FingerprintDialogCompat

FingerprintDialog from Android 28 (P) back ported to Android 23 (M).

Why do we need this libraryinterrobang

  • Fingerprint is currently the most secure and most user friendly way of authenticating the user in Android.

  • Android provides different APIs to deal with the fingerprint authentication. These APIs changed overtime.
    Android versions below API 23 did not support fingerprint hardware at all.
    Android versions between API 23 and API 27, uses FingerprintManager for fingerprint authentication. Developer has to manually authenticate by implementing bunch of APIs.
    Android version above API 28, uses FingerprintDialog for fingerprint authentication.

  • Due to the Android fragmentation developer has to implement all those APIs based on the android version.pensive It makes managing fingerprint authentication very hard.

  • This library aims to simplify fingerprint authentication by providing backport of the FingerprintDialog from Android P and provides single public APIs for the authentication all the way to API 14. So as a developer you don't have to deal with the complexity of dealing with different APIs.

Features:

  • Extremely lightweight.
  • Backport of FingerprintDialog from Android P, provides same fingerprint authentication on all Android versions.
  • Easy to integrate. All you have to do is implement the builder and you are done. The library will take care of authentication based on the device's android version.
  • Classifies different error codes provided by the Android framework and wraps them into different error callbacks for easy error handling.

How to use this library?

  • Gradle dependency:

    • Add below dependency into your build.gradle file.
      implementation 'com.kevalpatel2106:fingerprint-dialog-compat:1.0'

  • Prepare the builder.

    • Create the FingerprintDialogBuilder and provide the title, subtitle and the description. Application should explain why they need to access user's fingerprint.
      Dialog

    Java:

    final FingerprintDialogBuilder dialogBuilder = new FingerprintDialogBuilder(Activity.this)
    .setTitle(/* Title of the fingerprint dialog */)
    .setSubtitle(/* Subtitle of the fingerprint dialog */)
    .setDescription(/* Description of the fingerprint dialog */)
    .setNegativeButton(/* Negative button of the fingerprint dialog */);

    Kotlin:

    val dialogBuilder = FingerprintDialogBuilder(this)
    .set  Title(/* Title of the fingerprint dialog */)
    .setSubtitle(/* Subtitle of the fingerprint dialog */)
    .setDescription(/* Description of the fingerprint dialog */)
    .setNegativeButton(/* Negative button of the fingerprint dialog */)

  • Implement callbacks and show the dialog.

    • Implement the AuthenticationCallback to get callbacks for error or success from the fingerprint authentication dialog.

    Java:

    final AuthenticationCallback callback = new AuthenticationCallback() {
        @Override
        public void fingerprintAuthenticationNotSupported() {
            // Device doesn't support fingerprint authentication. May be device doesn't have fingerprint hardware or device is running on Android below Marshmallow.
            // Switch to alternate authentication method.
        }

        @Override
        public void hasNoFingerprintEnrolled() {
            // User has no fingerprint enrolled.
            // Application should redirect the user to the lock screen settings.
            // FingerprintUtils.openSecuritySettings(this)
        }

        @Override
        public void onAuthenticationError(final int errorCode, @Nullable final CharSequence errString) {
            // Unrecoverable error. Cannot use fingerprint scanner. Library will stop scanning for the fingerprint after this callback.
            // Switch to alternate authentication method.
        }

        @Override
        public void onAuthenticationHelp(final int helpCode, @Nullable final CharSequence helpString) {
            // Authentication process has some warning. such as "Sensor dirty, please clean it."
            // Handle it if you want. Library will continue scanning for the fingerprint after this callback.
        }

        @Override
        public void authenticationCanceledByUser() {
            // User canceled the authentication by tapping on the cancel button (which is at the bottom of the dialog).
        }

        @Override
        public void onAuthenticationSucceeded() {
            // Authentication success
            // Your user is now authenticated.
        }

        @Override
        public void onAuthenticationFailed() {
            // Authentication failed.
            // Library will continue scanning the fingerprint after this callback.
        }
    };

    Kotlin:

    val callback = object : AuthenticationCallback {

    override fun fingerprintAuthenticationNotSupported() {
        // Device doesn't support fingerprint authentication. May be device doesn't have fingerprint hardware or device is running on Android below Marshmallow.
        // Switch to alternate authentication method.
    }

    override fun hasNoFingerprintEnrolled() {
        // User has no fingerprint enrolled.
        // Application should redirect the user to the lock screen settings.
        // FingerprintUtils.openSecuritySettings(this@SecureActivity)
    }

    override fun onAuthenticationError(errorCode: Int, errString: CharSequence?) {    
        // Unrecoverable error. Cannot use fingerprint scanner. Library will stop scanning for the fingerprint after this callback.
        // Switch to alternate authentication method.
    }

    override fun onAuthenticationHelp(helpCode: Int, helpString: CharSequence?) {
        // Authentication process has some warning. such as "Sensor dirty, please clean it."
        // Handle it if you want. Library will continue scanning for the fingerprint after this callback.
    }

    override fun authenticationCanceledByUser() {
        // User canceled the authentication by tapping on the cancel button (which is at the bottom of the dialog).
    }

    override fun onAuthenticationSucceeded() {
        // Authentication success
        // Your user is now authenticated.
    }

    override fun onAuthenticationFailed() {
        // Authentication failed.
        // Library will continue scanning the fingerprint after this callback.
    }
}
    • Show the dialog and start fingerprint authentication.

    Java:

    dialogBuilder.show(getSupportFragmentanager(), callback);

    Kotlin:

    dialogBuilder.show(supportFragmentManager, callback)

auth_failed

auth_success

GitHub