2 * Copyright (C) 2006 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 import android.annotation.IntDef;
20 import android.graphics.Canvas;
21 import android.graphics.Paint;
22 import android.graphics.Path;
23 import android.graphics.Rect;
24 import android.text.method.TextKeyListener;
25 import android.text.style.AlignmentSpan;
26 import android.text.style.LeadingMarginSpan;
27 import android.text.style.LeadingMarginSpan.LeadingMarginSpan2;
28 import android.text.style.LineBackgroundSpan;
29 import android.text.style.ParagraphStyle;
30 import android.text.style.ReplacementSpan;
31 import android.text.style.TabStopSpan;
33 import com.android.internal.annotations.VisibleForTesting;
34 import com.android.internal.util.ArrayUtils;
35 import com.android.internal.util.GrowingArrayUtils;
37 import java.lang.annotation.Retention;
38 import java.lang.annotation.RetentionPolicy;
39 import java.util.Arrays;
42 * A base class that manages text layout in visual elements on
44 * <p>For text that will be edited, use a {@link DynamicLayout},
45 * which will be updated as the text changes.
46 * For text that will not change, use a {@link StaticLayout}.
48 public abstract class Layout {
50 @IntDef({BREAK_STRATEGY_SIMPLE, BREAK_STRATEGY_HIGH_QUALITY, BREAK_STRATEGY_BALANCED})
51 @Retention(RetentionPolicy.SOURCE)
52 public @interface BreakStrategy {}
55 * Value for break strategy indicating simple line breaking. Automatic hyphens are not added
56 * (though soft hyphens are respected), and modifying text generally doesn't affect the layout
57 * before it (which yields a more consistent user experience when editing), but layout may not
58 * be the highest quality.
60 public static final int BREAK_STRATEGY_SIMPLE = 0;
63 * Value for break strategy indicating high quality line breaking, including automatic
64 * hyphenation and doing whole-paragraph optimization of line breaks.
66 public static final int BREAK_STRATEGY_HIGH_QUALITY = 1;
69 * Value for break strategy indicating balanced line breaking. The breaks are chosen to
70 * make all lines as close to the same length as possible, including automatic hyphenation.
72 public static final int BREAK_STRATEGY_BALANCED = 2;
75 @IntDef({HYPHENATION_FREQUENCY_NORMAL, HYPHENATION_FREQUENCY_FULL,
76 HYPHENATION_FREQUENCY_NONE})
77 @Retention(RetentionPolicy.SOURCE)
78 public @interface HyphenationFrequency {}
81 * Value for hyphenation frequency indicating no automatic hyphenation. Useful
82 * for backward compatibility, and for cases where the automatic hyphenation algorithm results
83 * in incorrect hyphenation. Mid-word breaks may still happen when a word is wider than the
84 * layout and there is otherwise no valid break. Soft hyphens are ignored and will not be used
85 * as suggestions for potential line breaks.
87 public static final int HYPHENATION_FREQUENCY_NONE = 0;
90 * Value for hyphenation frequency indicating a light amount of automatic hyphenation, which
91 * is a conservative default. Useful for informal cases, such as short sentences or chat
94 public static final int HYPHENATION_FREQUENCY_NORMAL = 1;
97 * Value for hyphenation frequency indicating the full amount of automatic hyphenation, typical
98 * in typography. Useful for running text and where it's important to put the maximum amount of
99 * text in a screen with limited space.
101 public static final int HYPHENATION_FREQUENCY_FULL = 2;
103 private static final ParagraphStyle[] NO_PARA_SPANS =
104 ArrayUtils.emptyArray(ParagraphStyle.class);
107 @IntDef({JUSTIFICATION_MODE_NONE, JUSTIFICATION_MODE_INTER_WORD})
108 @Retention(RetentionPolicy.SOURCE)
109 public @interface JustificationMode {}
112 * Value for justification mode indicating no justification.
114 public static final int JUSTIFICATION_MODE_NONE = 0;
117 * Value for justification mode indicating the text is justified by stretching word spacing.
119 public static final int JUSTIFICATION_MODE_INTER_WORD = 1;
122 * Return how wide a layout must be in order to display the specified text with one line per
126 * {@link TextDirectionHeuristics#FIRSTSTRONG_LTR} as the default text direction heuristics. In
127 * the earlier versions uses {@link TextDirectionHeuristics#LTR} as the default.</p>
129 public static float getDesiredWidth(CharSequence source,
131 return getDesiredWidth(source, 0, source.length(), paint);
135 * Return how wide a layout must be in order to display the specified text slice with one
136 * line per paragraph.
139 * {@link TextDirectionHeuristics#FIRSTSTRONG_LTR} as the default text direction heuristics. In
140 * the earlier versions uses {@link TextDirectionHeuristics#LTR} as the default.</p>
142 public static float getDesiredWidth(CharSequence source, int start, int end, TextPaint paint) {
143 return getDesiredWidth(source, start, end, paint, TextDirectionHeuristics.FIRSTSTRONG_LTR);
147 * Return how wide a layout must be in order to display the
148 * specified text slice with one line per paragraph.
152 public static float getDesiredWidth(CharSequence source, int start, int end, TextPaint paint,
153 TextDirectionHeuristic textDir) {
157 for (int i = start; i <= end; i = next) {
158 next = TextUtils.indexOf(source, '\n', i, end);
163 // note, omits trailing paragraph char
164 float w = measurePara(paint, source, i, next, textDir);
176 * Subclasses of Layout use this constructor to set the display text,
177 * width, and other standard properties.
178 * @param text the text to render
179 * @param paint the default paint for the layout. Styles can override
180 * various attributes of the paint.
181 * @param width the wrapping width for the text.
182 * @param align whether to left, right, or center the text. Styles can
183 * override the alignment.
184 * @param spacingMult factor by which to scale the font size to get the
185 * default line spacing
186 * @param spacingAdd amount to add to the default line spacing
188 protected Layout(CharSequence text, TextPaint paint,
189 int width, Alignment align,
190 float spacingMult, float spacingAdd) {
191 this(text, paint, width, align, TextDirectionHeuristics.FIRSTSTRONG_LTR,
192 spacingMult, spacingAdd);
196 * Subclasses of Layout use this constructor to set the display text,
197 * width, and other standard properties.
198 * @param text the text to render
199 * @param paint the default paint for the layout. Styles can override
200 * various attributes of the paint.
201 * @param width the wrapping width for the text.
202 * @param align whether to left, right, or center the text. Styles can
203 * override the alignment.
204 * @param spacingMult factor by which to scale the font size to get the
205 * default line spacing
206 * @param spacingAdd amount to add to the default line spacing
210 protected Layout(CharSequence text, TextPaint paint,
211 int width, Alignment align, TextDirectionHeuristic textDir,
212 float spacingMult, float spacingAdd) {
215 throw new IllegalArgumentException("Layout: " + width + " < 0");
217 // Ensure paint doesn't have baselineShift set.
218 // While normally we don't modify the paint the user passed in,
219 // we were already doing this in Styled.drawUniformRun with both
220 // baselineShift and bgColor. We probably should reevaluate bgColor.
223 paint.baselineShift = 0;
230 mSpacingMult = spacingMult;
231 mSpacingAdd = spacingAdd;
232 mSpannedText = text instanceof Spanned;
237 protected void setJustificationMode(@JustificationMode int justificationMode) {
238 mJustificationMode = justificationMode;
242 * Replace constructor properties of this Layout with new ones. Be careful.
244 /* package */ void replaceWith(CharSequence text, TextPaint paint,
245 int width, Alignment align,
246 float spacingmult, float spacingadd) {
248 throw new IllegalArgumentException("Layout: " + width + " < 0");
255 mSpacingMult = spacingmult;
256 mSpacingAdd = spacingadd;
257 mSpannedText = text instanceof Spanned;
261 * Draw this Layout on the specified Canvas.
263 public void draw(Canvas c) {
264 draw(c, null, null, 0);
268 * Draw this Layout on the specified canvas, with the highlight path drawn
269 * between the background and the text.
271 * @param canvas the canvas
272 * @param highlight the path of the highlight or cursor; can be null
273 * @param highlightPaint the paint for the highlight
274 * @param cursorOffsetVertical the amount to temporarily translate the
275 * canvas while rendering the highlight
277 public void draw(Canvas canvas, Path highlight, Paint highlightPaint,
278 int cursorOffsetVertical) {
279 final long lineRange = getLineRangeForDraw(canvas);
280 int firstLine = TextUtils.unpackRangeStartFromLong(lineRange);
281 int lastLine = TextUtils.unpackRangeEndFromLong(lineRange);
282 if (lastLine < 0) return;
284 drawBackground(canvas, highlight, highlightPaint, cursorOffsetVertical,
285 firstLine, lastLine);
286 drawText(canvas, firstLine, lastLine);
289 private boolean isJustificationRequired(int lineNum) {
290 if (mJustificationMode == JUSTIFICATION_MODE_NONE) return false;
291 final int lineEnd = getLineEnd(lineNum);
292 return lineEnd < mText.length() && mText.charAt(lineEnd - 1) != '\n';
295 private float getJustifyWidth(int lineNum) {
296 Alignment paraAlign = mAlignment;
297 TabStops tabStops = null;
298 boolean tabStopsIsInitialized = false;
303 final int dir = getParagraphDirection(lineNum);
305 ParagraphStyle[] spans = NO_PARA_SPANS;
307 Spanned sp = (Spanned) mText;
308 final int start = getLineStart(lineNum);
310 final boolean isFirstParaLine = (start == 0 || mText.charAt(start - 1) == '\n');
312 if (isFirstParaLine) {
313 final int spanEnd = sp.nextSpanTransition(start, mText.length(),
314 ParagraphStyle.class);
315 spans = getParagraphSpans(sp, start, spanEnd, ParagraphStyle.class);
317 for (int n = spans.length - 1; n >= 0; n--) {
318 if (spans[n] instanceof AlignmentSpan) {
319 paraAlign = ((AlignmentSpan) spans[n]).getAlignment();
325 final int length = spans.length;
326 boolean useFirstLineMargin = isFirstParaLine;
327 for (int n = 0; n < length; n++) {
328 if (spans[n] instanceof LeadingMarginSpan2) {
329 int count = ((LeadingMarginSpan2) spans[n]).getLeadingMarginLineCount();
330 int startLine = getLineForOffset(sp.getSpanStart(spans[n]));
331 if (lineNum < startLine + count) {
332 useFirstLineMargin = true;
337 for (int n = 0; n < length; n++) {
338 if (spans[n] instanceof LeadingMarginSpan) {
339 LeadingMarginSpan margin = (LeadingMarginSpan) spans[n];
340 if (dir == DIR_RIGHT_TO_LEFT) {
341 right -= margin.getLeadingMargin(useFirstLineMargin);
343 left += margin.getLeadingMargin(useFirstLineMargin);
349 if (getLineContainsTab(lineNum)) {
350 tabStops = new TabStops(TAB_INCREMENT, spans);
353 final Alignment align;
354 if (paraAlign == Alignment.ALIGN_LEFT) {
355 align = (dir == DIR_LEFT_TO_RIGHT) ? Alignment.ALIGN_NORMAL : Alignment.ALIGN_OPPOSITE;
356 } else if (paraAlign == Alignment.ALIGN_RIGHT) {
357 align = (dir == DIR_LEFT_TO_RIGHT) ? Alignment.ALIGN_OPPOSITE : Alignment.ALIGN_NORMAL;
362 final int indentWidth;
363 if (align == Alignment.ALIGN_NORMAL) {
364 if (dir == DIR_LEFT_TO_RIGHT) {
365 indentWidth = getIndentAdjust(lineNum, Alignment.ALIGN_LEFT);
367 indentWidth = -getIndentAdjust(lineNum, Alignment.ALIGN_RIGHT);
369 } else if (align == Alignment.ALIGN_OPPOSITE) {
370 if (dir == DIR_LEFT_TO_RIGHT) {
371 indentWidth = -getIndentAdjust(lineNum, Alignment.ALIGN_RIGHT);
373 indentWidth = getIndentAdjust(lineNum, Alignment.ALIGN_LEFT);
375 } else { // Alignment.ALIGN_CENTER
376 indentWidth = getIndentAdjust(lineNum, Alignment.ALIGN_CENTER);
379 return right - left - indentWidth;
385 public void drawText(Canvas canvas, int firstLine, int lastLine) {
386 int previousLineBottom = getLineTop(firstLine);
387 int previousLineEnd = getLineStart(firstLine);
388 ParagraphStyle[] spans = NO_PARA_SPANS;
390 final TextPaint paint = mPaint;
391 CharSequence buf = mText;
393 Alignment paraAlign = mAlignment;
394 TabStops tabStops = null;
395 boolean tabStopsIsInitialized = false;
397 TextLine tl = TextLine.obtain();
399 // Draw the lines, one at a time.
400 // The baseline is the top of the following line minus the current line's descent.
401 for (int lineNum = firstLine; lineNum <= lastLine; lineNum++) {
402 int start = previousLineEnd;
403 previousLineEnd = getLineStart(lineNum + 1);
404 final boolean justify = isJustificationRequired(lineNum);
405 int end = getLineVisibleEnd(lineNum, start, previousLineEnd);
407 int ltop = previousLineBottom;
408 int lbottom = getLineTop(lineNum + 1);
409 previousLineBottom = lbottom;
410 int lbaseline = lbottom - getLineDescent(lineNum);
412 int dir = getParagraphDirection(lineNum);
417 Spanned sp = (Spanned) buf;
418 int textLength = buf.length();
419 boolean isFirstParaLine = (start == 0 || buf.charAt(start - 1) == '\n');
421 // New batch of paragraph styles, collect into spans array.
422 // Compute the alignment, last alignment style wins.
423 // Reset tabStops, we'll rebuild if we encounter a line with
425 // We expect paragraph spans to be relatively infrequent, use
426 // spanEnd so that we can check less frequently. Since
427 // paragraph styles ought to apply to entire paragraphs, we can
428 // just collect the ones present at the start of the paragraph.
429 // If spanEnd is before the end of the paragraph, that's not
431 if (start >= spanEnd && (lineNum == firstLine || isFirstParaLine)) {
432 spanEnd = sp.nextSpanTransition(start, textLength,
433 ParagraphStyle.class);
434 spans = getParagraphSpans(sp, start, spanEnd, ParagraphStyle.class);
436 paraAlign = mAlignment;
437 for (int n = spans.length - 1; n >= 0; n--) {
438 if (spans[n] instanceof AlignmentSpan) {
439 paraAlign = ((AlignmentSpan) spans[n]).getAlignment();
444 tabStopsIsInitialized = false;
447 // Draw all leading margin spans. Adjust left or right according
448 // to the paragraph direction of the line.
449 final int length = spans.length;
450 boolean useFirstLineMargin = isFirstParaLine;
451 for (int n = 0; n < length; n++) {
452 if (spans[n] instanceof LeadingMarginSpan2) {
453 int count = ((LeadingMarginSpan2) spans[n]).getLeadingMarginLineCount();
454 int startLine = getLineForOffset(sp.getSpanStart(spans[n]));
455 // if there is more than one LeadingMarginSpan2, use
456 // the count that is greatest
457 if (lineNum < startLine + count) {
458 useFirstLineMargin = true;
463 for (int n = 0; n < length; n++) {
464 if (spans[n] instanceof LeadingMarginSpan) {
465 LeadingMarginSpan margin = (LeadingMarginSpan) spans[n];
466 if (dir == DIR_RIGHT_TO_LEFT) {
467 margin.drawLeadingMargin(canvas, paint, right, dir, ltop,
468 lbaseline, lbottom, buf,
469 start, end, isFirstParaLine, this);
470 right -= margin.getLeadingMargin(useFirstLineMargin);
472 margin.drawLeadingMargin(canvas, paint, left, dir, ltop,
473 lbaseline, lbottom, buf,
474 start, end, isFirstParaLine, this);
475 left += margin.getLeadingMargin(useFirstLineMargin);
481 boolean hasTab = getLineContainsTab(lineNum);
482 // Can't tell if we have tabs for sure, currently
483 if (hasTab && !tabStopsIsInitialized) {
484 if (tabStops == null) {
485 tabStops = new TabStops(TAB_INCREMENT, spans);
487 tabStops.reset(TAB_INCREMENT, spans);
489 tabStopsIsInitialized = true;
492 // Determine whether the line aligns to normal, opposite, or center.
493 Alignment align = paraAlign;
494 if (align == Alignment.ALIGN_LEFT) {
495 align = (dir == DIR_LEFT_TO_RIGHT) ?
496 Alignment.ALIGN_NORMAL : Alignment.ALIGN_OPPOSITE;
497 } else if (align == Alignment.ALIGN_RIGHT) {
498 align = (dir == DIR_LEFT_TO_RIGHT) ?
499 Alignment.ALIGN_OPPOSITE : Alignment.ALIGN_NORMAL;
503 final int indentWidth;
504 if (align == Alignment.ALIGN_NORMAL) {
505 if (dir == DIR_LEFT_TO_RIGHT) {
506 indentWidth = getIndentAdjust(lineNum, Alignment.ALIGN_LEFT);
507 x = left + indentWidth;
509 indentWidth = -getIndentAdjust(lineNum, Alignment.ALIGN_RIGHT);
510 x = right - indentWidth;
513 int max = (int)getLineExtent(lineNum, tabStops, false);
514 if (align == Alignment.ALIGN_OPPOSITE) {
515 if (dir == DIR_LEFT_TO_RIGHT) {
516 indentWidth = -getIndentAdjust(lineNum, Alignment.ALIGN_RIGHT);
517 x = right - max - indentWidth;
519 indentWidth = getIndentAdjust(lineNum, Alignment.ALIGN_LEFT);
520 x = left - max + indentWidth;
522 } else { // Alignment.ALIGN_CENTER
523 indentWidth = getIndentAdjust(lineNum, Alignment.ALIGN_CENTER);
525 x = ((right + left - max) >> 1) + indentWidth;
529 paint.setHyphenEdit(getHyphen(lineNum));
530 Directions directions = getLineDirections(lineNum);
531 if (directions == DIRS_ALL_LEFT_TO_RIGHT && !mSpannedText && !hasTab && !justify) {
532 // XXX: assumes there's nothing additional to be done
533 canvas.drawText(buf, start, end, x, lbaseline, paint);
535 tl.set(paint, buf, start, end, dir, directions, hasTab, tabStops);
537 tl.justify(right - left - indentWidth);
539 tl.draw(canvas, x, ltop, lbaseline, lbottom);
541 paint.setHyphenEdit(0);
544 TextLine.recycle(tl);
550 public void drawBackground(Canvas canvas, Path highlight, Paint highlightPaint,
551 int cursorOffsetVertical, int firstLine, int lastLine) {
552 // First, draw LineBackgroundSpans.
553 // LineBackgroundSpans know nothing about the alignment, margins, or
554 // direction of the layout or line. XXX: Should they?
555 // They are evaluated at each line.
557 if (mLineBackgroundSpans == null) {
558 mLineBackgroundSpans = new SpanSet<LineBackgroundSpan>(LineBackgroundSpan.class);
561 Spanned buffer = (Spanned) mText;
562 int textLength = buffer.length();
563 mLineBackgroundSpans.init(buffer, 0, textLength);
565 if (mLineBackgroundSpans.numberOfSpans > 0) {
566 int previousLineBottom = getLineTop(firstLine);
567 int previousLineEnd = getLineStart(firstLine);
568 ParagraphStyle[] spans = NO_PARA_SPANS;
570 TextPaint paint = mPaint;
572 final int width = mWidth;
573 for (int i = firstLine; i <= lastLine; i++) {
574 int start = previousLineEnd;
575 int end = getLineStart(i + 1);
576 previousLineEnd = end;
578 int ltop = previousLineBottom;
579 int lbottom = getLineTop(i + 1);
580 previousLineBottom = lbottom;
581 int lbaseline = lbottom - getLineDescent(i);
583 if (start >= spanEnd) {
584 // These should be infrequent, so we'll use this so that
585 // we don't have to check as often.
586 spanEnd = mLineBackgroundSpans.getNextTransition(start, textLength);
587 // All LineBackgroundSpans on a line contribute to its background.
589 // Duplication of the logic of getParagraphSpans
590 if (start != end || start == 0) {
591 // Equivalent to a getSpans(start, end), but filling the 'spans' local
592 // array instead to reduce memory allocation
593 for (int j = 0; j < mLineBackgroundSpans.numberOfSpans; j++) {
594 // equal test is valid since both intervals are not empty by
596 if (mLineBackgroundSpans.spanStarts[j] >= end ||
597 mLineBackgroundSpans.spanEnds[j] <= start) continue;
598 spans = GrowingArrayUtils.append(
599 spans, spansLength, mLineBackgroundSpans.spans[j]);
605 for (int n = 0; n < spansLength; n++) {
606 LineBackgroundSpan lineBackgroundSpan = (LineBackgroundSpan) spans[n];
607 lineBackgroundSpan.drawBackground(canvas, paint, 0, width,
608 ltop, lbaseline, lbottom,
609 buffer, start, end, i);
613 mLineBackgroundSpans.recycle();
616 // There can be a highlight even without spans if we are drawing
617 // a non-spanned transformation of a spanned editing buffer.
618 if (highlight != null) {
619 if (cursorOffsetVertical != 0) canvas.translate(0, cursorOffsetVertical);
620 canvas.drawPath(highlight, highlightPaint);
621 if (cursorOffsetVertical != 0) canvas.translate(0, -cursorOffsetVertical);
627 * @return The range of lines that need to be drawn, possibly empty.
630 public long getLineRangeForDraw(Canvas canvas) {
633 synchronized (sTempRect) {
634 if (!canvas.getClipBounds(sTempRect)) {
635 // Negative range end used as a special flag
636 return TextUtils.packRangeInLong(0, -1);
639 dtop = sTempRect.top;
640 dbottom = sTempRect.bottom;
643 final int top = Math.max(dtop, 0);
644 final int bottom = Math.min(getLineTop(getLineCount()), dbottom);
646 if (top >= bottom) return TextUtils.packRangeInLong(0, -1);
647 return TextUtils.packRangeInLong(getLineForVertical(top), getLineForVertical(bottom));
651 * Return the start position of the line, given the left and right bounds
654 * @param line the line index
655 * @param left the left bounds (0, or leading margin if ltr para)
656 * @param right the right bounds (width, minus leading margin if rtl para)
657 * @return the start position of the line (to right of line if rtl para)
659 private int getLineStartPos(int line, int left, int right) {
660 // Adjust the point at which to start rendering depending on the
661 // alignment of the paragraph.
662 Alignment align = getParagraphAlignment(line);
663 int dir = getParagraphDirection(line);
665 if (align == Alignment.ALIGN_LEFT) {
666 align = (dir == DIR_LEFT_TO_RIGHT) ? Alignment.ALIGN_NORMAL : Alignment.ALIGN_OPPOSITE;
667 } else if (align == Alignment.ALIGN_RIGHT) {
668 align = (dir == DIR_LEFT_TO_RIGHT) ? Alignment.ALIGN_OPPOSITE : Alignment.ALIGN_NORMAL;
672 if (align == Alignment.ALIGN_NORMAL) {
673 if (dir == DIR_LEFT_TO_RIGHT) {
674 x = left + getIndentAdjust(line, Alignment.ALIGN_LEFT);
676 x = right + getIndentAdjust(line, Alignment.ALIGN_RIGHT);
679 TabStops tabStops = null;
680 if (mSpannedText && getLineContainsTab(line)) {
681 Spanned spanned = (Spanned) mText;
682 int start = getLineStart(line);
683 int spanEnd = spanned.nextSpanTransition(start, spanned.length(),
685 TabStopSpan[] tabSpans = getParagraphSpans(spanned, start, spanEnd,
687 if (tabSpans.length > 0) {
688 tabStops = new TabStops(TAB_INCREMENT, tabSpans);
691 int max = (int)getLineExtent(line, tabStops, false);
692 if (align == Alignment.ALIGN_OPPOSITE) {
693 if (dir == DIR_LEFT_TO_RIGHT) {
694 x = right - max + getIndentAdjust(line, Alignment.ALIGN_RIGHT);
696 // max is negative here
697 x = left - max + getIndentAdjust(line, Alignment.ALIGN_LEFT);
699 } else { // Alignment.ALIGN_CENTER
701 x = (left + right - max) >> 1 + getIndentAdjust(line, Alignment.ALIGN_CENTER);
708 * Return the text that is displayed by this Layout.
710 public final CharSequence getText() {
715 * Return the base Paint properties for this layout.
716 * Do NOT change the paint, which may result in funny
717 * drawing for this layout.
719 public final TextPaint getPaint() {
724 * Return the width of this layout.
726 public final int getWidth() {
731 * Return the width to which this Layout is ellipsizing, or
732 * {@link #getWidth} if it is not doing anything special.
734 public int getEllipsizedWidth() {
739 * Increase the width of this layout to the specified width.
740 * Be careful to use this only when you know it is appropriate—
741 * it does not cause the text to reflow to use the full new width.
743 public final void increaseWidthTo(int wid) {
745 throw new RuntimeException("attempted to reduce Layout width");
752 * Return the total height of this layout.
754 public int getHeight() {
755 return getLineTop(getLineCount());
759 * Return the total height of this layout.
761 * @param cap if true and max lines is set, returns the height of the layout at the max lines.
765 public int getHeight(boolean cap) {
770 * Return the base alignment of this layout.
772 public final Alignment getAlignment() {
777 * Return what the text height is multiplied by to get the line height.
779 public final float getSpacingMultiplier() {
784 * Return the number of units of leading that are added to each line.
786 public final float getSpacingAdd() {
791 * Return the heuristic used to determine paragraph text direction.
794 public final TextDirectionHeuristic getTextDirectionHeuristic() {
799 * Return the number of lines of text in this layout.
801 public abstract int getLineCount();
804 * Return the baseline for the specified line (0…getLineCount() - 1)
805 * If bounds is not null, return the top, left, right, bottom extents
806 * of the specified line in it.
807 * @param line which line to examine (0..getLineCount() - 1)
808 * @param bounds Optional. If not null, it returns the extent of the line
809 * @return the Y-coordinate of the baseline
811 public int getLineBounds(int line, Rect bounds) {
812 if (bounds != null) {
813 bounds.left = 0; // ???
814 bounds.top = getLineTop(line);
815 bounds.right = mWidth; // ???
816 bounds.bottom = getLineTop(line + 1);
818 return getLineBaseline(line);
822 * Return the vertical position of the top of the specified line
823 * (0…getLineCount()).
824 * If the specified line is equal to the line count, returns the
825 * bottom of the last line.
827 public abstract int getLineTop(int line);
830 * Return the descent of the specified line(0…getLineCount() - 1).
832 public abstract int getLineDescent(int line);
835 * Return the text offset of the beginning of the specified line (
836 * 0…getLineCount()). If the specified line is equal to the line
837 * count, returns the length of the text.
839 public abstract int getLineStart(int line);
842 * Returns the primary directionality of the paragraph containing the
843 * specified line, either 1 for left-to-right lines, or -1 for right-to-left
844 * lines (see {@link #DIR_LEFT_TO_RIGHT}, {@link #DIR_RIGHT_TO_LEFT}).
846 public abstract int getParagraphDirection(int line);
849 * Returns whether the specified line contains one or more
850 * characters that need to be handled specially, like tabs.
852 public abstract boolean getLineContainsTab(int line);
855 * Returns the directional run information for the specified line.
856 * The array alternates counts of characters in left-to-right
857 * and right-to-left segments of the line.
859 * <p>NOTE: this is inadequate to support bidirectional text, and will change.
861 public abstract Directions getLineDirections(int line);
864 * Returns the (negative) number of extra pixels of ascent padding in the
865 * top line of the Layout.
867 public abstract int getTopPadding();
870 * Returns the number of extra pixels of descent padding in the
871 * bottom line of the Layout.
873 public abstract int getBottomPadding();
876 * Returns the hyphen edit for a line.
880 public int getHyphen(int line) {
885 * Returns the left indent for a line.
889 public int getIndentAdjust(int line, Alignment alignment) {
894 * Returns true if the character at offset and the preceding character
895 * are at different run levels (and thus there's a split caret).
896 * @param offset the offset
897 * @return true if at a level boundary
900 public boolean isLevelBoundary(int offset) {
901 int line = getLineForOffset(offset);
902 Directions dirs = getLineDirections(line);
903 if (dirs == DIRS_ALL_LEFT_TO_RIGHT || dirs == DIRS_ALL_RIGHT_TO_LEFT) {
907 int[] runs = dirs.mDirections;
908 int lineStart = getLineStart(line);
909 int lineEnd = getLineEnd(line);
910 if (offset == lineStart || offset == lineEnd) {
911 int paraLevel = getParagraphDirection(line) == 1 ? 0 : 1;
912 int runIndex = offset == lineStart ? 0 : runs.length - 2;
913 return ((runs[runIndex + 1] >>> RUN_LEVEL_SHIFT) & RUN_LEVEL_MASK) != paraLevel;
917 for (int i = 0; i < runs.length; i += 2) {
918 if (offset == runs[i]) {
926 * Returns true if the character at offset is right to left (RTL).
927 * @param offset the offset
928 * @return true if the character is RTL, false if it is LTR
930 public boolean isRtlCharAt(int offset) {
931 int line = getLineForOffset(offset);
932 Directions dirs = getLineDirections(line);
933 if (dirs == DIRS_ALL_LEFT_TO_RIGHT) {
936 if (dirs == DIRS_ALL_RIGHT_TO_LEFT) {
939 int[] runs = dirs.mDirections;
940 int lineStart = getLineStart(line);
941 for (int i = 0; i < runs.length; i += 2) {
942 int start = lineStart + runs[i];
943 int limit = start + (runs[i+1] & RUN_LENGTH_MASK);
944 if (offset >= start && offset < limit) {
945 int level = (runs[i+1] >>> RUN_LEVEL_SHIFT) & RUN_LEVEL_MASK;
946 return ((level & 1) != 0);
949 // Should happen only if the offset is "out of bounds"
954 * Returns the range of the run that the character at offset belongs to.
955 * @param offset the offset
956 * @return The range of the run
959 public long getRunRange(int offset) {
960 int line = getLineForOffset(offset);
961 Directions dirs = getLineDirections(line);
962 if (dirs == DIRS_ALL_LEFT_TO_RIGHT || dirs == DIRS_ALL_RIGHT_TO_LEFT) {
963 return TextUtils.packRangeInLong(0, getLineEnd(line));
965 int[] runs = dirs.mDirections;
966 int lineStart = getLineStart(line);
967 for (int i = 0; i < runs.length; i += 2) {
968 int start = lineStart + runs[i];
969 int limit = start + (runs[i+1] & RUN_LENGTH_MASK);
970 if (offset >= start && offset < limit) {
971 return TextUtils.packRangeInLong(start, limit);
974 // Should happen only if the offset is "out of bounds"
975 return TextUtils.packRangeInLong(0, getLineEnd(line));
978 private boolean primaryIsTrailingPrevious(int offset) {
979 int line = getLineForOffset(offset);
980 int lineStart = getLineStart(line);
981 int lineEnd = getLineEnd(line);
982 int[] runs = getLineDirections(line).mDirections;
985 for (int i = 0; i < runs.length; i += 2) {
986 int start = lineStart + runs[i];
987 int limit = start + (runs[i+1] & RUN_LENGTH_MASK);
988 if (limit > lineEnd) {
991 if (offset >= start && offset < limit) {
992 if (offset > start) {
993 // Previous character is at same level, so don't use trailing.
996 levelAt = (runs[i+1] >>> RUN_LEVEL_SHIFT) & RUN_LEVEL_MASK;
1000 if (levelAt == -1) {
1001 // Offset was limit of line.
1002 levelAt = getParagraphDirection(line) == 1 ? 0 : 1;
1005 // At level boundary, check previous level.
1006 int levelBefore = -1;
1007 if (offset == lineStart) {
1008 levelBefore = getParagraphDirection(line) == 1 ? 0 : 1;
1011 for (int i = 0; i < runs.length; i += 2) {
1012 int start = lineStart + runs[i];
1013 int limit = start + (runs[i+1] & RUN_LENGTH_MASK);
1014 if (limit > lineEnd) {
1017 if (offset >= start && offset < limit) {
1018 levelBefore = (runs[i+1] >>> RUN_LEVEL_SHIFT) & RUN_LEVEL_MASK;
1024 return levelBefore < levelAt;
1028 * Get the primary horizontal position for the specified text offset.
1029 * This is the location where a new character would be inserted in
1030 * the paragraph's primary direction.
1032 public float getPrimaryHorizontal(int offset) {
1033 return getPrimaryHorizontal(offset, false /* not clamped */);
1037 * Get the primary horizontal position for the specified text offset, but
1038 * optionally clamp it so that it doesn't exceed the width of the layout.
1041 public float getPrimaryHorizontal(int offset, boolean clamped) {
1042 boolean trailing = primaryIsTrailingPrevious(offset);
1043 return getHorizontal(offset, trailing, clamped);
1047 * Get the secondary horizontal position for the specified text offset.
1048 * This is the location where a new character would be inserted in
1049 * the direction other than the paragraph's primary direction.
1051 public float getSecondaryHorizontal(int offset) {
1052 return getSecondaryHorizontal(offset, false /* not clamped */);
1056 * Get the secondary horizontal position for the specified text offset, but
1057 * optionally clamp it so that it doesn't exceed the width of the layout.
1060 public float getSecondaryHorizontal(int offset, boolean clamped) {
1061 boolean trailing = primaryIsTrailingPrevious(offset);
1062 return getHorizontal(offset, !trailing, clamped);
1065 private float getHorizontal(int offset, boolean primary) {
1066 return primary ? getPrimaryHorizontal(offset) : getSecondaryHorizontal(offset);
1069 private float getHorizontal(int offset, boolean trailing, boolean clamped) {
1070 int line = getLineForOffset(offset);
1072 return getHorizontal(offset, trailing, line, clamped);
1075 private float getHorizontal(int offset, boolean trailing, int line, boolean clamped) {
1076 int start = getLineStart(line);
1077 int end = getLineEnd(line);
1078 int dir = getParagraphDirection(line);
1079 boolean hasTab = getLineContainsTab(line);
1080 Directions directions = getLineDirections(line);
1082 TabStops tabStops = null;
1083 if (hasTab && mText instanceof Spanned) {
1084 // Just checking this line should be good enough, tabs should be
1085 // consistent across all lines in a paragraph.
1086 TabStopSpan[] tabs = getParagraphSpans((Spanned) mText, start, end, TabStopSpan.class);
1087 if (tabs.length > 0) {
1088 tabStops = new TabStops(TAB_INCREMENT, tabs); // XXX should reuse
1092 TextLine tl = TextLine.obtain();
1093 tl.set(mPaint, mText, start, end, dir, directions, hasTab, tabStops);
1094 float wid = tl.measure(offset - start, trailing, null);
1095 TextLine.recycle(tl);
1097 if (clamped && wid > mWidth) {
1100 int left = getParagraphLeft(line);
1101 int right = getParagraphRight(line);
1103 return getLineStartPos(line, left, right) + wid;
1107 * Get the leftmost position that should be exposed for horizontal
1108 * scrolling on the specified line.
1110 public float getLineLeft(int line) {
1111 int dir = getParagraphDirection(line);
1112 Alignment align = getParagraphAlignment(line);
1114 if (align == Alignment.ALIGN_LEFT) {
1116 } else if (align == Alignment.ALIGN_NORMAL) {
1117 if (dir == DIR_RIGHT_TO_LEFT)
1118 return getParagraphRight(line) - getLineMax(line);
1121 } else if (align == Alignment.ALIGN_RIGHT) {
1122 return mWidth - getLineMax(line);
1123 } else if (align == Alignment.ALIGN_OPPOSITE) {
1124 if (dir == DIR_RIGHT_TO_LEFT)
1127 return mWidth - getLineMax(line);
1128 } else { /* align == Alignment.ALIGN_CENTER */
1129 int left = getParagraphLeft(line);
1130 int right = getParagraphRight(line);
1131 int max = ((int) getLineMax(line)) & ~1;
1133 return left + ((right - left) - max) / 2;
1138 * Get the rightmost position that should be exposed for horizontal
1139 * scrolling on the specified line.
1141 public float getLineRight(int line) {
1142 int dir = getParagraphDirection(line);
1143 Alignment align = getParagraphAlignment(line);
1145 if (align == Alignment.ALIGN_LEFT) {
1146 return getParagraphLeft(line) + getLineMax(line);
1147 } else if (align == Alignment.ALIGN_NORMAL) {
1148 if (dir == DIR_RIGHT_TO_LEFT)
1151 return getParagraphLeft(line) + getLineMax(line);
1152 } else if (align == Alignment.ALIGN_RIGHT) {
1154 } else if (align == Alignment.ALIGN_OPPOSITE) {
1155 if (dir == DIR_RIGHT_TO_LEFT)
1156 return getLineMax(line);
1159 } else { /* align == Alignment.ALIGN_CENTER */
1160 int left = getParagraphLeft(line);
1161 int right = getParagraphRight(line);
1162 int max = ((int) getLineMax(line)) & ~1;
1164 return right - ((right - left) - max) / 2;
1169 * Gets the unsigned horizontal extent of the specified line, including
1170 * leading margin indent, but excluding trailing whitespace.
1172 public float getLineMax(int line) {
1173 float margin = getParagraphLeadingMargin(line);
1174 float signedExtent = getLineExtent(line, false);
1175 return margin + (signedExtent >= 0 ? signedExtent : -signedExtent);
1179 * Gets the unsigned horizontal extent of the specified line, including
1180 * leading margin indent and trailing whitespace.
1182 public float getLineWidth(int line) {
1183 float margin = getParagraphLeadingMargin(line);
1184 float signedExtent = getLineExtent(line, true);
1185 return margin + (signedExtent >= 0 ? signedExtent : -signedExtent);
1189 * Like {@link #getLineExtent(int,TabStops,boolean)} but determines the
1190 * tab stops instead of using the ones passed in.
1191 * @param line the index of the line
1192 * @param full whether to include trailing whitespace
1193 * @return the extent of the line
1195 private float getLineExtent(int line, boolean full) {
1196 int start = getLineStart(line);
1197 int end = full ? getLineEnd(line) : getLineVisibleEnd(line);
1199 boolean hasTabs = getLineContainsTab(line);
1200 TabStops tabStops = null;
1201 if (hasTabs && mText instanceof Spanned) {
1202 // Just checking this line should be good enough, tabs should be
1203 // consistent across all lines in a paragraph.
1204 TabStopSpan[] tabs = getParagraphSpans((Spanned) mText, start, end, TabStopSpan.class);
1205 if (tabs.length > 0) {
1206 tabStops = new TabStops(TAB_INCREMENT, tabs); // XXX should reuse
1209 Directions directions = getLineDirections(line);
1210 // Returned directions can actually be null
1211 if (directions == null) {
1214 int dir = getParagraphDirection(line);
1216 TextLine tl = TextLine.obtain();
1217 mPaint.setHyphenEdit(getHyphen(line));
1218 tl.set(mPaint, mText, start, end, dir, directions, hasTabs, tabStops);
1219 if (isJustificationRequired(line)) {
1220 tl.justify(getJustifyWidth(line));
1222 float width = tl.metrics(null);
1223 mPaint.setHyphenEdit(0);
1224 TextLine.recycle(tl);
1229 * Returns the signed horizontal extent of the specified line, excluding
1230 * leading margin. If full is false, excludes trailing whitespace.
1231 * @param line the index of the line
1232 * @param tabStops the tab stops, can be null if we know they're not used.
1233 * @param full whether to include trailing whitespace
1234 * @return the extent of the text on this line
1236 private float getLineExtent(int line, TabStops tabStops, boolean full) {
1237 int start = getLineStart(line);
1238 int end = full ? getLineEnd(line) : getLineVisibleEnd(line);
1239 boolean hasTabs = getLineContainsTab(line);
1240 Directions directions = getLineDirections(line);
1241 int dir = getParagraphDirection(line);
1243 TextLine tl = TextLine.obtain();
1244 mPaint.setHyphenEdit(getHyphen(line));
1245 tl.set(mPaint, mText, start, end, dir, directions, hasTabs, tabStops);
1246 if (isJustificationRequired(line)) {
1247 tl.justify(getJustifyWidth(line));
1249 float width = tl.metrics(null);
1250 mPaint.setHyphenEdit(0);
1251 TextLine.recycle(tl);
1256 * Get the line number corresponding to the specified vertical position.
1257 * If you ask for a position above 0, you get 0; if you ask for a position
1258 * below the bottom of the text, you get the last line.
1260 // FIXME: It may be faster to do a linear search for layouts without many lines.
1261 public int getLineForVertical(int vertical) {
1262 int high = getLineCount(), low = -1, guess;
1264 while (high - low > 1) {
1265 guess = (high + low) / 2;
1267 if (getLineTop(guess) > vertical)
1280 * Get the line number on which the specified text offset appears.
1281 * If you ask for a position before 0, you get 0; if you ask for a position
1282 * beyond the end of the text, you get the last line.
1284 public int getLineForOffset(int offset) {
1285 int high = getLineCount(), low = -1, guess;
1287 while (high - low > 1) {
1288 guess = (high + low) / 2;
1290 if (getLineStart(guess) > offset)
1304 * Get the character offset on the specified line whose position is
1305 * closest to the specified horizontal position.
1307 public int getOffsetForHorizontal(int line, float horiz) {
1308 return getOffsetForHorizontal(line, horiz, true);
1312 * Get the character offset on the specified line whose position is
1313 * closest to the specified horizontal position.
1315 * @param line the line used to find the closest offset
1316 * @param horiz the horizontal position used to find the closest offset
1317 * @param primary whether to use the primary position or secondary position to find the offset
1321 public int getOffsetForHorizontal(int line, float horiz, boolean primary) {
1322 // TODO: use Paint.getOffsetForAdvance to avoid binary search
1323 final int lineEndOffset = getLineEnd(line);
1324 final int lineStartOffset = getLineStart(line);
1326 Directions dirs = getLineDirections(line);
1328 TextLine tl = TextLine.obtain();
1329 // XXX: we don't care about tabs as we just use TextLine#getOffsetToLeftRightOf here.
1330 tl.set(mPaint, mText, lineStartOffset, lineEndOffset, getParagraphDirection(line), dirs,
1334 if (line == getLineCount() - 1) {
1335 max = lineEndOffset;
1337 max = tl.getOffsetToLeftRightOf(lineEndOffset - lineStartOffset,
1338 !isRtlCharAt(lineEndOffset - 1)) + lineStartOffset;
1340 int best = lineStartOffset;
1341 float bestdist = Math.abs(getHorizontal(best, primary) - horiz);
1343 for (int i = 0; i < dirs.mDirections.length; i += 2) {
1344 int here = lineStartOffset + dirs.mDirections[i];
1345 int there = here + (dirs.mDirections[i+1] & RUN_LENGTH_MASK);
1346 boolean isRtl = (dirs.mDirections[i+1] & RUN_RTL_FLAG) != 0;
1347 int swap = isRtl ? -1 : 1;
1351 int high = there - 1 + 1, low = here + 1 - 1, guess;
1353 while (high - low > 1) {
1354 guess = (high + low) / 2;
1355 int adguess = getOffsetAtStartOf(guess);
1357 if (getHorizontal(adguess, primary) * swap >= horiz * swap) {
1368 int aft = tl.getOffsetToLeftRightOf(low - lineStartOffset, isRtl) + lineStartOffset;
1369 low = tl.getOffsetToLeftRightOf(aft - lineStartOffset, !isRtl) + lineStartOffset;
1370 if (low >= here && low < there) {
1371 float dist = Math.abs(getHorizontal(low, primary) - horiz);
1373 float other = Math.abs(getHorizontal(aft, primary) - horiz);
1381 if (dist < bestdist) {
1388 float dist = Math.abs(getHorizontal(here, primary) - horiz);
1390 if (dist < bestdist) {
1396 float dist = Math.abs(getHorizontal(max, primary) - horiz);
1398 if (dist <= bestdist) {
1403 TextLine.recycle(tl);
1408 * Return the text offset after the last character on the specified line.
1410 public final int getLineEnd(int line) {
1411 return getLineStart(line + 1);
1415 * Return the text offset after the last visible character (so whitespace
1416 * is not counted) on the specified line.
1418 public int getLineVisibleEnd(int line) {
1419 return getLineVisibleEnd(line, getLineStart(line), getLineStart(line+1));
1422 private int getLineVisibleEnd(int line, int start, int end) {
1423 CharSequence text = mText;
1425 if (line == getLineCount() - 1) {
1429 for (; end > start; end--) {
1430 ch = text.charAt(end - 1);
1436 if (!TextLine.isLineEndSpace(ch)) {
1446 * Return the vertical position of the bottom of the specified line.
1448 public final int getLineBottom(int line) {
1449 return getLineTop(line + 1);
1453 * Return the vertical position of the baseline of the specified line.
1455 public final int getLineBaseline(int line) {
1456 // getLineTop(line+1) == getLineTop(line)
1457 return getLineTop(line+1) - getLineDescent(line);
1461 * Get the ascent of the text on the specified line.
1462 * The return value is negative to match the Paint.ascent() convention.
1464 public final int getLineAscent(int line) {
1465 // getLineTop(line+1) - getLineDescent(line) == getLineBaseLine(line)
1466 return getLineTop(line) - (getLineTop(line+1) - getLineDescent(line));
1469 public int getOffsetToLeftOf(int offset) {
1470 return getOffsetToLeftRightOf(offset, true);
1473 public int getOffsetToRightOf(int offset) {
1474 return getOffsetToLeftRightOf(offset, false);
1477 private int getOffsetToLeftRightOf(int caret, boolean toLeft) {
1478 int line = getLineForOffset(caret);
1479 int lineStart = getLineStart(line);
1480 int lineEnd = getLineEnd(line);
1481 int lineDir = getParagraphDirection(line);
1483 boolean lineChanged = false;
1484 boolean advance = toLeft == (lineDir == DIR_RIGHT_TO_LEFT);
1485 // if walking off line, look at the line we're headed to
1487 if (caret == lineEnd) {
1488 if (line < getLineCount() - 1) {
1492 return caret; // at very end, don't move
1496 if (caret == lineStart) {
1501 return caret; // at very start, don't move
1507 lineStart = getLineStart(line);
1508 lineEnd = getLineEnd(line);
1509 int newDir = getParagraphDirection(line);
1510 if (newDir != lineDir) {
1511 // unusual case. we want to walk onto the line, but it runs
1512 // in a different direction than this one, so we fake movement
1513 // in the opposite direction.
1519 Directions directions = getLineDirections(line);
1521 TextLine tl = TextLine.obtain();
1522 // XXX: we don't care about tabs
1523 tl.set(mPaint, mText, lineStart, lineEnd, lineDir, directions, false, null);
1524 caret = lineStart + tl.getOffsetToLeftRightOf(caret - lineStart, toLeft);
1525 tl = TextLine.recycle(tl);
1529 private int getOffsetAtStartOf(int offset) {
1530 // XXX this probably should skip local reorderings and
1531 // zero-width characters, look at callers
1535 CharSequence text = mText;
1536 char c = text.charAt(offset);
1538 if (c >= '\uDC00' && c <= '\uDFFF') {
1539 char c1 = text.charAt(offset - 1);
1541 if (c1 >= '\uD800' && c1 <= '\uDBFF')
1546 ReplacementSpan[] spans = ((Spanned) text).getSpans(offset, offset,
1547 ReplacementSpan.class);
1549 for (int i = 0; i < spans.length; i++) {
1550 int start = ((Spanned) text).getSpanStart(spans[i]);
1551 int end = ((Spanned) text).getSpanEnd(spans[i]);
1553 if (start < offset && end > offset)
1562 * Determine whether we should clamp cursor position. Currently it's
1563 * only robust for left-aligned displays.
1566 public boolean shouldClampCursor(int line) {
1567 // Only clamp cursor position in left-aligned displays.
1568 switch (getParagraphAlignment(line)) {
1572 return getParagraphDirection(line) > 0;
1579 * Fills in the specified Path with a representation of a cursor
1580 * at the specified offset. This will often be a vertical line
1581 * but can be multiple discontinuous lines in text with multiple
1584 public void getCursorPath(int point, Path dest,
1585 CharSequence editingBuffer) {
1588 int line = getLineForOffset(point);
1589 int top = getLineTop(line);
1590 int bottom = getLineTop(line+1);
1592 boolean clamped = shouldClampCursor(line);
1593 float h1 = getPrimaryHorizontal(point, clamped) - 0.5f;
1594 float h2 = isLevelBoundary(point) ? getSecondaryHorizontal(point, clamped) - 0.5f : h1;
1596 int caps = TextKeyListener.getMetaState(editingBuffer, TextKeyListener.META_SHIFT_ON) |
1597 TextKeyListener.getMetaState(editingBuffer, TextKeyListener.META_SELECTING);
1598 int fn = TextKeyListener.getMetaState(editingBuffer, TextKeyListener.META_ALT_ON);
1601 if (caps != 0 || fn != 0) {
1602 dist = (bottom - top) >> 2;
1615 if (Float.compare(h1, h2) == 0) {
1616 dest.moveTo(h1, top);
1617 dest.lineTo(h1, bottom);
1619 dest.moveTo(h1, top);
1620 dest.lineTo(h1, (top + bottom) >> 1);
1622 dest.moveTo(h2, (top + bottom) >> 1);
1623 dest.lineTo(h2, bottom);
1627 dest.moveTo(h2, bottom);
1628 dest.lineTo(h2 - dist, bottom + dist);
1629 dest.lineTo(h2, bottom);
1630 dest.lineTo(h2 + dist, bottom + dist);
1631 } else if (caps == 1) {
1632 dest.moveTo(h2, bottom);
1633 dest.lineTo(h2 - dist, bottom + dist);
1635 dest.moveTo(h2 - dist, bottom + dist - 0.5f);
1636 dest.lineTo(h2 + dist, bottom + dist - 0.5f);
1638 dest.moveTo(h2 + dist, bottom + dist);
1639 dest.lineTo(h2, bottom);
1643 dest.moveTo(h1, top);
1644 dest.lineTo(h1 - dist, top - dist);
1645 dest.lineTo(h1, top);
1646 dest.lineTo(h1 + dist, top - dist);
1647 } else if (fn == 1) {
1648 dest.moveTo(h1, top);
1649 dest.lineTo(h1 - dist, top - dist);
1651 dest.moveTo(h1 - dist, top - dist + 0.5f);
1652 dest.lineTo(h1 + dist, top - dist + 0.5f);
1654 dest.moveTo(h1 + dist, top - dist);
1655 dest.lineTo(h1, top);
1659 private void addSelection(int line, int start, int end,
1660 int top, int bottom, Path dest) {
1661 int linestart = getLineStart(line);
1662 int lineend = getLineEnd(line);
1663 Directions dirs = getLineDirections(line);
1665 if (lineend > linestart && mText.charAt(lineend - 1) == '\n')
1668 for (int i = 0; i < dirs.mDirections.length; i += 2) {
1669 int here = linestart + dirs.mDirections[i];
1670 int there = here + (dirs.mDirections[i+1] & RUN_LENGTH_MASK);
1672 if (there > lineend)
1675 if (start <= there && end >= here) {
1676 int st = Math.max(start, here);
1677 int en = Math.min(end, there);
1680 float h1 = getHorizontal(st, false, line, false /* not clamped */);
1681 float h2 = getHorizontal(en, true, line, false /* not clamped */);
1683 float left = Math.min(h1, h2);
1684 float right = Math.max(h1, h2);
1686 dest.addRect(left, top, right, bottom, Path.Direction.CW);
1693 * Fills in the specified Path with a representation of a highlight
1694 * between the specified offsets. This will often be a rectangle
1695 * or a potentially discontinuous set of rectangles. If the start
1696 * and end are the same, the returned path is empty.
1698 public void getSelectionPath(int start, int end, Path dest) {
1710 int startline = getLineForOffset(start);
1711 int endline = getLineForOffset(end);
1713 int top = getLineTop(startline);
1714 int bottom = getLineBottom(endline);
1716 if (startline == endline) {
1717 addSelection(startline, start, end, top, bottom, dest);
1719 final float width = mWidth;
1721 addSelection(startline, start, getLineEnd(startline),
1722 top, getLineBottom(startline), dest);
1724 if (getParagraphDirection(startline) == DIR_RIGHT_TO_LEFT)
1725 dest.addRect(getLineLeft(startline), top,
1726 0, getLineBottom(startline), Path.Direction.CW);
1728 dest.addRect(getLineRight(startline), top,
1729 width, getLineBottom(startline), Path.Direction.CW);
1731 for (int i = startline + 1; i < endline; i++) {
1732 top = getLineTop(i);
1733 bottom = getLineBottom(i);
1734 dest.addRect(0, top, width, bottom, Path.Direction.CW);
1737 top = getLineTop(endline);
1738 bottom = getLineBottom(endline);
1740 addSelection(endline, getLineStart(endline), end,
1743 if (getParagraphDirection(endline) == DIR_RIGHT_TO_LEFT)
1744 dest.addRect(width, top, getLineRight(endline), bottom, Path.Direction.CW);
1746 dest.addRect(0, top, getLineLeft(endline), bottom, Path.Direction.CW);
1751 * Get the alignment of the specified paragraph, taking into account
1752 * markup attached to it.
1754 public final Alignment getParagraphAlignment(int line) {
1755 Alignment align = mAlignment;
1758 Spanned sp = (Spanned) mText;
1759 AlignmentSpan[] spans = getParagraphSpans(sp, getLineStart(line),
1761 AlignmentSpan.class);
1763 int spanLength = spans.length;
1764 if (spanLength > 0) {
1765 align = spans[spanLength-1].getAlignment();
1773 * Get the left edge of the specified paragraph, inset by left margins.
1775 public final int getParagraphLeft(int line) {
1777 int dir = getParagraphDirection(line);
1778 if (dir == DIR_RIGHT_TO_LEFT || !mSpannedText) {
1779 return left; // leading margin has no impact, or no styles
1781 return getParagraphLeadingMargin(line);
1785 * Get the right edge of the specified paragraph, inset by right margins.
1787 public final int getParagraphRight(int line) {
1789 int dir = getParagraphDirection(line);
1790 if (dir == DIR_LEFT_TO_RIGHT || !mSpannedText) {
1791 return right; // leading margin has no impact, or no styles
1793 return right - getParagraphLeadingMargin(line);
1797 * Returns the effective leading margin (unsigned) for this line,
1798 * taking into account LeadingMarginSpan and LeadingMarginSpan2.
1799 * @param line the line index
1800 * @return the leading margin of this line
1802 private int getParagraphLeadingMargin(int line) {
1803 if (!mSpannedText) {
1806 Spanned spanned = (Spanned) mText;
1808 int lineStart = getLineStart(line);
1809 int lineEnd = getLineEnd(line);
1810 int spanEnd = spanned.nextSpanTransition(lineStart, lineEnd,
1811 LeadingMarginSpan.class);
1812 LeadingMarginSpan[] spans = getParagraphSpans(spanned, lineStart, spanEnd,
1813 LeadingMarginSpan.class);
1814 if (spans.length == 0) {
1815 return 0; // no leading margin span;
1820 boolean isFirstParaLine = lineStart == 0 ||
1821 spanned.charAt(lineStart - 1) == '\n';
1823 boolean useFirstLineMargin = isFirstParaLine;
1824 for (int i = 0; i < spans.length; i++) {
1825 if (spans[i] instanceof LeadingMarginSpan2) {
1826 int spStart = spanned.getSpanStart(spans[i]);
1827 int spanLine = getLineForOffset(spStart);
1828 int count = ((LeadingMarginSpan2) spans[i]).getLeadingMarginLineCount();
1829 // if there is more than one LeadingMarginSpan2, use the count that is greatest
1830 useFirstLineMargin |= line < spanLine + count;
1833 for (int i = 0; i < spans.length; i++) {
1834 LeadingMarginSpan span = spans[i];
1835 margin += span.getLeadingMargin(useFirstLineMargin);
1842 static float measurePara(TextPaint paint, CharSequence text, int start, int end,
1843 TextDirectionHeuristic textDir) {
1844 MeasuredText mt = MeasuredText.obtain();
1845 TextLine tl = TextLine.obtain();
1847 mt.setPara(text, start, end, textDir, null);
1848 Directions directions;
1851 directions = DIRS_ALL_LEFT_TO_RIGHT;
1852 dir = Layout.DIR_LEFT_TO_RIGHT;
1854 directions = AndroidBidi.directions(mt.mDir, mt.mLevels,
1855 0, mt.mChars, 0, mt.mLen);
1858 char[] chars = mt.mChars;
1860 boolean hasTabs = false;
1861 TabStops tabStops = null;
1862 // leading margins should be taken into account when measuring a paragraph
1864 if (text instanceof Spanned) {
1865 Spanned spanned = (Spanned) text;
1866 LeadingMarginSpan[] spans = getParagraphSpans(spanned, start, end,
1867 LeadingMarginSpan.class);
1868 for (LeadingMarginSpan lms : spans) {
1869 margin += lms.getLeadingMargin(true);
1872 for (int i = 0; i < len; ++i) {
1873 if (chars[i] == '\t') {
1875 if (text instanceof Spanned) {
1876 Spanned spanned = (Spanned) text;
1877 int spanEnd = spanned.nextSpanTransition(start, end,
1879 TabStopSpan[] spans = getParagraphSpans(spanned, start, spanEnd,
1881 if (spans.length > 0) {
1882 tabStops = new TabStops(TAB_INCREMENT, spans);
1888 tl.set(paint, text, start, end, dir, directions, hasTabs, tabStops);
1889 return margin + Math.abs(tl.metrics(null));
1891 TextLine.recycle(tl);
1892 MeasuredText.recycle(mt);
1899 /* package */ static class TabStops {
1900 private int[] mStops;
1901 private int mNumStops;
1902 private int mIncrement;
1904 TabStops(int increment, Object[] spans) {
1905 reset(increment, spans);
1908 void reset(int increment, Object[] spans) {
1909 this.mIncrement = increment;
1912 if (spans != null) {
1913 int[] stops = this.mStops;
1914 for (Object o : spans) {
1915 if (o instanceof TabStopSpan) {
1916 if (stops == null) {
1917 stops = new int[10];
1918 } else if (ns == stops.length) {
1919 int[] nstops = new int[ns * 2];
1920 for (int i = 0; i < ns; ++i) {
1921 nstops[i] = stops[i];
1925 stops[ns++] = ((TabStopSpan) o).getTabStop();
1929 Arrays.sort(stops, 0, ns);
1931 if (stops != this.mStops) {
1932 this.mStops = stops;
1935 this.mNumStops = ns;
1938 float nextTab(float h) {
1939 int ns = this.mNumStops;
1941 int[] stops = this.mStops;
1942 for (int i = 0; i < ns; ++i) {
1943 int stop = stops[i];
1949 return nextDefaultStop(h, mIncrement);
1952 public static float nextDefaultStop(float h, int inc) {
1953 return ((int) ((h + inc) / inc)) * inc;
1958 * Returns the position of the next tab stop after h on the line.
1960 * @param text the text
1961 * @param start start of the line
1962 * @param end limit of the line
1963 * @param h the current horizontal offset
1964 * @param tabs the tabs, can be null. If it is null, any tabs in effect
1965 * on the line will be used. If there are no tabs, a default offset
1966 * will be used to compute the tab stop.
1967 * @return the offset of the next tab stop.
1969 /* package */ static float nextTab(CharSequence text, int start, int end,
1970 float h, Object[] tabs) {
1971 float nh = Float.MAX_VALUE;
1972 boolean alltabs = false;
1974 if (text instanceof Spanned) {
1976 tabs = getParagraphSpans((Spanned) text, start, end, TabStopSpan.class);
1980 for (int i = 0; i < tabs.length; i++) {
1982 if (!(tabs[i] instanceof TabStopSpan))
1986 int where = ((TabStopSpan) tabs[i]).getTabStop();
1988 if (where < nh && where > h)
1992 if (nh != Float.MAX_VALUE)
1996 return ((int) ((h + TAB_INCREMENT) / TAB_INCREMENT)) * TAB_INCREMENT;
1999 protected final boolean isSpanned() {
2000 return mSpannedText;
2004 * Returns the same as <code>text.getSpans()</code>, except where
2005 * <code>start</code> and <code>end</code> are the same and are not
2006 * at the very beginning of the text, in which case an empty array
2007 * is returned instead.
2009 * This is needed because of the special case that <code>getSpans()</code>
2010 * on an empty range returns the spans adjacent to that range, which is
2011 * primarily for the sake of <code>TextWatchers</code> so they will get
2012 * notifications when text goes from empty to non-empty. But it also
2013 * has the unfortunate side effect that if the text ends with an empty
2014 * paragraph, that paragraph accidentally picks up the styles of the
2015 * preceding paragraph (even though those styles will not be picked up
2016 * by new text that is inserted into the empty paragraph).
2018 * The reason it just checks whether <code>start</code> and <code>end</code>
2019 * is the same is that the only time a line can contain 0 characters
2020 * is if it is the final paragraph of the Layout; otherwise any line will
2021 * contain at least one printing or newline character. The reason for the
2022 * additional check if <code>start</code> is greater than 0 is that
2023 * if the empty paragraph is the entire content of the buffer, paragraph
2024 * styles that are already applied to the buffer will apply to text that
2025 * is inserted into it.
2027 /* package */static <T> T[] getParagraphSpans(Spanned text, int start, int end, Class<T> type) {
2028 if (start == end && start > 0) {
2029 return ArrayUtils.emptyArray(type);
2032 if(text instanceof SpannableStringBuilder) {
2033 return ((SpannableStringBuilder) text).getSpans(start, end, type, false);
2035 return text.getSpans(start, end, type);
2039 private char getEllipsisChar(TextUtils.TruncateAt method) {
2040 return (method == TextUtils.TruncateAt.END_SMALL) ?
2041 TextUtils.ELLIPSIS_TWO_DOTS[0] :
2042 TextUtils.ELLIPSIS_NORMAL[0];
2045 private void ellipsize(int start, int end, int line,
2046 char[] dest, int destoff, TextUtils.TruncateAt method) {
2047 int ellipsisCount = getEllipsisCount(line);
2049 if (ellipsisCount == 0) {
2053 int ellipsisStart = getEllipsisStart(line);
2054 int linestart = getLineStart(line);
2056 for (int i = ellipsisStart; i < ellipsisStart + ellipsisCount; i++) {
2059 if (i == ellipsisStart) {
2060 c = getEllipsisChar(method); // ellipsis
2062 c = '\uFEFF'; // 0-width space
2065 int a = i + linestart;
2067 if (a >= start && a < end) {
2068 dest[destoff + a - start] = c;
2074 * Stores information about bidirectional (left-to-right or right-to-left)
2075 * text within the layout of a line.
2077 public static class Directions {
2078 // Directions represents directional runs within a line of text.
2079 // Runs are pairs of ints listed in visual order, starting from the
2080 // leading margin. The first int of each pair is the offset from
2081 // the first character of the line to the start of the run. The
2082 // second int represents both the length and level of the run.
2083 // The length is in the lower bits, accessed by masking with
2084 // DIR_LENGTH_MASK. The level is in the higher bits, accessed
2085 // by shifting by DIR_LEVEL_SHIFT and masking by DIR_LEVEL_MASK.
2086 // To simply test for an RTL direction, test the bit using
2087 // DIR_RTL_FLAG, if set then the direction is rtl.
2092 @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
2093 public int[] mDirections;
2098 @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
2099 public Directions(int[] dirs) {
2105 * Return the offset of the first character to be ellipsized away,
2106 * relative to the start of the line. (So 0 if the beginning of the
2107 * line is ellipsized, not getLineStart().)
2109 public abstract int getEllipsisStart(int line);
2112 * Returns the number of characters to be ellipsized away, or 0 if
2113 * no ellipsis is to take place.
2115 public abstract int getEllipsisCount(int line);
2117 /* package */ static class Ellipsizer implements CharSequence, GetChars {
2118 /* package */ CharSequence mText;
2119 /* package */ Layout mLayout;
2120 /* package */ int mWidth;
2121 /* package */ TextUtils.TruncateAt mMethod;
2123 public Ellipsizer(CharSequence s) {
2127 public char charAt(int off) {
2128 char[] buf = TextUtils.obtain(1);
2129 getChars(off, off + 1, buf, 0);
2132 TextUtils.recycle(buf);
2136 public void getChars(int start, int end, char[] dest, int destoff) {
2137 int line1 = mLayout.getLineForOffset(start);
2138 int line2 = mLayout.getLineForOffset(end);
2140 TextUtils.getChars(mText, start, end, dest, destoff);
2142 for (int i = line1; i <= line2; i++) {
2143 mLayout.ellipsize(start, end, i, dest, destoff, mMethod);
2147 public int length() {
2148 return mText.length();
2151 public CharSequence subSequence(int start, int end) {
2152 char[] s = new char[end - start];
2153 getChars(start, end, s, 0);
2154 return new String(s);
2158 public String toString() {
2159 char[] s = new char[length()];
2160 getChars(0, length(), s, 0);
2161 return new String(s);
2166 /* package */ static class SpannedEllipsizer extends Ellipsizer implements Spanned {
2167 private Spanned mSpanned;
2169 public SpannedEllipsizer(CharSequence display) {
2171 mSpanned = (Spanned) display;
2174 public <T> T[] getSpans(int start, int end, Class<T> type) {
2175 return mSpanned.getSpans(start, end, type);
2178 public int getSpanStart(Object tag) {
2179 return mSpanned.getSpanStart(tag);
2182 public int getSpanEnd(Object tag) {
2183 return mSpanned.getSpanEnd(tag);
2186 public int getSpanFlags(Object tag) {
2187 return mSpanned.getSpanFlags(tag);
2190 @SuppressWarnings("rawtypes")
2191 public int nextSpanTransition(int start, int limit, Class type) {
2192 return mSpanned.nextSpanTransition(start, limit, type);
2196 public CharSequence subSequence(int start, int end) {
2197 char[] s = new char[end - start];
2198 getChars(start, end, s, 0);
2200 SpannableString ss = new SpannableString(new String(s));
2201 TextUtils.copySpansFrom(mSpanned, start, end, Object.class, ss, 0);
2206 private CharSequence mText;
2207 private TextPaint mPaint;
2209 private Alignment mAlignment = Alignment.ALIGN_NORMAL;
2210 private float mSpacingMult;
2211 private float mSpacingAdd;
2212 private static final Rect sTempRect = new Rect();
2213 private boolean mSpannedText;
2214 private TextDirectionHeuristic mTextDir;
2215 private SpanSet<LineBackgroundSpan> mLineBackgroundSpans;
2216 private int mJustificationMode;
2218 public static final int DIR_LEFT_TO_RIGHT = 1;
2219 public static final int DIR_RIGHT_TO_LEFT = -1;
2221 /* package */ static final int DIR_REQUEST_LTR = 1;
2222 /* package */ static final int DIR_REQUEST_RTL = -1;
2223 /* package */ static final int DIR_REQUEST_DEFAULT_LTR = 2;
2224 /* package */ static final int DIR_REQUEST_DEFAULT_RTL = -2;
2226 /* package */ static final int RUN_LENGTH_MASK = 0x03ffffff;
2227 /* package */ static final int RUN_LEVEL_SHIFT = 26;
2228 /* package */ static final int RUN_LEVEL_MASK = 0x3f;
2229 /* package */ static final int RUN_RTL_FLAG = 1 << RUN_LEVEL_SHIFT;
2231 public enum Alignment {
2241 private static final int TAB_INCREMENT = 20;
2244 @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
2245 public static final Directions DIRS_ALL_LEFT_TO_RIGHT =
2246 new Directions(new int[] { 0, RUN_LENGTH_MASK });
2249 @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
2250 public static final Directions DIRS_ALL_RIGHT_TO_LEFT =
2251 new Directions(new int[] { 0, RUN_LENGTH_MASK | RUN_RTL_FLAG });