opt: multiSelect (#935)

lib/pages/common/multi_select_controller.dart

@@ -1,3 +1,4 @@
+import 'package:PiliPlus/http/loading_state.dart';
 import 'package:PiliPlus/pages/common/common_list_controller.dart';
 import 'package:get/get.dart';
 
@@ -5,35 +6,60 @@ mixin MultiSelectData {
   bool? checked;
 }
 
-abstract class MultiSelectController<R, T extends MultiSelectData>
-    extends CommonListController<R, T> {
+mixin MultiSelectMixin<T> {
   late final RxBool enableMultiSelect = false.obs;
-  late final RxInt checkedCount = 0.obs;
   late final allSelected = false.obs;
 
+  int get checkedCount;
+
+  void onSelect(T item, [bool disableSelect = true]);
+  void handleSelect([bool checked = false, bool disableSelect = true]);
+  void onConfirm();
+}
+
+abstract class MultiSelectController<R, T extends MultiSelectData>
+    extends CommonListController<R, T>
+    with MultiSelectMixin<T>, CommonMultiSelectMixin, DeleteItemMixin {}
+
+mixin CommonMultiSelectMixin<T extends MultiSelectData> on MultiSelectMixin<T> {
+  Rx<LoadingState<List<T>?>> get loadingState;
+  late final RxInt rxCount = 0.obs;
+
+  @override
+  int get checkedCount => rxCount.value;
+
+  Iterable<T> get allChecked =>
+      loadingState.value.data!.where((v) => v.checked == true);
+
+  @override
   void onSelect(T item, [bool disableSelect = true]) {
     List<T> list = loadingState.value.data!;
     item.checked = !(item.checked ?? false);
-    checkedCount.value = list.where((item) => item.checked == true).length;
+    if (item.checked!) {
+      rxCount.value++;
+    } else {
+      rxCount.value--;
+    }
     loadingState.refresh();
     if (disableSelect) {
-      if (checkedCount.value == 0) {
+      if (checkedCount == 0) {
         enableMultiSelect.value = false;
       }
     } else {
-      allSelected.value = checkedCount.value == list.length;
+      allSelected.value = checkedCount == list.length;
     }
   }
 
+  @override
   void handleSelect([bool checked = false, bool disableSelect = true]) {
     if (loadingState.value.isSuccess) {
-      List<T>? list = loadingState.value.data;
+      final list = loadingState.value.data;
       if (list?.isNotEmpty == true) {
-        for (T item in list!) {
+        for (var item in list!) {
           item.checked = checked;
         }
         loadingState.refresh();
-        checkedCount.value = checked ? list.length : 0;
+        rxCount.value = checked ? list.length : 0;
       }
     }
     if (disableSelect && !checked) {
@@ -41,3 +67,75 @@ abstract class MultiSelectController<R, T extends MultiSelectData>
     }
   }
 }
+
+mixin DeleteItemMixin<R, T extends MultiSelectData>
+    on CommonListController<R, T>, CommonMultiSelectMixin<T> {
+  Future<void> afterDelete(Set<T> result) async {
+    // TODO: result require hash
+    final remainList = loadingState.value.data!;
+    if (result.length == 1) {
+      remainList.remove(result.single);
+    } else {
+      remainList.removeWhere(result.contains);
+    }
+    if (remainList.isNotEmpty) {
+      loadingState.refresh();
+    } else if (!isEnd) {
+      onReload();
+    }
+    if (enableMultiSelect.value) {
+      rxCount.value = 0;
+      enableMultiSelect.value = false;
+    }
+  }
+}
+
+// abstract class SetMultiSelectController<R, T, I>
+//     extends CommonListController<R, T>
+//     with MultiSelectMixin<T>, SetCommonMultiSelectMixin<T, I> {}
+
+// mixin SetCommonMultiSelectMixin<T, R> on MultiSelectMixin<T> {
+//   Rx<LoadingState<List<T>?>> get loadingState;
+//   RxSet<R> get selected;
+
+//   @override
+//   int get checkedCount => selected.length;
+
+//   R getId(T item);
+
+//   @override
+//   void onSelect(T item, [bool disableSelect = true]) {
+//     final id = getId(item);
+//     if (selected.contains(id)) {
+//       selected.remove(id);
+//     } else {
+//       selected.add(id);
+//     }
+//     loadingState.refresh();
+//     if (disableSelect) {
+//       if (checkedCount == 0) {
+//         enableMultiSelect.value = false;
+//       }
+//     } else {
+//       allSelected.value = checkedCount == loadingState.value.data!.length;
+//     }
+//   }
+
+//   @override
+//   void handleSelect([bool checked = false, bool disableSelect = true]) {
+//     if (loadingState.value.isSuccess) {
+//       final list = loadingState.value.data;
+//       if (list?.isNotEmpty == true) {
+//         if (checked) {
+//           selected.addAll(list!.map(getId));
+//         } else {
+//           selected.clear();
+//         }
+//         loadingState.refresh();
+//       }
+//     }
+//     if (disableSelect && !checked) {
+//       enableMultiSelect.value = false;
+//     }
+//   }
+// }