Lazy-load folder content in random page order

A folder with several thousand posts took ~10 s to open because
FolderActivity and the Home row OK handler fetched every page before
showing anything. Pages are now fetched one at a time in a shuffled page
order (each page shuffled locally), the grid shows after the first page,
and the viewer shares the list and pager so it keeps paging the folder.
Reels use the same generic pager. Not a full shuffle: neighbours within
a page stay together.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 10 insertions, 12 deletions

diff --git a/app/src/main/java/mygram/droid/ViewerActivity.java b/app/src/main/java/mygram/droid/ViewerActivity.java
index 59e6948..4845cbd 100644
--- a/app/src/main/java/mygram/droid/ViewerActivity.java
+++ b/app/src/main/java/mygram/droid/ViewerActivity.java
@@ -131,7 +131,7 @@ public final class ViewerActivity extends Activity {
 
 		if (!Playlist.posts.isEmpty()) {
 			show(Playlist.start);
-		} else if (Playlist.reelsSeed != 0) {
+		} else if (Playlist.more != null) {
 			message.setText("Loading…");
 			maybeLoadMore();
 		} else {
@@ -330,35 +330,33 @@ public final class ViewerActivity extends Activity {
 		});
 	}
 
-	/** Reels only: fetches the next page when three posts remain. */
+	/** Fetches the next page when three posts remain. */
 	private void maybeLoadMore() {
-		if (Playlist.reelsSeed == 0 || loadingMore || index < Playlist.posts.size() - 3)
+		if (Playlist.more == null || loadingMore || index < Playlist.posts.size() - 3)
 			return;
 		loadingMore = true;
-		int page = Playlist.reelsPage + 1;
 		List<Post> list = Playlist.posts;
-		Api.async(() -> Api.reels(Playlist.reelsSeed, page), o -> {
+		Api.async(Playlist.more, page -> {
 			if (isDestroyed() || Playlist.posts != list)
 				return;
 			loadingMore = false;
-			Playlist.reelsPage = page;
 			boolean first = list.isEmpty();
 			int old = list.size();
-			list.addAll(Post.list(o, Prefs.server()));
-			if (!o.optBoolean("hasMore"))
-				Playlist.reelsSeed = 0;
+			if (page.isEmpty())
+				Playlist.more = null;
+			Playlist.append(page);
 			if (first && !list.isEmpty())
 				show(0);
 			else if (parkedAtEnd && index == old - 1 && list.size() > old)
 				show(index + 1);
-			else if (list.isEmpty() && Playlist.reelsSeed == 0)
-				message.setText("No reels");
+			else if (list.isEmpty() && Playlist.more == null)
+				message.setText("Nothing to show");
 		}, e -> {
 			if (isDestroyed())
 				return;
 			loadingMore = false;
 			if (Playlist.posts.isEmpty())
-				message.setText("Cannot load reels. Press Down to retry.");
+				message.setText("Cannot load posts. Press Down to retry.");
 			else
 				Toast.makeText(this, "Cannot load more: " + e.getMessage(), Toast.LENGTH_SHORT).show();
 		});