From cdfdcbe3f603c57c176bb41b9c7d2b7c6384e4b8 Mon Sep 17 00:00:00 2001
From: Gaurav Khuperkar <gauravkh@thoughtworks.com>
Date: Mon, 31 Oct 2022 16:23:05 +0530
Subject: [PATCH] Issue 49: Add Dark mode support for OSS Licenses Webview.

---
 app/build.gradle                              |  1 +
 .../czlucius/scan/ui/PreferencesFragment.java | 30 +++++++++++++++++--
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/app/build.gradle b/app/build.gradle
index 9a79183..56d9a05 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -82,6 +82,7 @@ dependencies {
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     implementation "androidx.annotation:annotation:1.5.0"
     implementation 'androidx.preference:preference:1.2.0'
+    implementation 'androidx.webkit:webkit:1.5.0'
 
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
diff --git a/app/src/main/java/com/czlucius/scan/ui/PreferencesFragment.java b/app/src/main/java/com/czlucius/scan/ui/PreferencesFragment.java
index 0081ab5..aa5f6f3 100644
--- a/app/src/main/java/com/czlucius/scan/ui/PreferencesFragment.java
+++ b/app/src/main/java/com/czlucius/scan/ui/PreferencesFragment.java
@@ -18,11 +18,15 @@
 
 package com.czlucius.scan.ui;
 
+import static androidx.webkit.WebViewFeature.ALGORITHMIC_DARKENING;
+import static androidx.webkit.WebViewFeature.isFeatureSupported;
+
 import android.content.Intent;
-import android.graphics.Color;
-import android.graphics.drawable.ColorDrawable;
+import android.content.res.Configuration;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -36,13 +40,16 @@
 import androidx.appcompat.app.AlertDialog;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceFragmentCompat;
+import androidx.webkit.WebSettingsCompat;
 
 import com.czlucius.scan.R;
 import com.czlucius.scan.Utils;
-import com.czlucius.scan.callbacks.ManualResetPreferenceClickListener;
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 
 public class PreferencesFragment extends PreferenceFragmentCompat {
+    private static final String TAG = PreferencesFragment.class.getSimpleName();
+
+    boolean nightModeActive = false;
 
     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
@@ -55,6 +62,16 @@ public View onCreateView(@NonNull LayoutInflater inflater, @Nullable @org.jetbra
         // Instantiate ads if on play flavour.
         View v = super.onCreateView(inflater, container, savedInstanceState);
 
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            Configuration configuration = v.getResources().getConfiguration();
+            if (configuration != null) {
+                nightModeActive = v.getResources().getConfiguration().isNightModeActive();
+                Log.d(TAG, "Is night mode active: " + nightModeActive);
+            } else {
+                Log.e(TAG, "Configuration is null");
+            }
+        }
+
         Preference oss_link = findPreference("open_source");
         if (oss_link != null) {
             oss_link.setOnPreferenceClickListener(preference -> {
@@ -147,6 +164,13 @@ private boolean shouldOverrideUrlLoading(Uri url) {
         });
         webView.zoomBy(0.5F);
 
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q && isFeatureSupported(ALGORITHMIC_DARKENING)) {
+            WebSettingsCompat.setAlgorithmicDarkeningAllowed(webView.getSettings(), nightModeActive);
+        } else if (nightModeActive) {
+            //TODO: Remove this else block once app sets minSdkVersion to 29
+            WebSettingsCompat.setForceDark(webView.getSettings(), WebSettingsCompat.FORCE_DARK_ON);
+        }
+
         MaterialAlertDialogBuilder ossDialog = new MaterialAlertDialogBuilder(requireContext());
         ossDialog.setView(webView);
         AlertDialog finalDialog = ossDialog.create();