/**
* Returns the next valid offset within this directional run, skipping conjuncts and zero-width
* characters. This should not be called to walk off the end of the line, since the returned
* values might not be valid on neighboring lines. If the returned offset is less than zero or
* greater than the line length, the offset should be recomputed on the preceding or following
* line, respectively.
*
* @param runIndex the run index
* @param runStart the start of the run
* @param runLimit the limit of the run
* @param runIsRtl true if the run is right-to-left
* @param offset the offset
* @param after true if the new offset should logically follow the provided offset
* @return the new offset
*/
private int getOffsetBeforeAfter(
int runIndex, int runStart, int runLimit, boolean runIsRtl, int offset, boolean after) {
if (runIndex < 0 || offset == (after ? mLen : 0)) {
// Walking off end of line. Since we don't know
// what cursor positions are available on other lines, we can't
// return accurate values. These are a guess.
if (after) {
return TextUtils.getOffsetAfter(mText, offset + mStart) - mStart;
}
return TextUtils.getOffsetBefore(mText, offset + mStart) - mStart;
}
TextPaint wp = mWorkPaint;
wp.set(mPaint);
int spanStart = runStart;
int spanLimit;
if (mSpanned == null) {
spanLimit = runLimit;
} else {
int target = after ? offset + 1 : offset;
int limit = mStart + runLimit;
while (true) {
spanLimit =
mSpanned.nextSpanTransition(mStart + spanStart, limit, MetricAffectingSpan.class)
- mStart;
if (spanLimit >= target) {
break;
}
spanStart = spanLimit;
}
MetricAffectingSpan[] spans =
mSpanned.getSpans(mStart + spanStart, mStart + spanLimit, MetricAffectingSpan.class);
spans = TextUtils.removeEmptySpans(spans, mSpanned, MetricAffectingSpan.class);
if (spans.length > 0) {
ReplacementSpan replacement = null;
for (int j = 0; j < spans.length; j++) {
MetricAffectingSpan span = spans[j];
if (span instanceof ReplacementSpan) {
replacement = (ReplacementSpan) span;
} else {
span.updateMeasureState(wp);
}
}
if (replacement != null) {
// If we have a replacement span, we're moving either to
// the start or end of this span.
return after ? spanLimit : spanStart;
}
}
}
int flags = runIsRtl ? Paint.DIRECTION_RTL : Paint.DIRECTION_LTR;
int cursorOpt = after ? Paint.CURSOR_AFTER : Paint.CURSOR_BEFORE;
if (mCharsValid) {
return wp.getTextRunCursor(
mChars, spanStart, spanLimit - spanStart, flags, offset, cursorOpt);
} else {
return wp.getTextRunCursor(
mText, mStart + spanStart, mStart + spanLimit, flags, mStart + offset, cursorOpt)
- mStart;
}
}
