core/java/android/text/MeasuredText.java - platform/frameworks/base - Git at Google

 /*
  * 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.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 StaticLayout.Builder mBuilder;

     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.finish();
         synchronized(sLock) {
             for (int i = 0; i < sCached.length; ++i) {
                 if (sCached[i] == null) {
                     sCached[i] = mt;
                     mt.mText = null;
                     break;
                 }
             }
         }
         return null;
     }

     void finish() {
         mText = null;
         mBuilder = null;
         if (mLen > 1000) {
             mWidths = null;
             mChars = null;
             mLevels = 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,
             StaticLayout.Builder builder) {
         mBuilder = builder;
         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;

         // try to do widths measurement in native code, but use Java if paint has been subclassed
         // FIXME: may want to eliminate special case for subclass
         float[] widths = null;
         if (mBuilder == null || paint.getClass() != TextPaint.class) {
             widths = mWidths;
         }
         if (mEasy) {
             boolean isRtl = mDir != Layout.DIR_LEFT_TO_RIGHT;
             float width = 0;
             if (widths != null) {
                 width = paint.getTextRunAdvances(mChars, p, len, p, len, isRtl, widths, p);
                 if (mBuilder != null) {
                     mBuilder.addMeasuredRun(p, p + len, widths);
                 }
             } else {
                 width = mBuilder.addStyleRun(paint, p, p + len, isRtl);
             }
             return width;
         }

         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;
                 if (widths != null) {
                     totalAdvance +=
                             paint.getTextRunAdvances(mChars, q, i - q, q, i - q, isRtl, widths, q);
                     if (mBuilder != null) {
                         mBuilder.addMeasuredRun(q, i, widths);
                     }
                 } else {
                     totalAdvance += mBuilder.addStyleRun(paint, q, i, isRtl);
                 }
                 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);
             if (mBuilder == null) {
                 float[] w = mWidths;
                 w[mPos] = wid;
                 for (int i = mPos + 1, e = mPos + len; i < e; i++)
                     w[i] = 0;
             } else {
                 mBuilder.addReplacementRun(mPos, mPos + len, wid);
             }
             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;
     }
 }
	/*
	* 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.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 StaticLayout.Builder mBuilder;

	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.finish();
	synchronized(sLock) {
	for (int i = 0; i < sCached.length; ++i) {
	if (sCached[i] == null) {
	sCached[i] = mt;
	mt.mText = null;
	break;
	}
	}
	}
	return null;
	}

	void finish() {
	mText = null;
	mBuilder = null;
	if (mLen > 1000) {
	mWidths = null;
	mChars = null;
	mLevels = 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,
	StaticLayout.Builder builder) {
	mBuilder = builder;
	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;

	// try to do widths measurement in native code, but use Java if paint has been subclassed
	// FIXME: may want to eliminate special case for subclass
	float[] widths = null;
	if (mBuilder == null \|\| paint.getClass() != TextPaint.class) {
	widths = mWidths;
	}
	if (mEasy) {
	boolean isRtl = mDir != Layout.DIR_LEFT_TO_RIGHT;
	float width = 0;
	if (widths != null) {
	width = paint.getTextRunAdvances(mChars, p, len, p, len, isRtl, widths, p);
	if (mBuilder != null) {
	mBuilder.addMeasuredRun(p, p + len, widths);
	}
	} else {
	width = mBuilder.addStyleRun(paint, p, p + len, isRtl);
	}
	return width;
	}

	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;
	if (widths != null) {
	totalAdvance +=
	paint.getTextRunAdvances(mChars, q, i - q, q, i - q, isRtl, widths, q);
	if (mBuilder != null) {
	mBuilder.addMeasuredRun(q, i, widths);
	}
	} else {
	totalAdvance += mBuilder.addStyleRun(paint, q, i, isRtl);
	}
	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);
	if (mBuilder == null) {
	float[] w = mWidths;
	w[mPos] = wid;
	for (int i = mPos + 1, e = mPos + len; i < e; i++)
	w[i] = 0;
	} else {
	mBuilder.addReplacementRun(mPos, mPos + len, wid);
	}
	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;
	}
	}