Install / Uninstall App from Another App Dynamically

If you want to install a custom app dynamically from your app, then it is quite simple. For this, you need to place APK on a downloadable URL, so that it can be downloaded directly. Then you can access app url and install. Since you want to install app from your app, then you need to download the APK first and then install your custom app. It thus need to do in background. 

Here is the code.

I installed custom app on launch of my app i.e. MainActivity

//Download APK and then Install Custom App

InstallApp customApp= new InstallApp();

customApp.setContext(myContext);

customApp.execute("http://APK-URL/AppName.apk");

Following is the code to download the apk in background then install app.

import android.content.Context;

import android.content.Intent;

import android.net.Uri;

import android.os.AsyncTask;

import android.os.Environment;

import android.util.Log;

import java.io.File;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

public class InstallApp extends AsyncTask<String,Void,Void> {

    private Context context;

    private final String TAG = "InstallApp";

    public void setContext(Context context){

        this.context = context;

    }

    @Override

    protected Void doInBackground(String... apk_url) {

        try {

            //URL of the APK, to download

            URL download_url = new URL(apk_url[0]);

            HttpURLConnection c = (HttpURLConnection) download_url.openConnection();

            c.setRequestMethod("GET");

            c.setDoOutput(true);

            c.connect();

            //Download APK to download folder. Save APK file with CustomApp.apk

            File file = new File(Environment.getExternalStorageDirectory() + "/download/");

            file.mkdirs();

            File downloadFile= new File(file, "CustomApp.apk");

            if(downloadFile.exists()){

                downloadFile.delete();

            }

            FileOutputStream fos = new FileOutputStream(downloadFile);

            InputStream is = c.getInputStream();

            byte[] buffer = new byte[1024];

            int lenght = 0;

            while ((lenght = is.read(buffer)) != -1) {

                fos.write(buffer, 0, lenght);

            }

            fos.close();

            is.close();

            //Install App Intent

            Intent install_intent = new Intent(Intent.ACTION_VIEW);

            install_intent.setDataAndType(Uri.fromFile(new File(Environment.getExternalStorageDirectory() + "/download/" + "CustomApp.apk")), "application/vnd.android.package-archive");

            install_intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

            context.startActivity(install_intent);

        } catch (Exception e) {

            Log.e(TAG, e.getMessage());

        }

        return null;

    }

}

Similarly, if you want to uninstall app from another app, then here is code:

 //Uninstall app

Uri packageUri = Uri.parse("package:"+"name of app  package");

//OS >= 14 supports ACTION_UNINSTALL_PACKAGE
//OS < 14 ACTION_DELETE
//Therefore, for all OS, use the following.

Intent appUninstall= new Intent( (Build.VERSION.SDK_INT >= 14)?Intent.ACTION_UNINSTALL_PACKAGE: Intent.ACTION_DELETE, packageUri);

startActivity(appUninstall);

Device Information in Android

If you are working with any app that needs android device information, then don't worry. Getting device information is quite easy. Although there are several solutions available, but may be in pieces. I am developing a Mobile Device Management (MDM) app for which I've to gather device information. So, I decided to put everything at one place which may be useful for my fellow developers. Here is implementation of explicit information about any Android Device i.e. Phone, Tablet, Phone / Tablet with or without SIM.

private String sim_serial = "", sim_carrier = "", sim_country = "", device_manufacturer = "", device_model = "";
private String device_imei = "", device_serial = "", device_manufacturer_serial = "", device_OS_version = "";


//Get Device Info
 private void getDeviceInformation(){

        try{

            TelephonyManager tm =(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
            boolean isSim = checkSIMCard();
            if(isSim){

                sim_serial =tm.getSimSerialNumber();
                sim_carrier=tm.getNetworkOperatorName();
                sim_country = tm.getSimCountryIso();
            }
            device_model = Build.MODEL;
            device_serial = Build.SERIAL;
            device_imei =tm.getDeviceId();
            device_manufacturer_serial = getManufacturerSerial();
            device_manufacturer = Build.MANUFACTURER;
            device_OS_version = android.os.Build.VERSION.RELEASE;
        }
        catch (Exception e){

            e.printStackTrace();
        }
    }

    //To check availability of SIM Card
    private boolean checkSIMCard(){

        TelephonyManager tm= (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        int simState = tm.getSimState();
        boolean isSIM = false;

        switch (simState) {

            case TelephonyManager.SIM_STATE_ABSENT:
                isSIM = false;
                break;

            case TelephonyManager.SIM_STATE_READY:
                isSIM = true;
                break;
        }
        return isSIM;
    }

    //Get manufacturer serial number, need in case of a non GSM Tablet.
    private String getManufacturerSerial() {

        String serial = null;
        try {
            Class<?> c = Class.forName("android.os.SystemProperties");
            Method get = c.getMethod("get", String.class, String.class);
            serial = (String) get.invoke(c, "ril.serialnumber", "unknown");
        } catch (Exception e) {

            e.printStackTrace();
        }
        return serial;
    }

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Cheers!

List of Installed Apps on Android Device

Here is an easy way to get a list of installed apps on Android phone / tablet. 

PackageManager packManager = null;
ArrayList<ApplicationInfo> installedAppsList = new ArrayList<>();

try {

    packManager = context.getPackageManager();

    if (packManager != null) {
        
        installedAppsList = packManager .getInstalledApplications(0);
    }
} catch (Exception ex) {

       ex.printStackTrace();

}

Cheers!

Create Button with Rounded Corners

Rounded corners buttons are very common for most of the applications. For this, it is more useful if you define a resource file in drawable folder for rounded corners. Define a custome style for button in styles file. Textcolor and background of button depends on your choice. You simply need to replace textcolor and background as per your needs. If you need only one button with rounded corners then you don't need to define style. Otherwise, for multiple buttons style will be very useful.

1. Create a resource rounded_corners.xml layout for rounded corners in @drawable.

This is rounded_corners_button.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:padding="10dp"
        android:shape="rectangle" >

        <!-- This is background color-->
        <solid android:color="#ffffff"/>
        <corners android:radius="5dp"/>
    </shape>
</resources>

2. Now, in styles file, define a custom style for a button with rounded corners. This style can be used for multiple Buttons of your application. Here is style for the button.

<style name="CutomButton" parent="android:style/Widget.Button" >

   <item name="android:layout_width">wrap_content</item>

   <item name="android:layout_height">wrap_content</item>

   <item name="android:textColor">#34bdab</item></item>  

   <item name="android:textSize">20sp</item></item>                   <item name="android:background">@drawable/rounded_corners_button</item>    

 </style>

3. Finally, in your activity layout, create a button and use above mentioned style for button as below:

<Button
             android:id="@+id/btn_signup"
             style="@style/CustomButton"
             android:text="@string/signup"
             android:layout_gravity="center_horizontal"/>

That's all you need for a rounded corner button.

RCPlease don't hesitate to contact me.
Thank you

RadioGroup - Radio Buttons with Selectors

In this post, I created a layout with three Radio buttons. Since all three radio buttons are distinct, therefore, one selector for each radio button. Selector is used to switch between Checked and Un-Checked states and load different images when radio button is checked and un-checked.

First things first, we create three selectors.

Selector One for First Radio Button:

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
          <item android:drawable="@drawable/one_selected" android:state_checked="true"/>
          <item android:drawable="@drawable/one_unselected" android:state_checked="false"/>
</selector>

Selector Two for Second Radio Button:

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
          <item android:drawable="@drawable/two_selected" android:state_checked="true"/>
          <item android:drawable="@drawable/two_unselected" android:state_checked="false"/>
</selector>

Selector Three for Third Radio Button:

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
          <item android:drawable="@drawable/three_selected" android:state_checked="true"/>
          <item android:drawable="@drawable/three_unselected" android:state_checked="false"/>
</selector>

*one_selected / one_unselected etc. are two images which are shown when button is checked OR unchecked accordingly. Similarly, images required for other two radio buttons.

Now, create a layout and use aforementioned three selectors in respective radio buttons as below:

<?xml version="1.0" encoding="UTF-8"?>
<RadioGroup xmlns:android="http://schemas.android.com/apk/res/android"
                 android:padding="5dp"
                 android:gravity="center"
                 android:layout_height="wrap_content"
                 android:layout_width="wrap_content"
                 android:layout_gravity="center_horizontal"
                 android:orientation="horizontal">

<RadioButton
                 android:layout_height="wrap_content"
                 android:layout_width="wrap_content" "
                 android:button="@null"
                 android:background="@drawable/selector_one"
                 android:layout_margin="5dp"
                 android:id="@+id/one"/>

<RadioButton
                 android:layout_height="wrap_content"
                 android:layout_width="wrap_content"
                 android:button="@null"
                 android:background="@drawable/selector_two"
                 android:layout_margin="5dp"
                 android:id="@+id/two"/>

<RadioButton
                 android:layout_height="wrap_content"
                 android:layout_width="wrap_content"
                 android:button="@null"
                 android:background="@drawable/selector_three"
                 android:layout_margin="5dp"
                 android:id="@+id/three"/>
</RadioGroup>

That's it.

Please don't hesitate to contact me.
Thank you

ImageView with Multiple TextViews - Custom Row

This is a custom row for a Listview. In this row, there is an ImageView to hold an image, and three TextViews for different texts. I created this layout for my Gym list, which contains the Picture / Thumbnail, Name, City, and Distance of the Gym.


<?xml version="1.0" encoding="UTF-8"?>
-<RelativeLayout
                xmlns:android="http://schemas.android.com/apk/res/android"
                android:padding="5dp"
                android:gravity="center"
                android:layout_height="wrap_content"
                android:layout_width="fill_parent" >

<!-- ImageView -->
-<LinearLayout
                android:padding="5dp"
                android:layout_height="wrap_content"
                android:layout_width="wrap_content"
                android:layout_alignParentLeft="true"
                android:id="@+id/gym_image">

<ImageView
                android:layout_height="80dp"
                android:layout_width="110dp"
                android:id="@+id/list_image"
                android:background="@drawable/gym_thumbnail"/>

</LinearLayout>

<!-- Gym Name-->
<TextView
                android:layout_height="wrap_content"
                android:layout_width="wrap_content"
                android:id="@+id/gym_name"
                android:textStyle="bold"
                android:textSize="20sp"
                android:typeface="sans"
                android:textColor="#040404"
                android:text="@string/gym_name"
                android:layout_toRightOf="@+id/gym_image"
                android:layout_marginTop="20dp"/>

<!-- Gym City -->
<TextView
                android:layout_height="wrap_content"
                android:layout_width="fill_parent"
                android:id="@+id/gym_location"
                android:textSize="15sp"
                android:textColor="#888888"
                android:text="@string/gym_city"
                android:layout_toRightOf="@+id/gym_image"
                android:layout_marginTop="1dip"
                android:layout_below="@id/gym_name"/>

<!-- Gym Distance -->
<TextView
                android:gravity="right"
                android:layout_height="wrap_content"
                android:layout_width="wrap_content"
                android:layout_marginRight="5dp"
                android:id="@+id/gym_distance"
                android:textStyle="bold"
                android:textSize="15sp"
                android:textColor="#888888"
                android:text="@string/gym_distance"
                android:layout_alignTop="@id/gym_name"
                android:layout_alignParentRight="true"/>

</RelativeLayout

While development, it isn't easy to create layouts from scratch and customize it as per needs. Therefore, it is more time saving to pick a readymade layout and require few changes only.

Please don't hesitate to contact me.

Thank you