/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.text;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.text.style.MetricAffectingSpan;
import android.text.style.ReplacementSpan;
import android.util.Log;
import com.android.internal.util.ArrayUtils;
/**
* @hide
*/
class MeasuredText {
private static final boolean localLOGV = false;
CharSequence mText;
int mTextStart;
float[] mWidths;
char[] mChars;
byte[] mLevels;
int mDir;
boolean mEasy;
int mLen;
private int mPos;
private TextPaint mWorkPaint;
private MeasuredText() {
mWorkPaint = new TextPaint();
}
private static final Object[] sLock = new Object[0];
private static final MeasuredText[] sCached = new MeasuredText[3];
static MeasuredText obtain() {
MeasuredText mt;
synchronized (sLock) {
for (int i = sCached.length; --i >= 0;) {
if (sCached[i] != null) {
mt = sCached[i];
sCached[i] = null;
return mt;
}
}
}
mt = new MeasuredText();
if (localLOGV) {
Log.v("MEAS", "new: " + mt);
}
return mt;
}
static MeasuredText recycle(MeasuredText mt) {
mt.mText = null;
if (mt.mLen < 1000) {
synchronized(sLock) {
for (int i = 0; i < sCached.length; ++i) {
if (sCached[i] == null) {
sCached[i] = mt;
mt.mText = null;
break;
}
}
}
}
return null;
}
void setPos(int pos) {
mPos = pos - mTextStart;
}
/**
* Analyzes text for bidirectional runs. Allocates working buffers.
*/
void setPara(CharSequence text, int start, int end, TextDirectionHeuristic textDir) {
mText = text;
mTextStart = start;
int len = end - start;
mLen = len;
mPos = 0;
if (mWidths == null || mWidths.length < len) {
mWidths = ArrayUtils.newUnpaddedFloatArray(len);
}
if (mChars == null || mChars.length < len) {
mChars = ArrayUtils.newUnpaddedCharArray(len);
}
TextUtils.getChars(text, start, end, mChars, 0);
if (text instanceof Spanned) {
Spanned spanned = (Spanned) text;
ReplacementSpan[] spans = spanned.getSpans(start, end,
ReplacementSpan.class);
for (int i = 0; i < spans.length; i++) {
int startInPara = spanned.getSpanStart(spans[i]) - start;
int endInPara = spanned.getSpanEnd(spans[i]) - start;
// The span interval may be larger and must be restricted to [start, end[
if (startInPara < 0) startInPara = 0;
if (endInPara > len) endInPara = len;
for (int j = startInPara; j < endInPara; j++) {
mChars[j] = '\uFFFC'; // object replacement character
}
}
}
if ((textDir == TextDirectionHeuristics.LTR ||
textDir == TextDirectionHeuristics.FIRSTSTRONG_LTR ||
textDir == TextDirectionHeuristics.ANYRTL_LTR) &&
TextUtils.doesNotNeedBidi(mChars, 0, len)) {
mDir = Layout.DIR_LEFT_TO_RIGHT;
mEasy = true;
} else {
if (mLevels == null || mLevels.length < len) {
mLevels = ArrayUtils.newUnpaddedByteArray(len);
}
int bidiRequest;
if (textDir == TextDirectionHeuristics.LTR) {
bidiRequest = Layout.DIR_REQUEST_LTR;
} else if (textDir == TextDirectionHeuristics.RTL) {
bidiRequest = Layout.DIR_REQUEST_RTL;
} else if (textDir == TextDirectionHeuristics.FIRSTSTRONG_LTR) {
bidiRequest = Layout.DIR_REQUEST_DEFAULT_LTR;
} else if (textDir == TextDirectionHeuristics.FIRSTSTRONG_RTL) {
bidiRequest = Layout.DIR_REQUEST_DEFAULT_RTL;
} else {
boolean isRtl = textDir.isRtl(mChars, 0, len);
bidiRequest = isRtl ? Layout.DIR_REQUEST_RTL : Layout.DIR_REQUEST_LTR;
}
mDir = AndroidBidi.bidi(bidiRequest, mChars, mLevels, len, false);
mEasy = false;
}
}
float addStyleRun(TextPaint paint, int len, Paint.FontMetricsInt fm) {
if (fm != null) {
paint.getFontMetricsInt(fm);
}
int p = mPos;
mPos = p + len;
if (mEasy) {
boolean isRtl = mDir != Layout.DIR_LEFT_TO_RIGHT;
return paint.getTextRunAdvances(mChars, p, len, p, len, isRtl, mWidths, p);
}
float totalAdvance = 0;
int level = mLevels[p];
for (int q = p, i = p + 1, e = p + len;; ++i) {
if (i == e || mLevels[i] != level) {
boolean isRtl = (level & 0x1) != 0;
totalAdvance +=
paint.getTextRunAdvances(mChars, q, i - q, q, i - q, isRtl, mWidths, q);
if (i == e) {
break;
}
q = i;
level = mLevels[i];
}
}
return totalAdvance;
}
float addStyleRun(TextPaint paint, MetricAffectingSpan[] spans, int len,
Paint.FontMetricsInt fm) {
TextPaint workPaint = mWorkPaint;
workPaint.set(paint);
// XXX paint should not have a baseline shift, but...
workPaint.baselineShift = 0;
ReplacementSpan replacement = null;
for (int i = 0; i < spans.length; i++) {
MetricAffectingSpan span = spans[i];
if (span instanceof ReplacementSpan) {
replacement = (ReplacementSpan)span;
} else {
span.updateMeasureState(workPaint);
}
}
float wid;
if (replacement == null) {
wid = addStyleRun(workPaint, len, fm);
} else {
// Use original text. Shouldn't matter.
wid = replacement.getSize(workPaint, mText, mTextStart + mPos,
mTextStart + mPos + len, fm);
float[] w = mWidths;
w[mPos] = wid;
for (int i = mPos + 1, e = mPos + len; i < e; i++)
w[i] = 0;
mPos += len;
}
if (fm != null) {
if (workPaint.baselineShift < 0) {
fm.ascent += workPaint.baselineShift;
fm.top += workPaint.baselineShift;
} else {
fm.descent += workPaint.baselineShift;
fm.bottom += workPaint.baselineShift;
}
}
return wid;
}
int breakText(int limit, boolean forwards, float width) {
float[] w = mWidths;
if (forwards) {
int i = 0;
while (i < limit) {
width -= w[i];
if (width < 0.0f) break;
i++;
}
while (i > 0 && mChars[i - 1] == ' ') i--;
return i;
} else {
int i = limit - 1;
while (i >= 0) {
width -= w[i];
if (width < 0.0f) break;
i--;
}
while (i < limit - 1 && mChars[i + 1] == ' ') i++;
return limit - i - 1;
}
}
float measure(int start, int limit) {
float width = 0;
float[] w = mWidths;
for (int i = start; i < limit; ++i) {
width += w[i];
}
return width;
}
}
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