Fix dark theme reset error due to WebView. Apply dark theme to web views.

app/build.gradle

@@ -62,6 +62,7 @@ dependencies {
     implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
     implementation 'androidx.localbroadcastmanager:localbroadcastmanager:1.0.0'
     implementation 'androidx.preference:preference:1.1.1'
+    implementation 'androidx.webkit:webkit:1.3.0-alpha02'
     implementation 'androidx.camera:camera-camera2:1.0.0-beta03'
     implementation 'androidx.camera:camera-lifecycle:1.0.0-beta03'
     implementation 'androidx.camera:camera-view:1.0.0-alpha10'

app/src/main/java/io/lbry/browser/MainActivity.java

@@ -35,6 +35,7 @@ import android.view.Menu;
 import android.view.WindowManager;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodManager;
+import android.webkit.WebView;
 import android.widget.EditText;
 import android.widget.ImageView;
 import android.widget.TextView;
@@ -337,6 +338,8 @@ public class MainActivity extends AppCompatActivity implements SdkStatusListener
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
+        // workaround to fix dark theme because https://issuetracker.google.com/issues/37124582
+        new WebView(this);
         AppCompatDelegate.setDefaultNightMode(isDarkMode() ? AppCompatDelegate.MODE_NIGHT_YES : AppCompatDelegate.MODE_NIGHT_NO);
 
         initKeyStore();

app/src/main/java/io/lbry/browser/ui/findcontent/FileViewFragment.java

@@ -37,6 +37,8 @@ import androidx.media.session.MediaButtonReceiver;
 import androidx.preference.PreferenceManager;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import androidx.webkit.WebSettingsCompat;
+import androidx.webkit.WebViewFeature;
 
 import com.bumptech.glide.Glide;
 import com.github.chrisbanes.photoview.PhotoView;
@@ -174,6 +176,9 @@ public class FileViewFragment extends BaseFragment implements
     private View layoutDisplayArea;
     private View layoutResolving;
 
+    private WebView webView;
+    private boolean webViewAdded;
+
     public View onCreateView(@NonNull LayoutInflater inflater,
                              ViewGroup container, Bundle savedInstanceState) {
         View root = inflater.inflate(R.layout.fragment_file_view, container, false);
@@ -360,13 +365,32 @@ public class FileViewFragment extends BaseFragment implements
     }
 
     private void initWebView(View root) {
-        WebView webView = root.findViewById(R.id.file_view_webview);
+        Context ctx = getContext();
-        webView.setWebViewClient(new LbryWebViewClient(getContext()));
+        if (ctx != null) {
+            if (webView == null) {
+                webView = new WebView(ctx);
+                webView.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT));
+                webView.setWebViewClient(new LbryWebViewClient(ctx));
                 WebSettings webSettings = webView.getSettings();
                 webSettings.setAllowFileAccess(true);
                 webSettings.setJavaScriptEnabled(true);
             }
 
+            if (!webViewAdded && root != null) {
+                ((RelativeLayout) root.findViewById(R.id.file_view_webview_container)).addView(webView);
+                webViewAdded = true;
+            }
+        }
+    }
+
+    private void applyThemeToWebView() {
+        Context context = getContext();
+        if (context instanceof MainActivity && webView != null && WebViewFeature.isFeatureSupported(WebViewFeature.FORCE_DARK)) {
+            MainActivity activity = (MainActivity) context;
+            WebSettingsCompat.setForceDark(webView.getSettings(), activity.isDarkMode() ? WebSettingsCompat.FORCE_DARK_ON : WebSettingsCompat.FORCE_DARK_OFF);
+        }
+    }
+
     private void logUrlEvent(String url) {
         Bundle bundle = new Bundle();
         bundle.putString("uri", url);
@@ -545,6 +569,13 @@ public class FileViewFragment extends BaseFragment implements
             activity.removeStoragePermissionListener(this);
             //activity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
         }
+
+        if (webView != null) {
+            webView.removeAllViews();
+            webView.loadUrl("about:blank");
+            webView.destroy();
+            webView = null;
+        }
     }
 
     private void setPlayerForPlayerView() {
@@ -1585,7 +1616,9 @@ public class FileViewFragment extends BaseFragment implements
                         } else if (mediaType.startsWith("text")) {
                             // show web view (and parse markdown too)
                             View container = root.findViewById(R.id.file_view_webview_container);
-                            WebView webView = root.findViewById(R.id.file_view_webview);
+                            initWebView(root);
+                            applyThemeToWebView();
+
                             if (Arrays.asList("text/markdown", "text/md").contains(mediaType.toLowerCase())) {
                                 loadMarkdownFromFile(claimFile.getDownloadPath());
                             } else {
@@ -1610,9 +1643,10 @@ public class FileViewFragment extends BaseFragment implements
             @Override
             public void onSuccess(String text) {
                 String html = buildMarkdownHtml(text);
-                WebView webView = getView().findViewById(R.id.file_view_webview);
+                if (webView != null) {
                     webView.loadData(html, "text/html", "utf-8");
                 }
+            }
 
             @Override
             public void onError(Exception error) {

app/src/main/res/layout/fragment_file_view.xml

@@ -633,9 +633,6 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:visibility="gone">
-        <WebView
+
-            android:id="@+id/file_view_webview"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent" />
     </RelativeLayout>
 </androidx.constraintlayout.widget.ConstraintLayout>