Implement line breaking using ICU break iterator

Change-Id: I4ad98757aa2eab5dbc2ae44c0391e900ef20c4d0
diff --git a/core/jni/android_text_StaticLayout.cpp b/core/jni/android_text_StaticLayout.cpp
new file mode 100644
index 0000000..696926c
--- /dev/null
+++ b/core/jni/android_text_StaticLayout.cpp
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#define LOG_TAG "StaticLayout"
+
+#include "ScopedIcuLocale.h"
+#include "unicode/locid.h"
+#include "unicode/brkiter.h"
+#include "utils/misc.h"
+#include "utils/Log.h"
+#include "ScopedPrimitiveArray.h"
+#include "JNIHelp.h"
+#include <android_runtime/AndroidRuntime.h>
+#include <vector>
+
+namespace android {
+
+class ScopedBreakIterator {
+    public:
+        ScopedBreakIterator(JNIEnv* env, BreakIterator* breakIterator, jcharArray inputText,
+                            jint length) : mBreakIterator(breakIterator), mChars(env, inputText) {
+            UErrorCode status = U_ZERO_ERROR;
+            mUText = utext_openUChars(NULL, mChars.get(), length, &status);
+            if (mUText == NULL) {
+                return;
+            }
+
+            mBreakIterator->setText(mUText, status);
+        }
+
+        inline BreakIterator* operator->() {
+            return mBreakIterator;
+        }
+
+        ~ScopedBreakIterator() {
+            utext_close(mUText);
+            delete mBreakIterator;
+        }
+    private:
+        BreakIterator* mBreakIterator;
+        ScopedCharArrayRO mChars;
+        UText* mUText;
+
+        // disable copying and assignment
+        ScopedBreakIterator(const ScopedBreakIterator&);
+        void operator=(const ScopedBreakIterator&);
+};
+
+static jintArray nLineBreakOpportunities(JNIEnv* env, jclass, jstring javaLocaleName,
+                                        jcharArray inputText, jint length,
+                                        jintArray recycle) {
+    jintArray ret;
+    std::vector<jint> breaks(16);
+
+    ScopedIcuLocale icuLocale(env, javaLocaleName);
+    if (icuLocale.valid()) {
+        UErrorCode status = U_ZERO_ERROR;
+        BreakIterator* it = BreakIterator::createLineInstance(icuLocale.locale(), status);
+        if (!U_SUCCESS(status) || it == NULL) {
+            if (it) {
+                delete it;
+            }
+        } else {
+            ScopedBreakIterator breakIterator(env, it, inputText, length);
+            for (int loc = breakIterator->first(); loc != BreakIterator::DONE;
+                    loc = breakIterator->next()) {
+                breaks.push_back(loc);
+            }
+        }
+    }
+
+    breaks.push_back(-1); // sentinel terminal value
+
+    if (recycle != NULL && env->GetArrayLength(recycle) >= breaks.size()) {
+        ret = recycle;
+    } else {
+        ret = env->NewIntArray(breaks.size());
+    }
+
+    if (ret != NULL) {
+        env->SetIntArrayRegion(ret, 0, breaks.size(), &breaks.front());
+    }
+
+    return ret;
+}
+
+static JNINativeMethod gMethods[] = {
+    {"nLineBreakOpportunities", "(Ljava/lang/String;[CI[I)[I", (void*) nLineBreakOpportunities}
+};
+
+int register_android_text_StaticLayout(JNIEnv* env)
+{
+    return AndroidRuntime::registerNativeMethods(env, "android/text/StaticLayout",
+            gMethods, NELEM(gMethods));
+}
+
+}