basiclistui.java

java jdk 1.4的源码

/*
 * @(#)BasicListUI.java	1.93 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.swing.plaf.basic;

import javax.swing.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
import javax.swing.text.Position;

import java.awt.*;
import java.awt.event.*;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.*;

import java.util.ArrayList;
import java.util.TooManyListenersException;

import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;

/**
 * A Windows L&F implementation of ListUI.
 * <p>
 *
 * @version 1.93 01/23/03
 * @author Hans Muller
 * @author Philip Milne
 */
public class BasicListUI extends ListUI
{
    protected JList list = null;
    protected CellRendererPane rendererPane;

    // Listeners that this UI attaches to the JList
    protected FocusListener focusListener;
    protected MouseInputListener mouseInputListener;
    protected ListSelectionListener listSelectionListener;
    protected ListDataListener listDataListener;
    protected PropertyChangeListener propertyChangeListener;
    private KeyListener keyListener;

    // PENDING(hmuller) need a doc pointer to #getRowHeight, #maybeUpdateLayoutState
    protected int[] cellHeights = null;
    protected int cellHeight = -1;
    protected int cellWidth = -1;
    protected int updateLayoutStateNeeded = modelChanged;
    /**
     * Height of the list. When asked to paint, if the current size of
     * the list differs, this will update the layout state.
     */
    private int listHeight;

    /**
     * Width of the list. When asked to paint, if the current size of
     * the list differs, this will update the layout state.
     */
    private int listWidth;

    /**
     * The layout orientation of the list.
     */
    private int layoutOrientation;

    // Following ivars are used if the list is laying out horizontally

    /**
     * Number of columns to create.
     */
    private int columnCount;
    /**
     * Preferred height to make the list, this is only used if the 
     * the list is layed out horizontally.
     */
    private int preferredHeight;
    /**
     * Number of rows per column. This is only used if the row height is
     * fixed.
     */
    private int rowsPerColumn;

    /* The bits below define JList property changes that affect layout.
     * When one of these properties changes we set a bit in
     * updateLayoutStateNeeded.  The change is dealt with lazily, see
     * maybeUpdateLayoutState.  Changes to the JLists model, e.g. the
     * models length changed, are handled similarly, see DataListener.
     */

    protected final static int modelChanged = 1 << 0;
    protected final static int selectionModelChanged = 1 << 1;
    protected final static int fontChanged = 1 << 2;
    protected final static int fixedCellWidthChanged = 1 << 3;
    protected final static int fixedCellHeightChanged = 1 << 4;
    protected final static int prototypeCellValueChanged = 1 << 5;
    protected final static int cellRendererChanged = 1 << 6;
    private final static int layoutOrientationChanged = 1 << 7;
    private final static int heightChanged = 1 << 8;
    private final static int widthChanged = 1 << 9;
    private final static int componentOrientationChanged = 1 << 10;


    /**
     * 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().
     *
     * @see #paint
     */
    protected void paintCell(
        Graphics g,
        int row,
        Rectangle rowBounds,
        ListCellRenderer cellRenderer,
        ListModel dataModel,
        ListSelectionModel selModel,
        int leadIndex)
    {
        Object value = dataModel.getElementAt(row);
        boolean cellHasFocus = list.hasFocus() && (row == leadIndex);
        boolean isSelected = selModel.isSelectedIndex(row);

        Component rendererComponent =
            cellRenderer.getListCellRendererComponent(list, value, row, isSelected, cellHasFocus);

        int cx = rowBounds.x;
        int cy = rowBounds.y;
        int cw = rowBounds.width;
        int ch = rowBounds.height;
        rendererPane.paintComponent(g, rendererComponent, list, cx, cy, cw, ch, true);
    }


    /**
     * Paint the rows that intersect the Graphics objects clipRect.  This
     * method calls paintCell as necessary.  Subclasses
     * may want to override these methods.
     *
     * @see #paintCell
     */
    public void paint(Graphics g, JComponent c)
    {
        switch (layoutOrientation) {
        case JList.VERTICAL_WRAP:
            if (list.getHeight() != listHeight) {
                updateLayoutStateNeeded |= heightChanged;
                redrawList();
            }
            break;
        case JList.HORIZONTAL_WRAP:
            if (list.getWidth() != listWidth) {
                updateLayoutStateNeeded |= widthChanged;
                redrawList();
            }
            break;
        default:
            break;
        }
        maybeUpdateLayoutState();

        ListCellRenderer renderer = list.getCellRenderer();
        ListModel dataModel = list.getModel();
        ListSelectionModel selModel = list.getSelectionModel();
        int size;

        if ((renderer == null) || (size = dataModel.getSize()) == 0) {
            return;
        }

        // Determine how many columns we need to paint
        Rectangle paintBounds = g.getClipBounds();

	int startColumn, endColumn;
	if (c.getComponentOrientation().isLeftToRight()) {
            startColumn = convertLocationToColumn(paintBounds.x,
                                                  paintBounds.y);
	    endColumn = convertLocationToColumn(paintBounds.x +
                                                paintBounds.width,
                                                paintBounds.y);
	} else {
	    startColumn = convertLocationToColumn(paintBounds.x +
                                                paintBounds.width,
                                                paintBounds.y);
            endColumn = convertLocationToColumn(paintBounds.x,
                                                  paintBounds.y);
	}
        int maxY = paintBounds.y + paintBounds.height;
        int leadIndex = list.getLeadSelectionIndex();
        int rowIncrement = (layoutOrientation == JList.HORIZONTAL_WRAP) ?
                           columnCount : 1;


        for (int colCounter = startColumn; colCounter <= endColumn;
             colCounter++) {
            // And then how many rows in this columnn
            int row = convertLocationToRowInColumn(paintBounds.y, colCounter);
            int rowCount = getRowCount(colCounter);
            int index = getModelIndex(colCounter, row);
            Rectangle rowBounds = getCellBounds(list, index, index);

            if (rowBounds == null) {
                // Not valid, bail!
                return;
            }
            while (row < rowCount && rowBounds.y < maxY &&
                   index < size) {
                rowBounds.height = getHeight(colCounter, row);
                g.setClip(rowBounds.x, rowBounds.y, rowBounds.width,
                          rowBounds.height);
                g.clipRect(paintBounds.x, paintBounds.y, paintBounds.width,
                           paintBounds.height);
                paintCell(g, index, rowBounds, renderer, dataModel, selModel,
                          leadIndex);
                rowBounds.y += rowBounds.height;
                index += rowIncrement;
                row++;
            }
        }
    }


    /**
     * The preferredSize of the list depends upon the layout orientation.
     * <table summary="Describes the preferred size for each layout orientation">
     * <tr><th>Layout Orientation</th><th>Preferred Size</th></tr>
     * <tr>
     *   <td>JList.VERTICAL
     *   <td>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.
     *   </td>
     * <tr>
     *   <td>JList.VERTICAL_WRAP
     *   <td>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.
     * <tr>
     *   <td>JList.HORIZONTAL_WRAP
     *   <td>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.
     *       <p>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 <code>JList</code> (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.
     * </table>
     * 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 <code>Insets</code> are determined from
     * <code>list.getInsets()</code>.
     *
     * @param c The JList component.
     * @return The total size of the list.
     */
    public Dimension getPreferredSize(JComponent c) {
        maybeUpdateLayoutState();

        int lastRow = list.getModel().getSize() - 1;
        if (lastRow < 0) {
            return new Dimension(0, 0);
        }

        Insets insets = list.getInsets();
        int width = cellWidth * columnCount + insets.left + insets.right;
        int height;

        if (layoutOrientation != JList.VERTICAL) {
            height = preferredHeight;
        }
        else {
            Rectangle bounds = getCellBounds(list, lastRow);

            if (bounds != null) {
                height = bounds.y + bounds.height + insets.bottom;
            }
            else {
                height = 0;
            }
        }
        return new Dimension(width, height);
    }


    /**
     * @return the preferred size
     * @see #getPreferredSize
     */
    public Dimension getMinimumSize(JComponent c) {
        return getPreferredSize(c);
    }


    /**
     * @return the preferred size
     * @see #getPreferredSize
     */
    public Dimension getMaximumSize(JComponent c) {
        return getPreferredSize(c);
    }


    /**
     * Selected the previous row and force it to be visible.
     *
     * @see JList#ensureIndexIsVisible
     */
    protected void selectPreviousIndex() {
        int s = list.getSelectedIndex();
        if(s > 0) {
            s -= 1;
            list.setSelectedIndex(s);
            list.ensureIndexIsVisible(s);
        }
    }


    /**
     * Selected the previous row and force it to be visible.
     *
     * @see JList#ensureIndexIsVisible
     */
    protected void selectNextIndex()
    {
        int s = list.getSelectedIndex();
        if((s + 1) < list.getModel().getSize()) {
            s += 1;
            list.setSelectedIndex(s);
            list.ensureIndexIsVisible(s);
        }
    }


    /**
     * Registers the keyboard bindings on the <code>JList</code> that the
     * <code>BasicListUI</code> is associated with. This method is called at
     * installUI() time.
     *
     * @see #installUI
     */
    protected void installKeyboardActions() {
	InputMap inputMap = getInputMap(JComponent.WHEN_FOCUSED);

	SwingUtilities.replaceUIInputMap(list, JComponent.WHEN_FOCUSED,
					   inputMap);

	ActionMap map = getActionMap();
	if (map != null) {
	    SwingUtilities.replaceUIActionMap(list, map);
	}
    }

    InputMap getInputMap(int condition) {
	if (condition == JComponent.WHEN_FOCUSED) {
	    InputMap keyMap = (InputMap)UIManager.get("List.focusInputMap");
	    InputMap rtlKeyMap;

	    if (list.getComponentOrientation().isLeftToRight() ||
		((rtlKeyMap = (InputMap)UIManager.get("List.focusInputMap.RightToLeft")) == null)) {
		    return keyMap;
	    } else {
		rtlKeyMap.setParent(keyMap);
		return rtlKeyMap;
	    }
	}
	return null;