Merge "Use SpanSet to accelerate Layout.drawBackground"

        // direction of the layout or line.  XXX: Should they?

        // They are evaluated at each line.

        if (mSpannedText) {

            if (lineBackgroundSpans == null) {

                lineBackgroundSpans = new SpanSet<LineBackgroundSpan>(LineBackgroundSpan.class);

            }

            Spanned buffer = (Spanned) mText;

            int textLength = buffer.length();

            lineBackgroundSpans.init(buffer, 0, textLength);

            if (lineBackgroundSpans.numberOfSpans > 0) {

                int previousLineBottom = getLineTop(firstLine);

                int previousLineEnd = getLineStart(firstLine);

                ParagraphStyle[] spans = NO_PARA_SPANS;

                int spansLength = 0;

                TextPaint paint = mPaint;

            CharSequence buf = mText;

                int spanEnd = 0;

                final int width = mWidth;

            Spanned sp = (Spanned) buf;

            int textLength = buf.length();

                for (int i = firstLine; i <= lastLine; i++) {

                    int start = previousLineEnd;

                    int end = getLineStart(i + 1);

                    if (start >= spanEnd) {

                        // These should be infrequent, so we'll use this so that

                        // we don't have to check as often.

                    spanEnd = sp.nextSpanTransition(start, textLength, LineBackgroundSpan.class);

                        spanEnd = lineBackgroundSpans.getNextTransition(start, textLength);

                        // All LineBackgroundSpans on a line contribute to its background.

                    spans = getParagraphSpans(sp, start, end, LineBackgroundSpan.class);

                }

                for (int n = 0; n < spans.length; n++) {

                    LineBackgroundSpan back = (LineBackgroundSpan) spans[n];

                    back.drawBackground(canvas, paint, 0, width,

                        spansLength = 0;

                        // Duplication of the logic of getParagraphSpans

                        if (start != end || start == 0) {

                            // Equivalent to a getSpans(start, end), but filling the 'spans' local

                            // array instead to reduce memory allocation

                            for (int j = 0; j < lineBackgroundSpans.numberOfSpans; j++) {

                                // equal test is valid since both intervals are not empty by construction

                                if (lineBackgroundSpans.spanStarts[j] >= end ||

                                        lineBackgroundSpans.spanEnds[j] <= start) continue;

                                if (spansLength == spans.length) {

                                    // The spans array needs to be expanded

                                    int newSize = ArrayUtils.idealObjectArraySize(2 * spansLength);

                                    ParagraphStyle[] newSpans = new ParagraphStyle[newSize];

                                    System.arraycopy(spans, 0, newSpans, 0, spansLength);

                                    spans = newSpans;

                                }

                                spans[spansLength++] = lineBackgroundSpans.spans[j];

                            }

                        }

                    }

                    for (int n = 0; n < spansLength; n++) {

                        LineBackgroundSpan lineBackgroundSpan = (LineBackgroundSpan) spans[n];

                        lineBackgroundSpan.drawBackground(canvas, paint, 0, width,

                                ltop, lbaseline, lbottom,

                            buf, start, end, i);

                                buffer, start, end, i);

                    }

                }

            }

            lineBackgroundSpans.recycle();

        }

        // There can be a highlight even without spans if we are drawing

    private static final Rect sTempRect = new Rect();

    private boolean mSpannedText;

    private TextDirectionHeuristic mTextDir;

    private SpanSet<LineBackgroundSpan> lineBackgroundSpans;

    public static final int DIR_LEFT_TO_RIGHT = 1;

    public static final int DIR_RIGHT_TO_LEFT = -1;