1 files changed, 22 insertions, 11 deletions

diff --git a/app/src/main/java/mygram/droid/Api.java b/app/src/main/java/mygram/droid/Api.java
index c7d08eb..6e4ce74 100644
--- a/app/src/main/java/mygram/droid/Api.java
+++ b/app/src/main/java/mygram/droid/Api.java
@@ -172,25 +172,36 @@ final class Api {
 		return out;
 	}
 
-	/** Pager over a folder: each call returns the next page, shuffled; empty once all pages are used. */
-	// ponytail: random page order plus in-page shuffle, not a full shuffle; neighbours within a page stay together; upgrade: fetch all ids once if that ever matters.
+	/** Folder orders: RANDOM shuffles, DATE keeps the server's order, NAME sorts by file name. */
+	static final int RANDOM = 0, DATE = 1, NAME = 2;
+
 	static Callable<List<Post>> folderPages(String slug, int count) {
+		return folderPages(slug, count, RANDOM);
+	}
+
+	/** Pager over a folder: each call returns the next page; empty once all pages are used. */
+	// ponytail: random page order plus in-page shuffle, not a full shuffle; neighbours within a page stay together; upgrade: fetch all ids once if that ever matters.
+	// ponytail: NAME fetches every page in its first call, since the server cannot sort by name; slow on folders of thousands.
+	// DATE is the server's order: newest first unless the instance's default folder order says oldest.
+	static Callable<List<Post>> folderPages(String slug, int count, int order) {
 		List<Integer> pages = new ArrayList<>();
 		for (int p = 1; p <= (count + PAGE - 1) / PAGE; p++)
 			pages.add(p);
-		Collections.shuffle(pages);
+		if (order == RANDOM)
+			Collections.shuffle(pages);
 		String path = "/folders/" + Uri.encode(slug) + "/images?limit=" + PAGE + "&page=";
 		int[] next = {0};
 		return () -> {
 			synchronized (next) {
-				while (next[0] < pages.size()) { // imageCount counts carousel slides, so later pages may be empty
-					List<Post> posts = Post.list(call("GET", path + pages.get(next[0]++)), Prefs.server());
-					if (!posts.isEmpty()) {
-						Collections.shuffle(posts);
-						return posts;
-					}
-				}
-				return new ArrayList<>();
+				List<Post> out = new ArrayList<>();
+				// imageCount counts carousel slides, so later pages may be empty
+				while (next[0] < pages.size() && (order == NAME || out.isEmpty()))
+					out.addAll(Post.list(call("GET", path + pages.get(next[0]++)), Prefs.server()));
+				if (order == RANDOM)
+					Collections.shuffle(out);
+				else if (order == NAME)
+					out.sort((a, b) -> String.CASE_INSENSITIVE_ORDER.compare(a.filename, b.filename));
+				return out;
 			}
 		};
 	}