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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License
     15  */
     16 
     17 package com.example.android.fingerprintdialog;
     18 
     19 import android.hardware.fingerprint.FingerprintManager;
     20 import android.os.CancellationSignal;
     21 import android.widget.ImageView;
     22 import android.widget.TextView;
     23 
     24 /**
     25  * Small helper class to manage text/icon around fingerprint authentication UI.
     26  */
     27 public class FingerprintUiHelper extends FingerprintManager.AuthenticationCallback {
     28 
     29     private static final long ERROR_TIMEOUT_MILLIS = 1600;
     30     private static final long SUCCESS_DELAY_MILLIS = 1300;
     31 
     32     private final FingerprintManager mFingerprintManager;
     33     private final ImageView mIcon;
     34     private final TextView mErrorTextView;
     35     private final Callback mCallback;
     36     private CancellationSignal mCancellationSignal;
     37 
     38     private boolean mSelfCancelled;
     39 
     40     /**
     41      * Constructor for {@link FingerprintUiHelper}.
     42      */
     43     FingerprintUiHelper(FingerprintManager fingerprintManager,
     44             ImageView icon, TextView errorTextView, Callback callback) {
     45         mFingerprintManager = fingerprintManager;
     46         mIcon = icon;
     47         mErrorTextView = errorTextView;
     48         mCallback = callback;
     49     }
     50 
     51     public boolean isFingerprintAuthAvailable() {
     52         // The line below prevents the false positive inspection from Android Studio
     53         // noinspection ResourceType
     54         return mFingerprintManager.isHardwareDetected()
     55                 && mFingerprintManager.hasEnrolledFingerprints();
     56     }
     57 
     58     public void startListening(FingerprintManager.CryptoObject cryptoObject) {
     59         if (!isFingerprintAuthAvailable()) {
     60             return;
     61         }
     62         mCancellationSignal = new CancellationSignal();
     63         mSelfCancelled = false;
     64         // The line below prevents the false positive inspection from Android Studio
     65         // noinspection ResourceType
     66         mFingerprintManager
     67                 .authenticate(cryptoObject, mCancellationSignal, 0 /* flags */, this, null);
     68         mIcon.setImageResource(R.drawable.ic_fp_40px);
     69     }
     70 
     71     public void stopListening() {
     72         if (mCancellationSignal != null) {
     73             mSelfCancelled = true;
     74             mCancellationSignal.cancel();
     75             mCancellationSignal = null;
     76         }
     77     }
     78 
     79     @Override
     80     public void onAuthenticationError(int errMsgId, CharSequence errString) {
     81         if (!mSelfCancelled) {
     82             showError(errString);
     83             mIcon.postDelayed(new Runnable() {
     84                 @Override
     85                 public void run() {
     86                     mCallback.onError();
     87                 }
     88             }, ERROR_TIMEOUT_MILLIS);
     89         }
     90     }
     91 
     92     @Override
     93     public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
     94         showError(helpString);
     95     }
     96 
     97     @Override
     98     public void onAuthenticationFailed() {
     99         showError(mIcon.getResources().getString(
    100                 R.string.fingerprint_not_recognized));
    101     }
    102 
    103     @Override
    104     public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
    105         mErrorTextView.removeCallbacks(mResetErrorTextRunnable);
    106         mIcon.setImageResource(R.drawable.ic_fingerprint_success);
    107         mErrorTextView.setTextColor(
    108                 mErrorTextView.getResources().getColor(R.color.success_color, null));
    109         mErrorTextView.setText(
    110                 mErrorTextView.getResources().getString(R.string.fingerprint_success));
    111         mIcon.postDelayed(new Runnable() {
    112             @Override
    113             public void run() {
    114                 mCallback.onAuthenticated();
    115             }
    116         }, SUCCESS_DELAY_MILLIS);
    117     }
    118 
    119     private void showError(CharSequence error) {
    120         mIcon.setImageResource(R.drawable.ic_fingerprint_error);
    121         mErrorTextView.setText(error);
    122         mErrorTextView.setTextColor(
    123                 mErrorTextView.getResources().getColor(R.color.warning_color, null));
    124         mErrorTextView.removeCallbacks(mResetErrorTextRunnable);
    125         mErrorTextView.postDelayed(mResetErrorTextRunnable, ERROR_TIMEOUT_MILLIS);
    126     }
    127 
    128     private Runnable mResetErrorTextRunnable = new Runnable() {
    129         @Override
    130         public void run() {
    131             mErrorTextView.setTextColor(
    132                     mErrorTextView.getResources().getColor(R.color.hint_color, null));
    133             mErrorTextView.setText(
    134                     mErrorTextView.getResources().getString(R.string.fingerprint_hint));
    135             mIcon.setImageResource(R.drawable.ic_fp_40px);
    136         }
    137     };
    138 
    139     public interface Callback {
    140 
    141         void onAuthenticated();
    142 
    143         void onError();
    144     }
    145 }
    146