Avoid merging app sections across scripts.

import com.android.launcher3.compat.AlphabeticIndexCompat;

import com.android.launcher3.model.AppNameComparator;

import java.nio.charset.CharsetEncoder;

import java.nio.charset.StandardCharsets;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

     * Common interface for different merging strategies.

     */

    private interface MergeAlgorithm {

        boolean continueMerging(int sectionAppCount, int numAppsPerRow, int mergeCount);

        boolean continueMerging(SectionInfo section, SectionInfo withSection,

                int sectionAppCount, int numAppsPerRow, int mergeCount);

    }

    /**

     * The logic we use to merge sections on tablets.

     * The logic we use to merge sections on tablets.  Currently, we don't show section names on

     * tablet layouts, so just merge all the sections indiscriminately.

     */

    private static class TabletMergeAlgorithm implements MergeAlgorithm {

        @Override

        public boolean continueMerging(int sectionAppCount, int numAppsPerRow, int mergeCount) {

        public boolean continueMerging(SectionInfo section, SectionInfo withSection,

                int sectionAppCount, int numAppsPerRow, int mergeCount) {

            // Merge EVERYTHING

            return true;

        }

    }

    /**

     * The logic we use to merge sections on phones.

     * The logic we use to merge sections on phones.  We only merge sections when their final row

     * contains less than a certain number of icons, and stop at a specified max number of merges.

     * In addition, we will try and not merge sections that identify apps from different scripts.

     */

    private static class PhoneMergeAlgorithm implements MergeAlgorithm {

        private int mMinAppsPerRow;

        private int mMinRowsInMergedSection;

        private int mMaxAllowableMerges;

        private CharsetEncoder mAsciiEncoder;

        public PhoneMergeAlgorithm(int minAppsPerRow, int minRowsInMergedSection, int maxNumMerges) {

            mMinAppsPerRow = minAppsPerRow;

            mMinRowsInMergedSection = minRowsInMergedSection;

            mMaxAllowableMerges = maxNumMerges;

            mAsciiEncoder = StandardCharsets.US_ASCII.newEncoder();

        }

        @Override

        public boolean continueMerging(int sectionAppCount, int numAppsPerRow, int mergeCount) {

        public boolean continueMerging(SectionInfo section, SectionInfo withSection,

                int sectionAppCount, int numAppsPerRow, int mergeCount) {

            // Continue merging if the number of hanging apps on the final row is less than some

            // fixed number (ragged), the merged rows has yet to exceed some minimum row count,

            // and while the number of merged sections is less than some fixed number of merges

            int rows = sectionAppCount / numAppsPerRow;

            int cols = sectionAppCount % numAppsPerRow;

            // Ensure that we do not merge across scripts, currently we only allow for english and

            // native scripts so we can test if both can just be ascii encoded

            boolean isCrossScript = false;

            if (section.firstAppItem != null && withSection.firstAppItem != null) {

                isCrossScript = mAsciiEncoder.canEncode(section.firstAppItem.sectionName) !=

                        mAsciiEncoder.canEncode(withSection.firstAppItem.sectionName);

            }

            return (0 < cols && cols < mMinAppsPerRow) &&

                    rows < mMinRowsInMergedSection &&

                    mergeCount < mMaxAllowableMerges;

                    mergeCount < mMaxAllowableMerges &&

                    !isCrossScript;

        }

    }

        // Go through each section and try and merge some of the sections

        if (AllAppsContainerView.GRID_MERGE_SECTIONS && !hasFilter()) {

            int sectionAppCount = 0;

            for (int i = 0; i < mSections.size(); i++) {

            for (int i = 0; i < mSections.size() - 1; i++) {

                SectionInfo section = mSections.get(i);

                SectionInfo nextSection = mSections.get(i + 1);

                sectionAppCount = section.numApps;

                int mergeCount = 1;

                // Merge rows based on the current strategy

                while (mMergeAlgorithm.continueMerging(sectionAppCount, mNumAppsPerRow, mergeCount) &&

                        (i + 1) < mSections.size()) {

                    SectionInfo nextSection = mSections.remove(i + 1);

                while (mMergeAlgorithm.continueMerging(section, nextSection, sectionAppCount,

                        mNumAppsPerRow, mergeCount)) {

                    nextSection = mSections.remove(i + 1);

                    // Remove the next section break

                    mAdapterItems.remove(nextSection.sectionBreakItem);