Implementation of AsyncTask in a Fragment

Question

Right now I have three scrollable tab fragments each with a list of installed apps. However, when I hit the button to go to the activity and then scroll through the listview it is extremely slow.

enter image description here

I am trying to create an AsyncTask subclass in my fragments and prepare my adapter in doInBackground() and call setAdapter in onPostExecute().

I have tried these:

implement AsyncTask in Fragment android

http://javatechig.com/android/how-to-get-list-of-installed-apps-in-android

but not too much luck.

This is my modified code:

package com.spicycurryman.getdisciplined10.app;

import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageItemInfo;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;

import com.ibc.android.demo.appslist.app.ApkAdapter;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;


public class InstalledAppActivity extends Fragment
        implements OnItemClickListener {

    PackageManager packageManager;
    ListView apkList;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        setHasOptionsMenu(true);
        View rootView = inflater.inflate(R.layout.user_installed, container, false);
        AppBoost appBoost = new AppBoost();
        appBoost.execute(apkList);


        return rootView;

    }



    private class AppBoost extends AsyncTask{
        ListView apkList;

        @Override
        protected Object doInBackground(Object[] objects) {
            packageManager = getActivity().getPackageManager();
            List<PackageInfo> packageList = packageManager
                    .getInstalledPackages(PackageManager.GET_PERMISSIONS);

            List<PackageInfo> packageList1 = new ArrayList<PackageInfo>();

        /*To filter out System apps*/
            for(PackageInfo pi : packageList) {
                boolean b = isSystemPackage(pi);
                if(!b) {
                    packageList1.add(pi);
                }
            }

            //sort by application name

            final PackageItemInfo.DisplayNameComparator comparator = new PackageItemInfo.DisplayNameComparator(packageManager);

            Collections.sort(packageList1, new Comparator<PackageInfo>() {
                @Override
                public int compare(PackageInfo lhs, PackageInfo rhs) {
                    return comparator.compare(lhs.applicationInfo, rhs.applicationInfo);
                }


            });


            apkList.setAdapter(new ApkAdapter(getActivity(), packageList1, packageManager));

            apkList.setOnItemClickListener((OnItemClickListener) this);


            return apkList;
        }




    }

    /**
     * Return whether the given PackgeInfo represents a system package or not.
     * User-installed packages (Market or otherwise) should not be denoted as
     * system packages.
     *
     * @param pkgInfo
     * @return boolean
     */
    private boolean isSystemPackage(PackageInfo pkgInfo) {
        return ((pkgInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) ? true
                : false;
    }


// Don't need in Fragment
/*@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.block, menu);
   // super.onCreateOptionsMenu(menu,inflater);
}*/

    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

    }
}

I'm not sure what I am doing wrong. Nothing shows up in the current tab, but it seems like I implemented everything properly.

Edit: Here is my adapter:

package com.ibc.android.demo.appslist.app;

import android.app.Activity;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.TextView;
import android.view.View.OnClickListener;

import com.spicycurryman.getdisciplined10.app.R;

import java.util.List;

public class ApkAdapter extends BaseAdapter {


    List<PackageInfo> packageList;
    Activity context;
    PackageManager packageManager;
    boolean[] itemChecked;

    public ApkAdapter(Activity context, List<PackageInfo> packageList,
                      PackageManager packageManager) {
        super();
        this.context = context;
        this.packageList = packageList;
        this.packageManager = packageManager;
        itemChecked = new boolean[packageList.size()];
    }

    private class ViewHolder {
        TextView apkName;
        CheckBox ck1;
    }

    public int getCount() {
        return packageList.size();
    }

    public Object getItem(int position) {
        return packageList.get(position);
    }

    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        final ViewHolder holder;

        LayoutInflater inflater = context.getLayoutInflater();

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.installed_apps, null);
            holder = new ViewHolder();

            holder.apkName = (TextView) convertView
                    .findViewById(R.id.appname);
            holder.ck1 = (CheckBox) convertView
                    .findViewById(R.id.checkBox1);

            convertView.setTag(holder);
             //holder.ck1.setTag(packageList.get(position));

        } else {

            holder = (ViewHolder) convertView.getTag();
        }
        // ViewHolder holder = (ViewHolder) convertView.getTag();
        PackageInfo packageInfo = (PackageInfo) getItem(position);

        Drawable appIcon = packageManager
                .getApplicationIcon(packageInfo.applicationInfo);
        String appName = packageManager.getApplicationLabel(
                packageInfo.applicationInfo).toString();
        appIcon.setBounds(0, 0, 75, 75);
        holder.apkName.setCompoundDrawables(appIcon, null, null, null);
        holder.apkName.setCompoundDrawablePadding(15);
        holder.apkName.setText(appName);
        holder.ck1.setChecked(false);

        if (itemChecked[position])
            holder.ck1.setChecked(true);
        else
            holder.ck1.setChecked(false);

        holder.ck1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if (holder.ck1.isChecked())
                    itemChecked[position] = true;
                else
                    itemChecked[position] = false;
            }
        });

        return convertView;

    }



}

do not play with any ui components at doInBackground method, all ui operation must be done at UI thread. Take your listview operations to onPostExecute method. Also try to debug your code. You'll find your problem. — Devrim, Jul 22 '14 at 17:29
How do I know if it is a ui component? and how to run onPostExecute? I get runtime errors when I call it. — Rohit Tigga, Jul 22 '14 at 17:32
You know, listView is a UI component. You may read more about async tasks. onPostExecute is one of the methods of async task which runs on UI Thread. (doInBackground runs on a seperate thread). — Devrim, Jul 22 '14 at 17:37
onPostExecute() should automatically get called once doInBackground() finished. — Veselin Romić, Jul 22 '14 at 17:37
Also, @aegean, you can run UI code in doInBackground() too, just call runOnUiThread() for the code that needs to interact with the UI. — Veselin Romić, Jul 22 '14 at 17:38

score 2 · Accepted Answer · answered Jul 31 '14 at 17:22

Here's an example:

PackageManager packageManager;
    ListView apkList;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        setHasOptionsMenu(true);
        View rootView = inflater.inflate(R.layout.user_installed, container, false);
        packageManager = getActivity().getPackageManager();


        /*To filter out System apps*/

        apkList = (ListView) rootView.findViewById(R.id.applist);

        new LoadApplications(getActivity().getApplicationContext()).execute();


        return rootView;
    }

    /**
     * Return whether the given PackageInfo represents a system package or not.
     * User-installed packages (Market or otherwise) should not be denoted as
     * system packages.
     *
     * @param pkgInfo
     * @return boolean
     */
    private boolean isSystemPackage(PackageInfo pkgInfo) {
        return ((pkgInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) ? true
                : false;
    }

    private boolean isSystemPackage1(PackageInfo pkgInfo) {
        return ((pkgInfo.applicationInfo.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0) ? false
                : true;
    }


// Don't need in Fragment
/*@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.block, menu);
   // super.onCreateOptionsMenu(menu,inflater);
}*/

    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

    }


    private class LoadApplications extends AsyncTask<Void, Void, Void> {

        Context mContext;

        private ProgressDialog pDialog;
        List<PackageInfo> packageList1 = new ArrayList<PackageInfo>();

        public LoadApplications(Context context){
            Context mContext = context;
        }




        @Override
        protected Void doInBackground(Void... params) {

            List<PackageInfo> packageList = packageManager
                    .getInstalledPackages(PackageManager.GET_PERMISSIONS);


          /*  List<ApplicationInfo> list = mContext.getPackageManager().getInstalledApplications(PackageManager.GET_UNINSTALLED_PACKAGES);


            for(int n = 0;n<list.size();n++){
                if ((list.get(n).flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP))
            }*/


            for(PackageInfo pi : packageList) {
                boolean b = isSystemPackage(pi);
                boolean c = isSystemPackage1(pi);

                if(!b || !c ) {
                    packageList1.add(pi);
                }
            }

            //sort by application name

            final PackageItemInfo.DisplayNameComparator comparator = new PackageItemInfo.DisplayNameComparator(packageManager);

            Collections.sort(packageList1, new Comparator<PackageInfo>() {
                @Override
                public int compare(PackageInfo lhs, PackageInfo rhs) {
                    return comparator.compare(lhs.applicationInfo, rhs.applicationInfo);
                }
            });



            return null;
        }

Devrim · Answer 2 · 2014-07-22T17:47:56.223

0

At getView method you have queries with PackageManager and that takes time which leads a delay on scrolling.

Drawable appIcon = packageManager.getApplicationIcon(packageInfo.applicationInfo);
String appName = packageManager.getApplicationLabel(packageInfo.applicationInfo).toString();

To solve it, you can get all icons and application names with an async task before filling the list or execute an asyncTask at getView method to get those data.

edited Jul 22 '14 at 17:47

answered Jul 22 '14 at 17:34

Devrim

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That is exactly what I am trying to do, but I am trying to figure out how – Rohit Tigga Jul 22 '14 at 17:38
I can not write the code for you, sorry. Just read more about async tasks. You'll figure it out shortly. – Devrim Jul 22 '14 at 17:44
wait but I do the asynctask in my adapter class? – Rohit Tigga Jul 22 '14 at 17:59
Why not? That is an option too. Just google it, I've seen many examples like what you are trying to do. – Devrim Jul 22 '14 at 18:44
Okay I'll figure this out then. Thanks for the help. – Rohit Tigga Jul 22 '14 at 18:49
I was just tryna confirm whether it is optimal to do it in the adapter or separately in each fragment because I have 3 fragments – Rohit Tigga Jul 22 '14 at 18:50

Implementation of AsyncTask in a Fragment

2 Answers2