/*
 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.java.swing.plaf.windows;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.lang.ref.*;
import java.util.*;
import javax.swing.plaf.basic.*;
import javax.swing.*;
import javax.swing.plaf.ComponentUI;

import static com.sun.java.swing.plaf.windows.TMSchema.*;
import static com.sun.java.swing.plaf.windows.XPStyle.Skin;


Windows rendition of the component.

Warning:
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.  A future release of Swing will provide support for
long term persistence.
/**
 * Windows rendition of the component.
 * <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.  A future release of Swing will provide support for
 * long term persistence.
 */
public class WindowsScrollBarUI extends BasicScrollBarUI {
    private Grid thumbGrid;
    private Grid highlightGrid;
    private Dimension horizontalThumbSize;
    private Dimension verticalThumbSize;

    
Creates a UI for a JScrollBar.
Params:
c – the text field
Returns:
the UI/**
     * Creates a UI for a JScrollBar.
     *
     * @param c the text field
     * @return the UI
     */
    public static ComponentUI createUI(JComponent c) {
        return new WindowsScrollBarUI();
    }

    protected void installDefaults() {
        super.installDefaults();

        XPStyle xp = XPStyle.getXP();
        if (xp != null) {
            scrollbar.setBorder(null);
            horizontalThumbSize = getSize(scrollbar, xp, Part.SBP_THUMBBTNHORZ);
            verticalThumbSize = getSize(scrollbar, xp, Part.SBP_THUMBBTNVERT);
        } else {
            horizontalThumbSize = null;
            verticalThumbSize = null;
        }
    }

    private static Dimension getSize(Component component, XPStyle xp, Part part) {
        Skin skin = xp.getSkin(component, part);
        return new Dimension(skin.getWidth(), skin.getHeight());
    }

    @Override
    protected Dimension getMinimumThumbSize() {
        if ((horizontalThumbSize == null) || (verticalThumbSize == null)) {
            return super.getMinimumThumbSize();
        }
        return JScrollBar.HORIZONTAL == scrollbar.getOrientation()
                ? horizontalThumbSize
                : verticalThumbSize;
    }

    public void uninstallUI(JComponent c) {
        super.uninstallUI(c);
        thumbGrid = highlightGrid = null;
    }

    protected void configureScrollBarColors() {
        super.configureScrollBarColors();
        Color color = UIManager.getColor("ScrollBar.trackForeground");
        if (color != null && trackColor != null) {
            thumbGrid = Grid.getGrid(color, trackColor);
        }

        color = UIManager.getColor("ScrollBar.trackHighlightForeground");
        if (color != null && trackHighlightColor != null) {
            highlightGrid = Grid.getGrid(color, trackHighlightColor);
        }
    }

    protected JButton createDecreaseButton(int orientation)  {
        return new WindowsArrowButton(orientation,
                                    UIManager.getColor("ScrollBar.thumb"),
                                    UIManager.getColor("ScrollBar.thumbShadow"),
                                    UIManager.getColor("ScrollBar.thumbDarkShadow"),
                                    UIManager.getColor("ScrollBar.thumbHighlight"));
    }

    protected JButton createIncreaseButton(int orientation)  {
        return new WindowsArrowButton(orientation,
                                    UIManager.getColor("ScrollBar.thumb"),
                                    UIManager.getColor("ScrollBar.thumbShadow"),
                                    UIManager.getColor("ScrollBar.thumbDarkShadow"),
                                    UIManager.getColor("ScrollBar.thumbHighlight"));
    }

    
{@inheritDoc}
Since:
1.6/**
     * {@inheritDoc}
     * @since 1.6
     */
    @Override
    protected ArrowButtonListener createArrowButtonListener(){
        // we need to repaint the entire scrollbar because state change for each
        // button causes a state change for the thumb and other button on Vista
        if(XPStyle.isVista()) {
            return new ArrowButtonListener() {
                public void mouseEntered(MouseEvent evt) {
                    repaint();
                    super.mouseEntered(evt);
                }
                public void mouseExited(MouseEvent evt) {
                    repaint();
                    super.mouseExited(evt);
                }
                private void repaint() {
                    scrollbar.repaint();
                }
            };
        } else {
            return super.createArrowButtonListener();
        }
    }

    protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds){
        boolean v = (scrollbar.getOrientation() == JScrollBar.VERTICAL);

        XPStyle xp = XPStyle.getXP();
        if (xp != null) {
            JScrollBar sb = (JScrollBar)c;
            State state = State.NORMAL;
            // Pending: Implement rollover (hot) and pressed
            if (!sb.isEnabled()) {
                state = State.DISABLED;
            }
            Part part = v ? Part.SBP_LOWERTRACKVERT : Part.SBP_LOWERTRACKHORZ;
            xp.getSkin(sb, part).paintSkin(g, trackBounds, state);
        } else if (thumbGrid == null) {
            super.paintTrack(g, c, trackBounds);
        }
        else {
            thumbGrid.paint(g, trackBounds.x, trackBounds.y, trackBounds.width,
                            trackBounds.height);
            if (trackHighlight == DECREASE_HIGHLIGHT) {
                paintDecreaseHighlight(g);
            }
            else if (trackHighlight == INCREASE_HIGHLIGHT) {
                paintIncreaseHighlight(g);
            }
        }
    }

    protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
        boolean v = (scrollbar.getOrientation() == JScrollBar.VERTICAL);

        XPStyle xp = XPStyle.getXP();
        if (xp != null) {
            JScrollBar sb = (JScrollBar)c;
            State state = State.NORMAL;
            if (!sb.isEnabled()) {
                state = State.DISABLED;
            } else if (isDragging) {
                state = State.PRESSED;
            } else if (isThumbRollover()) {
                state = State.HOT;
            } else if (XPStyle.isVista()) {
                if ((incrButton != null && incrButton.getModel().isRollover()) ||
                    (decrButton != null && decrButton.getModel().isRollover())) {
                    state = State.HOVER;
                }
            }
            // Paint thumb
            Part thumbPart = v ? Part.SBP_THUMBBTNVERT : Part.SBP_THUMBBTNHORZ;
            xp.getSkin(sb, thumbPart).paintSkin(g, thumbBounds, state);
            // Paint gripper
            Part gripperPart = v ? Part.SBP_GRIPPERVERT : Part.SBP_GRIPPERHORZ;
            Skin skin = xp.getSkin(sb, gripperPart);
            Insets gripperInsets = xp.getMargin(c, thumbPart, null, Prop.CONTENTMARGINS);
            if (gripperInsets == null ||
                (v && (thumbBounds.height - gripperInsets.top -
                       gripperInsets.bottom >= skin.getHeight())) ||
                (!v && (thumbBounds.width - gripperInsets.left -
                        gripperInsets.right >= skin.getWidth()))) {
                skin.paintSkin(g,
                               thumbBounds.x + (thumbBounds.width  - skin.getWidth()) / 2,
                               thumbBounds.y + (thumbBounds.height - skin.getHeight()) / 2,
                               skin.getWidth(), skin.getHeight(), state);
            }
        } else {
            super.paintThumb(g, c, thumbBounds);
        }
    }


    protected void paintDecreaseHighlight(Graphics g) {
        if (highlightGrid == null) {
            super.paintDecreaseHighlight(g);
        }
        else {
            Insets insets = scrollbar.getInsets();
            Rectangle thumbR = getThumbBounds();
            int x, y, w, h;

            if (scrollbar.getOrientation() == JScrollBar.VERTICAL) {
                x = insets.left;
                y = decrButton.getY() + decrButton.getHeight();
                w = scrollbar.getWidth() - (insets.left + insets.right);
                h = thumbR.y - y;
            }
            else {
                x = decrButton.getX() + decrButton.getHeight();
                y = insets.top;
                w = thumbR.x - x;
                h = scrollbar.getHeight() - (insets.top + insets.bottom);
            }
            highlightGrid.paint(g, x, y, w, h);
        }
    }


    protected void paintIncreaseHighlight(Graphics g) {
        if (highlightGrid == null) {
            super.paintDecreaseHighlight(g);
        }
        else {
            Insets insets = scrollbar.getInsets();
            Rectangle thumbR = getThumbBounds();
            int x, y, w, h;

            if (scrollbar.getOrientation() == JScrollBar.VERTICAL) {
                x = insets.left;
                y = thumbR.y + thumbR.height;
                w = scrollbar.getWidth() - (insets.left + insets.right);
                h = incrButton.getY() - y;
            }
            else {
                x = thumbR.x + thumbR.width;
                y = insets.top;
                w = incrButton.getX() - x;
                h = scrollbar.getHeight() - (insets.top + insets.bottom);
            }
            highlightGrid.paint(g, x, y, w, h);
        }
    }


    
{@inheritDoc}
Since:
1.6/**
     * {@inheritDoc}
     * @since 1.6
     */
    @Override
    protected void setThumbRollover(boolean active) {
        boolean old = isThumbRollover();
        super.setThumbRollover(active);
        // we need to repaint the entire scrollbar because state change for thumb
        // causes state change for incr and decr buttons on Vista
        if(XPStyle.isVista() && active != old) {
            scrollbar.repaint();
        }
    }

    
WindowsArrowButton is used for the buttons to position the
document up/down. It differs from BasicArrowButton in that the
preferred size is always a square.
/**
     * WindowsArrowButton is used for the buttons to position the
     * document up/down. It differs from BasicArrowButton in that the
     * preferred size is always a square.
     */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    private class WindowsArrowButton extends BasicArrowButton {

        public WindowsArrowButton(int direction, Color background, Color shadow,
                         Color darkShadow, Color highlight) {
            super(direction, background, shadow, darkShadow, highlight);
        }

        public WindowsArrowButton(int direction) {
            super(direction);
        }

        public void paint(Graphics g) {
            XPStyle xp = XPStyle.getXP();
            if (xp != null) {
                ButtonModel model = getModel();
                Skin skin = xp.getSkin(this, Part.SBP_ARROWBTN);
                State state = null;

                boolean jointRollover = XPStyle.isVista() && (isThumbRollover() ||
                    (this == incrButton && decrButton.getModel().isRollover()) ||
                    (this == decrButton && incrButton.getModel().isRollover()));

                // normal, rollover, pressed, disabled
                if (model.isArmed() && model.isPressed()) {
                    switch (direction) {
                        case NORTH: state = State.UPPRESSED;    break;
                        case SOUTH: state = State.DOWNPRESSED;  break;
                        case WEST:  state = State.LEFTPRESSED;  break;
                        case EAST:  state = State.RIGHTPRESSED; break;
                    }
                } else if (!model.isEnabled()) {
                    switch (direction) {
                        case NORTH: state = State.UPDISABLED;    break;
                        case SOUTH: state = State.DOWNDISABLED;  break;
                        case WEST:  state = State.LEFTDISABLED;  break;
                        case EAST:  state = State.RIGHTDISABLED; break;
                    }
                } else if (model.isRollover() || model.isPressed()) {
                    switch (direction) {
                        case NORTH: state = State.UPHOT;    break;
                        case SOUTH: state = State.DOWNHOT;  break;
                        case WEST:  state = State.LEFTHOT;  break;
                        case EAST:  state = State.RIGHTHOT; break;
                    }
                } else if (jointRollover) {
                    switch (direction) {
                        case NORTH: state = State.UPHOVER;    break;
                        case SOUTH: state = State.DOWNHOVER;  break;
                        case WEST:  state = State.LEFTHOVER;  break;
                        case EAST:  state = State.RIGHTHOVER; break;
                    }
                } else {
                    switch (direction) {
                        case NORTH: state = State.UPNORMAL;    break;
                        case SOUTH: state = State.DOWNNORMAL;  break;
                        case WEST:  state = State.LEFTNORMAL;  break;
                        case EAST:  state = State.RIGHTNORMAL; break;
                    }
                }

                skin.paintSkin(g, 0, 0, getWidth(), getHeight(), state);
            } else {
                super.paint(g);
            }
        }

        public Dimension getPreferredSize() {
            int size = 16;
            if (scrollbar != null) {
                switch (scrollbar.getOrientation()) {
                case JScrollBar.VERTICAL:
                    size = scrollbar.getWidth();
                    break;
                case JScrollBar.HORIZONTAL:
                    size = scrollbar.getHeight();
                    break;
                }
                size = Math.max(size, 5);
            }
            return new Dimension(size, size);
        }
    }


    
This should be pulled out into its own class if more classes need to
use it.

Grid is used to draw the track for windows scrollbars. Grids
are cached in a HashMap, with the key being the rgb components
of the foreground/background colors. Further the Grid is held through
a WeakRef so that it can be freed when no longer needed. As the
Grid is rather expensive to draw, it is drawn in a BufferedImage.
/**
     * This should be pulled out into its own class if more classes need to
     * use it.
     * <p>
     * Grid is used to draw the track for windows scrollbars. Grids
     * are cached in a HashMap, with the key being the rgb components
     * of the foreground/background colors. Further the Grid is held through
     * a WeakRef so that it can be freed when no longer needed. As the
     * Grid is rather expensive to draw, it is drawn in a BufferedImage.
     */
    private static class Grid {
        private static final int BUFFER_SIZE = 64;
        private static HashMap<String, WeakReference<Grid>> map;

        private BufferedImage image;

        static {
            map = new HashMap<String, WeakReference<Grid>>();
        }

        public static Grid getGrid(Color fg, Color bg) {
            String key = fg.getRGB() + " " + bg.getRGB();
            WeakReference<Grid> ref = map.get(key);
            Grid grid = (ref == null) ? null : ref.get();
            if (grid == null) {
                grid = new Grid(fg, bg);
                map.put(key, new WeakReference<Grid>(grid));
            }
            return grid;
        }

        public Grid(Color fg, Color bg) {
            int[] cmap = { fg.getRGB(), bg.getRGB() };
            IndexColorModel icm = new IndexColorModel(8, 2, cmap, 0, false, -1,
                                                      DataBuffer.TYPE_BYTE);
            image = new BufferedImage(BUFFER_SIZE, BUFFER_SIZE,
                                      BufferedImage.TYPE_BYTE_INDEXED, icm);
            Graphics g = image.getGraphics();
            try {
                g.setClip(0, 0, BUFFER_SIZE, BUFFER_SIZE);
                paintGrid(g, fg, bg);
            }
            finally {
                g.dispose();
            }
        }

        
Paints the grid into the specified Graphics at the specified
location.
/**
         * Paints the grid into the specified Graphics at the specified
         * location.
         */
        public void paint(Graphics g, int x, int y, int w, int h) {
            Rectangle clipRect = g.getClipBounds();
            int minX = Math.max(x, clipRect.x);
            int minY = Math.max(y, clipRect.y);
            int maxX = Math.min(clipRect.x + clipRect.width, x + w);
            int maxY = Math.min(clipRect.y + clipRect.height, y + h);

            if (maxX <= minX || maxY <= minY) {
                return;
            }
            int xOffset = (minX - x) % 2;
            for (int xCounter = minX; xCounter < maxX;
                 xCounter += BUFFER_SIZE) {
                int yOffset = (minY - y) % 2;
                int width = Math.min(BUFFER_SIZE - xOffset,
                                     maxX - xCounter);

                for (int yCounter = minY; yCounter < maxY;
                     yCounter += BUFFER_SIZE) {
                    int height = Math.min(BUFFER_SIZE - yOffset,
                                          maxY - yCounter);

                    g.drawImage(image, xCounter, yCounter,
                                xCounter + width, yCounter + height,
                                xOffset, yOffset,
                                xOffset + width, yOffset + height, null);
                    if (yOffset != 0) {
                        yCounter -= yOffset;
                        yOffset = 0;
                    }
                }
                if (xOffset != 0) {
                    xCounter -= xOffset;
                    xOffset = 0;
                }
            }
        }

        
Actually renders the grid into the Graphics g.
/**
         * Actually renders the grid into the Graphics <code>g</code>.
         */
        private void paintGrid(Graphics g, Color fg, Color bg) {
            Rectangle clipRect = g.getClipBounds();
            g.setColor(bg);
            g.fillRect(clipRect.x, clipRect.y, clipRect.width,
                       clipRect.height);
            g.setColor(fg);
            g.translate(clipRect.x, clipRect.y);
            int width = clipRect.width;
            int height = clipRect.height;
            int xCounter = clipRect.x % 2;
            for (int end = width - height; xCounter < end; xCounter += 2) {
                g.drawLine(xCounter, 0, xCounter + height, height);
            }
            for (int end = width; xCounter < end; xCounter += 2) {
                g.drawLine(xCounter, 0, width, width - xCounter);
            }

            int yCounter = ((clipRect.x % 2) == 0) ? 2 : 1;
            for (int end = height - width; yCounter < end; yCounter += 2) {
                g.drawLine(0, yCounter, width, yCounter + width);
            }
            for (int end = height; yCounter < end; yCounter += 2) {
                g.drawLine(0, yCounter, height - yCounter, height);
            }
            g.translate(-clipRect.x, -clipRect.y);
        }
    }
}