Show indicator when loading download dialog

app/src/main/java/org/schabi/newpipe/RouterActivity.java

@@ -45,6 +45,7 @@
 import org.schabi.newpipe.databinding.ListRadioIconItemBinding;
 import org.schabi.newpipe.databinding.SingleChoiceDialogViewBinding;
 import org.schabi.newpipe.download.DownloadDialog;
+import org.schabi.newpipe.download.LoadingDialog;
 import org.schabi.newpipe.error.ErrorInfo;
 import org.schabi.newpipe.error.ErrorUtil;
 import org.schabi.newpipe.error.ReCaptchaActivity;
@@ -789,10 +790,10 @@ public void onResume(@NonNull final LifecycleOwner owner) {
                     }
                 }
 
-            }, () -> {
+            }, () ->
                 // this branch is executed if there is no activity context
-                inFlight(false);
-            });
+                inFlight(false)
+            );
         }
 
         <T> Single<T> pleaseWait(final Single<T> single) {
@@ -812,19 +813,24 @@ <T> Single<T> pleaseWait(final Single<T> single) {
         @SuppressLint("CheckResult")
         private void openDownloadDialog(final int currentServiceId, final String currentUrl) {
             inFlight(true);
+            final LoadingDialog loadingDialog = new LoadingDialog(R.string.loading_metadata_title);
+            loadingDialog.show(getParentFragmentManager(), "loadingDialog");
             disposables.add(ExtractorHelper.getStreamInfo(currentServiceId, currentUrl, true)
                     .subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
                     .compose(this::pleaseWait)
                     .subscribe(result ->
                         runOnVisible(ctx -> {
+                            loadingDialog.dismiss();
                             final FragmentManager fm = ctx.getSupportFragmentManager();
                             final DownloadDialog downloadDialog = new DownloadDialog(ctx, result);
                             // dismiss listener to be handled by FragmentManager
                             downloadDialog.show(fm, "downloadDialog");
                         }
-                    ), throwable -> runOnVisible(ctx ->
-                            ((RouterActivity) ctx).showUnsupportedUrlDialog(currentUrl))));
+                        ), throwable -> runOnVisible(ctx -> {
+                        loadingDialog.dismiss();
+                        ((RouterActivity) ctx).showUnsupportedUrlDialog(currentUrl);
+                    })));
         }
 
         private void openAddToPlaylistDialog(final int currentServiceId, final String currentUrl) {

app/src/main/java/org/schabi/newpipe/download/LoadingDialog.java

@@ -0,0 +1,87 @@
+package org.schabi.newpipe.download;
+
+import android.os.Bundle;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+import androidx.appcompat.widget.Toolbar;
+import androidx.fragment.app.DialogFragment;
+
+import org.schabi.newpipe.MainActivity;
+import org.schabi.newpipe.R;
+import org.schabi.newpipe.databinding.DownloadLoadingDialogBinding;
+
+/**
+ * This class contains a dialog which shows a loading indicator and has a customizable title.
+ */
+public class LoadingDialog extends DialogFragment {
+    private static final String TAG = "LoadingDialog";
+    private static final boolean DEBUG = MainActivity.DEBUG;
+    private DownloadLoadingDialogBinding dialogLoadingBinding;
+    private final @StringRes int title;
+
+    /**
+     * <p>Create a new LoadingDialog.</p>
+     *
+     * <p>
+     *     The dialog contains a loading indicator and has a customizable title.
+     *     <br/>
+     *     Use {@code show()} to display the dialog to the user.
+     * </p>
+     *
+     * @param title an informative title shown in the dialog's toolbar
+     */
+    public LoadingDialog(final @StringRes int title) {
+        this.title = title;
+    }
+
+    @Override
+    public void onCreate(@Nullable final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        if (DEBUG) {
+            Log.d(TAG, "onCreate() called with: "
+                    + "savedInstanceState = [" + savedInstanceState + "]");
+        }
+        this.setCancelable(false);
+    }
+
+    @Override
+    public View onCreateView(
+            @NonNull final LayoutInflater inflater,
+            final ViewGroup container,
+            final Bundle savedInstanceState) {
+        if (DEBUG) {
+            Log.d(TAG, "onCreateView() called with: "
+                    + "inflater = [" + inflater + "], container = [" + container + "], "
+                    + "savedInstanceState = [" + savedInstanceState + "]");
+        }
+        return inflater.inflate(R.layout.download_loading_dialog, container);
+    }
+
+    @Override
+    public void onViewCreated(@NonNull final View view, @Nullable final Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        dialogLoadingBinding = DownloadLoadingDialogBinding.bind(view);
+        initToolbar(dialogLoadingBinding.toolbarLayout.toolbar);
+    }
+
+    private void initToolbar(final Toolbar toolbar) {
+        if (DEBUG) {
+            Log.d(TAG, "initToolbar() called with: toolbar = [" + toolbar + "]");
+        }
+        toolbar.setTitle(requireContext().getString(title));
+        toolbar.setNavigationOnClickListener(v -> dismiss());
+
+    }
+
+    @Override
+    public void onDestroyView() {
+        dialogLoadingBinding = null;
+        super.onDestroyView();
+    }
+}

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

@@ -0,0 +1,18 @@
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <include
+        android:id="@+id/toolbar_layout"
+        layout="@layout/toolbar_layout" />
+
+    <ProgressBar
+        android:id="@+id/loader"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="150dp"
+        android:layout_marginBottom="100dp"
+        android:layout_centerHorizontal="true"
+        android:indeterminate="true" />
+</RelativeLayout>

app/src/main/res/values/strings.xml

@@ -167,6 +167,7 @@
     <string name="duration_live">Live</string>
     <string name="downloads">Downloads</string>
     <string name="downloads_title">Downloads</string>
+    <string name="loading_metadata_title">Loading Metadata…</string>
     <string name="error_report_title">Error report</string>
     <string name="all">All</string>
     <string name="channels">Channels</string>