LatinIME/java/src/com/android/inputmethod/event/MyanmarReordering.java
Ken Wakasa 9342484e8d Move Constants.java to the latin.common package
Our intention is to have classes of latinime-common under the common
package as much as we can.

Change-Id: I76efbbbe7bebf1a4aa943715cdff64f91675e20d
2014-10-23 20:27:37 +09:00

265 lines
11 KiB
Java

/*
* 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.
*/
package com.android.inputmethod.event;
import com.android.inputmethod.latin.common.Constants;
import java.util.ArrayList;
import java.util.Arrays;
import javax.annotation.Nonnull;
/**
* A combiner that reorders input for Myanmar.
*/
public class MyanmarReordering implements Combiner {
// U+1031 MYANMAR VOWEL SIGN E
private final static int VOWEL_E = 0x1031; // Code point for vowel E that we need to reorder
// U+200C ZERO WIDTH NON-JOINER
// U+200B ZERO WIDTH SPACE
private final static int ZERO_WIDTH_NON_JOINER = 0x200B; // should be 0x200C
private final ArrayList<Event> mCurrentEvents = new ArrayList<>();
// List of consonants :
// U+1000 MYANMAR LETTER KA
// U+1001 MYANMAR LETTER KHA
// U+1002 MYANMAR LETTER GA
// U+1003 MYANMAR LETTER GHA
// U+1004 MYANMAR LETTER NGA
// U+1005 MYANMAR LETTER CA
// U+1006 MYANMAR LETTER CHA
// U+1007 MYANMAR LETTER JA
// U+1008 MYANMAR LETTER JHA
// U+1009 MYANMAR LETTER NYA
// U+100A MYANMAR LETTER NNYA
// U+100B MYANMAR LETTER TTA
// U+100C MYANMAR LETTER TTHA
// U+100D MYANMAR LETTER DDA
// U+100E MYANMAR LETTER DDHA
// U+100F MYANMAR LETTER NNA
// U+1010 MYANMAR LETTER TA
// U+1011 MYANMAR LETTER THA
// U+1012 MYANMAR LETTER DA
// U+1013 MYANMAR LETTER DHA
// U+1014 MYANMAR LETTER NA
// U+1015 MYANMAR LETTER PA
// U+1016 MYANMAR LETTER PHA
// U+1017 MYANMAR LETTER BA
// U+1018 MYANMAR LETTER BHA
// U+1019 MYANMAR LETTER MA
// U+101A MYANMAR LETTER YA
// U+101B MYANMAR LETTER RA
// U+101C MYANMAR LETTER LA
// U+101D MYANMAR LETTER WA
// U+101E MYANMAR LETTER SA
// U+101F MYANMAR LETTER HA
// U+1020 MYANMAR LETTER LLA
// U+103F MYANMAR LETTER GREAT SA
private static boolean isConsonant(final int codePoint) {
return (codePoint >= 0x1000 && codePoint <= 0x1020) || 0x103F == codePoint;
}
// List of medials :
// U+103B MYANMAR CONSONANT SIGN MEDIAL YA
// U+103C MYANMAR CONSONANT SIGN MEDIAL RA
// U+103D MYANMAR CONSONANT SIGN MEDIAL WA
// U+103E MYANMAR CONSONANT SIGN MEDIAL HA
// U+105E MYANMAR CONSONANT SIGN MON MEDIAL NA
// U+105F MYANMAR CONSONANT SIGN MON MEDIAL MA
// U+1060 MYANMAR CONSONANT SIGN MON MEDIAL LA
// U+1082 MYANMAR CONSONANT SIGN SHAN MEDIAL WA
private static int[] MEDIAL_LIST = { 0x103B, 0x103C, 0x103D, 0x103E,
0x105E, 0x105F, 0x1060, 0x1082};
private static boolean isMedial(final int codePoint) {
return Arrays.binarySearch(MEDIAL_LIST, codePoint) >= 0;
}
private static boolean isConsonantOrMedial(final int codePoint) {
return isConsonant(codePoint) || isMedial(codePoint);
}
private Event getLastEvent() {
final int size = mCurrentEvents.size();
if (size <= 0) {
return null;
}
return mCurrentEvents.get(size - 1);
}
private CharSequence getCharSequence() {
final StringBuilder s = new StringBuilder();
for (final Event e : mCurrentEvents) {
s.appendCodePoint(e.mCodePoint);
}
return s;
}
/**
* Clears the currently combining stream of events and returns the resulting software text
* event corresponding to the stream. Optionally adds a new event to the cleared stream.
* @param newEvent the new event to add to the stream. null if none.
* @return the resulting software text event. Never null.
*/
@Nonnull
private Event clearAndGetResultingEvent(final Event newEvent) {
final CharSequence combinedText;
if (mCurrentEvents.size() > 0) {
combinedText = getCharSequence();
mCurrentEvents.clear();
} else {
combinedText = null;
}
if (null != newEvent) {
mCurrentEvents.add(newEvent);
}
return null == combinedText ? Event.createConsumedEvent(newEvent)
: Event.createSoftwareTextEvent(combinedText, Event.NOT_A_KEY_CODE);
}
@Override
@Nonnull
public Event processEvent(ArrayList<Event> previousEvents, Event newEvent) {
final int codePoint = newEvent.mCodePoint;
if (VOWEL_E == codePoint) {
final Event lastEvent = getLastEvent();
if (null == lastEvent) {
mCurrentEvents.add(newEvent);
return Event.createConsumedEvent(newEvent);
}
if (isConsonantOrMedial(lastEvent.mCodePoint)) {
final Event resultingEvent = clearAndGetResultingEvent(null);
mCurrentEvents.add(Event.createSoftwareKeypressEvent(ZERO_WIDTH_NON_JOINER,
Event.NOT_A_KEY_CODE,
Constants.NOT_A_COORDINATE, Constants.NOT_A_COORDINATE,
false /* isKeyRepeat */));
mCurrentEvents.add(newEvent);
return resultingEvent;
}
// VOWEL_E == lastCodePoint. But if that was anything else this is correct too.
return clearAndGetResultingEvent(newEvent);
}
if (isConsonant(codePoint)) {
final Event lastEvent = getLastEvent();
if (null == lastEvent) {
mCurrentEvents.add(newEvent);
return Event.createConsumedEvent(newEvent);
}
if (VOWEL_E == lastEvent.mCodePoint) {
final int eventSize = mCurrentEvents.size();
if (eventSize >= 2
&& mCurrentEvents.get(eventSize - 2).mCodePoint == ZERO_WIDTH_NON_JOINER) {
// We have a ZWJN before a vowel E. We need to remove the ZWNJ and then
// reorder the vowel with respect to the consonant.
mCurrentEvents.remove(eventSize - 1);
mCurrentEvents.remove(eventSize - 2);
mCurrentEvents.add(newEvent);
mCurrentEvents.add(lastEvent);
return Event.createConsumedEvent(newEvent);
}
// If there is already a consonant, then we are starting a new syllable.
for (int i = eventSize - 2; i >= 0; --i) {
if (isConsonant(mCurrentEvents.get(i).mCodePoint)) {
return clearAndGetResultingEvent(newEvent);
}
}
// If we come here, we didn't have a consonant so we reorder
mCurrentEvents.remove(eventSize - 1);
mCurrentEvents.add(newEvent);
mCurrentEvents.add(lastEvent);
return Event.createConsumedEvent(newEvent);
}
// lastCodePoint is a consonant/medial. But if it's something else it's fine
return clearAndGetResultingEvent(newEvent);
}
if (isMedial(codePoint)) {
final Event lastEvent = getLastEvent();
if (null == lastEvent) {
mCurrentEvents.add(newEvent);
return Event.createConsumedEvent(newEvent);
}
if (VOWEL_E == lastEvent.mCodePoint) {
final int eventSize = mCurrentEvents.size();
// If there is already a consonant, then we are in the middle of a syllable, and we
// need to reorder.
boolean hasConsonant = false;
for (int i = eventSize - 2; i >= 0; --i) {
if (isConsonant(mCurrentEvents.get(i).mCodePoint)) {
hasConsonant = true;
break;
}
}
if (hasConsonant) {
mCurrentEvents.remove(eventSize - 1);
mCurrentEvents.add(newEvent);
mCurrentEvents.add(lastEvent);
return Event.createConsumedEvent(newEvent);
}
// Otherwise, we just commit everything.
return clearAndGetResultingEvent(null);
}
// lastCodePoint is a consonant/medial. But if it's something else it's fine
return clearAndGetResultingEvent(newEvent);
}
final Event lastEvent = getLastEvent();
if (Constants.CODE_DELETE == newEvent.mKeyCode && null != lastEvent) {
final int eventSize = mCurrentEvents.size();
if (VOWEL_E == lastEvent.mCodePoint) {
// We have a VOWEL_E at the end. There are four cases.
// - The vowel is the only code point in the buffer. Remove it.
// - The vowel is preceded by a ZWNJ. Remove both vowel E and ZWNJ.
// - The vowel is preceded by a consonant/medial, remove the consonant/medial.
// - In all other cases, it's strange, so just remove the last code point.
if (eventSize <= 1) {
mCurrentEvents.clear();
} else { // eventSize >= 2
final int previousCodePoint = mCurrentEvents.get(eventSize - 2).mCodePoint;
if (previousCodePoint == ZERO_WIDTH_NON_JOINER) {
mCurrentEvents.remove(eventSize - 1);
mCurrentEvents.remove(eventSize - 2);
} else if (isConsonantOrMedial(previousCodePoint)) {
mCurrentEvents.remove(eventSize - 2);
} else {
mCurrentEvents.remove(eventSize - 1);
}
}
return Event.createConsumedEvent(newEvent);
} else if (eventSize > 0) {
mCurrentEvents.remove(eventSize - 1);
return Event.createConsumedEvent(newEvent);
}
}
// This character is not part of the combining scheme, so we should reset everything.
if (mCurrentEvents.size() > 0) {
// If we have events in flight, then add the new event and return the resulting event.
mCurrentEvents.add(newEvent);
return clearAndGetResultingEvent(null);
}
// If we don't have any events in flight, then just pass this one through.
return newEvent;
}
@Override
public CharSequence getCombiningStateFeedback() {
return getCharSequence();
}
@Override
public void reset() {
mCurrentEvents.clear();
}
}