[QRCode] Created a open settings sheet which is displayed when

the user denies permission for Chrome to prompt for camera permission.

Screenshot:
https://screenshot.googleplex.com/himQOS9PQrY

Bug: 1046574
Change-Id: I0df3cf870f0f08e5f0bc08e0dd4f8d963f4797ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2037860
Commit-Queue: Tanya Gupta <tgupta@chromium.org>
Reviewed-by: Gayane Petrosyan <gayane@chromium.org>
Cr-Commit-Position: refs/heads/master@{#741571}

chrome/browser/share/android/java/res/layout/qrcode_open_settings_layout.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2020 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/permission_layout"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+    <org.chromium.ui.widget.ChromeImageView
+        android:id="@+id/camera_icon"
+        android:layout_marginTop="200dp"
+        android:layout_gravity="center_horizontal"
+        android:layout_width="125dp"
+        android:layout_height="125dp"
+        android:scaleType="center"
+        android:importantForAccessibility="no"
+        android:src="@drawable/camera" />
+
+    <TextView
+        android:id="@+id/qrcode_permission_image"
+        android:layout_width="250dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="80dp"
+        android:drawablePadding="24dp"
+        android:gravity="center_horizontal"
+        android:layout_gravity="center_horizontal"
+        android:text="@string/qr_code_open_settings_description"/>
+
+    <org.chromium.ui.widget.ButtonCompat
+        android:id="@+id/open_settings_button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_horizontal"
+        android:layout_marginTop="30dp"
+        android:text="@string/qr_code_open_settings_label"
+        style="@style/TextButton"/>
+</LinearLayout>
\ No newline at end of file

chrome/browser/share/android/java/src/org/chromium/chrome/browser/share/qrcode/QrCodeDialog.java

@@ -24,7 +24,11 @@ import java.util.ArrayList;
 public class QrCodeDialog extends DialogFragment {
     private ArrayList<QrCodeDialogTab> mTabs;
 
-    /** The QrCodeDialog constructor. */
+    /**
+     * The QrCodeDialog constructor.
+     * TODO(tgupta): This causes an NPE when the user moves away from Chrome
+     * and comes back. Fix this issue.
+     */
     public QrCodeDialog() {}
 
     /**

chrome/browser/share/android/java/src/org/chromium/chrome/browser/share/qrcode/scan_tab/QrCodeScanMediator.java

@@ -60,9 +60,7 @@ public class QrCodeScanMediator implements Camera.PreviewCallback {
         mPropertyModel = propertyModel;
         mPermissionDelegate = new ActivityAndroidPermissionDelegate(
                 new WeakReference<Activity>((Activity) mContext));
-        mPropertyModel.set(QrCodeScanViewProperties.HAS_CAMERA_PERMISSION, hasCameraPermission());
-        mPropertyModel.set(
-                QrCodeScanViewProperties.CAN_PROMPT_FOR_PERMISSION, canPromptForPermission());
+        updatePermissionSettings();
         mDetector = new BarcodeDetector.Builder(context).build();
         mNavigationObserver = observer;
         mTabCreator = tabCreator;
@@ -75,17 +73,31 @@ public class QrCodeScanMediator implements Camera.PreviewCallback {
                 == PackageManager.PERMISSION_GRANTED;
     }
 
-    /** Returns whether the user has granted camera permissions. */
+    /** Returns whether the user can be prompted for camera permissions. */
     private Boolean canPromptForPermission() {
         return mPermissionDelegate.canRequestPermission(permission.CAMERA);
     }
 
+    /** Updates the permission settings with the latest values. */
+    private void updatePermissionSettings() {
+        mPropertyModel.set(
+                QrCodeScanViewProperties.CAN_PROMPT_FOR_PERMISSION, canPromptForPermission());
+        mPropertyModel.set(QrCodeScanViewProperties.HAS_CAMERA_PERMISSION, hasCameraPermission());
+    }
+
     /**
      * Sets whether QrCode UI is on foreground.
      *
      * @param isOnForeground Indicates whether this component UI is current on foreground.
      */
     public void setIsOnForeground(boolean isOnForeground) {
+        // If the app is in the foreground, the permissions need to be checked again to ensure
+        // the user is seeing the right thing.
+        if (isOnForeground) {
+            updatePermissionSettings();
+        }
+        // This is intentionally done last so that the view is updated according to the latest
+        // permissions.
         mPropertyModel.set(QrCodeScanViewProperties.IS_ON_FOREGROUND, isOnForeground);
     }
 
@@ -104,11 +116,14 @@ public class QrCodeScanMediator implements Camera.PreviewCallback {
                 if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                     mPropertyModel.set(QrCodeScanViewProperties.HAS_CAMERA_PERMISSION, true);
                 } else {
-                    mPropertyModel.set(QrCodeScanViewProperties.HAS_CAMERA_PERMISSION, false);
+                    // The order in which these fields are important because it causes updates to
+                    // the view. CanPromptForPermission must be updated first so that it doesn't
+                    // cause the view to be updated twice creating a flicker effect.
                     if (!mPermissionDelegate.canRequestPermission(permission.CAMERA)) {
                         mPropertyModel.set(
                                 QrCodeScanViewProperties.CAN_PROMPT_FOR_PERMISSION, false);
                     }
+                    mPropertyModel.set(QrCodeScanViewProperties.HAS_CAMERA_PERMISSION, false);
                 }
             }
         };

chrome/browser/share/android/java/src/org/chromium/chrome/browser/share/qrcode/scan_tab/QrCodeScanView.java

@@ -4,10 +4,14 @@
 
 package org.chromium.chrome.browser.share.qrcode.scan_tab;
 
+import android.app.Activity;
 import android.content.Context;
+import android.content.Intent;
 import android.hardware.Camera;
 import android.hardware.Camera.ErrorCallback;
 import android.hardware.Camera.PreviewCallback;
+import android.net.Uri;
+import android.provider.Settings;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
@@ -22,6 +26,7 @@ import org.chromium.ui.widget.ButtonCompat;
  */
 class QrCodeScanView {
     public interface PermissionPrompter { void promptForCameraPermission(); }
+    public interface PermissionPromptAllowedChecker { Boolean canPromptForPermission(); }
 
     private final Context mContext;
     private final FrameLayout mView;
@@ -33,6 +38,7 @@ class QrCodeScanView {
     private CameraPreview mCameraPreview;
     private View mPermissionsView;
     private View mCameraErrorView;
+    private View mOpenSettingsView;
 
     /**
      * The QrCodeScanView constructor.
@@ -45,16 +51,13 @@ class QrCodeScanView {
         mContext = context;
         mCameraPreviewCallback = cameraCallback;
         mView = new FrameLayout(context);
+        mOpenSettingsView = createOpenSettingsView(context);
         mView.setLayoutParams(
                 new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
         mPermissionsView = createPermissionView(context, permissionPrompter);
         mCameraErrorView = createCameraErrorView(context);
     }
 
-    public View getView() {
-        return mView;
-    }
-
     private View createPermissionView(Context context, PermissionPrompter permissionPrompter) {
         View permissionView = (View) LayoutInflater.from(context).inflate(
                 org.chromium.chrome.browser.share.qrcode.R.layout.qrcode_permission_layout, null,
@@ -106,6 +109,31 @@ class QrCodeScanView {
         }
     };
 
+    public View getView() {
+        return mView;
+    }
+
+    /**
+     * Creates a view that opens the settings page for the app and allows the user to
+     * to update permissions including give the app camera permission.
+     */
+    private View createOpenSettingsView(Context context) {
+        View openSettingsView = (View) LayoutInflater.from(context).inflate(
+                org.chromium.chrome.browser.share.qrcode.R.layout.qrcode_open_settings_layout, null,
+                false);
+
+        ButtonCompat cameraPermissionPrompt = openSettingsView.findViewById(
+                org.chromium.chrome.browser.share.qrcode.R.id.open_settings_button);
+        cameraPermissionPrompt.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Intent openSettingsIntent = getAppInfoIntent(context.getPackageName());
+                ((Activity) context).startActivity(openSettingsIntent);
+            }
+        });
+        return openSettingsView;
+    }
+
     /**
      * Sets camera if possible.
      *
@@ -119,13 +147,30 @@ class QrCodeScanView {
             return;
         }
         mHasCameraPermission = hasCameraPermission;
+        updateView();
+    }
+
+    /**
+     * Update the view based on the latest environment:
+     * - app is in the foreground
+     * - user has given camera permission
+     * - user can be prompted for camera permission
+     */
+    private void updateView() {
+        // The scan tab is not in the foreground so don't do any rendering.
+        if (!mIsOnForeground) {
+            return;
+        }
+
         // Check that the camera permission has changed and that it is now set to true.
-        if (hasCameraPermission) {
+        if (mHasCameraPermission && mCameraPreview == null) {
             setCameraPreview();
-        } else {
-            // TODO(tgupta): Check that the user can be prompted. If not, show the error
-            // screen instead.
+        } else if (mHasCameraPermission && mCameraPreview != null) {
+            updateCameraPreviewState();
+        } else if (mCanPromptForPermission) {
             displayPermissionDialog();
+        } else {
+            displayOpenSettingsDialog();
         }
     }
 
@@ -133,23 +178,26 @@ class QrCodeScanView {
      * Checks whether Chrome can prompt the user for Camera permission. Updates the view accordingly
      * to let the user know if the permission has been permanently denied.
      *
-     * @param canPromptForPermission
+     * @param canPromptForPermission Indicates whether the user can be prompted for camera
+     * permission
      */
     public void canPromptForPermissionChanged(Boolean canPromptForPermission) {
-        if (mCanPromptForPermission != canPromptForPermission && !canPromptForPermission) {
-            // User chose the "don't ask again option, display the appropriate message
-            // TODO (tgupta): Update this message
-        }
+        mCanPromptForPermission = canPromptForPermission;
+        updateView();
     }
 
     /**
      * Applies changes necessary to camera preview.
      *
-     * @param isOnForeground Indicates whether this component UI is current on foreground.
+     * @param isOnForeground Indicates whether this component UI is currently on foreground.
      */
     public void onForegroundChanged(Boolean isOnForeground) {
         mIsOnForeground = isOnForeground;
-        updateCameraPreviewState();
+        if (!mIsOnForeground && mCameraPreview != null) {
+            mCameraPreview.stopCamera();
+        } else {
+            updateView();
+        }
     }
 
     /** Creates and sets the camera preview. */
@@ -176,7 +224,7 @@ class QrCodeScanView {
             return;
         }
 
-        if (mIsOnForeground) {
+        if (mIsOnForeground && mHasCameraPermission) {
             mCameraPreview.startCamera();
         } else {
             mCameraPreview.stopCamera();
@@ -201,4 +249,20 @@ class QrCodeScanView {
         mView.removeAllViews();
         mView.addView(mCameraErrorView);
     }
+
+    /**
+     * Displays the open settings dialog.
+     */
+    private void displayOpenSettingsDialog() {
+        mView.removeAllViews();
+        mView.addView(mOpenSettingsView);
+    }
+    /**
+     * Returns an Intent to show the App Info page for the current app.
+     */
+    private Intent getAppInfoIntent(String packageName) {
+        Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
+        intent.setData(new Uri.Builder().scheme("package").opaquePart(packageName).build());
+        return intent;
+    }
 }

chrome/browser/ui/android/strings/android_chrome_strings.grd

@@ -3998,6 +3998,10 @@ The site does NOT gain access to the camera. The camera images are only visible
         Please enable your camera to scan a QR code
       </message>
 
+      <message name="IDS_QR_CODE_OPEN_SETTINGS_DESCRIPTION" desc="Text on QR code sharing tab indicating that user needs to open settings to give camera permission.">
+        To scan a QR code, change your settings so that Chrome can use your camera
+      </message>
+
       <message name="IDS_QR_CODE_PERMISSION_CONTINUE_LABEL" desc="Text on button on QR code sharing tab triggering camera permission dialog.">
         Continue
       </message>
@@ -4018,6 +4022,10 @@ The site does NOT gain access to the camera. The camera images are only visible
         Can't open your camera. Something went wrong.
       </message>
 
+      <message name="IDS_QR_CODE_OPEN_SETTINGS_LABEL" desc="Text on button on QR code sharing tab triggering Android settings.">
+        Open Settings
+      </message>
+
       <!-- Chime DFM module strings -->
       <message name="IDS_CHIME_MODULE_TITLE" desc="Text shown when the chime module is referenced in install start, success, failure UI (e.g. in IDS_MODULE_INSTALL_START_TEXT, which will expand to 'Installing Google Notifications Platform for Chrome…').">
         Google Notifications Platform