectionModel as needed. Subclasses can override this method to return a custom ListSelectionListener, e.g. 
         class MyListUI extends BasicListUI {
    protected ListSelectionListener createListSelectionListener() {
        return new MySelectionListener();
    }
    public class MySelectionListener extends ListSelectionHandler {
        public void valueChanged(ListSelectionEvent e) {
            // do some extra work when the selection changes
            super.valueChange(e);
        }
    }
 }
        Returns:
        an instance of ListSelectionHandler
        See Also:
        BasicListUI.ListSelectionHandler, installUI(javax.swing.JComponent)

      • createListDataListener

        protected ListDataListener createListDataListener()
        Creates an instance of ListDataListener that's added to the JLists by model as needed. Subclasses can override this method to return a custom ListDataListener, e.g. 
         class MyListUI extends BasicListUI {
    protected ListDataListener createListDataListener() {
        return new MyListDataListener();
    }
    public class MyListDataListener extends ListDataHandler {
        public void contentsChanged(ListDataEvent e) {
            // do some extra work when the models contents change
            super.contentsChange(e);
        }
    }
 }
        Returns:
        an instance of ListDataListener
        See Also:
        ListDataListener, JList.getModel(), installUI(javax.swing.JComponent)

      • createPropertyChangeListener

        protected PropertyChangeListener createPropertyChangeListener()
        Creates an instance of PropertyChangeHandler that's added to the JList by installUI(). Subclasses can override this method to return a custom PropertyChangeListener, e.g. 
         class MyListUI extends BasicListUI {
    protected PropertyChangeListener createPropertyChangeListener() {
        return new MyPropertyChangeListener();
    }
    public class MyPropertyChangeListener extends PropertyChangeHandler {
        public void propertyChange(PropertyChangeEvent e) {
            if (e.getPropertyName().equals("model")) {
                // do some extra work when the model changes
            }
            super.propertyChange(e);
        }
    }
 }
        Returns:
        an instance of PropertyChangeHandler
        See Also:
        PropertyChangeListener, installUI(javax.swing.JComponent)