4/n: Add basic enrollment for Face

Bug: 110589286

Test: fingerprint enrolling still works
Test: enrollment flow with and without a pin set up still works properly
Test: enrollment continues when configuration changes, stops otherwise

Change-Id: I39f76c7f1a16e9533cef573f87cf4b81cb20cb18

src/com/android/settings/biometrics/BiometricsEnrollEnrolling.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2018 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.biometrics;
+
+import android.content.Intent;
+import android.os.UserHandle;
+import android.view.View;
+
+import com.android.settings.R;
+import com.android.settings.password.ChooseLockSettingsHelper;
+
+/**
+ * Abstract base activity which handles the actual enrolling for biometrics.
+ */
+public abstract class BiometricsEnrollEnrolling extends BiometricEnrollBase
+        implements BiometricEnrollSidecar.Listener {
+
+    private static final String TAG_SIDECAR = "sidecar";
+
+    protected BiometricEnrollSidecar mSidecar;
+
+    /**
+     * @return the intent for the finish activity
+     */
+    protected abstract Intent getFinishIntent();
+
+    /**
+     * @return an instance of the biometric enroll sidecar
+     */
+    protected abstract BiometricEnrollSidecar getSidecar();
+
+    /**
+     * @return true if enrollment should start automatically.
+     */
+    protected abstract boolean shouldStartAutomatically();
+
+    /**
+     * @return true if enrollment should finish when onStop is called.
+     */
+    protected boolean shouldFinishOnStop() {
+        return true;
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        if (shouldStartAutomatically()) {
+            startEnrollment();
+        }
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        if (mSidecar != null) {
+            mSidecar.setListener(null);
+        }
+
+        if (shouldFinishOnStop() && !isChangingConfigurations()) {
+            if (mSidecar != null) {
+                mSidecar.cancelEnrollment();
+                getFragmentManager().beginTransaction().remove(mSidecar).commitAllowingStateLoss();
+            }
+            finish();
+        }
+    }
+
+    @Override
+    public void onBackPressed() {
+        if (mSidecar != null) {
+            mSidecar.setListener(null);
+            mSidecar.cancelEnrollment();
+            getFragmentManager().beginTransaction().remove(mSidecar).commitAllowingStateLoss();
+            mSidecar = null;
+        }
+        super.onBackPressed();
+    }
+
+    @Override
+    public void onClick(View v) {
+        switch (v.getId()) {
+            case R.id.skip_button:
+                setResult(RESULT_SKIP);
+                finish();
+                break;
+            default:
+                super.onClick(v);
+        }
+    }
+
+    public void startEnrollment() {
+        mSidecar = (BiometricEnrollSidecar) getFragmentManager().findFragmentByTag(TAG_SIDECAR);
+        if (mSidecar == null) {
+            mSidecar = getSidecar();
+            getFragmentManager().beginTransaction().add(mSidecar, TAG_SIDECAR).commit();
+        }
+        mSidecar.setListener(this);
+    }
+
+    protected void launchFinish(byte[] token) {
+        Intent intent = getFinishIntent();
+        intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT
+                | Intent.FLAG_ACTIVITY_CLEAR_TOP
+                | Intent.FLAG_ACTIVITY_SINGLE_TOP);
+        intent.putExtra(ChooseLockSettingsHelper.EXTRA_KEY_CHALLENGE_TOKEN, token);
+        if (mUserId != UserHandle.USER_NULL) {
+            intent.putExtra(Intent.EXTRA_USER_ID, mUserId);
+        }
+        startActivity(intent);
+        overridePendingTransition(R.anim.suw_slide_next_in, R.anim.suw_slide_next_out);
+        finish();
+    }
+
+}