How to show installed app list in a listview without Checkbox getting unchecked when listview is scrolled?

Question

My goal is to display the list of installed apps in a custom listview (within an Activity) without checkbox getting unchecked (when listview is scrolled).

The Problem: When Listview is scrolled, the checked status of the checkbox becomes unchecked.

My Progress So Far: While this blog entry clearly shows how to get rid of the problem of checkboxes in listview getting unchecked, the difference is that it uses Model as the custom class whereas in my case it is a system class [i.e. the packageList1 = packageManager.getInstalledPackages(0);]

How can I resolve this? Below is my code attempt. I am able to successfully display apps in a listviw with checkboxes, just that checked status is getting unchecked when listview is scrolled.

I AM OPEN TO ANY METHOD AS AN ANSWER THAT WILL ENABLE ME TO SHOW LIST OF INSTALLED APPS IN A LISTVIEW WITHOUT THE CHECKED STATUS OF CHECKBOXES BECOMING UNCHECKED

My Custom Listadapter class:

public class Listadapter extends BaseAdapter {

private static String TAG = "focus";
List<PackageInfo> packageList;
Activity context;
PackageManager packageManager;
boolean[] itemChecked;

List<String> appNamestoBlock_local;

public Listadapter(Activity context, List<PackageInfo> packageList,
        PackageManager packageManager, List<String> appNamestoBlock) {
    super();
    this.context = context;
    this.packageList = packageList;
    this.packageManager = packageManager;
    this.appNamestoBlock_local = appNamestoBlock;

    itemChecked = new boolean[packageList.size()];
}

private String getSerializedBlockedAppNames() {
    String serializedBlockedAppNames;
    Log.v(TAG,
            "-------- List<String> list = "
                    + TextUtils.join(",", appNamestoBlock_local));
    serializedBlockedAppNames = TextUtils.join(",", appNamestoBlock_local);
    return serializedBlockedAppNames;
}

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.list_item, null);
        holder = new ViewHolder();

        holder.apkName = (TextView) convertView
                .findViewById(R.id.textView1);
        holder.ck1 = (CheckBox) convertView.findViewById(R.id.checkBox1);

        holder.ck1.setFocusable(false);
        convertView.setTag(holder);

    } else {

        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, 40, 40);
    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);

    // Log.v(TAG,
    // "-------- checking in getView() in ListAdapter if appName is in getSerializedBlockedAppNames()");
    if (getSerializedBlockedAppNames().contains(appName)) {
        Log.v(TAG + " ListAdapter",
                "-------- YES, appName is in getSerializedBlockedAppNames(), appName = "
                        + appName);
        holder.ck1.setChecked(true);
    }

    holder.ck1.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton buttonView,
                boolean isChecked) {
            if (isChecked) {
                itemChecked[position] = true;
            } else {
                itemChecked[position] = false;
            }
        }
    });

    return convertView;

}

}

In onCreate function of my main activity:

PackageManager packageManager = getPackageManager();
List<PackageInfo> packageList1 = packageManager.getInstalledPackages(0);

Listadapter Adapter = new Listadapter(MainActivityCircularSeekbar.this, packageList1, packageManager, blockedApps);

Answer 1

Activity

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.pm.PackageInfo;
import android.os.Bundle;
import android.widget.ListView;

public class AppScreen extends Activity {
private ListView list;
ArrayList<Datamodel> res;
MyAdapter _adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.app_screen);

    list = (ListView) findViewById(R.id.list);
    List<PackageInfo> _myapps = getPackageManager().getInstalledPackages(0);
    res = new ArrayList<Datamodel>();
    for (int i = 0; i < _myapps.size(); i++) {
        PackageInfo p = _myapps.get(i);

        Datamodel _model  = new Datamodel();
        _model.setAppname(p.applicationInfo.loadLabel(getPackageManager()).toString());
        res.add(_model);
        System.out.println("ajajajja" + res.size() + res.get(i).getAppname());
    }
    _adapter = new MyAdapter(getApplicationContext(), res);
    _adapter.notifyDataSetChanged();
    list.setAdapter(_adapter);


}

}

Datamodel class

public class Datamodel {

public String appname = "";
private boolean selected;

public String getAppname() {
    return appname;
}

public void setAppname(String appname) {
    this.appname = appname;
}

public boolean isSelected() {
    return selected;
}

public void setSelected(boolean isChecked) {
    this.selected = isChecked;
}

}

Adapter class

public class MyAdapter extends BaseAdapter {
Context _ctx;
LayoutInflater inflater;
public ArrayList<Datamodel> data;

public MyAdapter(Context c, ArrayList<Datamodel> _arraylist) {
    this._ctx = c;
    this.data = _arraylist;
}

@Override
public int getCount() {
    return data.size();
}

@Override
public Object getItem(int position) {
    return position;
}

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

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    inflater = (LayoutInflater) _ctx.getApplicationContext()
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View itemView = inflater.inflate(R.layout.inflator, parent, false);
    final CheckBox checks = (CheckBox) itemView.findViewById(R.id.b);
    final TextView _setappname = (TextView) itemView.findViewById(R.id.a);
    checks.setChecked(data.get(position).isSelected());

    Datamodel obj = data.get(position);
    _setappname.setText(obj.getAppname());
    checks.setTag(position);

    checks.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton buttonView,
                boolean isChecked) {                    
            int getPosition = (Integer) buttonView.getTag();
            Datamodel _obj = data.get(getPosition);
            data.get(position).setSelected(isChecked);
            String ss = _obj.getAppname();
            System.out.println("pos is" + getPosition);

        }
    });

    return itemView;
}

}

Activity XML

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.installedapps.AppScreen" >

<ListView 
    android:id="@+id/list"
    android:layout_height="fill_parent"
    android:layout_width="fill_parent">

</ListView>

Inflator xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="60dp"
android:gravity="center"
android:layout_gravity="center"
android:orientation="horizontal"
android:weightSum="2" >

<TextView
    android:id="@+id/a"
    android:layout_width="0dp"
    android:layout_height="fill_parent"
    android:textColor="#000"
    android:layout_gravity="center"
    android:gravity="center"
    android:layout_weight="1.7" />

<CheckBox
    android:id="@+id/b"
    android:layout_width="0dp"
     android:layout_gravity="center"
    android:gravity="center"
    android:layout_weight="0.3"
    android:layout_height="wrap_content" />

</LinearLayout>