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package android.text;
import com.android.annotations.NonNull;
import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
import android.text.StaticLayout.LineBreaks;
import android.text.Primitive.PrimitiveType;
import java.util.ArrayList;
import java.util.List;
import com.ibm.icu.text.BreakIterator;
import com.ibm.icu.util.ULocale;
import javax.swing.text.Segment;
/**
* Delegate that provides implementation for native methods in {@link android.text.StaticLayout}
* <p/>
* Through the layoutlib_create tool, selected methods of Handler have been replaced by calls to
* methods of the same name in this delegate class.
*/
public class StaticLayout_Delegate {
private static final char CHAR_SPACE = 0x20;
private static final char CHAR_TAB = 0x09;
private static final char CHAR_NEWLINE = 0x0A;
private static final char CHAR_ZWSP = 0x200B; // Zero width space.
@LayoutlibDelegate
/*package*/ static int nComputeLineBreaks(String locale, char[] inputText, float[] widths,
int length, float firstWidth, int firstWidthLineCount, float restWidth,
int[] variableTabStops, int defaultTabStop, boolean optimize, LineBreaks recycle,
int[] recycleBreaks, float[] recycleWidths, boolean[] recycleFlags, int recycleLength) {
// compute all possible breakpoints.
BreakIterator it = BreakIterator.getLineInstance(new ULocale(locale));
it.setText(new Segment(inputText, 0, length));
// average word length in english is 5. So, initialize the possible breaks with a guess.
List<Integer> breaks = new ArrayList<Integer>((int) Math.ceil(length / 5d));
int loc;
it.first();
while ((loc = it.next()) != BreakIterator.DONE) {
breaks.add(loc);
}
LineWidth lineWidth = new LineWidth(firstWidth, firstWidthLineCount, restWidth);
TabStops tabStopCalculator = new TabStops(variableTabStops, defaultTabStop);
List<Primitive> primitives = computePrimitives(inputText, widths, length, breaks);
LineBreaker lineBreaker;
if (optimize) {
lineBreaker = new OptimizingLineBreaker(primitives, lineWidth, tabStopCalculator);
} else {
lineBreaker = new GreedyLineBreaker(primitives, lineWidth, tabStopCalculator);
}
lineBreaker.computeBreaks(recycle);
return recycle.breaks.length;
}
/**
* Compute metadata each character - things which help in deciding if it's possible to break
* at a point or not.
*/
@NonNull
private static List<Primitive> computePrimitives(@NonNull char[] text, @NonNull float[] widths,
int length, @NonNull List<Integer> breaks) {
// Initialize the list with a guess of the number of primitives:
// 2 Primitives per non-whitespace char and approx 5 chars per word (i.e. 83% chars)
List<Primitive> primitives = new ArrayList<Primitive>(((int) Math.ceil(length * 1.833)));
int breaksSize = breaks.size();
int breakIndex = 0;
for (int i = 0; i < length; i++) {
char c = text[i];
if (c == CHAR_SPACE || c == CHAR_ZWSP) {
primitives.add(PrimitiveType.GLUE.getNewPrimitive(i, widths[i]));
} else if (c == CHAR_TAB) {
primitives.add(PrimitiveType.VARIABLE.getNewPrimitive(i));
} else if (c != CHAR_NEWLINE) {
while (breakIndex < breaksSize && breaks.get(breakIndex) < i) {
breakIndex++;
}
Primitive p;
if (widths[i] != 0) {
if (breakIndex < breaksSize && breaks.get(breakIndex) == i) {
p = PrimitiveType.PENALTY.getNewPrimitive(i, 0, 0);
} else {
p = PrimitiveType.WORD_BREAK.getNewPrimitive(i, 0);
}
primitives.add(p);
}
primitives.add(PrimitiveType.BOX.getNewPrimitive(i, widths[i]));
}
}
// final break at end of everything
primitives.add(
PrimitiveType.PENALTY.getNewPrimitive(length, 0, -PrimitiveType.PENALTY_INFINITY));
return primitives;
}
}
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