Runtime permissions

Output:

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/bt_location"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Location permission"
        android:textAllCaps="false"/>
    <Button
        android:id="@+id/bt_contact"
        android:layout_below="@+id/bt_location"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Contact permission"
        android:textAllCaps="false"/>
    
</RelativeLayout>

MainActivity.java

public class MainActivity extends BaseActivity implements View.OnClickListener {

    private Button mBTLocation;
    private Button mBTContact;

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

        mBTLocation = findViewById(R.id.bt_location);
        mBTContact = findViewById(R.id.bt_contact);

        mBTLocation.setOnClickListener(this);
        mBTContact.setOnClickListener(this);
    }

    @Override
    public void permissionGranted(String permission, int requestCode) {
        if (permission.equals(Manifest.permission.ACCESS_FINE_LOCATION) && requestCode == 10)
            Toast.makeText(this, "Location permission granted", Toast.LENGTH_SHORT).show();
        if (permission.equals(Manifest.permission.READ_CONTACTS) && requestCode == 20)
            Toast.makeText(this, "Contact read permission granted", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.bt_location:
                requestPermission(Manifest.permission.ACCESS_FINE_LOCATION, 10, 
                        "Please accept now location permission",
                        "You denied permission of location, please accept in permissions settings page");
                break;
            case R.id.bt_contact:
                requestPermission(Manifest.permission.READ_CONTACTS, 20, 
                        "Please accept now contact permission",
                        "You denied permission of contact, please accept in permissions settings page");
                break;
        }
    }
}

Manifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.procon.marshmallowpermissions">
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.READ_CONTACTS"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

BaseActivity.java

public abstract class BaseActivity extends AppCompatActivity {
    public abstract void permissionGranted(String permission, int requestCode);
    public String manualPermissionDesc;
    public String permission;
    public int requestCode;
    //public abstract void onFragmentInteraction(String grantedPermissionDesc);

    /**
     * Request and check any permission, show explanation dialogue, state granted permissions.
     * @param permission run-time permission
     * @param description for explanation dialogue.
     */
    protected void requestPermission(String permission, int requestCode, String description, String manualPermissionDesc) {
        this.manualPermissionDesc = manualPermissionDesc;
        this.permission = permission;
        this.requestCode = requestCode;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            /* Read contacts*/
            if (ContextCompat.checkSelfPermission(this, permission)
                    != PackageManager.PERMISSION_GRANTED) {
                if( ActivityCompat.shouldShowRequestPermissionRationale(this,
                        permission)){
                    showPermissionDialog(permission, description);
                }else {
                    ActivityCompat.requestPermissions( this, new String[]{permission},
                            requestCode);
                }
            } else {
                permissionGranted(permission, this.requestCode);
            }
        } else {
            permissionGranted(permission, this.requestCode);
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull final String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (grantResults.length > 0) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
                permissionGranted(permissions[0], this.requestCode);
            else if (grantResults[0] == PackageManager.PERMISSION_DENIED &&
                    !ActivityCompat.shouldShowRequestPermissionRationale(this,
                            permissions[0])) {
                showPermissionDialog(null, manualPermissionDesc);
            }
        }
    }



    public void showPermissionDialog(final String permission, String description) {
        final AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        dialog.setMessage(description);
        dialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                if (permission == null) {
                    Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                    intent.setData(Uri.fromParts("package", getPackageName(), null));
                    // Same request code transferred to activity.
                    startActivityForResult(intent, requestCode);
                }else{
                    ActivityCompat.requestPermissions(BaseActivity.this, new String[]{permission},
                            requestCode);
                }
                dialog.dismiss();
            }
        });
        dialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        dialog.create().show();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (this.requestCode == requestCode) {
          if(ContextCompat.checkSelfPermission(this, permission)
                  == PackageManager.PERMISSION_GRANTED)
            permissionGranted(permission, this.requestCode);
        }
    }
}