Refactor cancelable task logic

lib/src/components/dialogs.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:org_flutter/org_flutter.dart';
+import 'package:orgro/src/debug.dart';
 import 'package:orgro/src/preferences.dart';
 import 'package:orgro/src/serialization.dart';
 import 'package:share_plus/share_plus.dart';
@@ -164,6 +165,47 @@ class InputPasswordDialog extends StatelessWidget {
  }
 }
 
+Future<({bool succeeded, T? result})> cancelableProgressTask<T>(
+ BuildContext context, {
+ required Future<T> task,
+ required String dialogTitle,
+}) async {
+ var canceled = false;
+
+ final dialogFuture = showDialog<(T, Object?)>(
+ context: context,
+ builder: (context) => ProgressIndicatorDialog(
+ title: dialogTitle,
+ dismissable: true,
+ ),
+ );
+
+ task.then((result) {
+ if (!canceled && context.mounted) Navigator.pop(context, (result, null));
+ }).onError((error, stackTrace) {
+ if (context.mounted) showErrorSnackBar(context, error);
+ logError(error, stackTrace);
+ if (!canceled && context.mounted) Navigator.pop(context, (null, error));
+ });
+
+ // Popped will be one of:
+ // - null if the user closed the dialog by tapping outside or using the back
+ // button/gesture
+ // - (task result, null) if completed normally
+ // - (null, error) if completed with error
+ final popped = await dialogFuture;
+
+ if (popped == null) {
+ canceled = true;
+ return (succeeded: false, result: null);
+ }
+
+ final (result, error) = popped;
+ return error == null
+ ? (succeeded: true, result: result)
+ : (succeeded: false, result: null);
+}
+
 class ProgressIndicatorDialog extends StatelessWidget {
  const ProgressIndicatorDialog({
  required this.title,

lib/src/pages/document/encryption.dart

@@ -24,28 +24,14 @@ extension EncryptionHandler on DocumentPageState {
  );
  if (password == null) return;
  if (!mounted) return;
- var canceled = false;
- time('decrypt', () => compute(decrypt, (blocks, password)))
- .then((decrypted) {
- if (!canceled && mounted) Navigator.pop(context, decrypted);
- }).onError((error, stackTrace) {
- if (mounted) showErrorSnackBar(context, error);
- logError(error, stackTrace);
- if (!canceled && mounted) Navigator.pop(context);
- });
- final result = await showDialog<List<String?>>(
- context: context,
- builder: (context) => ProgressIndicatorDialog(
- title: AppLocalizations.of(context)!.decryptingProgressDialogTitle,
- dismissable: true,
- ),
+
+ final (succeeded: succeeded, result: result) = await cancelableProgressTask(
+ context,
+ task: time('decrypt', () => compute(decrypt, (blocks, password))),
+ dialogTitle: AppLocalizations.of(context)!.decryptingProgressDialogTitle,
  );
- if (!mounted) return;
- if (result == null) {
- // Canceled
- canceled = true;
- return;
- }
+ if (!succeeded || result == null) return;
+
  OrgTree newDoc = doc;
  final toRemember = <OrgroPassword>[];
  for (final (i, cleartext) in result.indexed) {

lib/src/pages/document/links.dart

@@ -61,39 +61,27 @@ extension LinkHandler on DocumentPageState {
  final targetId = parseOrgIdUrl(url);
  final requestId = Object().hashCode.toString();
 
- var canceled = false;
- time(
- 'find file with ID',
- () => findFileForId(
- requestId: requestId,
- orgId: targetId,
- dirIdentifier: dataSource.rootDirIdentifier!,
- ),
- ).then((found) {
- if (!canceled && mounted) Navigator.pop(context, (found, true));
- }).onError((error, stackTrace) {
- if (mounted) showErrorSnackBar(context, error);
- logError(error, stackTrace);
- if (!canceled && mounted) Navigator.pop(context);
- });
-
- final result = await showDialog<(NativeDataSource?, bool)>(
- context: context,
- builder: (context) => ProgressIndicatorDialog(
- title: AppLocalizations.of(context)!.searchingProgressDialogTitle,
- dismissable: true,
+ final (succeeded: succeeded, result: foundFile) =
+ await cancelableProgressTask(
+ context,
+ task: time(
+ 'find file with ID',
+ () => findFileForId(
+ requestId: requestId,
+ orgId: targetId,
+ dirIdentifier: dataSource.rootDirIdentifier!,
+ ),
  ),
+ dialogTitle: AppLocalizations.of(context)!.searchingProgressDialogTitle,
  );
 
- if (result == null) {
- canceled = true;
+ if (!succeeded) {
  cancelFindFileForId(requestId: requestId);
  return false;
  }
+
  if (!mounted) return false;
 
- final (foundFile, searchCompleted) = result;
- assert(searchCompleted);
  if (foundFile == null) {
  showErrorSnackBar(context,
  AppLocalizations.of(context)!.errorExternalIdNotFound(targetId));