In this Android tip, I am going to show you how to query and display the installed applications on an Android device. A useful class that is used to achieve this goal is PackageManager. You obtain a PackageManager instance by calling the getPackageManager() method of your activity. From the PackageManager instance, you can get a list of installed apps using the queryIntentActivities() method. You will an Intent object and a flag to the method. The Intent object is created for the ACTION_MAIN action. The category of the Intent will be CATEGORY_LAUNCHER. The PackageManager instance can also be used to get app icon and title using the getApplicationIcon() and getApplicationLabel() method. You will pass to these methods an ApplicationInfo object. The ApplicationInfo object can be obtained from a ResolverInfo instance. The ResolverInfo instance stored information that is returned from resolving an intent against an IntentFilter. In the example application below, the app icons and titles are displayed in a ListView.









How let create an example application on listing installed apps in a ListView. You create a new Android project. In the activity_main.xml file, you add a ListView.

<RelativeLayout xmlns:android= "http://schemas.android.com/apk/res/android"

   xmlns:tools= "http://schemas.android.com/tools" android:layout_width="match_parent"

   android:layout_height="match_parent" android:paddingLeft= "@dimen/activity_horizontal_margin"

   android:paddingRight= "@dimen/activity_horizontal_margin"

   android:paddingTop= "@dimen/activity_vertical_margin"

   android:paddingBottom= "@dimen/activity_vertical_margin" tools:context=".MainActivity">

   <ListView

      android:id="@+id/list"

      android:layout_width="match_parent"

      android:layout_height="match_parent"

      />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

   android:layout_width="fill_parent"

   android:layout_height="wrap_content"

   android:orientation="horizontal"

   android:background="#000000"

   android:padding="5dip" >



   <ImageView

      android:id="@+id/appicon"

      android:layout_width="30dp"

      android:layout_height="30dp"

      android:padding="5sp"

      android:contentDescription="icon"

      />

   <TextView

      android:id="@+id/appname"

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:padding="10sp"

      android:textSize="20sp"

      android:textColor="#ffffff"

      android:textStyle="bold" >

   </TextView>



</LinearLayout> 

import android.graphics.drawable.Drawable;

public class InstalledApp {

   private String appTitle;

   private Drawable appIcon;

   public void setAppTitle(String appTitle){this.appTitle=appTitle;}

   public void setAppIcon(Drawable appIcon){this.appIcon=appIcon;}

   public String getAppTitle(){return appTitle;}

   public Drawable getAppIcon(){return appIcon;}

}

import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ArrayAdapter;

import android.widget.ImageView;

import android.widget.TextView;

import java.util.ArrayList;

public class ListAdapter extends ArrayAdapter {

   int vg;

   ArrayList<InstalledApp> apps;

   Context context;

   public ListAdapter(Context context, int vg, int id, ArrayList<InstalledApp> apps) {

      super(context, vg, apps);

      this.context = context;

      this.vg = vg;

      this.apps= apps;



   }

   public View getView(int position, View convertView, ViewGroup parent) {

      LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

      View itemView = inflater.inflate(vg, parent, false);

      ImageView imageView = (ImageView) itemView.findViewById(R.id.appicon);

      imageView.setImageDrawable(apps.get(position).getAppIcon());

      TextView textAppName = (TextView) itemView.findViewById(R.id.appname);

      textAppName.setText(apps.get(position).getAppTitle());

      return itemView;

   }

}

import android.content.Intent;

import android.content.pm.PackageManager;

import android.content.pm.ResolveInfo;

import android.graphics.drawable.Drawable;

import android.support.v7.app.ActionBarActivity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.ListView;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends ActionBarActivity {

   @Override

   protected void onCreate(Bundle savedInstanceState) {

      super.onCreate(savedInstanceState);

      setContentView(R.layout.activity_main);

      displayInstalledApps();

   }

   public void displayInstalledApps(){

      // Create an ArrayList object to store installed apps

      ArrayList<InstalledApp> apps_list=new ArrayList<InstalledApp>();

      // Create Intent object for ACTION_MAIN

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

      // We wish to query the installed apps so let specify CATEGORY_LAUNCHER to the intent's category

      mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);

      // Query the installed apps

      PackageManager packManager=getPackageManager();

      List appsList =packManager.queryIntentActivities( mainIntent, 0);

      // Get app titles and icons

      for (Object object : appsList) {



        ResolveInfo info = (ResolveInfo) object;

        Drawable icon= packManager.getApplicationIcon(info.activityInfo.applicationInfo);

        String appTitle=packManager.getApplicationLabel(info.activityInfo.applicationInfo).toString();

        InstalledApp app=new InstalledApp();

        app.setAppTitle(appTitle);

        app.setAppIcon(icon);

        apps_list.add(app);



      }

      // Show the app icons and titles in a ListView

      ListView list=(ListView)findViewById(R.id.list);

      ListAdapter adapter=new ListAdapter(this,R.layout.row_layout,R.id.appname,apps_list);

      list.setAdapter(adapter);



   }

}

Posted by: Dara | post date: 03-29-2015 | Subject: Android Apps Development