Use SparseIntArray instead of TreeMap<Integer, Integer>

package com.android.inputmethod.latin.spellcheck;

import android.util.SparseIntArray;

import com.android.inputmethod.keyboard.ProximityInfo;

import com.android.inputmethod.latin.CollectionUtils;

import com.android.inputmethod.latin.Constants;

import java.util.TreeMap;

public final class SpellCheckerProximityInfo extends ProximityInfo {

    public SpellCheckerProximityInfo(final int script) {

        super(getProximityForScript(script), PROXIMITY_GRID_WIDTH, PROXIMITY_GRID_HEIGHT);

    public static final int NOT_A_COORDINATE_PAIR = -1;

    // Helper methods

    static void buildProximityIndices(final int[] proximity,

            final TreeMap<Integer, Integer> indices) {

        for (int i = 0; i < proximity.length; i += ROW_SIZE) {

            if (NUL != proximity[i]) indices.put(proximity[i], i / ROW_SIZE);

    static void buildProximityIndices(final int[] proximity, final int rowSize,

            final SparseIntArray indices) {

        for (int i = 0; i < proximity.length; i += rowSize) {

            if (NUL != proximity[i]) indices.put(proximity[i], i / rowSize);

        }

    }

    static int computeIndex(final int characterCode,

            final TreeMap<Integer, Integer> indices) {

        final Integer result = indices.get(characterCode);

        if (null == result) return NOT_AN_INDEX;

        return result;

    }

    private static final class Latin {

        // This is a map from the code point to the index in the PROXIMITY array.

        // At the time the native code to read the binary dictionary needs the proximity info be

        // passed as a flat array spaced by MAX_PROXIMITY_CHARS_SIZE columns, one for each input

        // character.

        // Since we need to build such an array, we want to be able to search in our big proximity

        // data quickly by character, and a map is probably the best way to do this.

        private static final TreeMap<Integer, Integer> INDICES = CollectionUtils.newTreeMap();

        // The proximity here is the union of

        // - the proximity for a QWERTY keyboard.

        // - the proximity for an AZERTY keyboard.

            NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL,

        };

        static {

            buildProximityIndices(PROXIMITY, INDICES);

        }

        // This is a mapping array from the code point to the index in the PROXIMITY array.

        // When we check the spelling of a word, we need to pass (x,y) coordinates to the native

        // code for each letter of the word. These are most easily computed from the index in the

        // PROXIMITY array. Since we'll need to do that very often, the index lookup from the code

        // point needs to be as fast as possible, and a map is probably the best way to do this.

        // To avoid unnecessary boxing conversion to Integer, here we use SparseIntArray.

        static final SparseIntArray INDICES = new SparseIntArray(PROXIMITY.length / ROW_SIZE);

        static int getIndexOf(int characterCode) {

            return computeIndex(characterCode, INDICES);

        static {

            buildProximityIndices(PROXIMITY, ROW_SIZE, INDICES);

        }

    }

    private static final class Cyrillic {

        private static final TreeMap<Integer, Integer> INDICES = CollectionUtils.newTreeMap();

        // TODO: The following table is solely based on the keyboard layout. Consult with Russian

        // speakers on commonly misspelled words/letters.

        /*

            NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL,

        };

        static {

            buildProximityIndices(PROXIMITY, INDICES);

        }

        static final SparseIntArray INDICES = new SparseIntArray(PROXIMITY.length / ROW_SIZE);

        static int getIndexOf(int characterCode) {

            return computeIndex(characterCode, INDICES);

        static {

            buildProximityIndices(PROXIMITY, ROW_SIZE, INDICES);

        }

    }

    private static final class Greek {

        private static final TreeMap<Integer, Integer> INDICES = CollectionUtils.newTreeMap();

        // TODO: The following table is solely based on the keyboard layout. Consult with Greek

        // speakers on commonly misspelled words/letters.

        /*

            NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL, NUL,

        };

        static {

            buildProximityIndices(PROXIMITY, INDICES);

        }

        static final SparseIntArray INDICES = new SparseIntArray(PROXIMITY.length / ROW_SIZE);

        static int getIndexOf(int characterCode) {

            return computeIndex(characterCode, INDICES);

        static {

            buildProximityIndices(PROXIMITY, ROW_SIZE, INDICES);

        }

    }

    private static int getIndexOfCodeForScript(final int codePoint, final int script) {

        switch (script) {

        case AndroidSpellCheckerService.SCRIPT_LATIN:

            return Latin.getIndexOf(codePoint);

            return Latin.INDICES.get(codePoint, NOT_AN_INDEX);

        case AndroidSpellCheckerService.SCRIPT_CYRILLIC:

            return Cyrillic.getIndexOf(codePoint);

            return Cyrillic.INDICES.get(codePoint, NOT_AN_INDEX);

        case AndroidSpellCheckerService.SCRIPT_GREEK:

            return Greek.getIndexOf(codePoint);

            return Greek.INDICES.get(codePoint, NOT_AN_INDEX);

        default:

            throw new RuntimeException("Wrong script supplied: " + script);

        }