From 384c64b1cc143479c487c67cf1cb90a9e69ee9cd Mon Sep 17 00:00:00 2001
From: Vishesh Handa <me@vhanda.in>
Date: Tue, 25 May 2021 12:57:06 +0200
Subject: [PATCH] null safety++
---
lib/editors/disposable_change_notifier.dart | 123 ++++++++++++--------
lib/widgets/folder_tree_view.dart | 24 ++--
lib/widgets/note_editor_selector.dart | 4 +-
3 files changed, 88 insertions(+), 63 deletions(-)
diff --git a/lib/editors/disposable_change_notifier.dart b/lib/editors/disposable_change_notifier.dart
index ba8e8f5f..7e1f922e 100644
--- a/lib/editors/disposable_change_notifier.dart
+++ b/lib/editors/disposable_change_notifier.dart
@@ -1,19 +1,27 @@
-// @dart=2.9
+import 'dart:collection';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
/// A duplicate of the ChangeNotifier class which has the dispose method
-/// renamed to disposeListeners. This is done so that it can be used
+/// renamed to disposeListenables. This is done so that it can be used
/// as a mixin with a State class which also has a dispose method
+
+class _ListenerEntry extends LinkedListEntry<_ListenerEntry> {
+ _ListenerEntry(this.listener);
+ final VoidCallback listener;
+}
+
class DisposableChangeNotifier implements Listenable {
- ObserverList<VoidCallback> _listeners = ObserverList<VoidCallback>();
+ LinkedList<_ListenerEntry>? _listeners = LinkedList<_ListenerEntry>();
bool _debugAssertNotDisposed() {
assert(() {
if (_listeners == null) {
- throw FlutterError('A $runtimeType was used after being disposed.\n'
- 'Once you have called dispose() on a $runtimeType, it can no longer be used.');
+ throw FlutterError(
+ 'A $runtimeType was used after being disposed.\n'
+ 'Once you have called dispose() on a $runtimeType, it can no longer be used.',
+ );
}
return true;
}());
@@ -38,16 +46,39 @@ class DisposableChangeNotifier implements Listenable {
@protected
bool get hasListeners {
assert(_debugAssertNotDisposed());
- return _listeners.isNotEmpty;
+ return _listeners!.isNotEmpty;
}
/// Register a closure to be called when the object changes.
///
+ /// If the given closure is already registered, an additional instance is
+ /// added, and must be removed the same number of times it is added before it
+ /// will stop being called.
+ ///
/// This method must not be called after [dispose] has been called.
+ ///
+ /// {@template flutter.foundation.ChangeNotifier.addListener}
+ /// If a listener is added twice, and is removed once during an iteration
+ /// (e.g. in response to a notification), it will still be called again. If,
+ /// on the other hand, it is removed as many times as it was registered, then
+ /// it will no longer be called. This odd behavior is the result of the
+ /// [ChangeNotifier] not being able to determine which listener is being
+ /// removed, since they are identical, therefore it will conservatively still
+ /// call all the listeners when it knows that any are still registered.
+ ///
+ /// This surprising behavior can be unexpectedly observed when registering a
+ /// listener on two separate objects which are both forwarding all
+ /// registrations to a common upstream object.
+ /// {@endtemplate}
+ ///
+ /// See also:
+ ///
+ /// * [removeListener], which removes a previously registered closure from
+ /// the list of closures that are notified when the object changes.
@override
void addListener(VoidCallback listener) {
assert(_debugAssertNotDisposed());
- _listeners.add(listener);
+ _listeners!.add(_ListenerEntry(listener));
}
/// Remove a previously registered closure from the list of closures that are
@@ -57,22 +88,21 @@ class DisposableChangeNotifier implements Listenable {
///
/// This method must not be called after [dispose] has been called.
///
- /// If a listener had been added twice, and is removed once during an
- /// iteration (i.e. in response to a notification), it will still be called
- /// again. If, on the other hand, it is removed as many times as it was
- /// registered, then it will no longer be called. This odd behavior is the
- /// result of the [ChangeNotifier] not being able to determine which listener
- /// is being removed, since they are identical, and therefore conservatively
- /// still calling all the listeners when it knows that any are still
- /// registered.
+ /// {@macro flutter.foundation.ChangeNotifier.addListener}
///
- /// This surprising behavior can be unexpectedly observed when registering a
- /// listener on two separate objects which are both forwarding all
- /// registrations to a common upstream object.
+ /// See also:
+ ///
+ /// * [addListener], which registers a closure to be called when the object
+ /// changes.
@override
void removeListener(VoidCallback listener) {
assert(_debugAssertNotDisposed());
- _listeners.remove(listener);
+ for (final _ListenerEntry entry in _listeners!) {
+ if (entry.listener == listener) {
+ entry.unlink();
+ return;
+ }
+ }
}
/// Discards any resources used by the object. After this is called, the
@@ -90,46 +120,45 @@ class DisposableChangeNotifier implements Listenable {
/// Call all the registered listeners.
///
/// Call this method whenever the object changes, to notify any clients the
- /// object may have. Listeners that are added during this iteration will not
- /// be visited. Listeners that are removed during this iteration will not be
- /// visited after they are removed.
+ /// object may have changed. Listeners that are added during this iteration
+ /// will not be visited. Listeners that are removed during this iteration will
+ /// not be visited after they are removed.
///
/// Exceptions thrown by listeners will be caught and reported using
/// [FlutterError.reportError].
///
/// This method must not be called after [dispose] has been called.
///
- /// Surprising behavior can result when reentrantly removing a listener (i.e.
+ /// Surprising behavior can result when reentrantly removing a listener (e.g.
/// in response to a notification) that has been registered multiple times.
/// See the discussion at [removeListener].
@protected
@visibleForTesting
void notifyListeners() {
assert(_debugAssertNotDisposed());
- if (_listeners != null) {
- final List<VoidCallback> localListeners =
- List<VoidCallback>.from(_listeners);
- for (final VoidCallback listener in localListeners) {
- try {
- if (_listeners.contains(listener)) {
- listener();
- }
- } catch (exception, stack) {
- FlutterError.reportError(FlutterErrorDetails(
- exception: exception,
- stack: stack,
- library: 'foundation library',
- context: ErrorDescription(
- 'while dispatching notifications for $runtimeType'),
- informationCollector: () sync* {
- yield DiagnosticsProperty<DisposableChangeNotifier>(
- 'The $runtimeType sending notification was',
- this,
- style: DiagnosticsTreeStyle.errorProperty,
- );
- },
- ));
- }
+ if (_listeners!.isEmpty) return;
+
+ final List<_ListenerEntry> localListeners =
+ List<_ListenerEntry>.from(_listeners!);
+
+ for (final _ListenerEntry entry in localListeners) {
+ try {
+ if (entry.list != null) entry.listener();
+ } catch (exception, stack) {
+ FlutterError.reportError(FlutterErrorDetails(
+ exception: exception,
+ stack: stack,
+ library: 'foundation library',
+ context: ErrorDescription(
+ 'while dispatching notifications for $runtimeType'),
+ informationCollector: () sync* {
+ yield DiagnosticsProperty<DisposableChangeNotifier>(
+ 'The $runtimeType sending notification was',
+ this,
+ style: DiagnosticsTreeStyle.errorProperty,
+ );
+ },
+ ));
}
}
}
diff --git a/lib/widgets/folder_tree_view.dart b/lib/widgets/folder_tree_view.dart
index a8f6997e..b3c29326 100644
--- a/lib/widgets/folder_tree_view.dart
+++ b/lib/widgets/folder_tree_view.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
import 'package:flutter/material.dart';
import 'package:gitjournal/core/notes_folder_fs.dart';
@@ -14,9 +12,9 @@ class FolderTreeView extends StatefulWidget {
final FolderSelectedCallback onFolderEntered;
FolderTreeView({
- Key key,
- @required this.rootFolder,
- @required this.onFolderEntered,
+ Key? key,
+ required this.rootFolder,
+ required this.onFolderEntered,
this.onFolderSelected = _doNothing,
this.onFolderUnselected = _doNothing,
}) : super(key: key);
@@ -29,7 +27,7 @@ class FolderTreeView extends StatefulWidget {
class FolderTreeViewState extends State<FolderTreeView> {
bool inSelectionMode = false;
- NotesFolderFS selectedFolder;
+ NotesFolderFS? selectedFolder;
@override
Widget build(BuildContext context) {
@@ -73,13 +71,13 @@ class FolderTile extends StatefulWidget {
final NotesFolderFS folder;
final FolderSelectedCallback onTap;
final FolderSelectedCallback onLongPress;
- final NotesFolderFS selectedFolder;
+ final NotesFolderFS? selectedFolder;
FolderTile({
- @required this.folder,
- @required this.onTap,
- @required this.onLongPress,
- @required this.selectedFolder,
+ required this.folder,
+ required this.onTap,
+ required this.onLongPress,
+ required this.selectedFolder,
});
@override
@@ -127,7 +125,7 @@ class FolderTileState extends State<FolderTile> {
var publicName = folder.publicName;
if (folder.parent != null) {
- publicName = publicName.substring(folder.parent.pathSpec().length);
+ publicName = publicName.substring(folder.parent!.pathSpec().length);
if (publicName.startsWith('/')) {
publicName = publicName.substring(1);
}
@@ -167,7 +165,7 @@ class FolderTileState extends State<FolderTile> {
var children = <FolderTile>[];
widget.folder.subFolders.forEach((folder) {
children.add(FolderTile(
- folder: folder,
+ folder: folder as NotesFolderFS,
onTap: widget.onTap,
onLongPress: widget.onLongPress,
selectedFolder: widget.selectedFolder,
diff --git a/lib/widgets/note_editor_selector.dart b/lib/widgets/note_editor_selector.dart
index 330fbfa1..63350365 100644
--- a/lib/widgets/note_editor_selector.dart
+++ b/lib/widgets/note_editor_selector.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
/*
Copyright 2020-2021 Vishesh Handa <me@vhanda.in>
@@ -85,7 +83,7 @@ class NoteEditorSelector extends StatelessWidget {
var selected = et == currentEditor;
var theme = Theme.of(context);
var listTileTheme = ListTileTheme.of(context);
- var textStyle = theme.textTheme.bodyText2.copyWith(
+ var textStyle = theme.textTheme.bodyText2!.copyWith(
color: selected ? theme.primaryColor : listTileTheme.textColor,
);