basicscrollpaneui.java

java jdk 1.4的源码

/*
 * @(#)BasicScrollPaneUI.java	1.66 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.border.*;
import javax.swing.plaf.*;

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

import java.awt.Component;
import java.awt.Container;
import java.awt.LayoutManager;
import java.awt.Rectangle;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Insets;
import java.awt.Graphics;
import java.awt.event.*;
import java.io.Serializable;
import java.awt.Toolkit;

/**
 * A default L&F implementation of ScrollPaneUI.
 *
 * @version 1.66 01/23/03
 * @author Hans Muller
 */
public class BasicScrollPaneUI
    extends ScrollPaneUI implements ScrollPaneConstants
{
    protected JScrollPane scrollpane;
    protected ChangeListener vsbChangeListener;
    protected ChangeListener hsbChangeListener;
    protected ChangeListener viewportChangeListener;
    protected PropertyChangeListener spPropertyChangeListener;
    private MouseWheelListener mouseScrollListener;

    /**
     * PropertyChangeListener installed on the vertical scrollbar.
     */
    private PropertyChangeListener vsbPropertyChangeListener;

    /**
     * PropertyChangeListener installed on the horizontal scrollbar.
     */
    private PropertyChangeListener hsbPropertyChangeListener;

    /**
     * The default implementation of createHSBPropertyChangeListener and
     * createVSBPropertyChangeListener share the PropertyChangeListener, which
     * is this ivar.
     */
    private PropertyChangeListener sbPropertyChangeListener;

    /**
     * State flag that shows whether setValue() was called from a user program
     * before the value of "extent" was set in right-to-left component
     * orientation.
     */
    private boolean setValueCalled = false;

    public static ComponentUI createUI(JComponent x) {
	return new BasicScrollPaneUI();
    }


    public void paint(Graphics g, JComponent c) {
	Border vpBorder = scrollpane.getViewportBorder();
	if (vpBorder != null) {
	    Rectangle r = scrollpane.getViewportBorderBounds();
	    vpBorder.paintBorder(scrollpane, g, r.x, r.y, r.width, r.height);
	}
    }


    /**
     * @return null which indicates that the LayoutManager will compute the value
     * @see JComponent#getPreferredSize
     */
    public Dimension getPreferredSize(JComponent c) {
	return null;
    }


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


    /**
     * @return new Dimension(Short.MAX_VALUE, Short.MAX_VALUE)
     */
    public Dimension getMaximumSize(JComponent c) {
	return new Dimension(Short.MAX_VALUE, Short.MAX_VALUE);
    }


    protected void installDefaults(JScrollPane scrollpane) 
    {
	LookAndFeel.installBorder(scrollpane, "ScrollPane.border");
	LookAndFeel.installColorsAndFont(scrollpane, 
	    "ScrollPane.background", 
	    "ScrollPane.foreground", 
            "ScrollPane.font");

        Border vpBorder = scrollpane.getViewportBorder();
        if ((vpBorder == null) ||( vpBorder instanceof UIResource)) {
	    vpBorder = UIManager.getBorder("ScrollPane.viewportBorder");
	    scrollpane.setViewportBorder(vpBorder);
        }
    }


    protected void installListeners(JScrollPane c) 
    {
	vsbChangeListener = createVSBChangeListener();
        vsbPropertyChangeListener = createVSBPropertyChangeListener();
	hsbChangeListener = createHSBChangeListener();
        hsbPropertyChangeListener = createHSBPropertyChangeListener();
	viewportChangeListener = createViewportChangeListener();
	spPropertyChangeListener = createPropertyChangeListener();

	JViewport viewport = scrollpane.getViewport();
	JScrollBar vsb = scrollpane.getVerticalScrollBar();
	JScrollBar hsb = scrollpane.getHorizontalScrollBar();

	if (viewport != null) {
	    viewport.addChangeListener(viewportChangeListener);
	}
	if (vsb != null) {
	    vsb.getModel().addChangeListener(vsbChangeListener);
            vsb.addPropertyChangeListener(vsbPropertyChangeListener);
	}
	if (hsb != null) {
	    hsb.getModel().addChangeListener(hsbChangeListener);
            hsb.addPropertyChangeListener(hsbPropertyChangeListener);
	}

	scrollpane.addPropertyChangeListener(spPropertyChangeListener);

    mouseScrollListener = createMouseWheelListener();
    scrollpane.addMouseWheelListener(mouseScrollListener);

    }

    protected void installKeyboardActions(JScrollPane c) {
	InputMap inputMap = getInputMap(JComponent.
				  WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);

	SwingUtilities.replaceUIInputMap(c, JComponent.
			       WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, inputMap);
	ActionMap actionMap = getActionMap();

	SwingUtilities.replaceUIActionMap(c, actionMap);
    }

    InputMap getInputMap(int condition) {
	if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT) {
	    InputMap keyMap = (InputMap)UIManager.get("ScrollPane.ancestorInputMap");
	    InputMap rtlKeyMap;

	    if (scrollpane.getComponentOrientation().isLeftToRight() ||
		((rtlKeyMap = (InputMap)UIManager.get("ScrollPane.ancestorInputMap.RightToLeft")) == null)) {
		return keyMap;
	    } else {
		rtlKeyMap.setParent(keyMap);
		return rtlKeyMap;
	    }
	}
	return null;
    }

    ActionMap getActionMap() {
	ActionMap map = (ActionMap)UIManager.get("ScrollPane.actionMap");

	if (map == null) {
	    map = createActionMap();
	    if (map != null) {
		UIManager.getLookAndFeelDefaults().put("ScrollPane.actionMap",
                                                       map);
	    }
	}
	return map;
    }

    ActionMap createActionMap() {
	ActionMap map = new ActionMapUIResource();
	map.put("scrollUp", new ScrollAction("scrollUp", SwingConstants.
						 VERTICAL, -1, true));
	map.put("scrollDown", new ScrollAction("scrollDown",
				     SwingConstants.VERTICAL, 1, true));
	map.put("scrollHome", new ScrollHomeAction("ScrollHome"));
	map.put("scrollEnd", new ScrollEndAction("ScrollEnd"));
	map.put("unitScrollUp", new ScrollAction
	       ("UnitScrollUp", SwingConstants.VERTICAL, -1,false));
	map.put("unitScrollDown", new ScrollAction
	       ("UnitScrollDown", SwingConstants.VERTICAL, 1, false));

	if (scrollpane.getComponentOrientation().isLeftToRight()) {
	    map.put("scrollLeft", new ScrollAction("scrollLeft",
				  SwingConstants.HORIZONTAL, -1, true));
	    map.put("scrollRight", new ScrollAction("ScrollRight",
					SwingConstants.HORIZONTAL, 1, true));
	    map.put("unitScrollRight", new ScrollAction
	       ("UnitScrollRight", SwingConstants.HORIZONTAL, 1, false));
	    map.put("unitScrollLeft", new ScrollAction
	       ("UnitScrollLeft", SwingConstants.HORIZONTAL, -1, false));
	} else {
	    map.put("scrollLeft", new ScrollAction("scrollLeft",
				  SwingConstants.HORIZONTAL, 1, true));
	    map.put("scrollRight", new ScrollAction("ScrollRight",
					SwingConstants.HORIZONTAL, -1, true));
	    map.put("unitScrollRight", new ScrollAction
	       ("UnitScrollRight", SwingConstants.HORIZONTAL, -1, false));
	    map.put("unitScrollLeft", new ScrollAction
	       ("UnitScrollLeft", SwingConstants.HORIZONTAL, 1, false));
	}
	return map;
    }

    public void installUI(JComponent x) {
	scrollpane = (JScrollPane)x;
	installDefaults(scrollpane);
	installListeners(scrollpane);
	installKeyboardActions(scrollpane);
    }


    protected void uninstallDefaults(JScrollPane c) {
	LookAndFeel.uninstallBorder(scrollpane);

        if (scrollpane.getViewportBorder() instanceof UIResource) {
            scrollpane.setViewportBorder(null);
        }
    }


    protected void uninstallListeners(JComponent c) {
	JViewport viewport = scrollpane.getViewport();
	JScrollBar vsb = scrollpane.getVerticalScrollBar();
	JScrollBar hsb = scrollpane.getHorizontalScrollBar();

	if (viewport != null) {
	    viewport.removeChangeListener(viewportChangeListener);
	}
	if (vsb != null) {
	    vsb.getModel().removeChangeListener(vsbChangeListener);
            vsb.removePropertyChangeListener(vsbPropertyChangeListener);
	}
	if (hsb != null) {
	    hsb.getModel().removeChangeListener(hsbChangeListener);
            hsb.removePropertyChangeListener(hsbPropertyChangeListener);
	}

	scrollpane.removePropertyChangeListener(spPropertyChangeListener);

    if (mouseScrollListener != null) {
        scrollpane.removeMouseWheelListener(mouseScrollListener);
    }

	vsbChangeListener = null;
	hsbChangeListener = null;
	viewportChangeListener = null;
	spPropertyChangeListener = null;
        mouseScrollListener = null;
    }


    protected void uninstallKeyboardActions(JScrollPane c) {
	SwingUtilities.replaceUIActionMap(c, null);
	SwingUtilities.replaceUIInputMap(c, JComponent.
			   WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, null);
    }


    public void uninstallUI(JComponent c) {
	uninstallDefaults(scrollpane);
	uninstallListeners(scrollpane);
	uninstallKeyboardActions(scrollpane);
	scrollpane = null;
    }


    protected void syncScrollPaneWithViewport()
    {
	JViewport viewport = scrollpane.getViewport();
	JScrollBar vsb = scrollpane.getVerticalScrollBar();
	JScrollBar hsb = scrollpane.getHorizontalScrollBar();
	JViewport rowHead = scrollpane.getRowHeader();
	JViewport colHead = scrollpane.getColumnHeader();
	boolean ltr = scrollpane.getComponentOrientation().isLeftToRight();

	if (viewport != null) {
	    Dimension extentSize = viewport.getExtentSize();
	    Dimension viewSize = viewport.getViewSize();
	    Point viewPosition = viewport.getViewPosition();

	    if (vsb != null) {
		int extent = extentSize.height;
		int max = viewSize.height;
		int value = Math.max(0, Math.min(viewPosition.y, max - extent));
		vsb.setValues(value, extent, 0, max);
	    }

	    if (hsb != null) {
		int extent = extentSize.width;
		int max = viewSize.width;
		int value;

		if (ltr) {
		    value = Math.max(0, Math.min(viewPosition.x, max - extent));
		} else {
		    int currentValue = hsb.getValue();

		    /* Use a particular formula to calculate "value"
		     * until effective x coordinate is calculated.
		     */
		    if (setValueCalled && ((max - currentValue) == viewPosition.x)) {
			value = Math.max(0, Math.min(max - extent, currentValue));
			/* After "extent" is set, turn setValueCalled flag off.
			 */
			if (extent != 0) {
			    setValueCalled = false;
			}
		    } else {
			if (extent > max) {
			    viewPosition.x = max - extent;
			    viewport.setViewPosition(viewPosition);
			    value = 0;
			} else {
			   /* The following line can't handle a small value of
			    * viewPosition.x like Integer.MIN_VALUE correctly
			    * because (max - extent - viewPositoiin.x) causes
			    * an overflow. As a result, value becomes zero.
			    * (e.g. setViewPosition(Integer.MAX_VALUE, ...)
			    *       in a user program causes a overflow.
			    *       Its expected value is (max - extent).)
			    * However, this seems a trivial bug and adding a
			    * fix makes this often-called method slow, so I'll
			    * leave it until someone claims.
			    */
			    value = Math.max(0, Math.min(max - extent, max - extent - viewPosition.x));
			}
		    }
		}
		hsb.setValues(value, extent, 0, max);
	    }

	    if (rowHead != null) {
		Point p = rowHead.getViewPosition();
		p.y = viewport.getViewPosition().y;
                p.x = 0;
		rowHead.setViewPosition(p);
	    }

	    if (colHead != null) {
		Point p = colHead.getViewPosition();
		if (ltr) {
		    p.x = viewport.getViewPosition().x;
		} else {
		    p.x = Math.max(0, viewport.getViewPosition().x);
		}
                p.y = 0;
		colHead.setViewPosition(p);
	    }
	}
    }


    /**
     * Listener for viewport events.
     */
    public class ViewportChangeHandler implements ChangeListener
    {
	public void stateChanged(ChangeEvent e) {
	    syncScrollPaneWithViewport();
	}
    }

    protected ChangeListener createViewportChangeListener() {
	return new ViewportChangeHandler();
    }


    /**
     * Horizontal scrollbar listener.
     */
    public class HSBChangeListener implements ChangeListener
    {
	public void stateChanged(ChangeEvent e)
	{
	    JViewport viewport = scrollpane.getViewport();
	    if (viewport != null) {
		BoundedRangeModel model = (BoundedRangeModel)(e.getSource());
		Point p = viewport.getViewPosition();
		int value = model.getValue();
		if (scrollpane.getComponentOrientation().isLeftToRight()) {
		    p.x = value;
		} else {
		    int max = viewport.getViewSize().width;
		    int extent = viewport.getExtentSize().width;
		    int oldX = p.x;

		    /* Set new X coordinate based on "value".
		     */
		    p.x = max - extent - value;

		    /* If setValue() was called before "extent" was fixed,
		     * turn setValueCalled flag on.
		     */
		    if ((extent == 0) && (value != 0) && (oldX == max)) {
			setValueCalled = true;
		    } else {
			/* When a pane without a horizontal scroll bar was
			 * reduced and the bar appeared, the viewport should
			 * show the right side of the view.
			 */
			if ((extent != 0) && (oldX < 0) && (p.x == 0)) {
			    p.x += value;
			}
		    }
		}
		viewport.setViewPosition(p);
	    }
	}
    }

    /**
     * Returns a <code>PropertyChangeListener</code> that will be installed
     * on the horizontal <code>JScrollBar</code>.
     */
    private PropertyChangeListener createHSBPropertyChangeListener() {
        return getSBPropertyChangeListener();
    }

    /**
     * Returns a shared <code>PropertyChangeListener</code> that will update
     * the listeners installed on the scrollbars as the model changes.
     */
    private PropertyChangeListener getSBPropertyChangeListener() {
        if (sbPropertyChangeListener == null) {
            sbPropertyChangeListener = new ScrollBarPropertyChangeHandler();
        }