ListSamples.java

package com.codetroopers.betterpickers.sample;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import java.text.Collator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ListSamples extends AppCompatActivity {

    public static final String INTENT_PATH = "com.doomonafireball.betterpickers.sample.Path";
    public static final String INTENT_SAMPLE = "com.doomonafireball.betterpickers.sample.SAMPLE";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list);

        Intent intent = getIntent();
        String path = intent.getStringExtra(INTENT_PATH);

        if (path == null) {
            path = "";
        } else {
            getSupportActionBar().setTitle(path);
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        }

        final ListView list = (ListView) findViewById(R.id.list);
        list.setAdapter(new SimpleAdapter(this, getData(path),
                android.R.layout.simple_list_item_1, new String[]{"title"},
                new int[]{android.R.id.text1}));
        list.setTextFilterEnabled(true);
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Map<String, Object> map = (Map<String, Object>) list.getItemAtPosition(position);

                Intent intent = (Intent) map.get("intent");
                startActivity(intent);
            }
        });
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                finish();
                return true;
        }
        return true;
    }

    protected List<Map<String, Object>> getData(String prefix) {
        List<Map<String, Object>> myData = new ArrayList<Map<String, Object>>();

        Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
        mainIntent.addCategory(INTENT_SAMPLE);

        PackageManager pm = getPackageManager();
        List<ResolveInfo> list = pm.queryIntentActivities(mainIntent, 0);

        if (null == list) {
            return myData;
        }

        String[] prefixPath;
        String prefixWithSlash = prefix;

        if (prefix.equals("")) {
            prefixPath = null;
        } else {
            prefixPath = prefix.split("/");
            prefixWithSlash = prefix + "/";
        }

        int len = list.size();

        Map<String, Boolean> entries = new HashMap<String, Boolean>();

        for (int i = 0; i < len; i++) {
            ResolveInfo info = list.get(i);
            CharSequence labelSeq = info.loadLabel(pm);
            String label = labelSeq != null
                    ? labelSeq.toString()
                    : info.activityInfo.name;

            if (prefixWithSlash.length() == 0 || label.startsWith(prefixWithSlash)) {

                String[] labelPath = label.split("/");

                String nextLabel = prefixPath == null ? labelPath[0] : labelPath[prefixPath.length];

                if ((prefixPath != null ? prefixPath.length : 0) == labelPath.length - 1) {
                    addItem(myData, nextLabel, activityIntent(
                            info.activityInfo.applicationInfo.packageName,
                            info.activityInfo.name));
                } else {
                    if (entries.get(nextLabel) == null) {
                        addItem(myData, nextLabel,
                                browseIntent(prefix.equals("") ? nextLabel : prefix + "/" + nextLabel));
                        entries.put(nextLabel, true);
                    }
                }
            }
        }

        Collections.sort(myData, NAME_COMPARATOR);

        return myData;
    }

    private final static Comparator<Map<String, Object>> NAME_COMPARATOR =
            new Comparator<Map<String, Object>>() {
                private final Collator collator = Collator.getInstance();

                public int compare(Map<String, Object> map1, Map<String, Object> map2) {
                    return collator.compare(map1.get("title"), map2.get("title"));
                }
            };

    protected Intent activityIntent(String pkg, String componentName) {
        Intent result = new Intent();
        result.setClassName(pkg, componentName);
        return result;
    }

    protected Intent browseIntent(String path) {
        Intent result = new Intent();
        result.setClass(this, ListSamples.class);
        result.putExtra(INTENT_PATH, path);
        return result;
    }

    protected void addItem(List<Map<String, Object>> data, String name, Intent intent) {
        Map<String, Object> temp = new HashMap<String, Object>();
        temp.put("title", name);
        temp.put("intent", intent);
        data.add(temp);
    }
}