Consolidate frontend scanner, pagination, and tick-timer duplication

Collapse the five scanner status models into two shared shapes, ActiveScannerStatus and PassiveScannerStatus, mirroring the backend's active/passive vocabulary. Replace the five near-identical per-scanner detail card files with a single scanner_status_cards.dart (two shared resolvers plus a config list), and rebuild the combined home card to iterate a list of scanners with two shape resolvers instead of five copy-pasted resolve methods. Extract two reusable mixins: - PeriodicRebuild: the shared once-a-second "rebuild to refresh elapsed text" timer used by the scanner cards and the stale indicator. - PaginatedListState: the shared pagination state, page-size/page-count getters, cancel-token-aware fetch orchestration, and disposal used by the device and notification lists. No behaviour change; ~900 lines removed. Tests and analyzer pass.
2026-07-08 19:21:54 +02:00 · 2026-06-05 21:57:58 -04:00
parent 6b044a6739
commit 48d73fb207
22 changed files with 533 additions and 859 deletions
@@ -0,0 +1,93 @@
+import 'package:dio/dio.dart';
+import 'package:flutter/material.dart';
+
+import '../theme/dimens.dart';
+import '../widgets/pagination_progress.dart';
+import 'api/api_error.dart';
+
+/// Shared state and orchestration for screens that show a paged, server-backed
+/// list (devices, notifications). Provides the common pagination state, the
+/// responsive page-size/page-count getters, the cancel-token-aware [runFetch]
+/// helper, and disposal of the scroll controller and in-flight token.
+///
+/// Subclasses supply [phonePageSize], [widePageSize] and [isListEmpty], call
+/// [runFetch] to load a page, and chain [dispose] via `super.dispose()`.
+mixin PaginatedListState<W extends StatefulWidget> on State<W> {
+  int currentPage = 0;
+  // Total items matching the current filters, used to show how many pages exist
+  // and to offer "go to last page".
+  int totalCount = 0;
+  bool isLoading = false;
+  bool isPaging = false;
+  bool didInitialFetch = false;
+  String? error;
+  CancelToken? fetchToken;
+  final ScrollController scrollController = ScrollController();
+
+  /// Page sizes for the phone and wider layouts.
+  int get phonePageSize;
+  int get widePageSize;
+
+  /// Whether the list currently has no items. Controls whether a fetch shows
+  /// the full loading state or refreshes the current page in place.
+  bool get isListEmpty;
+
+  int get pageSize => MediaQuery.sizeOf(context).width < Breakpoints.medium
+      ? phonePageSize
+      : widePageSize;
+  int get totalPages => (totalCount / pageSize).ceil().clamp(1, 1 << 30);
+
+  /// Runs a paged fetch with the orchestration shared by every paged list:
+  /// optional scroll-to-top, cancel-token swap, loading flags, the
+  /// unmounted/superseded guard, and error handling. [fetch] performs the
+  /// request for the given page; [onResult] applies a still-current result to
+  /// state (it is not called for cancelled, superseded, or failed fetches).
+  Future<void> runFetch<R>(
+    int page, {
+    bool scrollToTop = false,
+    bool paging = false,
+    required Future<R> Function(int page, int perPage, CancelToken token) fetch,
+    required void Function(R result) onResult,
+  }) async {
+    if (scrollToTop && scrollController.hasClients) {
+      scrollController.animateTo(
+        0,
+        duration: const Duration(milliseconds: 300),
+        curve: Curves.easeOut,
+      );
+    }
+    fetchToken?.cancel();
+    final token = CancelToken();
+    fetchToken = token;
+    setState(() {
+      isLoading = isListEmpty;
+      isPaging = paging;
+      error = null;
+    });
+    paginationLoading.value = paging;
+    try {
+      final result = await fetch(page, pageSize, token);
+      if (!mounted || token != fetchToken) return;
+      paginationLoading.value = false;
+      onResult(result);
+    } catch (e) {
+      if (!mounted || token != fetchToken) return;
+      if (e is DioException && e.type == DioExceptionType.cancel) return;
+      setState(() {
+        error = dioErrorToUserMessage(e);
+        isLoading = false;
+        isPaging = false;
+      });
+      paginationLoading.value = false;
+    }
+  }
+
+  @override
+  void dispose() {
+    fetchToken?.cancel();
+    scrollController.dispose();
+    // Clear any in-flight cue so it doesn't linger after leaving the page.
+    paginationLoading.value = false;
+    super.dispose();
+  }
+}