Implement line breaking using ICU break iterator
Change-Id: I4ad98757aa2eab5dbc2ae44c0391e900ef20c4d0
diff --git a/core/java/android/text/StaticLayout.java b/core/java/android/text/StaticLayout.java
index 0db00f0..fb4fd59 100644
--- a/core/java/android/text/StaticLayout.java
+++ b/core/java/android/text/StaticLayout.java
@@ -161,6 +161,9 @@
float spacingadd, boolean includepad,
boolean trackpad, float ellipsizedWidth,
TextUtils.TruncateAt ellipsize) {
+ int[] breakOpp = null;
+ final String localeLanguageTag = paint.getTextLocale().toLanguageTag();
+
mLineCount = 0;
int v = 0;
@@ -175,8 +178,6 @@
if (source instanceof Spanned)
spanned = (Spanned) source;
- int DEFAULT_DIR = DIR_LEFT_TO_RIGHT; // XXX
-
int paraEnd;
for (int paraStart = bufStart; paraStart <= bufEnd; paraStart = paraEnd) {
paraEnd = TextUtils.indexOf(source, CHAR_NEW_LINE, paraStart, bufEnd);
@@ -242,6 +243,9 @@
int dir = measured.mDir;
boolean easy = measured.mEasy;
+ breakOpp = nLineBreakOpportunities(localeLanguageTag, chs, paraEnd - paraStart, breakOpp);
+ int breakOppIndex = 0;
+
int width = firstWidth;
float w = 0;
@@ -354,15 +358,12 @@
if (fmBottom > fitBottom)
fitBottom = fmBottom;
- // From the Unicode Line Breaking Algorithm (at least approximately)
- boolean isLineBreak = isSpaceOrTab ||
- // / is class SY and - is class HY, except when followed by a digit
- ((c == CHAR_SLASH || c == CHAR_HYPHEN) &&
- (j + 1 >= spanEnd || !Character.isDigit(chs[j + 1 - paraStart]))) ||
- // Ideographs are class ID: breakpoints when adjacent, except for NS
- // (non-starters), which can be broken after but not before
- (c >= CHAR_FIRST_CJK && isIdeographic(c, true) &&
- j + 1 < spanEnd && isIdeographic(chs[j + 1 - paraStart], false));
+ while (breakOpp[breakOppIndex] != -1
+ && breakOpp[breakOppIndex] < j - paraStart + 1) {
+ breakOppIndex++;
+ }
+ boolean isLineBreak = breakOppIndex < breakOpp.length &&
+ breakOpp[breakOppIndex] == j - paraStart + 1;
if (isLineBreak) {
okWidth = w;
@@ -490,97 +491,6 @@
}
}
- /**
- * Returns true if the specified character is one of those specified
- * as being Ideographic (class ID) by the Unicode Line Breaking Algorithm
- * (http://www.unicode.org/unicode/reports/tr14/), and is therefore OK
- * to break between a pair of.
- *
- * @param includeNonStarters also return true for category NS
- * (non-starters), which can be broken
- * after but not before.
- */
- private static final boolean isIdeographic(char c, boolean includeNonStarters) {
- if (c >= '\u2E80' && c <= '\u2FFF') {
- return true; // CJK, KANGXI RADICALS, DESCRIPTION SYMBOLS
- }
- if (c == '\u3000') {
- return true; // IDEOGRAPHIC SPACE
- }
- if (c >= '\u3040' && c <= '\u309F') {
- if (!includeNonStarters) {
- switch (c) {
- case '\u3041': // # HIRAGANA LETTER SMALL A
- case '\u3043': // # HIRAGANA LETTER SMALL I
- case '\u3045': // # HIRAGANA LETTER SMALL U
- case '\u3047': // # HIRAGANA LETTER SMALL E
- case '\u3049': // # HIRAGANA LETTER SMALL O
- case '\u3063': // # HIRAGANA LETTER SMALL TU
- case '\u3083': // # HIRAGANA LETTER SMALL YA
- case '\u3085': // # HIRAGANA LETTER SMALL YU
- case '\u3087': // # HIRAGANA LETTER SMALL YO
- case '\u308E': // # HIRAGANA LETTER SMALL WA
- case '\u3095': // # HIRAGANA LETTER SMALL KA
- case '\u3096': // # HIRAGANA LETTER SMALL KE
- case '\u309B': // # KATAKANA-HIRAGANA VOICED SOUND MARK
- case '\u309C': // # KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK
- case '\u309D': // # HIRAGANA ITERATION MARK
- case '\u309E': // # HIRAGANA VOICED ITERATION MARK
- return false;
- }
- }
- return true; // Hiragana (except small characters)
- }
- if (c >= '\u30A0' && c <= '\u30FF') {
- if (!includeNonStarters) {
- switch (c) {
- case '\u30A0': // # KATAKANA-HIRAGANA DOUBLE HYPHEN
- case '\u30A1': // # KATAKANA LETTER SMALL A
- case '\u30A3': // # KATAKANA LETTER SMALL I
- case '\u30A5': // # KATAKANA LETTER SMALL U
- case '\u30A7': // # KATAKANA LETTER SMALL E
- case '\u30A9': // # KATAKANA LETTER SMALL O
- case '\u30C3': // # KATAKANA LETTER SMALL TU
- case '\u30E3': // # KATAKANA LETTER SMALL YA
- case '\u30E5': // # KATAKANA LETTER SMALL YU
- case '\u30E7': // # KATAKANA LETTER SMALL YO
- case '\u30EE': // # KATAKANA LETTER SMALL WA
- case '\u30F5': // # KATAKANA LETTER SMALL KA
- case '\u30F6': // # KATAKANA LETTER SMALL KE
- case '\u30FB': // # KATAKANA MIDDLE DOT
- case '\u30FC': // # KATAKANA-HIRAGANA PROLONGED SOUND MARK
- case '\u30FD': // # KATAKANA ITERATION MARK
- case '\u30FE': // # KATAKANA VOICED ITERATION MARK
- return false;
- }
- }
- return true; // Katakana (except small characters)
- }
- if (c >= '\u3400' && c <= '\u4DB5') {
- return true; // CJK UNIFIED IDEOGRAPHS EXTENSION A
- }
- if (c >= '\u4E00' && c <= '\u9FBB') {
- return true; // CJK UNIFIED IDEOGRAPHS
- }
- if (c >= '\uF900' && c <= '\uFAD9') {
- return true; // CJK COMPATIBILITY IDEOGRAPHS
- }
- if (c >= '\uA000' && c <= '\uA48F') {
- return true; // YI SYLLABLES
- }
- if (c >= '\uA490' && c <= '\uA4CF') {
- return true; // YI RADICALS
- }
- if (c >= '\uFE62' && c <= '\uFE66') {
- return true; // SMALL PLUS SIGN to SMALL EQUALS SIGN
- }
- if (c >= '\uFF10' && c <= '\uFF19') {
- return true; // WIDE DIGITS
- }
-
- return false;
- }
-
private int out(CharSequence text, int start, int end,
int above, int below, int top, int bottom, int v,
float spacingmult, float spacingadd,
@@ -929,6 +839,11 @@
mMeasured = MeasuredText.recycle(mMeasured);
}
+ // returns an array with terminal sentinel value -1 to indicate end
+ // this is so that arrays can be recycled instead of allocating new arrays
+ // every time
+ private static native int[] nLineBreakOpportunities(String locale, char[] text, int length, int[] recycle);
+
private int mLineCount;
private int mTopPadding, mBottomPadding;
private int mColumns;
@@ -954,13 +869,9 @@
private static final int TAB_INCREMENT = 20; // same as Layout, but that's private
- private static final char CHAR_FIRST_CJK = '\u2E80';
-
private static final char CHAR_NEW_LINE = '\n';
private static final char CHAR_TAB = '\t';
private static final char CHAR_SPACE = ' ';
- private static final char CHAR_SLASH = '/';
- private static final char CHAR_HYPHEN = '-';
private static final char CHAR_ZWSP = '\u200B';
private static final double EXTRA_ROUNDING = 0.5;
diff --git a/core/jni/Android.mk b/core/jni/Android.mk
index f287fca..38a7fa5 100644
--- a/core/jni/Android.mk
+++ b/core/jni/Android.mk
@@ -67,6 +67,7 @@
android_view_VelocityTracker.cpp \
android_text_AndroidCharacter.cpp \
android_text_AndroidBidi.cpp \
+ android_text_StaticLayout.cpp \
android_os_Debug.cpp \
android_os_MemoryFile.cpp \
android_os_MessageQueue.cpp \
diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index 598d6c1..4798f58 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -157,6 +157,7 @@
extern int register_android_net_NetworkUtils(JNIEnv* env);
extern int register_android_net_TrafficStats(JNIEnv* env);
extern int register_android_text_AndroidCharacter(JNIEnv *env);
+extern int register_android_text_StaticLayout(JNIEnv *env);
extern int register_android_text_AndroidBidi(JNIEnv *env);
extern int register_android_opengl_classes(JNIEnv *env);
extern int register_android_server_fingerprint_FingerprintService(JNIEnv* env);
@@ -1228,6 +1229,7 @@
REG_JNI(register_android_content_XmlBlock),
REG_JNI(register_android_emoji_EmojiFactory),
REG_JNI(register_android_text_AndroidCharacter),
+ REG_JNI(register_android_text_StaticLayout),
REG_JNI(register_android_text_AndroidBidi),
REG_JNI(register_android_view_InputDevice),
REG_JNI(register_android_view_KeyCharacterMap),
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));
+}
+
+}