feat(YouTube - Download Playlist Button): Add playlist download button

app/src/main/java/app/revanced/integrations/youtube/patches/misc/HookDownloadAction.java

@@ -0,0 +1,28 @@
+package app.revanced.integrations.youtube.patches.misc;
+
+import app.revanced.integrations.youtube.settings.Settings;
+import app.revanced.integrations.youtube.utils.VideoUtils;
+
+@SuppressWarnings("unused")
+public class HookDownloadAction {
+
+    /*
+     * Injection point
+     */
+    public static boolean isPlaylistDownloadButtonHooked() {
+        return Settings.HOOK_PLAYLIST_DOWNLOAD_BUTTON.get();
+    }
+
+    /*
+     * Injection point
+     */
+    public static String startPlaylistDownloadActivity(String playlistId) {
+        if (!isPlaylistDownloadButtonHooked()) return playlistId;
+
+        VideoUtils.launchPlaylistExternalDownloader(playlistId);
+
+        // return an empty string to prevent
+        // the original implementation from being called
+        return "";
+    }
+}

app/src/main/java/app/revanced/integrations/youtube/settings/Settings.java

@@ -136,6 +136,7 @@ public class Settings extends BaseSettings {
     public static final BooleanSetting HIDE_GRAY_SEPARATOR = new BooleanSetting("revanced_hide_gray_separator", TRUE);
     public static final BooleanSetting HIDE_SNACK_BAR = new BooleanSetting("revanced_hide_snack_bar", FALSE);
     public static final BooleanSetting REMOVE_VIEWER_DISCRETION_DIALOG = new BooleanSetting("revanced_remove_viewer_discretion_dialog", FALSE);
+    public static final BooleanSetting HOOK_PLAYLIST_DOWNLOAD_BUTTON = new BooleanSetting("revanced_hook_playlist_download_button", TRUE);
 
     public static final BooleanSetting ENABLE_PHONE_LAYOUT = new BooleanSetting("revanced_enable_phone_layout", FALSE, true);
     public static final BooleanSetting ENABLE_TABLET_LAYOUT = new BooleanSetting("revanced_enable_tablet_layout", FALSE, true);

app/src/main/java/app/revanced/integrations/youtube/settings/preference/ExternalDownloaderPreference.java

@@ -160,4 +160,10 @@ public static boolean checkPackageIsEnabled() {
         return checkPackageIsValid(context, packageName);
     }
 
+    public static boolean checkPackageIsEnabled(String packageName) {
+        final Context context = Utils.getActivity();
+        mClickedDialogEntryIndex = Arrays.asList(mEntryValues).indexOf(packageName);
+        return checkPackageIsValid(context, packageName);
+    }
+
 }

app/src/main/java/app/revanced/integrations/youtube/utils/VideoUtils.java

@@ -109,6 +109,7 @@ public static void launchExternalDownloader() {
 
     public static void launchExternalDownloader(@NonNull String videoId) {
         try {
+
             String downloaderPackageName = externalDownloaderPackageName.get().trim();
 
             if (downloaderPackageName.isEmpty()) {
@@ -121,7 +122,9 @@ public static void launchExternalDownloader(@NonNull String videoId) {
             }
 
             isExternalDownloaderLaunched.compareAndSet(false, true);
+
             final String content = String.format("https://youtu.be/%s", videoId);
+
             launchExternalDownloader(content, downloaderPackageName);
         } catch (Exception ex) {
             Logger.printException(() -> "launchExternalDownloader failure", ex);
@@ -130,6 +133,27 @@ public static void launchExternalDownloader(@NonNull String videoId) {
         }
     }
 
+    public static void launchPlaylistExternalDownloader(@NonNull String playlistId) {
+        try {
+            // use default downloader (YTDLnis) if user tries to download a playlist
+            // because most downloaders don't support playlist download
+            String downloaderPackageName = "com.deniscerri.ytdl";
+
+            final String content = String.format("https://www.youtube.com/playlist?list=%s", playlistId);
+
+            if (!checkPackageIsEnabled(downloaderPackageName)) {
+                return;
+            }
+
+            isExternalDownloaderLaunched.compareAndSet(false, true);
+            launchExternalDownloader(content, downloaderPackageName);
+        } catch (Exception ex) {
+            Logger.printException(() -> "launchPlaylistExternalDownloader failure", ex);
+        } finally {
+            runOnMainThreadDelayed(() -> isExternalDownloaderLaunched.compareAndSet(true, false), 500);
+        }
+    }
+
     /**
      * Create playlist from all channel videos from oldest to newest,
      * starting from the video where button is clicked.