Android Studio from Basic Development Introduction with Presentation

Android 9 Pie Updates

Updated Android 9 (API level 28) introduce great new features and capabilities for users and developers.

Some important features points are given below.

• Device Indoor positioning with Wi-Fi RTT

- support for the IEEE 802.11mc Wi-Fi protocol

- The device must have location services enabled and Wi-Fi scanning turned on

- Need ACCESS_FINE_LOCATION permission

• Device Display cutout support

- lets you find out the location and shape of the non-functional areas where content shouldn't be displayed.

- use the getDisplayCutout() method.

- attribute, layoutInDisplayCutoutMode, allows your app to lay out its content around a device's cutouts.

- attribute

LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT

LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES

LAYOUT_IN_DISPLAY_CUTOUT_MODE_NEVER

• Device Notifications Updated

 Enhanced messaging experience

- The Person class is used to identify people  their avatars and URIs

- other APIs, such as addMessage()

- The Person class also supports the Builder design pattern.

• Device Channel settings, broadcasts, and Do Not Disturb

You can use the isBlocked() method 

up settings using the new getNotificationChannelGroup() method.

NotificationManager reference

• Device now Multi-camera support and camera updates

ImageDecoder for drawables and bitmaps

• Device Animation

HDR VP9 Video, HEIF image compression, and Media APIs

supported in the MediaMuxer and MediaExtractor classes

• Device Data cost sensitivity in JobScheduler

• Device Neural Networks API 1.1

• Device having Autofill framework

• Device Security enhancements

• Device having Android Protected Confirmation

• Device having Hardware security module

• Device APK signature scheme with key rotation

• Device Option to allow key decryption only on unlocked devices

• Device have Legacy encryption support

• Device Deprecation of WPS

• Android backups

• Device Client-side encryption backups

• Define device conditions required for backup

• Accessibility

• Navigation semantics

• Accessibility pane titles

• Heading-based navigation

• Group navigation and output

• Window change details

• Rotation

• Text

• Power management

• Privacy changes

• Limited access to sensors in background

• Restricted access to call logs

How to get Device(Mobile) IME Number in Android Pro-grammatically

Need to add require permission in Android Manifest.xml file

<uses-permission android:name="android.permission.READ_PHONE_STATE" />

Now need to Allow user permission at run time in your AppCompatActivity

public void FindIME() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE)
                != PackageManager.PERMISSION_GRANTED) {
            // your READ_PHONE_STATE permission yet not granted.
            DevicePermission();
        } else {
            // your READ_PHONE_STATE permission is already been granted.
            ActivityCompat.requestPermissions(FlashScreen.this, new String[]{Manifest.permission.READ_PHONE_STATE}, PERMISSION_READ_STATE);
            GetIME();
        }
    }

Here we need to ask for user  permission

private static final int MY_PERMISSIONS_REQUEST_READ_PHONE_STATE = 0;
private void DevicePermission() {
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.READ_PHONE_STATE)) {
   
       new AlertDialog.Builder(FlashScreen.this)
                    .setTitle("Permission Request")
                    .setMessage(getString(R.string.permission_read_phone_state_rationale))
                    .setCancelable(false)
                    .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            //re-request
                            ActivityCompat.requestPermissions(FlashScreen.this,
                                    new String[]{Manifest.permission.READ_PHONE_STATE},
                                    MY_PERMISSIONS_REQUEST_READ_PHONE_STATE);
                        }
                    })
                    .setIcon(R.drawable.ic_login)
                    .show();
        } else {
            // READ_PHONE_STATE permission has not been granted yet. Request it directly.
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_PHONE_STATE},
                    MY_PERMISSIONS_REQUEST_READ_PHONE_STATE);
        }
 }

public void GetIME() {
        String deviceUniqueIdentifier = null;
        TelephonyManager tm = (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);
        if (null != tm) {
            deviceUniqueIdentifier = tm.getDeviceId();
        }
        if (null == deviceUniqueIdentifier || 0 == deviceUniqueIdentifier.length()) {
            deviceUniqueIdentifier = Settings.Secure.getString(this.getContentResolver(), Settings.Secure.ANDROID_ID);
        }

        IME_Device = deviceUniqueIdentifier;
        Log.i("Device Ime", "Value--------->" + IME_Device);
     
    }

@Override
 public void onRequestPermissionsResult(int requestCode,
 String permissions[], int[] grantResults) {
        switch (requestCode) {

            case MY_PERMISSIONS_REQUEST_READ_PHONE_STATE: {

                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // permission granted!
                 
                    GetIME();
                } else {
                    // permission denied
                    Toast.makeText(mContext, "Need to allow Read Phone state ..", Toast.LENGTH_LONG).show();
                }
            }
            break;

            case PERMISSION_READ_STATE: {
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // permission granted!
                 
                } else {
                    // permission denied
                    Toast.makeText(mContext, "Need to allow Read Phone state ..", Toast.LENGTH_LONG).show();
                }

            }
            break;
        }

    }

Device's Estimated Battery Time calculation

How to Calculate Android Estimated Battery Remaining Time. 

within your AppCompatActivity

need to do register Battery change event listener with BroadcastReceiver like  

this.registerReceiver(this.mBatInfoReceiver, 
new IntentFilter(Intent.ACTION_BATTERY_CHANGED));

Now you need to declare with Activity or where you need BroadcastReceiver 

int expectedlevel;
boolean isFirstAllow = true;
int second;

String strFirstTime,strSecondTime;

private BroadcastReceiver mBatInfoReceiver = new BroadcastReceiver(){
    @Override    public void onReceive(Context ctxt, Intent intent) {
        
        int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);

        SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
        Calendar c = Calendar.getInstance();

        if(isFirstAllow) {

            String formattedDate = format.format(c.getTime());
            strFirstTime  = formattedDate;

            expectedlevel = level - 1;
            isFirstAllow = false;
            second = new Time(System.currentTimeMillis()).getSeconds();
        }

        if(!isFirstAllow && level == expectedlevel){

            strSecondTime  = format.format(c.getTime());

            Date d1 = null;
            Date d2 = null;

            try {
                d1 = format.parse(strFirstTime);
                d2 = format.parse(strSecondTime);

                //in milliseconds               
               long diff = d2.getTime() - d1.getTime();

                long diffSeconds = diff / 1000 % 60;
                long diffMinutes = diff / (60 * 1000) % 60;
                long diffHours = diff / (60 * 60 * 1000) % 24;
                long diffDays = diff / (24 * 60 * 60 * 1000);

                System.out.print(diffDays + " days, ");
                System.out.print(diffHours + " hours, ");
                System.out.print(diffMinutes + " minutes, ");
                System.out.print(diffSeconds + " seconds.");

       // Now again we need percentage * difference time  = total long time value.
                long totalMinues =  diffMinutes * expectedlevel;
                long totalSecond  = diffSeconds * expectedlevel;
                long converttoMinutes = totalSecond/60;
                long addedAllMinues = totalMinues + converttoMinutes;

                // Now convert total minitues to millisecond;                
                 long AllMillisond = addedAllMinues * 60000;
     // Now Again convert this total Millisond to hours,minutes, second
                // for Battery Hours;
                long FinaldiffSeconds = AllMillisond / 1000 % 60;
                long FinaldiffMinutes = AllMillisond / (60 * 1000) % 60;
                long FinaldiffHours = AllMillisond / (60 * 60 * 1000) % 24;
                long FinaldiffDays = AllMillisond / (24 * 60 * 60 * 1000);

                System.out.print(FinaldiffDays + " days, ");
                System.out.print(FinaldiffHours + " hours, ");
                System.out.print(FinaldiffMinutes + " minutes, ");
                System.out.print(FinaldiffSeconds + " seconds.");

new AlertDialog.Builder(mcontext)
.setTitle("Battery Remaning Time")
.setMessage(FinaldiffDays + " days, "+""+FinaldiffHours + " hours," +
""+""+FinaldiffMinutes + " minutes, "+FinaldiffSeconds + " seconds.")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Continue with delete operation
   }
 })
.setNegativeButton(android.R.string.no, null)
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

    }
};

Apply Multiple Permissions RunTime

How to  give and apply run time multiple permissions in android,

First yo have to add permissions in Manifest file like below.

<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

<uses-permission android:name="android.permission.READ_CONTACTS"/>

Then, you have to code for the check permissions,add button in activitymain.xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout    
xmlns:android="http://schemas.android.com/apk/res/android"    
android:id="@+id/root_layout"    
android:layout_width="match_parent"    
android:layout_height="match_parent"    
android:padding="16dp"    
android:orientation="vertical"    
android:background="#e5ead3"   
android:gravity="center" >
    
<Button        
android:id="@+id/btn_do_task"        
android:layout_width="wrap_content"        
android:layout_height="wrap_content"        
android:text="Check Permissions"        
android:layout_gravity="center"/>
</LinearLayout>

After add button in xml file now add code in MainActivity.java file

import android.Manifest;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private Context mContext;
    private Activity mActivity;

    private Button btn_checkpermi;

    private static final int MY_PERMISSIONS_REQUEST_CODE = 123;
    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mContext = getApplicationContext();
        mActivity = MainActivity.this;
        
        btn_checkpermi = findViewById(R.id.btn_checkpermi);

        btn_checkpermi.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View view) {
                if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
                    checkPermission();
                }
            }
        });
    }

    protected void checkPermission(){
        if(ContextCompat.checkSelfPermission(mActivity,Manifest.permission.CAMERA)
                + ContextCompat.checkSelfPermission(
                mActivity,Manifest.permission.READ_CONTACTS)
                + ContextCompat.checkSelfPermission(
                mActivity,Manifest.permission.READ_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED){

            // when permissions not granted            
             if(ActivityCompat.shouldShowRequestPermissionRationale(
                    mActivity,Manifest.permission.CAMERA)
                    || ActivityCompat.shouldShowRequestPermissionRationale(
                    mActivity,Manifest.permission.READ_CONTACTS)
                    || ActivityCompat.shouldShowRequestPermissionRationale(
                    mActivity,Manifest.permission.READ_EXTERNAL_STORAGE)){
                // If we should give explanation of requested permissions
                // Show an alert dialog for request explanation                
                AlertDialog.Builder builder = new AlertDialog.Builder(mActivity);
                builder.setMessage("Camera, Read Contacts and Read External" +
                        " Storage permissions are required to do the task.");
                builder.setTitle("Please grant those permissions");
                builder.setPositiveButton("OK", new DialogInterface.OnClickListener() 
                {
                    @Override                    
                public void onClick(DialogInterface dialogInterface, int i) {
                        ActivityCompat.requestPermissions(
                                mActivity,
                                new String[]{
                                        Manifest.permission.CAMERA,
                                        Manifest.permission.READ_CONTACTS,
                                        Manifest.permission.READ_EXTERNAL_STORAGE },
                                MY_PERMISSIONS_REQUEST_CODE  );
                    }
                });
                builder.setNeutralButton("Cancel",null);
                AlertDialog dialog = builder.create();
                dialog.show();
            }else{
                //  request directly required permissions                
                        ActivityCompat.requestPermissions(
                        mActivity,
                        new String[]{
                                Manifest.permission.CAMERA,
                                Manifest.permission.READ_CONTACTS,
                                Manifest.permission.READ_EXTERNAL_STORAGE},
                        MY_PERMISSIONS_REQUEST_CODE );
            }
        }else {
            // Do your stuff here, permissions are already granted            
     Toast.makeText(mContext,"Permissions already granted",Toast.LENGTH_SHORT).show();
        }
    }

    @Override    
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults){
        switch (requestCode){
            case MY_PERMISSIONS_REQUEST_CODE:{
                // When request is cancelled, the results array are empty                
                    if(
                        (grantResults.length >0) &&
                                (grantResults[0]
                                        + grantResults[1]
                                        + grantResults[2]
                                        == PackageManager.PERMISSION_GRANTED                                )
                ){
                    // Permissions are granted                    
                    Toast.makeText(mContext,"Permissions granted.",Toast.LENGTH_SHORT).show();
                }else {
                    // Permissions are denied                    
                   Toast.makeText(mContext,"Permissions denied.",Toast.LENGTH_SHORT).show();
                }
                return;
            }
        }
    }
}

How to Bitmap Compress reduce size and Compress format

Here you can reduce Bitmap Size and Compress in specific file format

Button click take Camera Picture in Fragment and Save on External Storage

Fragment 
do with below Button Click code

mCamerabtn.setOnClickListener(new View.OnClickListener() {
    @Override    public void onClick(View v) {

        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());


        if (checkPermission(wantCameraPermission)) {

            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            File file = new File(Environment.getExternalStorageDirectory(),"test.jpg");

            outputFileUri = Uri.fromFile(file);

            Log.d("TAG", "outputFileUri intent" + outputFileUri);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            startActivityForResult(intent, 111);

        } else {

            requestPermission(wantCameraPermission, PERMISSION_REQUEST_CODE_Camera);
        }

        dialog.cancel();

    }

});

Check for require permission above 6.0

private boolean checkPermission(String permission) {

    if (Build.VERSION.SDK_INT >= 23) {
        int result = ContextCompat.checkSelfPermission(mcontext, permission);
        if (result == PackageManager.PERMISSION_GRANTED) {
            return true;
        } else {

            return false;
        }
    } else {
        return true;
    }
}

private void requestPermission(String permission, int permission_requestcode) {

        requestPermissions(new String[]{permission}, permission_requestcode);
}

@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grants) {
    List<Fragment> fragments = getChildFragmentManager().getFragments();

    //==================Start
    switch (requestCode) {

        case PERMISSION_REQUEST_CODE_Camera:


            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            File file = new File(Environment.getExternalStorageDirectory(),

                    "test.jpg");

            outputFileUri = Uri.fromFile(file);
            Log.d("TAG", "outputFileUri intent" + outputFileUri);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            getActivity().startActivityForResult(intent, 111);

            break;
        case PERMISSION_REQUEST_CODE:
            if (grants.length > 0 && grants[0] == PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(mcontext, "Permission Granted. Now you can Read data.",
                        Toast.LENGTH_LONG).show();

                ImageLoad();
            } else {
                Toast.makeText(mcontext, "Permission Denied. You cannot Read data.",
                        Toast.LENGTH_LONG).show();
            }
            break;
    }

    //================End
    if (fragments != null) {
        for (Fragment fragment : fragments) {
            if (fragment != null) {
                fragment.onRequestPermissionsResult(requestCode, permissions, grants);


            }
        }
    }
}

After Intent pass, we can Create Bitmap from Uri Code within onActivityResult

@Overridepublic void onActivityResult(int reqCode, int resultCode, Intent data) {
    super.onActivityResult(reqCode, resultCode, data);

    switch (reqCode) {

        case 111:

if (resultCode == RESULT_OK) {

    Log.d("TAG", "outputFileUri RESULT_OK" + outputFileUri);

    if (outputFileUri != null) {

    Bitmap bitmap = decodeSampledBitmapFromUri(outputFileUri, 300, 400);

      // Now this Bitmap you can set as per need in Imageview  imagePhoto

    imagePhoto.setImageBitmap(bitmap);

 break;
}
}

Here in below function we  need to pass Uri, int reqWidth, int reqHeight

public Bitmap decodeSampledBitmapFromUri(Uri uri, int reqWidth, int reqHeight) {
        Bitmap bm = null;

        try {
            final BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(((AppCompatActivity) mcontext).getContentResolver().openInputStream(uri), null, options);
            // Calculate inSampleSize            

           options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
            // Decode bitmap with inSampleSize set            

            options.inJustDecodeBounds = false;

            bm = BitmapFactory.decodeStream(((AppCompatActivity) mcontext).getContentResolver().openInputStream(uri), null, options);

        } catch (FileNotFoundException e) {
            e.printStackTrace();
            Toast.makeText(mcontext, e.toString(), Toast.LENGTH_LONG).show();
        }
        return bm;

    }