Merge "Implement LineBreaker callback and fix indent repeating."

apct-tests/perftests/core/src/android/text/StaticLayoutPerfTest.java

@@ -88,4 +88,15 @@ public class StaticLayoutPerfTest {
                     .build();
         }
     }
+
+    @Test
+    public void testCreateRandom_breakBalanced() {
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        while (state.keepRunning()) {
+            final CharSequence text = generateRandomParagraph(9);
+            StaticLayout.Builder.obtain(text, 0, text.length(), PAINT, TEXT_WIDTH)
+                    .setBreakStrategy(Layout.BREAK_STRATEGY_BALANCED)
+                    .build();
+        }
+    }
 }

core/java/android/text/StaticLayout.java

@@ -780,9 +780,7 @@ public class StaticLayout extends Layout {
                     firstWidth, firstWidthLineCount, restWidth,
                     variableTabStops, TAB_INCREMENT, b.mBreakStrategy, b.mHyphenationFrequency,
                     // TODO: Support more justification mode, e.g. letter spacing, stretching.
-                    b.mJustificationMode != Layout.JUSTIFICATION_MODE_NONE,
-                    (indents != null && indents.length > mLineCount) ? indents : null,
-                    mLineCount);
+                    b.mJustificationMode != Layout.JUSTIFICATION_MODE_NONE, indents, mLineCount);
 
             // measurement has to be done before performing line breaking
             // but we don't want to recompute fontmetrics or span ranges the
@@ -1506,7 +1504,7 @@ public class StaticLayout extends Layout {
             @FloatRange(from = 0.0f) float restWidth, @Nullable int[] variableTabStops,
             int defaultTabStop, @BreakStrategy int breakStrategy,
             @HyphenationFrequency int hyphenationFrequency, boolean isJustified,
-            @Nullable int[] indents, @IntRange(from = 0) int intentsOffset);
+            @Nullable int[] indents, @IntRange(from = 0) int indentsOffset);
 
     private static native float nAddStyleRun(long nativePtr, long nativePaint, int start, int end,
             boolean isRtl);

core/jni/android_text_StaticLayout.cpp

@@ -52,17 +52,46 @@ struct JLineBreaksID {
 static jclass gLineBreaks_class;
 static JLineBreaksID gLineBreaks_fieldID;
 
+class JNILineBreakerLineWidth : public minikin::LineBreaker::LineWidthDelegate {
+    public:
+        JNILineBreakerLineWidth(float firstWidth, int32_t firstLineCount, float restWidth,
+                std::vector<float>&& indents, int32_t indentsOffset)
+            : mFirstWidth(firstWidth), mFirstLineCount(firstLineCount), mRestWidth(restWidth),
+              mIndents(std::move(indents)), mIndentsOffset(indentsOffset) {}
+
+        float getLineWidth(size_t lineNo) override {
+            const float width = ((ssize_t)lineNo < (ssize_t)mFirstLineCount)
+                    ? mFirstWidth : mRestWidth;
+            if (mIndents.empty()) {
+                return width;
+            }
+
+            const size_t indentIndex = lineNo + mIndentsOffset;
+            if (indentIndex < mIndents.size()) {
+                return width - mIndents[indentIndex];
+            } else {
+                return width - mIndents.back();
+            }
+        }
+
+    private:
+        const float mFirstWidth;
+        const int32_t mFirstLineCount;
+        const float mRestWidth;
+        const std::vector<float> mIndents;
+        const int32_t mIndentsOffset;
+};
+
 // set text and set a number of parameters for creating a layout (width, tabstops, strategy,
 // hyphenFrequency)
 static void nSetupParagraph(JNIEnv* env, jclass, jlong nativePtr, jcharArray text, jint length,
         jfloat firstWidth, jint firstWidthLineLimit, jfloat restWidth,
         jintArray variableTabStops, jint defaultTabStop, jint strategy, jint hyphenFrequency,
-        jboolean isJustified, jintArray indents, jint insetsOffset) {
+        jboolean isJustified, jintArray indents, jint indentsOffset) {
     minikin::LineBreaker* b = reinterpret_cast<minikin::LineBreaker*>(nativePtr);
     b->resize(length);
     env->GetCharArrayRegion(text, 0, length, b->buffer());
     b->setText();
-    b->setLineWidths(firstWidth, firstWidthLineLimit, restWidth);
     if (variableTabStops == nullptr) {
         b->setTabStops(nullptr, 0, defaultTabStop);
     } else {
@@ -73,17 +102,14 @@ static void nSetupParagraph(JNIEnv* env, jclass, jlong nativePtr, jcharArray tex
     b->setHyphenationFrequency(static_cast<minikin::HyphenationFrequency>(hyphenFrequency));
     b->setJustified(isJustified);
 
+    std::vector<float> indentVec;
     // TODO: copy indents only once when LineBreaker is started to be used.
     if (indents != nullptr) {
-        // If indents is not null, it is guaranteed that lineOffset is less than the size of array.
         ScopedIntArrayRO indentArr(env, indents);
-        std::vector<float> indentVec(
-            indentArr.get() + insetsOffset, indentArr.get() + indentArr.size());
-        b->setIndents(indentVec);
-    } else {
-        b->setIndents(std::vector<float>());
+        indentVec.assign(indentArr.get(), indentArr.get() + indentArr.size());
     }
-
+    b->setLineWidthDelegate(std::make_unique<JNILineBreakerLineWidth>(
+            firstWidth, firstWidthLineLimit, restWidth, std::move(indentVec), indentsOffset));
 }
 
 static void recycleCopy(JNIEnv* env, jobject recycle, jintArray recycleBreaks,