Fingerprint Introduction FragmentActivity

Introducing MVVM architecture & fragments to biometric settings.
Here, we modify the first page of FingerprintEnrollIntroduction to use
new MVVM with Fragment architecture.

And with this new architecture, unit test and screen order will be
easier to be written or changed.

Bug: 236072782
Test: atest FingerprintEnrollmentViewModelTest AutoCredentialViewModelTest
	    FingerprintEnrollIntroViewModelTest FingerprintRepositoryTest
Change-Id: Icf12c91625db86c2c99081a0108203e607e77f74

src/com/android/settings/biometrics2/ui/model/CredentialModel.java

@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.biometrics2.ui.model;
+
+import static com.android.settings.biometrics.BiometricEnrollBase.EXTRA_KEY_CHALLENGE;
+import static com.android.settings.biometrics.BiometricEnrollBase.EXTRA_KEY_SENSOR_ID;
+import static com.android.settings.password.ChooseLockSettingsHelper.EXTRA_KEY_CHALLENGE_TOKEN;
+import static com.android.settings.password.ChooseLockSettingsHelper.EXTRA_KEY_GK_PW_HANDLE;
+
+import android.content.Intent;
+import android.os.UserHandle;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+
+import java.time.Clock;
+
+/**
+ * Secret credential data including
+ * 1. userId
+ * 2. sensorId
+ * 3. challenge
+ * 4. token
+ * 5. gkPwHandle
+ */
+public final class CredentialModel {
+
+    /**
+     * Default value for an invalid challenge
+     */
+    @VisibleForTesting
+    public static final long INVALID_CHALLENGE = -1L;
+
+    /**
+     * Default value if GkPwHandle is invalid.
+     */
+    public static final long INVALID_GK_PW_HANDLE = 0L;
+
+    /**
+     * Default value for a invalid sensor id
+     */
+    @VisibleForTesting
+    public static final int INVALID_SENSOR_ID = -1;
+
+    private final Clock mClock;
+
+    private final long mInitMillis;
+
+    private final int mUserId;
+
+    private int mSensorId;
+    @Nullable
+    private Long mUpdateSensorIdMillis = null;
+
+    private long mChallenge;
+    @Nullable
+    private Long mUpdateChallengeMillis = null;
+
+    @Nullable
+    private byte[] mToken;
+    @Nullable
+    private Long mUpdateTokenMillis = null;
+
+    private long mGkPwHandle;
+    @Nullable
+    private Long mClearGkPwHandleMillis = null;
+
+    public CredentialModel(@NonNull Intent intent, @NonNull Clock clock) {
+        mUserId = intent.getIntExtra(Intent.EXTRA_USER_ID, UserHandle.myUserId());
+        mSensorId = intent.getIntExtra(EXTRA_KEY_SENSOR_ID, INVALID_SENSOR_ID);
+        mChallenge = intent.getLongExtra(EXTRA_KEY_CHALLENGE, INVALID_CHALLENGE);
+        mToken = intent.getByteArrayExtra(EXTRA_KEY_CHALLENGE_TOKEN);
+        mGkPwHandle = intent.getLongExtra(EXTRA_KEY_GK_PW_HANDLE,
+                INVALID_GK_PW_HANDLE);
+        mClock = clock;
+        mInitMillis = mClock.millis();
+    }
+
+    /**
+     * Get userId for this credential
+     */
+    public int getUserId() {
+        return mUserId;
+    }
+
+    /**
+     * Check user id is valid or not
+     */
+    public static boolean isValidUserId(int userId) {
+        return userId != UserHandle.USER_NULL;
+    }
+
+    /**
+     * Get challenge
+     */
+    public long getChallenge() {
+        return mChallenge;
+    }
+
+    /**
+     * Set challenge
+     */
+    public void setChallenge(long value) {
+        mUpdateChallengeMillis = mClock.millis();
+        mChallenge = value;
+    }
+
+    /**
+     * Get challenge token
+     */
+    @Nullable
+    public byte[] getToken() {
+        return mToken;
+    }
+
+    /**
+     * Set challenge token
+     */
+    public void setToken(@Nullable byte[] value) {
+        mUpdateTokenMillis = mClock.millis();
+        mToken = value;
+    }
+
+    /**
+     * Check challengeToken is valid or not
+     */
+    public static boolean isValidToken(@Nullable byte[] token) {
+        return token != null;
+    }
+
+    /**
+     * Get gatekeeper password handle
+     */
+    public long getGkPwHandle() {
+        return mGkPwHandle;
+    }
+
+    /**
+     * Clear gatekeeper password handle data
+     */
+    public void clearGkPwHandle() {
+        mClearGkPwHandleMillis = mClock.millis();
+        mGkPwHandle = INVALID_GK_PW_HANDLE;
+    }
+
+    /**
+     * Check gkPwHandle is valid or not
+     */
+    public static boolean isValidGkPwHandle(long gkPwHandle) {
+        return gkPwHandle != INVALID_GK_PW_HANDLE;
+    }
+
+    /**
+     * Get sensor id
+     */
+    public int getSensorId() {
+        return mSensorId;
+    }
+
+    /**
+     * Set sensor id
+     */
+    public void setSensorId(int value) {
+        mUpdateSensorIdMillis = mClock.millis();
+        mSensorId = value;
+    }
+
+    /**
+     * Returns a string representation of the object
+     */
+    @Override
+    public String toString() {
+        final int gkPwHandleLen = ("" + mGkPwHandle).length();
+        final int tokenLen = mToken == null ? 0 : mToken.length;
+        final int challengeLen = ("" + mChallenge).length();
+        return getClass().getSimpleName() + ":{initMillis:" + mInitMillis
+                + ", userId:" + mUserId
+                + ", challenge:{len:" + challengeLen
+                + ", updateMillis:" + mUpdateChallengeMillis + "}"
+                + ", token:{len:" + tokenLen + ", isValid:" + isValidToken(mToken)
+                + ", updateMillis:" + mUpdateTokenMillis + "}"
+                + ", gkPwHandle:{len:" + gkPwHandleLen + ", isValid:"
+                + isValidGkPwHandle(mGkPwHandle) + ", clearMillis:" + mClearGkPwHandleMillis + "}"
+                + ", mSensorId:{id:" + mSensorId + ", updateMillis:" + mUpdateSensorIdMillis + "}"
+                + " }";
+    }
+}