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.asymmetricfingerprintdialog; 18 19 import com.google.common.annotations.VisibleForTesting; 20 21 import android.hardware.fingerprint.FingerprintManager; 22 import android.os.CancellationSignal; 23 import android.widget.ImageView; 24 import android.widget.TextView; 25 26 import javax.inject.Inject; 27 28 /** 29 * Small helper class to manage text/icon around fingerprint authentication UI. 30 * This class assumes that the {@link android.Manifest.permission#USE_FINGERPRINT} 31 * permission has already been granted. (As of API 23 this permission is normal instead of dangerous 32 * and is granted at install time.) 33 */ 34 @SuppressWarnings("MissingPermission") 35 public class FingerprintUiHelper extends FingerprintManager.AuthenticationCallback { 36 37 @VisibleForTesting static final long ERROR_TIMEOUT_MILLIS = 1600; 38 @VisibleForTesting static final long SUCCESS_DELAY_MILLIS = 1300; 39 40 private final FingerprintManager mFingerprintManager; 41 private final ImageView mIcon; 42 private final TextView mErrorTextView; 43 private final Callback mCallback; 44 private CancellationSignal mCancellationSignal; 45 46 @VisibleForTesting boolean mSelfCancelled; 47 48 /** 49 * Builder class for {@link FingerprintUiHelper} in which injected fields from Dagger 50 * holds its fields and takes other arguments in the {@link #build} method. 51 */ 52 public static class FingerprintUiHelperBuilder { 53 private final FingerprintManager mFingerPrintManager; 54 55 @Inject FingerprintUiHelperBuilder(FingerprintManager fingerprintManager)56 public FingerprintUiHelperBuilder(FingerprintManager fingerprintManager) { 57 mFingerPrintManager = fingerprintManager; 58 } 59 build(ImageView icon, TextView errorTextView, Callback callback)60 public FingerprintUiHelper build(ImageView icon, TextView errorTextView, Callback callback) { 61 return new FingerprintUiHelper(mFingerPrintManager, icon, errorTextView, 62 callback); 63 } 64 } 65 66 /** 67 * Constructor for {@link FingerprintUiHelper}. This method is expected to be called from 68 * only the {@link FingerprintUiHelperBuilder} class. 69 */ FingerprintUiHelper(FingerprintManager fingerprintManager, ImageView icon, TextView errorTextView, Callback callback)70 private FingerprintUiHelper(FingerprintManager fingerprintManager, 71 ImageView icon, TextView errorTextView, Callback callback) { 72 mFingerprintManager = fingerprintManager; 73 mIcon = icon; 74 mErrorTextView = errorTextView; 75 mCallback = callback; 76 } 77 isFingerprintAuthAvailable()78 public boolean isFingerprintAuthAvailable() { 79 return mFingerprintManager.isHardwareDetected() 80 && mFingerprintManager.hasEnrolledFingerprints(); 81 } 82 startListening(FingerprintManager.CryptoObject cryptoObject)83 public void startListening(FingerprintManager.CryptoObject cryptoObject) { 84 if (!isFingerprintAuthAvailable()) { 85 return; 86 } 87 mCancellationSignal = new CancellationSignal(); 88 mSelfCancelled = false; 89 mFingerprintManager 90 .authenticate(cryptoObject, mCancellationSignal, 0 /* flags */, this, null); 91 mIcon.setImageResource(R.drawable.ic_fp_40px); 92 } 93 stopListening()94 public void stopListening() { 95 if (mCancellationSignal != null) { 96 mSelfCancelled = true; 97 mCancellationSignal.cancel(); 98 mCancellationSignal = null; 99 } 100 } 101 102 @Override onAuthenticationError(int errMsgId, CharSequence errString)103 public void onAuthenticationError(int errMsgId, CharSequence errString) { 104 if (!mSelfCancelled) { 105 showError(errString); 106 mIcon.postDelayed(new Runnable() { 107 @Override 108 public void run() { 109 mCallback.onError(); 110 } 111 }, ERROR_TIMEOUT_MILLIS); 112 } 113 } 114 115 @Override onAuthenticationHelp(int helpMsgId, CharSequence helpString)116 public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) { 117 showError(helpString); 118 } 119 120 @Override onAuthenticationFailed()121 public void onAuthenticationFailed() { 122 showError(mIcon.getResources().getString( 123 R.string.fingerprint_not_recognized)); 124 } 125 126 @Override onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result)127 public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) { 128 mErrorTextView.removeCallbacks(mResetErrorTextRunnable); 129 mIcon.setImageResource(R.drawable.ic_fingerprint_success); 130 mErrorTextView.setTextColor( 131 mErrorTextView.getResources().getColor(R.color.success_color, null)); 132 mErrorTextView.setText( 133 mErrorTextView.getResources().getString(R.string.fingerprint_success)); 134 mIcon.postDelayed(new Runnable() { 135 @Override 136 public void run() { 137 mCallback.onAuthenticated(); 138 } 139 }, SUCCESS_DELAY_MILLIS); 140 } 141 showError(CharSequence error)142 private void showError(CharSequence error) { 143 mIcon.setImageResource(R.drawable.ic_fingerprint_error); 144 mErrorTextView.setText(error); 145 mErrorTextView.setTextColor( 146 mErrorTextView.getResources().getColor(R.color.warning_color, null)); 147 mErrorTextView.removeCallbacks(mResetErrorTextRunnable); 148 mErrorTextView.postDelayed(mResetErrorTextRunnable, ERROR_TIMEOUT_MILLIS); 149 } 150 151 @VisibleForTesting 152 Runnable mResetErrorTextRunnable = new Runnable() { 153 @Override 154 public void run() { 155 mErrorTextView.setTextColor( 156 mErrorTextView.getResources().getColor(R.color.hint_color, null)); 157 mErrorTextView.setText( 158 mErrorTextView.getResources().getString(R.string.fingerprint_hint)); 159 mIcon.setImageResource(R.drawable.ic_fp_40px); 160 } 161 }; 162 163 public interface Callback { 164 onAuthenticated()165 void onAuthenticated(); 166 onError()167 void onError(); 168 } 169 } 170