basiclistui.java

JAVA的一些源码 JAVA2 STANDARD EDITION DEVELOPMENT KIT 5.0

    protected void maybeUpdateLayoutState()
    {
        if (updateLayoutStateNeeded != 0) {
            updateLayoutState();
            updateLayoutStateNeeded = 0;
        }
    }


    /**
     * 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 #maybeUpdateLayoutState
     */
    protected void updateLayoutState()
    {
        /* If both JList fixedCellWidth and fixedCellHeight have been
         * set, then initialize cellWidth and cellHeight, and set
         * cellHeights to null.
         */

        int fixedCellHeight = list.getFixedCellHeight();
        int fixedCellWidth = list.getFixedCellWidth();

        cellWidth = (fixedCellWidth != -1) ? fixedCellWidth : -1;

        if (fixedCellHeight != -1) {
            cellHeight = fixedCellHeight;
            cellHeights = null;
        }
        else {
            cellHeight = -1;
            cellHeights = new int[list.getModel().getSize()];
        }

        /* If either of  JList fixedCellWidth and fixedCellHeight haven't
         * been set, then initialize cellWidth and cellHeights by
         * scanning through the entire model.  Note: if the renderer is
         * null, we just set cellWidth and cellHeights[*] to zero,
         * if they're not set already.
         */

        if ((fixedCellWidth == -1) || (fixedCellHeight == -1)) {

            ListModel dataModel = list.getModel();
            int dataModelSize = dataModel.getSize();
            ListCellRenderer renderer = list.getCellRenderer();

            if (renderer != null) {
                for(int index = 0; index < dataModelSize; index++) {
                    Object value = dataModel.getElementAt(index);
                    Component c = renderer.getListCellRendererComponent(list, value, index, false, false);
                    rendererPane.add(c);
                    Dimension cellSize = c.getPreferredSize();
                    if (fixedCellWidth == -1) {
                        cellWidth = Math.max(cellSize.width, cellWidth);
                    }
                    if (fixedCellHeight == -1) {
                        cellHeights[index] = cellSize.height;
                    }
                }
            }
            else {
                if (cellWidth == -1) {
                    cellWidth = 0;
                }
                if (cellHeights == null) {
                    cellHeights = new int[dataModelSize];
                }
                for(int index = 0; index < dataModelSize; index++) {
                    cellHeights[index] = 0;
                }
            }
        }

        columnCount = 1;
        if (layoutOrientation != JList.VERTICAL) {
            updateHorizontalLayoutState(fixedCellWidth, fixedCellHeight);
        }
    }

    /**
     * Invoked when the list is layed out horizontally to determine how
     * many columns to create.
     * <p>
     * This updates the <code>rowsPerColumn, </code><code>columnCount</code>,
     * <code>preferredHeight</code> and potentially <code>cellHeight</code>
     * instance variables.
     */
    private void updateHorizontalLayoutState(int fixedCellWidth,
                                             int fixedCellHeight) {
        int visRows = list.getVisibleRowCount();
        int dataModelSize = list.getModel().getSize();
        Insets insets = list.getInsets();

        listHeight = list.getHeight();
        listWidth = list.getWidth();

        if (dataModelSize == 0) {
            rowsPerColumn = columnCount = 0;
            preferredHeight = insets.top + insets.bottom;
            return;
        }

        int height;

        if (fixedCellHeight != -1) {
            height = fixedCellHeight;
        }
        else {
            // Determine the max of the renderer heights.
            int maxHeight = 0;
            if (cellHeights.length > 0) {
                maxHeight = cellHeights[cellHeights.length - 1];
                for (int counter = cellHeights.length - 2;
                     counter >= 0; counter--) {
                    maxHeight = Math.max(maxHeight, cellHeights[counter]);
                }
            }
            height = cellHeight = maxHeight;
            cellHeights = null;
        }
        // The number of rows is either determined by the visible row
        // count, or by the height of the list.
        rowsPerColumn = dataModelSize;
        if (visRows > 0) {
            rowsPerColumn = visRows;
            columnCount = Math.max(1, dataModelSize / rowsPerColumn);
            if (dataModelSize > 0 && dataModelSize > rowsPerColumn &&
                dataModelSize % rowsPerColumn != 0) {
                columnCount++;
            }
            if (layoutOrientation == JList.HORIZONTAL_WRAP) {
                // Because HORIZONTAL_WRAP flows differently, the 
                // rowsPerColumn needs to be adjusted.
                rowsPerColumn = (dataModelSize / columnCount);
                if (dataModelSize % columnCount > 0) {
                    rowsPerColumn++;
                }
            }
        }
        else if (layoutOrientation == JList.VERTICAL_WRAP && height != 0) {
            rowsPerColumn = Math.max(1, (listHeight - insets.top -
                                         insets.bottom) / height);
            columnCount = Math.max(1, dataModelSize / rowsPerColumn);
            if (dataModelSize > 0 && dataModelSize > rowsPerColumn &&
                dataModelSize % rowsPerColumn != 0) {
                columnCount++;
            }
        }
        else if (layoutOrientation == JList.HORIZONTAL_WRAP && cellWidth > 0 &&
                 listWidth > 0) {
            columnCount = Math.max(1, (listWidth - insets.left -
                                       insets.right) / cellWidth);
            rowsPerColumn = dataModelSize / columnCount;
            if (dataModelSize % columnCount > 0) {
                rowsPerColumn++;
            }
        }
        preferredHeight = rowsPerColumn * cellHeight + insets.top +
                              insets.bottom;
    }

    private Handler getHandler() {
        if (handler == null) {
            handler = DRAG_FIX ? new DragFixHandler() : new Handler();
        }
        return handler;
    }

    /**
     * Mouse input, and focus handling for JList.  An instance of this
     * class is added to the appropriate java.awt.Component lists
     * at installUI() time.  Note keyboard input is handled with JComponent
     * KeyboardActions, see installKeyboardActions().
     * <p>
     * <strong>Warning:</strong>
     * 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<sup><font size="-2">TM</font></sup>
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     *
     * @see #createMouseInputListener
     * @see #installKeyboardActions
     * @see #installUI
     */
    public class MouseInputHandler implements MouseInputListener
    {
        public void mouseClicked(MouseEvent e) {
            getHandler().mouseClicked(e);
        }

        public void mouseEntered(MouseEvent e) {
            getHandler().mouseEntered(e);
        }

        public void mouseExited(MouseEvent e) {
            getHandler().mouseExited(e);
        }

        public void mousePressed(MouseEvent e) {
            getHandler().mousePressed(e);
	}

        public void mouseDragged(MouseEvent e) {
            getHandler().mouseDragged(e);
        }

        public void mouseMoved(MouseEvent e) {
            getHandler().mouseMoved(e);
        }

        public void mouseReleased(MouseEvent e) {
            getHandler().mouseReleased(e);
        }
    }


    /**
     * 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.
     * <pre>
     * class MyListUI extends BasicListUI {
     *    protected MouseInputListener <b>createMouseInputListener</b>() {
     *        return new MyMouseInputHandler();
     *    }
     *    public class MyMouseInputHandler extends MouseInputHandler {
     *        public void mouseMoved(MouseEvent e) {
     *            // do some extra work when the mouse moves
     *            super.mouseMoved(e);
     *        }
     *    }
     * }
     * </pre>
     *
     * @see MouseInputHandler
     * @see #installUI
     */
    protected MouseInputListener createMouseInputListener() {
        return getHandler();
    }

    /**
     * This inner class is marked &quot;public&quot; due to a compiler bug.
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicTableUI.
     */
    public class FocusHandler implements FocusListener
    {
        protected void repaintCellFocus()
        {
            getHandler().repaintCellFocus();
        }

        /* The focusGained() focusLost() methods run when the JList
         * focus changes.
         */

        public void focusGained(FocusEvent e) {
            getHandler().focusGained(e);
        }

        public void focusLost(FocusEvent e) {
            getHandler().focusLost(e);
        }
    }

    protected FocusListener createFocusListener() {
        return getHandler();
    }

    /**
     * The ListSelectionListener that's added to the JLists selection
     * model at installUI time, and whenever the JList.selectionModel property
     * changes.  When the selection changes we repaint the affected rows.
     * <p>
     * <strong>Warning:</strong>
     * 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<sup><font size="-2">TM</font></sup>
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     *
     * @see #createListSelectionListener
     * @see #getCellBounds
     * @see #installUI
     */
    public class ListSelectionHandler implements ListSelectionListener
    {
        public void valueChanged(ListSelectionEvent e)
        {
            getHandler().valueChanged(e);
        }
    }


    /**
     * 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.
     * <pre>
     * class MyListUI extends BasicListUI {
     *    protected ListSelectionListener <b>createListSelectionListener</b>() {
     *        return new MySelectionListener();
     *    }
     *    public class MySelectionListener extends ListSelectionHandler {
     *        public void valueChanged(ListSelectionEvent e) {
     *            // do some extra work when the selection changes
     *            super.valueChange(e);
     *        }
     *    }
     * }
     * </pre>
     *
     * @see ListSelectionHandler
     * @see #installUI
     */
    protected ListSelectionListener createListSelectionListener() {
        return getHandler();
    }


    private void redrawList() {
	list.revalidate();
	list.repaint();
    }


    /**
     * The ListDataListener that's added to the JLists model at
     * installUI time, and whenever the JList.model property changes.
     * <p>
     * <strong>Warning:</strong>
     * 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<sup><font size="-2">TM</font></sup>
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     *
     * @see JList#getModel
     * @see #maybeUpdateLayoutState
     * @see #createListDataListener
     * @see #installUI
     */
    public class ListDataHandler implements ListDataListener
    {
        public void intervalAdded(ListDataEvent e) {
            getHandler().intervalAdded(e);
        }


        public void intervalRemoved(ListDataEvent e)
        {
            getHandler().intervalRemoved(e);
        }