Solian/lib/controllers/post_list_controller.dart
2024-07-25 16:08:46 +08:00

129 lines
3.3 KiB
Dart

import 'package:get/get.dart';
import 'package:infinite_scroll_pagination/infinite_scroll_pagination.dart';
import 'package:solian/models/pagination.dart';
import 'package:solian/models/post.dart';
import 'package:solian/providers/content/posts.dart';
class PostListController extends GetxController {
/// The polling source modifier.
/// - `0`: default recommendations
/// - `1`: shuffle mode
RxInt mode = 0.obs;
/// The paging controller for infinite loading.
/// Only available when mode is `0`.
PagingController<int, Post> pagingController =
PagingController(firstPageKey: 0);
PostListController() {
_initPagingController();
}
/// Initialize a compatibility layer to paging controller
void _initPagingController() {
pagingController.addPageRequestListener(_onPagingControllerRequest);
}
Future<void> _onPagingControllerRequest(int pageKey) async {
try {
final result = await loadMore();
if (result != null && hasMore.value) {
pagingController.appendPage(result, nextPageKey.value);
} else if (result != null) {
pagingController.appendLastPage(result);
}
} catch (e) {
pagingController.error = e;
}
}
void _resetPagingController() {
pagingController.removePageRequestListener(_onPagingControllerRequest);
pagingController.nextPageKey = nextPageKey.value;
pagingController.itemList?.clear();
}
RxBool isBusy = false.obs;
RxBool isPreparing = false.obs;
RxInt focusCursor = 0.obs;
Post get focusPost => postList[focusCursor.value];
RxInt postTotal = 0.obs;
RxList<Post> postList = RxList.empty(growable: true);
RxInt nextPageKey = 0.obs;
RxBool hasMore = true.obs;
Future<void> reloadAllOver() async {
isPreparing.value = true;
focusCursor.value = 0;
nextPageKey.value = 0;
postList.clear();
hasMore.value = true;
_resetPagingController();
final result = await loadMore();
if (result != null && hasMore.value) {
pagingController.appendPage(result, nextPageKey.value);
} else if (result != null) {
pagingController.appendLastPage(result);
}
_initPagingController();
isPreparing.value = false;
}
Future<List<Post>?> loadMore() async {
final result = await _loadPosts(nextPageKey.value);
if (result != null && result.length >= 10) {
postList.addAll(result);
nextPageKey.value += result.length;
hasMore.value = true;
} else if (result != null) {
postList.addAll(result);
nextPageKey.value += result.length;
hasMore.value = false;
}
final idx = <dynamic>{};
postList.retainWhere((x) => idx.add(x.id));
return result;
}
Future<List<Post>?> _loadPosts(int pageKey) async {
isBusy.value = true;
final PostProvider provider = Get.find();
Response resp;
try {
resp = await provider.listRecommendations(
pageKey,
channel: mode.value == 0 ? null : 'shuffle',
);
} catch (e) {
rethrow;
} finally {
isBusy.value = false;
}
final PaginationResult result = PaginationResult.fromJson(resp.body);
final out = result.data?.map((e) => Post.fromJson(e)).toList();
postTotal.value = result.count;
return out;
}
@override
void dispose() {
pagingController.dispose();
super.dispose();
}
}