Integrate QrCode Camera with WifiDppQrCodeScannerFragment

Bug: 118797380
Test: RunSettingsRoboTests
Change-Id: I328bebbbcf44136df2c18ca1929a5da377a0cf6b

res/layout-land/wifi_dpp_qrcode_scanner_fragment.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     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.
+-->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/root"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <include layout="@layout/wifi_dpp_fragment_header"/>
+
+    <FrameLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+        <SurfaceView
+            android:id="@+id/preview_view"
+            android:layout_width="426dp"
+            android:layout_height="320dp"
+            android:layout_gravity="center"/>
+        <com.android.settings.wifi.qrcode.QrDecorateView
+            android:id="@+id/decorate_view"
+            android:layout_width="426dp"
+            android:layout_height="320dp"
+            android:layout_gravity="center"/>
+    </FrameLayout>
+
+    <TextView android:id="@+id/error_message"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"/>
+
+    <include layout="@layout/wifi_dpp_fragment_footer"
+        android:gravity="center|bottom"/>
+
+</LinearLayout>
+

res/layout/wifi_dpp_qrcode_scanner_fragment.xml

@@ -32,7 +32,7 @@
             android:layout_width="320dp"
             android:layout_height="426dp"
             android:layout_gravity="center"/>
-        <ImageView
+        <com.android.settings.wifi.qrcode.QrDecorateView
             android:id="@+id/decorate_view"
             android:layout_width="320dp"
             android:layout_height="426dp"

src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivity.java

@@ -21,6 +21,7 @@ import android.app.Activity;
 import android.os.Bundle;
 import android.util.Log;
 
+import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
 
@@ -86,21 +87,21 @@ public class WifiDppConfiguratorActivity extends InstrumentedActivity {
     }
 
     private void addQrCodeScannerFragment() {
-        WifiDppQrCodeScannerFragment fragment = new WifiDppQrCodeScannerFragment();
+        final WifiDppQrCodeScannerFragment fragment = new WifiDppQrCodeScannerFragment();
         mFragmentTransaction.add(R.id.fragment_container, fragment);
-        mFragmentTransaction.addToBackStack(null);
+        mFragmentTransaction.addToBackStack(/* name */ null);
         mFragmentTransaction.commit();
     }
 
     private void addQrCodeGeneratorFragment() {
-        WifiDppQrCodeGeneratorFragment fragment = new WifiDppQrCodeGeneratorFragment();
+        final WifiDppQrCodeGeneratorFragment fragment = new WifiDppQrCodeGeneratorFragment();
         mFragmentTransaction.add(R.id.fragment_container, fragment);
-        mFragmentTransaction.addToBackStack(null);
+        mFragmentTransaction.addToBackStack(/* name */ null);
         mFragmentTransaction.commit();
     }
 
     private void addChooseSavedWifiNetworkFragment() {
-        ActionBar action = getActionBar();
+        final ActionBar action = getActionBar();
         if (action != null) {
             action.hide();
         }
@@ -108,7 +109,18 @@ public class WifiDppConfiguratorActivity extends InstrumentedActivity {
         WifiDppChooseSavedWifiNetworkFragment fragment =
                 new WifiDppChooseSavedWifiNetworkFragment();
         mFragmentTransaction.add(R.id.fragment_container, fragment);
-        mFragmentTransaction.addToBackStack(null);
+        mFragmentTransaction.addToBackStack(/* name */ null);
         mFragmentTransaction.commit();
     }
+
+    @Override
+    protected void onStop() {
+        final Fragment fragment = mFragmentManager.findFragmentById(R.id.fragment_container);
+        if (fragment != null) {
+            // Remove it to prevent stacking multiple fragments after screen rotated.
+            mFragmentManager.beginTransaction().remove(fragment).commit();
+        }
+
+        super.onStop();
+    }
 }

src/com/android/settings/wifi/dpp/WifiDppQrCodeScannerFragment.java

@@ -16,13 +16,28 @@
 
 package com.android.settings.wifi.dpp;
 
+import android.annotation.Nullable;
 import android.app.Activity;
 import android.content.Intent;
+import android.graphics.Rect;
 import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Size;
+import android.view.SurfaceHolder;
+import android.view.SurfaceView;
+import android.view.View;
 
 import com.android.settings.R;
+import com.android.settings.wifi.qrcode.QrCamera;
+import com.android.settings.wifi.qrcode.QrDecorateView;
+
+public class WifiDppQrCodeScannerFragment extends WifiDppQrCodeBaseFragment implements
+        SurfaceHolder.Callback,
+        QrCamera.ScannerCallback {
+    private QrCamera mCamera;
+    private SurfaceView mSurfaceView;
+    private QrDecorateView mDecorateView;
 
-public class WifiDppQrCodeScannerFragment extends WifiDppQrCodeBaseFragment {
     @Override
     protected int getLayout() {
         return R.layout.wifi_dpp_qrcode_scanner_fragment;
@@ -34,12 +49,15 @@ public class WifiDppQrCodeScannerFragment extends WifiDppQrCodeBaseFragment {
 
         setTitle(getString(R.string.wifi_dpp_add_device_to_network));
 
-        String ssid = "";
+        String ssid = null;
-        Intent intent = getActivity().getIntent();
+        final Intent intent = getActivity().getIntent();
-        if (intent != null)
+        if (intent != null) {
             ssid = intent.getStringExtra(WifiDppConfiguratorActivity.EXTRA_SSID);
-        String description = getString(R.string.wifi_dpp_center_qr_code, ssid);
+        }
-        setDescription(description);
+        if (TextUtils.isEmpty(ssid)) {
+            throw new IllegalArgumentException("Invalid SSID");
+        }
+        setDescription(getString(R.string.wifi_dpp_center_qr_code, ssid));
 
         hideRightButton();
 
@@ -47,6 +65,71 @@ public class WifiDppQrCodeScannerFragment extends WifiDppQrCodeBaseFragment {
 
         setLeftButtonOnClickListener((view) -> {
             getActivity().setResult(Activity.RESULT_CANCELED);
-                getActivity().finish();});
+            getActivity().finish();
+        });
+    }
+
+    @Override
+    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+
+        mSurfaceView = (SurfaceView) view.findViewById(R.id.preview_view);
+        final SurfaceHolder surfaceHolder = mSurfaceView.getHolder();
+        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
+        surfaceHolder.addCallback(this);
+
+        mDecorateView = (QrDecorateView) view.findViewById(R.id.decorate_view);
+    }
+
+    @Override
+    public void surfaceCreated(final SurfaceHolder holder) {
+        initCamera(holder);
+    }
+
+    @Override
+    public void surfaceDestroyed(SurfaceHolder holder) {
+        destroyCamera();
+    }
+
+    @Override
+    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
+        // Do nothing
+    }
+
+    @Override
+    public Size getViewSize() {
+        return new Size(mSurfaceView.getWidth(), mSurfaceView.getHeight());
+    }
+
+    @Override
+    public Rect getFramePosition(Size previewSize, int cameraOrientation) {
+        return new Rect(0, 0, previewSize.getHeight(), previewSize.getHeight());
+    }
+
+    @Override
+    public void handleSuccessfulResult(String qrCode) {
+        destroyCamera();
+        mDecorateView.setFocused(true);
+        // TODO(b/120243131): Add a network by Wi-Fi Network config shared via QR code.
+    }
+
+    @Override
+    public void handleCameraFailure() {
+        destroyCamera();
+    }
+
+    private void initCamera(SurfaceHolder holder) {
+        // Check if the camera has already created.
+        if (mCamera == null) {
+            mCamera = new QrCamera(getContext(), this);
+            mCamera.start(holder);
+        }
+    }
+
+    private void destroyCamera() {
+        if (mCamera != null) {
+            mCamera.stop();
+            mCamera = null;
+        }
     }
 }

src/com/android/settings/wifi/qrcode/QrCamera.java

@@ -43,6 +43,7 @@ import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.Executors;
 import java.util.concurrent.Semaphore;
 
 import androidx.annotation.VisibleForTesting;
@@ -85,14 +86,26 @@ public class QrCamera extends Handler {
         mReader.setHints(HINTS);
     }
 
-    void start(SurfaceHolder surfaceHolder) {
+    /**
+     * The function start camera preview and capture pictures to decode QR code continuously in a
+     * background task.
+     *
+     * @param surfaceHolder the Surface to be used for live preview, must already contain a surface
+     *                      when this method is called.
+     */
+    public void start(SurfaceHolder surfaceHolder) {
         if (mDecodeTask == null) {
             mDecodeTask = new DecodingTask(surfaceHolder);
-            mDecodeTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+            // Execute in the separate thread pool to prevent block other AsyncTask.
+            mDecodeTask.executeOnExecutor(Executors.newSingleThreadExecutor());
         }
     }
 
-    void stop() {
+    /**
+     * The function stop camera preview and background decode task. Caller call this function when
+     * the surface is being destroyed.
+     */
+    public void stop() {
         removeMessages(MSG_AUTO_FOCUS);
         if (mDecodeTask != null) {
             mDecodeTask.cancel(true);
@@ -104,7 +117,7 @@ public class QrCamera extends Handler {
     }
 
     /** The scanner which includes this QrCamera class should implement this */
-    interface ScannerCallback {
+    public interface ScannerCallback {
 
         /**
          * The function used to handle the decoding result of the QR code.

tests/unit/src/com/android/settings/wifi/dpp/WifiDppQrCodeScannerFragmentTest.java

@@ -24,6 +24,7 @@ import static com.google.common.truth.Truth.assertThat;
 
 import android.app.Activity;
 import android.content.Intent;
+import android.content.pm.ActivityInfo;
 import android.support.test.rule.ActivityTestRule;
 import android.support.test.runner.AndroidJUnit4;
 
@@ -53,4 +54,12 @@ public class WifiDppQrCodeScannerFragmentTest {
         assertThat(mActivityRule.getActivityResult().getResultCode()).
                 isEqualTo(Activity.RESULT_CANCELED);
     }
+
+    @Test
+    public void rotateScreen_shouldNotCrash() {
+        mActivityRule.getActivity().setRequestedOrientation(
+                ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
+        mActivityRule.getActivity().setRequestedOrientation(
+                ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
+    }
 }