Restore license pop up after orientation change

app/src/main/java/org/schabi/newpipe/about/License.java

@@ -4,10 +4,12 @@ import android.net.Uri;
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import java.io.Serializable;
+
 /**
  * Class for storing information about a software license.
  */
-public class License implements Parcelable {
+public class License implements Parcelable, Serializable {
     public static final Creator<License> CREATOR = new Creator<License>() {
         @Override
         public License createFromParcel(final Parcel source) {

app/src/main/java/org/schabi/newpipe/about/LicenseFragment.java

@@ -1,7 +1,6 @@
 package org.schabi.newpipe.about;
 
 import android.app.Activity;
-import android.content.Context;
 import android.os.Bundle;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
@@ -11,12 +10,14 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 
 import org.schabi.newpipe.R;
 import org.schabi.newpipe.util.ShareUtils;
 
+import java.io.Serializable;
 import java.util.Arrays;
 
 /**
@@ -26,6 +27,8 @@ public class LicenseFragment extends Fragment {
     private static final String ARG_COMPONENTS = "components";
     private SoftwareComponent[] softwareComponents;
     private SoftwareComponent componentForContextMenu;
+    private License activeLicense;
+    private static final String LICENSE_KEY = "ACTIVE_LICENSE";
 
     public static LicenseFragment newInstance(final SoftwareComponent[] softwareComponents) {
         if (softwareComponents == null) {
@@ -44,8 +47,8 @@ public class LicenseFragment extends Fragment {
      * @param context the context to use
      * @param license the license to show
      */
-    private static void showLicense(final Context context, final License license) {
+    private static void showLicense(final Activity context, final License license) {
-        new LicenseFragmentHelper((Activity) context).execute(license);
+        new LicenseFragmentHelper(context).execute(license);
     }
 
     @Override
@@ -54,6 +57,12 @@ public class LicenseFragment extends Fragment {
         softwareComponents = (SoftwareComponent[]) getArguments()
                 .getParcelableArray(ARG_COMPONENTS);
 
+        if (savedInstanceState != null) {
+            final Serializable license = savedInstanceState.getSerializable(LICENSE_KEY);
+            if (license != null) {
+                activeLicense = (License) license;
+            }
+        }
         // Sort components by name
         Arrays.sort(softwareComponents, (o1, o2) -> o1.getName().compareTo(o2.getName()));
     }
@@ -66,8 +75,10 @@ public class LicenseFragment extends Fragment {
         final ViewGroup softwareComponentsView = rootView.findViewById(R.id.software_components);
 
         final View licenseLink = rootView.findViewById(R.id.app_read_license);
-        licenseLink.setOnClickListener(v ->
+        licenseLink.setOnClickListener(v -> {
-                showLicense(getActivity(), StandardLicenses.GPL3));
+                activeLicense = StandardLicenses.GPL3;
+                showLicense(getActivity(), StandardLicenses.GPL3);
+        });
 
         for (final SoftwareComponent component : softwareComponents) {
             final View componentView = inflater
@@ -81,11 +92,16 @@ public class LicenseFragment extends Fragment {
                     component.getLicense().getAbbreviation()));
 
             componentView.setTag(component);
-            componentView.setOnClickListener(v ->
+            componentView.setOnClickListener(v -> {
-                    showLicense(getActivity(), component.getLicense()));
+                activeLicense = component.getLicense();
+                showLicense(getActivity(), component.getLicense());
+            });
             softwareComponentsView.addView(componentView);
             registerForContextMenu(componentView);
         }
+        if (activeLicense != null) {
+            showLicense(getActivity(), activeLicense);
+        }
         return rootView;
     }
 
@@ -101,7 +117,7 @@ public class LicenseFragment extends Fragment {
     }
 
     @Override
-    public boolean onContextItemSelected(final MenuItem item) {
+    public boolean onContextItemSelected(@NonNull final MenuItem item) {
         // item.getMenuInfo() is null so we use the tag of the view
         final SoftwareComponent component = componentForContextMenu;
         if (component == null) {
@@ -116,4 +132,12 @@ public class LicenseFragment extends Fragment {
         }
         return false;
     }
+
+    @Override
+    public void onSaveInstanceState(@NonNull final Bundle savedInstanceState) {
+        super.onSaveInstanceState(savedInstanceState);
+        if (activeLicense != null) {
+            savedInstanceState.putSerializable(LICENSE_KEY, activeLicense);
+        }
+    }
 }