Make BulletSpan more flexible and update JavaDoc.

    ctor public BulletSpan();

    ctor public BulletSpan(int);

    ctor public BulletSpan(int, int);

    ctor public BulletSpan(int, int, int);

    ctor public BulletSpan(android.os.Parcel);

    method public int describeContents();

    method public void drawLeadingMargin(android.graphics.Canvas, android.graphics.Paint, int, int, int, int, int, java.lang.CharSequence, int, int, boolean, android.text.Layout);

    method public int getBulletRadius();

    method public int getColor();

    method public int getGapWidth();

    method public int getLeadingMargin(boolean);

    method public int getSpanTypeId();

    method public void writeToParcel(android.os.Parcel, int);

package android.text.style;

import android.annotation.ColorInt;

import android.annotation.IntRange;

import android.annotation.NonNull;

import android.annotation.Nullable;

import android.annotation.Px;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Path;

import android.text.Spanned;

import android.text.TextUtils;

/**

 * A span which styles paragraphs as bullet points (respecting layout direction).

 * <p>

 * BulletSpans must be attached from the first character to the last character of a single

 * paragraph, otherwise the bullet point will not be displayed but the first paragraph encountered

 * will have a leading margin.

 * <p>

 * BulletSpans allow configuring the following elements:

 * <ul>

 * <li><b>gap width</b> - the distance, in pixels, between the bullet point and the paragraph.

 * Default value is 2px.</li>

 * <li><b>color</b> - the bullet point color. By default, the bullet point color is 0 - no color,

 * so it uses the TextView's text color.</li>

 * <li><b>bullet radius</b> - the radius, in pixels, of the bullet point. Default value is

 * 4px.</li>

 * </ul>

 * For example, a BulletSpan using the default values can be constructed like this:

 * <pre>{@code

 *  SpannableString string = new SpannableString("Text with\nBullet point");

 *string.setSpan(new BulletSpan(), 10, 22, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);}</pre>

 * <img src="{@docRoot}reference/android/images/text/style/defaultbulletspan.png" />

 * <figcaption>BulletSpan constructed with default values.</figcaption>

 * <p>

 * <p>

 * To construct a BulletSpan with a gap width of 40px, green bullet point and bullet radius of

 * 20px:

 * <pre>{@code

 *  SpannableString string = new SpannableString("Text with\nBullet point");

 *string.setSpan(new BulletSpan(40, color, 20), 10, 22, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);}</pre>

 * <img src="{@docRoot}reference/android/images/text/style/custombulletspan.png" />

 * <figcaption>Customized BulletSpan.</figcaption>

 */

public class BulletSpan implements LeadingMarginSpan, ParcelableSpan {

    private final int mGapWidth;

    private final boolean mWantColor;

    private final int mColor;

    // Bullet is slightly bigger to avoid aliasing artifacts on mdpi devices.

    private static final float BULLET_RADIUS = 3 * 1.2f;

    private static Path sBulletPath = null;

    private static final int STANDARD_BULLET_RADIUS = 4;

    public static final int STANDARD_GAP_WIDTH = 2;

    private static final int STANDARD_COLOR = 0;

    @Px

    private final int mGapWidth;

    @Px

    private final int mBulletRadius;

    private Path mBulletPath = null;

    @ColorInt

    private final int mColor;

    private final boolean mWantColor;

    /**

     * Creates a {@link BulletSpan} with the default values.

     */

    public BulletSpan() {

        mGapWidth = STANDARD_GAP_WIDTH;

        mWantColor = false;

        mColor = 0;

        this(STANDARD_GAP_WIDTH, STANDARD_COLOR, false, STANDARD_BULLET_RADIUS);

    }

    /**

     * Creates a {@link BulletSpan} based on a gap width

     *

     * @param gapWidth the distance, in pixels, between the bullet point and the paragraph.

     */

    public BulletSpan(int gapWidth) {

        mGapWidth = gapWidth;

        mWantColor = false;

        mColor = 0;

        this(gapWidth, STANDARD_COLOR, false, STANDARD_BULLET_RADIUS);

    }

    /**

     * Creates a {@link BulletSpan} based on a gap width and a color integer.

     *

     * @param gapWidth the distance, in pixels, between the bullet point and the paragraph.

     * @param color    the bullet point color, as a color integer

     * @see android.content.res.Resources#getColor(int, Resources.Theme)

     */

    public BulletSpan(int gapWidth, @ColorInt int color) {

        this(gapWidth, color, true, STANDARD_BULLET_RADIUS);

    }

    public BulletSpan(int gapWidth, int color) {

    /**

     * Creates a {@link BulletSpan} based on a gap width and a color integer.

     *

     * @param gapWidth     the distance, in pixels, between the bullet point and the paragraph.

     * @param color        the bullet point color, as a color integer.

     * @param bulletRadius the radius of the bullet point, in pixels.

     * @see android.content.res.Resources#getColor(int, Resources.Theme)

     */

    public BulletSpan(int gapWidth, @ColorInt int color, @IntRange(from = 0) int bulletRadius) {

        this(gapWidth, color, true, bulletRadius);

    }

    private BulletSpan(int gapWidth, @ColorInt int color, boolean wantColor,

            @IntRange(from = 0) int bulletRadius) {

        mGapWidth = gapWidth;

        mWantColor = true;

        mBulletRadius = bulletRadius;

        mColor = color;

        mWantColor = wantColor;

    }

    public BulletSpan(Parcel src) {

    /**

     * Creates a {@link BulletSpan} from a parcel.

     */

    public BulletSpan(@NonNull Parcel src) {

        mGapWidth = src.readInt();

        mWantColor = src.readInt() != 0;

        mColor = src.readInt();

        mBulletRadius = src.readInt();

    }

    @Override

    }

    @Override

    public void writeToParcel(Parcel dest, int flags) {

    public void writeToParcel(@NonNull Parcel dest, int flags) {

        writeToParcelInternal(dest, flags);

    }

    /** @hide */

    @Override

    public void writeToParcelInternal(Parcel dest, int flags) {

    public void writeToParcelInternal(@NonNull Parcel dest, int flags) {

        dest.writeInt(mGapWidth);

        dest.writeInt(mWantColor ? 1 : 0);

        dest.writeInt(mColor);

        dest.writeInt(mBulletRadius);

    }

    @Override

    public int getLeadingMargin(boolean first) {

        return (int) (2 * BULLET_RADIUS + mGapWidth);

        return 2 * mBulletRadius + mGapWidth;

    }

    /**

     * Get the distance, in pixels, between the bullet point and the paragraph.

     *

     * @return the distance, in pixels, between the bullet point and the paragraph.

     */

    public int getGapWidth() {

        return mGapWidth;

    }

    /**

     * Get the radius, in pixels, of the bullet point.

     *

     * @return the radius, in pixels, of the bullet point.

     */

    public int getBulletRadius() {

        return mBulletRadius;

    }

    /**

     * Get the bullet point color.

     *

     * @return the bullet point color

     */

    public int getColor() {

        return mColor;

    }

    @Override

    public void drawLeadingMargin(Canvas c, Paint p, int x, int dir,

    public void drawLeadingMargin(@NonNull Canvas canvas, @NonNull Paint paint, int x, int dir,

            int top, int baseline, int bottom,

                                  CharSequence text, int start, int end,

                                  boolean first, Layout l) {

            @NonNull CharSequence text, int start, int end,

            boolean first, @Nullable Layout layout) {

        if (((Spanned) text).getSpanStart(this) == start) {

            Paint.Style style = p.getStyle();

            Paint.Style style = paint.getStyle();

            int oldcolor = 0;

            if (mWantColor) {

                oldcolor = p.getColor();

                p.setColor(mColor);

                oldcolor = paint.getColor();

                paint.setColor(mColor);

            }

            p.setStyle(Paint.Style.FILL);

            paint.setStyle(Paint.Style.FILL);

            if (l != null) {

            if (layout != null) {

                // "bottom" position might include extra space as a result of line spacing

                // configuration. Subtract extra space in order to show bullet in the vertical

                // center of characters.

                final int line = l.getLineForOffset(start);

                bottom = bottom - l.getLineExtra(line);

                final int line = layout.getLineForOffset(start);

                bottom = bottom - layout.getLineExtra(line);

            }

            final float y = (top + bottom) / 2f;

            final float yPosition = (top + bottom) / 2f;

            final float xPosition = x + dir * mBulletRadius;

            if (c.isHardwareAccelerated()) {

                if (sBulletPath == null) {

                    sBulletPath = new Path();

                    sBulletPath.addCircle(0.0f, 0.0f, BULLET_RADIUS, Direction.CW);

            if (canvas.isHardwareAccelerated()) {

                if (mBulletPath == null) {

                    mBulletPath = new Path();

                    mBulletPath.addCircle(0.0f, 0.0f, mBulletRadius, Direction.CW);

                }

                c.save();

                c.translate(x + dir * BULLET_RADIUS, y);

                c.drawPath(sBulletPath, p);

                c.restore();

                canvas.save();

                canvas.translate(xPosition, yPosition);

                canvas.drawPath(mBulletPath, paint);

                canvas.restore();

            } else {

                c.drawCircle(x + dir * BULLET_RADIUS, y, BULLET_RADIUS, p);

                canvas.drawCircle(xPosition, yPosition, mBulletRadius, paint);

            }

            if (mWantColor) {

                p.setColor(oldcolor);

                paint.setColor(oldcolor);

            }

            p.setStyle(style);

            paint.setStyle(style);

        }

    }

}