FingerprintUiHelper.java revision fa47bc02900d407e1a730039e94221c2efc160d0 
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
17package com.android.settings.fingerprint;
18
19import android.hardware.fingerprint.FingerprintManager;
20import android.os.CancellationSignal;
21import android.os.Vibrator;
22import android.view.View;
23import android.widget.ImageView;
24import android.widget.TextView;
25
26import com.android.settings.R;
27
28/**
29 * Small helper class to manage text/icon around fingerprint authentication UI.
30 */
31public class FingerprintUiHelper extends FingerprintManager.AuthenticationCallback {
32
33    private static final long ERROR_TIMEOUT = 1300;
34    private static final long[] FP_ERROR_VIBRATE_PATTERN = new long[] {0, 30, 100, 30};
35    private static final long[] FP_SUCCESS_VIBRATE_PATTERN = new long[] {0, 30};
36
37    private ImageView mIcon;
38    private TextView mErrorTextView;
39    private CancellationSignal mCancellationSignal;
40
41    private Callback mCallback;
42    private FingerprintManager mFingerprintManager;
43
44    public FingerprintUiHelper(ImageView icon, TextView errorTextView, Callback callback) {
45        mFingerprintManager = icon.getContext().getSystemService(FingerprintManager.class);
46        mIcon = icon;
47        mErrorTextView = errorTextView;
48        mCallback = callback;
49    }
50
51    public void startListening() {
52        if (mFingerprintManager.getEnrolledFingerprints().size() > 0) {
53            mCancellationSignal = new CancellationSignal();
54            mFingerprintManager.authenticate(null, mCancellationSignal, 0 /* flags */, this, null);
55            setFingerprintIconVisibility(true);
56            mIcon.setImageResource(R.drawable.ic_fingerprint);
57        }
58    }
59
60    public void stopListening() {
61        if (mCancellationSignal != null) {
62            mCancellationSignal.cancel();
63            mCancellationSignal = null;
64        }
65    }
66
67    private boolean isListening() {
68        return mCancellationSignal != null && !mCancellationSignal.isCanceled();
69    }
70
71    private void setFingerprintIconVisibility(boolean visible) {
72        mIcon.setVisibility(visible ? View.VISIBLE : View.GONE);
73        mCallback.onFingerprintIconVisibilityChanged(visible);
74    }
75
76    @Override
77    public void onAuthenticationError(int errMsgId, CharSequence errString) {
78        showError(errString);
79        setFingerprintIconVisibility(false);
80    }
81
82    @Override
83    public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
84        showError(helpString);
85    }
86
87    @Override
88    public void onAuthenticationFailed() {
89        showError(mIcon.getResources().getString(
90                R.string.fingerprint_not_recognized));
91    }
92
93    @Override
94    public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
95        vibrateFingerprintSuccess();
96        mCallback.onAuthenticated();
97    }
98
99    private void showError(CharSequence error) {
100        if (!isListening()) {
101            return;
102        }
103
104        vibrateFingerprintError();
105        mIcon.setImageResource(R.drawable.ic_fingerprint_error);
106        mErrorTextView.setText(error);
107        mErrorTextView.removeCallbacks(mResetErrorTextRunnable);
108        mErrorTextView.postDelayed(mResetErrorTextRunnable, ERROR_TIMEOUT);
109    }
110
111    private void vibrateFingerprintError() {
112        mIcon.getContext().getSystemService(Vibrator.class).vibrate(FP_ERROR_VIBRATE_PATTERN, -1);
113    }
114
115    private void vibrateFingerprintSuccess() {
116        mIcon.getContext().getSystemService(Vibrator.class).vibrate(FP_SUCCESS_VIBRATE_PATTERN, -1);
117    }
118
119    private Runnable mResetErrorTextRunnable = new Runnable() {
120        @Override
121        public void run() {
122            mErrorTextView.setText("");
123            mIcon.setImageResource(R.drawable.ic_fingerprint);
124        }
125    };
126
127    public interface Callback {
128        void onAuthenticated();
129        void onFingerprintIconVisibilityChanged(boolean visible);
130    }
131}
132