1package android.text; 2 3import com.android.layoutlib.bridge.impl.DelegateManager; 4import com.android.tools.layoutlib.annotations.LayoutlibDelegate; 5 6import android.annotation.NonNull; 7import android.graphics.BidiRenderer; 8import android.graphics.Paint; 9import android.graphics.Paint_Delegate; 10import android.graphics.RectF; 11import android.icu.text.BreakIterator; 12import android.icu.util.ULocale; 13import android.text.Primitive.PrimitiveType; 14import android.text.StaticLayout.LineBreaks; 15 16import java.util.ArrayList; 17import java.util.Arrays; 18import java.util.List; 19 20import javax.swing.text.Segment; 21 22/** 23 * Delegate that provides implementation for native methods in {@link android.text.StaticLayout} 24 * <p/> 25 * Through the layoutlib_create tool, selected methods of StaticLayout have been replaced 26 * by calls to methods of the same name in this delegate class. 27 * 28 */ 29public class StaticLayout_Delegate { 30 31 private static final char CHAR_SPACE = 0x20; 32 private static final char CHAR_TAB = 0x09; 33 private static final char CHAR_NEWLINE = 0x0A; 34 private static final char CHAR_ZWSP = 0x200B; // Zero width space. 35 36 // ---- Builder delegate manager ---- 37 private static final DelegateManager<Builder> sBuilderManager = 38 new DelegateManager<Builder>(Builder.class); 39 40 @LayoutlibDelegate 41 /*package*/ static long nNewBuilder() { 42 return sBuilderManager.addNewDelegate(new Builder()); 43 } 44 45 @LayoutlibDelegate 46 /*package*/ static void nFreeBuilder(long nativeBuilder) { 47 sBuilderManager.removeJavaReferenceFor(nativeBuilder); 48 } 49 50 @LayoutlibDelegate 51 /*package*/ static void nFinishBuilder(long nativeBuilder) { 52 } 53 54 @LayoutlibDelegate 55 /*package*/ static long nLoadHyphenator(String patternData) { 56 return Hyphenator_Delegate.loadHyphenator(patternData); 57 } 58 59 @LayoutlibDelegate 60 /*package*/ static void nSetLocale(long nativeBuilder, String locale, long nativeHyphenator) { 61 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 62 if (builder != null) { 63 builder.mLocale = locale; 64 builder.mNativeHyphenator = nativeHyphenator; 65 } 66 } 67 68 @LayoutlibDelegate 69 /*package*/ static void nSetIndents(long nativeBuilder, int[] indents) { 70 // TODO. 71 } 72 73 @LayoutlibDelegate 74 /*package*/ static void nSetupParagraph(long nativeBuilder, char[] text, int length, 75 float firstWidth, int firstWidthLineCount, float restWidth, 76 int[] variableTabStops, int defaultTabStop, int breakStrategy, 77 int hyphenationFrequency) { 78 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 79 if (builder == null) { 80 return; 81 } 82 83 builder.mText = text; 84 builder.mWidths = new float[length]; 85 builder.mLineWidth = new LineWidth(firstWidth, firstWidthLineCount, restWidth); 86 builder.mTabStopCalculator = new TabStops(variableTabStops, defaultTabStop); 87 } 88 89 @LayoutlibDelegate 90 /*package*/ static float nAddStyleRun(long nativeBuilder, long nativePaint, long nativeTypeface, 91 int start, int end, boolean isRtl) { 92 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 93 94 int bidiFlags = isRtl ? Paint.BIDI_FORCE_RTL : Paint.BIDI_FORCE_LTR; 95 return builder == null ? 0 : 96 measureText(nativePaint, builder.mText, start, end - start, builder.mWidths, 97 bidiFlags); 98 } 99 100 @LayoutlibDelegate 101 /*package*/ static void nAddMeasuredRun(long nativeBuilder, int start, int end, float[] widths) { 102 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 103 if (builder != null) { 104 System.arraycopy(widths, start, builder.mWidths, start, end - start); 105 } 106 } 107 108 @LayoutlibDelegate 109 /*package*/ static void nAddReplacementRun(long nativeBuilder, int start, int end, float width) { 110 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 111 if (builder == null) { 112 return; 113 } 114 builder.mWidths[start] = width; 115 Arrays.fill(builder.mWidths, start + 1, end, 0.0f); 116 } 117 118 @LayoutlibDelegate 119 /*package*/ static void nGetWidths(long nativeBuilder, float[] floatsArray) { 120 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 121 if (builder != null) { 122 System.arraycopy(builder.mWidths, 0, floatsArray, 0, builder.mWidths.length); 123 } 124 } 125 126 @LayoutlibDelegate 127 /*package*/ static int nComputeLineBreaks(long nativeBuilder, 128 LineBreaks recycle, int[] recycleBreaks, float[] recycleWidths, 129 int[] recycleFlags, int recycleLength) { 130 131 Builder builder = sBuilderManager.getDelegate(nativeBuilder); 132 if (builder == null) { 133 return 0; 134 } 135 136 // compute all possible breakpoints. 137 int length = builder.mWidths.length; 138 BreakIterator it = BreakIterator.getLineInstance(new ULocale(builder.mLocale)); 139 it.setText(new Segment(builder.mText, 0, length)); 140 141 // average word length in english is 5. So, initialize the possible breaks with a guess. 142 List<Integer> breaks = new ArrayList<Integer>((int) Math.ceil(length / 5d)); 143 int loc; 144 it.first(); 145 while ((loc = it.next()) != BreakIterator.DONE) { 146 breaks.add(loc); 147 } 148 149 List<Primitive> primitives = 150 computePrimitives(builder.mText, builder.mWidths, length, breaks); 151 switch (builder.mBreakStrategy) { 152 case Layout.BREAK_STRATEGY_SIMPLE: 153 builder.mLineBreaker = new GreedyLineBreaker(primitives, builder.mLineWidth, 154 builder.mTabStopCalculator); 155 break; 156 case Layout.BREAK_STRATEGY_HIGH_QUALITY: 157 // TODO 158// break; 159 case Layout.BREAK_STRATEGY_BALANCED: 160 builder.mLineBreaker = new OptimizingLineBreaker(primitives, builder.mLineWidth, 161 builder.mTabStopCalculator); 162 break; 163 default: 164 throw new AssertionError("Unknown break strategy: " + builder.mBreakStrategy); 165 } 166 builder.mLineBreaker.computeBreaks(recycle); 167 return recycle.breaks.length; 168 } 169 170 /** 171 * Compute metadata each character - things which help in deciding if it's possible to break 172 * at a point or not. 173 */ 174 @NonNull 175 private static List<Primitive> computePrimitives(@NonNull char[] text, @NonNull float[] widths, 176 int length, @NonNull List<Integer> breaks) { 177 // Initialize the list with a guess of the number of primitives: 178 // 2 Primitives per non-whitespace char and approx 5 chars per word (i.e. 83% chars) 179 List<Primitive> primitives = new ArrayList<Primitive>(((int) Math.ceil(length * 1.833))); 180 int breaksSize = breaks.size(); 181 int breakIndex = 0; 182 for (int i = 0; i < length; i++) { 183 char c = text[i]; 184 if (c == CHAR_SPACE || c == CHAR_ZWSP) { 185 primitives.add(PrimitiveType.GLUE.getNewPrimitive(i, widths[i])); 186 } else if (c == CHAR_TAB) { 187 primitives.add(PrimitiveType.VARIABLE.getNewPrimitive(i)); 188 } else if (c != CHAR_NEWLINE) { 189 while (breakIndex < breaksSize && breaks.get(breakIndex) < i) { 190 breakIndex++; 191 } 192 Primitive p; 193 if (widths[i] != 0) { 194 if (breakIndex < breaksSize && breaks.get(breakIndex) == i) { 195 p = PrimitiveType.PENALTY.getNewPrimitive(i, 0, 0); 196 } else { 197 p = PrimitiveType.WORD_BREAK.getNewPrimitive(i, 0); 198 } 199 primitives.add(p); 200 } 201 202 primitives.add(PrimitiveType.BOX.getNewPrimitive(i, widths[i])); 203 } 204 } 205 // final break at end of everything 206 primitives.add( 207 PrimitiveType.PENALTY.getNewPrimitive(length, 0, -PrimitiveType.PENALTY_INFINITY)); 208 return primitives; 209 } 210 211 private static float measureText(long nativePaint, char []text, int index, int count, 212 float[] widths, int bidiFlags) { 213 Paint_Delegate paint = Paint_Delegate.getDelegate(nativePaint); 214 RectF bounds = new BidiRenderer(null, paint, text) 215 .renderText(index, index + count, bidiFlags, widths, 0, false); 216 return bounds.right - bounds.left; 217 } 218 219 // TODO: Rename to LineBreakerRef and move everything other than LineBreaker to LineBreaker. 220 /** 221 * Java representation of the native Builder class. 222 */ 223 private static class Builder { 224 String mLocale; 225 char[] mText; 226 float[] mWidths; 227 LineBreaker mLineBreaker; 228 long mNativeHyphenator; 229 int mBreakStrategy; 230 LineWidth mLineWidth; 231 TabStops mTabStopCalculator; 232 } 233} 234