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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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package javax.swing.text.html;

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Polygon;
import java.awt.Rectangle;
import java.awt.Shape;
import java.util.HashMap;
import java.util.Map;
import javax.swing.border.AbstractBorder;
import javax.swing.text.AttributeSet;
import javax.swing.text.View;
import javax.swing.text.html.CSS.Attribute;
import javax.swing.text.html.CSS.BorderStyle;
import javax.swing.text.html.CSS.BorderWidthValue;
import javax.swing.text.html.CSS.ColorValue;
import javax.swing.text.html.CSS.CssValue;
import javax.swing.text.html.CSS.LengthValue;
import javax.swing.text.html.CSS.Value;

CSS-style borders for HTML elements.
Author:
Sergey Groznyh/**
 * CSS-style borders for HTML elements.
 *
 * @author Sergey Groznyh
 */
@SuppressWarnings("serial") // Superclass is not serializable across versions
class CSSBorder extends AbstractBorder {

    
Indices for the attribute groups.  /** Indices for the attribute groups.  */
    static final int COLOR = 0, STYLE = 1, WIDTH = 2;

    
Indices for the box sides within the attribute group.  /** Indices for the box sides within the attribute group.  */
    static final int TOP = 0, RIGHT = 1, BOTTOM = 2, LEFT = 3;

    
The attribute groups.  /** The attribute groups.  */
    static final Attribute[][] ATTRIBUTES = {
        { Attribute.BORDER_TOP_COLOR, Attribute.BORDER_RIGHT_COLOR,
          Attribute.BORDER_BOTTOM_COLOR, Attribute.BORDER_LEFT_COLOR, },
        { Attribute.BORDER_TOP_STYLE, Attribute.BORDER_RIGHT_STYLE,
          Attribute.BORDER_BOTTOM_STYLE, Attribute.BORDER_LEFT_STYLE, },
        { Attribute.BORDER_TOP_WIDTH, Attribute.BORDER_RIGHT_WIDTH,
          Attribute.BORDER_BOTTOM_WIDTH, Attribute.BORDER_LEFT_WIDTH, },
    };

    
Parsers for the border properties.  /** Parsers for the border properties.  */
    static final CssValue[] PARSERS = {
        new ColorValue(), new BorderStyle(), new BorderWidthValue(null, 0),
    };

    
Default values for the border properties.  /** Default values for the border properties.  */
    static final Object[] DEFAULTS = {
        Attribute.BORDER_COLOR, // marker: value will be computed on request
        PARSERS[1].parseCssValue(Attribute.BORDER_STYLE.getDefaultValue()),
        PARSERS[2].parseCssValue(Attribute.BORDER_WIDTH.getDefaultValue()),
    };

    
Attribute set containing border properties.  /** Attribute set containing border properties.  */
    final AttributeSet attrs;

    
Initialize the attribute set.
/**
     * Initialize the attribute set.
     */
    CSSBorder(AttributeSet attrs) {
        this.attrs = attrs;
    }

    
Return the border color for the given side.
/**
     * Return the border color for the given side.
     */
    private Color getBorderColor(int side) {
        Object o = attrs.getAttribute(ATTRIBUTES[COLOR][side]);
        ColorValue cv;
        if (o instanceof ColorValue) {
            cv = (ColorValue) o;
        } else {
            // Marker for the default value.  Use 'color' property value as the
            // computed value of the 'border-color' property (CSS2 8.5.2)
            cv = (ColorValue) attrs.getAttribute(Attribute.COLOR);
            if (cv == null) {
                cv = (ColorValue) PARSERS[COLOR].parseCssValue(
                                            Attribute.COLOR.getDefaultValue());
            }
        }
        return cv.getValue();
    }

    
Return the border width for the given side.
/**
     * Return the border width for the given side.
     */
    private int getBorderWidth(int side) {
        int width = 0;
        BorderStyle bs = (BorderStyle) attrs.getAttribute(
                                                    ATTRIBUTES[STYLE][side]);
        if ((bs != null) && (bs.getValue() != Value.NONE)) {
            // The 'border-style' value of "none" forces the computed value
            // of 'border-width' to be 0 (CSS2 8.5.3)
            LengthValue bw = (LengthValue) attrs.getAttribute(
                                                    ATTRIBUTES[WIDTH][side]);
            if (bw == null) {
                bw = (LengthValue) DEFAULTS[WIDTH];
            }
            width = (int) bw.getValue(true);
        }
        return width;
    }

    
Return an array of border widths in the TOP, RIGHT, BOTTOM, LEFT order.
/**
     * Return an array of border widths in the TOP, RIGHT, BOTTOM, LEFT order.
     */
    private int[] getWidths() {
        int[] widths = new int[4];
        for (int i = 0; i < widths.length; i++) {
            widths[i] = getBorderWidth(i);
        }
        return widths;
    }

    
Return the border style for the given side.
/**
     * Return the border style for the given side.
     */
    private Value getBorderStyle(int side) {
        BorderStyle style =
                    (BorderStyle) attrs.getAttribute(ATTRIBUTES[STYLE][side]);
        if (style == null) {
            style = (BorderStyle) DEFAULTS[STYLE];
        }
        return style.getValue();
    }

    
Return border shape for side as if the border has zero interior length. Shape start is at (0,0); points are added clockwise. /**
     * Return border shape for {@code side} as if the border has zero interior
     * length.  Shape start is at (0,0); points are added clockwise.
     */
    private Polygon getBorderShape(int side) {
        Polygon shape = null;
        int[] widths = getWidths();
        if (widths[side] != 0) {
            shape = new Polygon(new int[4], new int[4], 0);
            shape.addPoint(0, 0);
            shape.addPoint(-widths[(side + 3) % 4], -widths[side]);
            shape.addPoint(widths[(side + 1) % 4], -widths[side]);
            shape.addPoint(0, 0);
        }
        return shape;
    }

    
Return the border painter appropriate for the given side.
/**
     * Return the border painter appropriate for the given side.
     */
    private BorderPainter getBorderPainter(int side) {
        Value style = getBorderStyle(side);
        return borderPainters.get(style);
    }

    
Return the color with brightness adjusted by the specified factor.
The factor values are between 0.0 (no change) and 1.0 (turn into white).
Negative factor values decrease brigthness (ie, 1.0 turns into black).
/**
     * Return the color with brightness adjusted by the specified factor.
     *
     * The factor values are between 0.0 (no change) and 1.0 (turn into white).
     * Negative factor values decrease brigthness (ie, 1.0 turns into black).
     */
    static Color getAdjustedColor(Color c, double factor) {
        double f = 1 - Math.min(Math.abs(factor), 1);
        double inc = (factor > 0 ? 255 * (1 - f) : 0);
        return new Color((int) (c.getRed() * f + inc),
                         (int) (c.getGreen() * f + inc),
                         (int) (c.getBlue() * f + inc));
    }


    /* The javax.swing.border.Border methods.  */

    public Insets getBorderInsets(Component c, Insets insets) {
        int[] widths = getWidths();
        insets.set(widths[TOP], widths[LEFT], widths[BOTTOM], widths[RIGHT]);
        return insets;
    }

    public void paintBorder(Component c, Graphics g,
                                        int x, int y, int width, int height) {
        if (!(g instanceof Graphics2D)) {
            return;
        }

        Graphics2D g2 = (Graphics2D) g.create();

        int[] widths = getWidths();

        // Position and size of the border interior.
        int intX = x + widths[LEFT];
        int intY = y + widths[TOP];
        int intWidth = width - (widths[RIGHT] + widths[LEFT]);
        int intHeight = height - (widths[TOP] + widths[BOTTOM]);

        // Coordinates of the interior corners, from NW clockwise.
        int[][] intCorners = {
            { intX, intY },
            { intX + intWidth, intY },
            { intX + intWidth, intY + intHeight },
            { intX, intY + intHeight, },
        };

        // Draw the borders for all sides.
        for (int i = 0; i < 4; i++) {
            Value style = getBorderStyle(i);
            Polygon shape = getBorderShape(i);
            if ((style != Value.NONE) && (shape != null)) {
                int sideLength = (i % 2 == 0 ? intWidth : intHeight);

                // "stretch" the border shape by the interior area dimension
                shape.xpoints[2] += sideLength;
                shape.xpoints[3] += sideLength;
                Color color = getBorderColor(i);
                BorderPainter painter = getBorderPainter(i);

                double angle = i * Math.PI / 2;
                g2.setClip(g.getClip()); // Restore initial clip
                g2.translate(intCorners[i][0], intCorners[i][1]);
                g2.rotate(angle);
                g2.clip(shape);
                painter.paint(shape, g2, color, i);
                g2.rotate(-angle);
                g2.translate(-intCorners[i][0], -intCorners[i][1]);
            }
        }
        g2.dispose();
    }


    /* Border painters.  */

    interface BorderPainter {
        
The painter should paint the border as if it were at the top and the
coordinates of the NW corner of the interior area is (0, 0).  The
caller is responsible for the appropriate affine transformations.
Clip is set by the caller to the exact border shape so it's safe to
simply draw into the shape's bounding rectangle.
/**
         * The painter should paint the border as if it were at the top and the
         * coordinates of the NW corner of the interior area is (0, 0).  The
         * caller is responsible for the appropriate affine transformations.
         *
         * Clip is set by the caller to the exact border shape so it's safe to
         * simply draw into the shape's bounding rectangle.
         */
        void paint(Polygon shape, Graphics g, Color color, int side);
    }

    
Painter for the "none" and "hidden" CSS border styles.
/**
     * Painter for the "none" and "hidden" CSS border styles.
     */
    static class NullPainter implements BorderPainter {
        public void paint(Polygon shape, Graphics g, Color color, int side) {
            // Do nothing.
        }
    }

    
Painter for the "solid" CSS border style.
/**
     * Painter for the "solid" CSS border style.
     */
    static class SolidPainter implements BorderPainter {
        public void paint(Polygon shape, Graphics g, Color color, int side) {
            g.setColor(color);
            g.fillPolygon(shape);
        }
    }

    
Defines a method for painting strokes in the specified direction using
the given length and color patterns.
/**
     * Defines a method for painting strokes in the specified direction using
     * the given length and color patterns.
     */
    abstract static class StrokePainter implements BorderPainter {
        
Paint strokes repeatedly using the given length and color patterns.
/**
         * Paint strokes repeatedly using the given length and color patterns.
         */
        void paintStrokes(Rectangle r, Graphics g, int axis,
                                int[] lengthPattern, Color[] colorPattern) {
            boolean xAxis = (axis == View.X_AXIS);
            int start = 0;
            int end = (xAxis ? r.width : r.height);
            while (start < end) {
                for (int i = 0; i < lengthPattern.length; i++) {
                    if (start >= end) {
                        break;
                    }
                    int length = lengthPattern[i];
                    Color c = colorPattern[i];
                    if (c != null) {
                        int x = r.x + (xAxis ? start : 0);
                        int y = r.y + (xAxis ? 0 : start);
                        int width = xAxis ? length : r.width;
                        int height = xAxis ? r.height : length;
                        g.setColor(c);
                        g.fillRect(x, y, width, height);
                    }
                    start += length;
                }
            }
        }
    }

    
Painter for the "double" CSS border style.
/**
     * Painter for the "double" CSS border style.
     */
    static class DoublePainter extends StrokePainter {
        public void paint(Polygon shape, Graphics g, Color color, int side) {
            Rectangle r = shape.getBounds();
            int length = Math.max(r.height / 3, 1);
            int[] lengthPattern = { length, length };
            Color[] colorPattern = { color, null };
            paintStrokes(r, g, View.Y_AXIS, lengthPattern, colorPattern);
        }
    }

    
Painter for the "dotted" and "dashed" CSS border styles.
/**
     * Painter for the "dotted" and "dashed" CSS border styles.
     */
    static class DottedDashedPainter extends StrokePainter {
        final int factor;

        DottedDashedPainter(int factor) {
            this.factor = factor;
        }

        public void paint(Polygon shape, Graphics g, Color color, int side) {
            Rectangle r = shape.getBounds();
            int length = r.height * factor;
            int[] lengthPattern = { length, length };
            Color[] colorPattern = { color, null };
            paintStrokes(r, g, View.X_AXIS, lengthPattern, colorPattern);
        }
    }

    
Painter that defines colors for "shadow" and "light" border sides.
/**
     * Painter that defines colors for "shadow" and "light" border sides.
     */
    abstract static class ShadowLightPainter extends StrokePainter {
        
Return the "shadow" border side color.
/**
         * Return the "shadow" border side color.
         */
        static Color getShadowColor(Color c) {
            return CSSBorder.getAdjustedColor(c, -0.3);
        }

        
Return the "light" border side color.
/**
         * Return the "light" border side color.
         */
        static Color getLightColor(Color c) {
            return CSSBorder.getAdjustedColor(c, 0.7);
        }
    }

    
Painter for the "groove" and "ridge" CSS border styles.
/**
     * Painter for the "groove" and "ridge" CSS border styles.
     */
    static class GrooveRidgePainter extends ShadowLightPainter {
        final Value type;

        GrooveRidgePainter(Value type) {
            this.type = type;
        }

        public void paint(Polygon shape, Graphics g, Color color, int side) {
            Rectangle r = shape.getBounds();
            int length = Math.max(r.height / 2, 1);
            int[] lengthPattern = { length, length };
            Color[] colorPattern =
                             ((side + 1) % 4 < 2) == (type == Value.GROOVE) ?
                new Color[] { getShadowColor(color), getLightColor(color) } :
                new Color[] { getLightColor(color), getShadowColor(color) };
            paintStrokes(r, g, View.Y_AXIS, lengthPattern, colorPattern);
        }
    }

    
Painter for the "inset" and "outset" CSS border styles.
/**
     * Painter for the "inset" and "outset" CSS border styles.
     */
    static class InsetOutsetPainter extends ShadowLightPainter {
        Value type;

        InsetOutsetPainter(Value type) {
            this.type = type;
        }

        public void paint(Polygon shape, Graphics g, Color color, int side) {
            g.setColor(((side + 1) % 4 < 2) == (type == Value.INSET) ?
                                getShadowColor(color) : getLightColor(color));
            g.fillPolygon(shape);
        }
    }

    
Add the specified painter to the painters map.
/**
     * Add the specified painter to the painters map.
     */
    static void registerBorderPainter(Value style, BorderPainter painter) {
        borderPainters.put(style, painter);
    }

    
Map the border style values to the border painter objects.  /** Map the border style values to the border painter objects.  */
    static Map<Value, BorderPainter> borderPainters =
                                        new HashMap<Value, BorderPainter>();

    /* Initialize the border painters map with the pre-defined values.  */
    static {
        registerBorderPainter(Value.NONE, new NullPainter());
        registerBorderPainter(Value.HIDDEN, new NullPainter());
        registerBorderPainter(Value.SOLID, new SolidPainter());
        registerBorderPainter(Value.DOUBLE, new DoublePainter());
        registerBorderPainter(Value.DOTTED, new DottedDashedPainter(1));
        registerBorderPainter(Value.DASHED, new DottedDashedPainter(3));
        registerBorderPainter(Value.GROOVE, new GrooveRidgePainter(Value.GROOVE));
        registerBorderPainter(Value.RIDGE, new GrooveRidgePainter(Value.RIDGE));
        registerBorderPainter(Value.INSET, new InsetOutsetPainter(Value.INSET));
        registerBorderPainter(Value.OUTSET, new InsetOutsetPainter(Value.OUTSET));
    }
}