durations cleanup

lib/model/terms.dart

@@ -15,4 +15,3 @@ __We collect anonymous data to improve the app.__ We use Google Firebase for Ana
 ## Links
 [Sources](https://github.com/deckerst/aves)
 ''';
-

lib/utils/constants.dart

@@ -19,9 +19,6 @@ class Constants {
     ],
   );
 
-  // ref _PopupMenuRoute._kMenuDuration
-  static const popupMenuTransitionDuration = Duration(milliseconds: 300);
-
   static const svgBackground = Colors.white;
   static const svgColorFilter = ColorFilter.mode(svgBackground, BlendMode.dstOver);
 

lib/utils/durations.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/scheduler.dart';
+
+class Durations {
+  // common animations
+  static const iconAnimation = Duration(milliseconds: 300);
+  static const opToastAnimation = Duration(milliseconds: 600);
+  static const sweeperOpacityAnimation = Duration(milliseconds: 150);
+  static const sweepingAnimation = Duration(milliseconds: 650);
+  static const popupMenuAnimation = Duration(milliseconds: 300); // ref _PopupMenuRoute._kMenuDuration
+  static const staggeredAnimation = Duration(milliseconds: 375);
+
+  // collection animations
+  static const appBarTitleAnimation = Duration(milliseconds: 300);
+  static const filterBarRemovalAnimation = Duration(milliseconds: 200);
+  static const collectionOpOverlayAnimation = Duration(milliseconds: 300);
+  static const collectionScalingBackgroundAnimation = Duration(milliseconds: 200);
+  static const sectionHeaderAnimation = Duration(milliseconds: 200);
+  static const thumbnailTransition = Duration(milliseconds: 200);
+  static const thumbnailOverlayAnimation = Duration(milliseconds: 200);
+
+  // search animations
+  static const filterRowExpandAnimation = Duration(milliseconds: 300);
+
+  // fullscreen animations
+  static const fullscreenPageAnimation = Duration(milliseconds: 300);
+  static const fullscreenOverlayAnimation = Duration(milliseconds: 200);
+
+  // delays & refresh intervals
+  static const opToastDisplay = Duration(seconds: 2);
+  static const collectionScrollMonitoringTimerDelay = Duration(milliseconds: 100);
+  static const collectionScalingCompleteNotificationDelay = Duration(milliseconds: 300);
+  static const appBarProgressTimerInterval = Duration(seconds: 1);
+  static const videoProgressTimerInterval = Duration(milliseconds: 300);
+  static var staggeredAnimationDelay = Durations.staggeredAnimation ~/ 6 * timeDilation;
+}

lib/widgets/about/licenses.dart

@@ -1,4 +1,5 @@
 import 'package:aves/utils/constants.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:aves/widgets/common/menu_row.dart';
 import 'package:collection/collection.dart';
@@ -48,7 +49,8 @@ class _LicensesState extends State<Licenses> {
             final child = LicenseRow(_packages[index]);
             return AnimationConfiguration.staggeredList(
               position: index,
-              duration: const Duration(milliseconds: 375),
+              duration: Durations.staggeredAnimation,
+              delay: Durations.staggeredAnimationDelay,
               child: SlideAnimation(
                 verticalOffset: 50.0,
                 child: FadeInAnimation(

lib/widgets/album/app_bar.dart

@@ -5,7 +5,7 @@ import 'package:aves/model/collection_lens.dart';
 import 'package:aves/model/collection_source.dart';
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/model/settings.dart';
-import 'package:aves/utils/constants.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/filter_bar.dart';
 import 'package:aves/widgets/album/search/search_delegate.dart';
 import 'package:aves/widgets/common/action_delegates/selection_action_delegate.dart';
@@ -49,7 +49,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
       collection: collection,
     );
     _browseToSelectAnimation = AnimationController(
-      duration: const Duration(milliseconds: 300),
+      duration: Durations.iconAnimation,
       vsync: this,
     );
     _registerWidget(widget);
@@ -142,7 +142,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
               valueListenable: collection.source.stateNotifier,
               builder: (context, sourceState, child) {
                 return AnimatedSwitcher(
-                  duration: Duration(milliseconds: (300 * timeDilation).toInt()),
+                  duration: Durations.appBarTitleAnimation,
                   transitionBuilder: (child, animation) => FadeTransition(
                     opacity: animation,
                     child: SizeTransition(
@@ -297,7 +297,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
 
   void _onCollectionActionSelected(CollectionAction action) async {
     // wait for the popup menu to hide before proceeding with the action
-    await Future.delayed(Constants.popupMenuTransitionDuration);
+    await Future.delayed(Durations.popupMenuAnimation * timeDilation);
     switch (action) {
       case CollectionAction.copy:
       case CollectionAction.move:
@@ -384,7 +384,7 @@ class _SourceStateSubtitleState extends State<SourceStateSubtitle> {
   @override
   void initState() {
     super.initState();
-    _progressTimer = Timer.periodic(const Duration(milliseconds: 1000), (timer) => setState(() {}));
+    _progressTimer = Timer.periodic(Durations.appBarProgressTimerInterval, (_) => setState(() {}));
   }
 
   @override

lib/widgets/album/filter_bar.dart

@@ -1,4 +1,5 @@
 import 'package:aves/model/filters/filters.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_filter_chip.dart';
 import 'package:flutter/material.dart';
 
@@ -56,7 +57,7 @@ class _FilterBarState extends State<FilterBar> {
                   ),
                 )
             : (context, animation) => _buildChip(filter),
-        duration: animate ? const Duration(milliseconds: 200) : Duration.zero,
+        duration: animate ? Durations.filterBarRemovalAnimation : Duration.zero,
       );
     });
     added.forEach((filter) {

lib/widgets/album/grid/header_generic.dart

@@ -4,12 +4,12 @@ import 'package:aves/model/collection_lens.dart';
 import 'package:aves/model/collection_source.dart';
 import 'package:aves/utils/android_file_utils.dart';
 import 'package:aves/utils/constants.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/grid/header_album.dart';
 import 'package:aves/widgets/album/grid/header_date.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter/scheduler.dart';
 import 'package:provider/provider.dart';
 
 class SectionHeader extends StatelessWidget {
@@ -190,11 +190,11 @@ class SectionSelectableLeading extends StatelessWidget {
                   final sectionEntries = collection.sections[sectionKey];
                   final selected = collection.isSelected(sectionEntries);
                   final child = TooltipTheme(
+                    key: ValueKey(selected),
                     data: TooltipTheme.of(context).copyWith(
                       preferBelow: false,
                     ),
                     child: IconButton(
-                      key: ValueKey(selected),
                       iconSize: 26,
                       padding: const EdgeInsets.only(top: 1),
                       alignment: Alignment.topLeft,
@@ -214,7 +214,7 @@ class SectionSelectableLeading extends StatelessWidget {
                     ),
                   );
                   return AnimatedSwitcher(
-                    duration: Duration(milliseconds: (200 * timeDilation).toInt()),
+                    duration: Durations.sectionHeaderAnimation,
                     switchInCurve: Curves.easeOutBack,
                     switchOutCurve: Curves.easeOutBack,
                     transitionBuilder: (child, animation) => ScaleTransition(
@@ -227,7 +227,7 @@ class SectionSelectableLeading extends StatelessWidget {
               )
             : browsingBuilder?.call(context) ?? const SizedBox(height: leadingDimension);
         return AnimatedSwitcher(
-          duration: Duration(milliseconds: (200 * timeDilation).toInt()),
+          duration: Durations.sectionHeaderAnimation,
           switchInCurve: Curves.easeInOut,
           switchOutCurve: Curves.easeInOut,
           transitionBuilder: (child, animation) {

lib/widgets/album/grid/scaling.dart

@@ -2,6 +2,7 @@ import 'dart:math';
 import 'dart:ui' as ui;
 
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/grid/list_section_layout.dart';
 import 'package:aves/widgets/album/grid/list_sliver.dart';
 import 'package:aves/widgets/album/grid/tile_extent_manager.dart';
@@ -118,7 +119,7 @@ class _GridScaleGestureDetectorState extends State<GridScaleGestureDetector> {
             _scrollToEntry(entry);
             // warning: posting `onScaled` in the next frame with `addPostFrameCallback`
             // would trigger only when the scrollable offset actually changes
-            Future.delayed(const Duration(milliseconds: 300)).then((_) => widget.onScaled?.call(entry));
+            Future.delayed(Durations.collectionScalingCompleteNotificationDelay).then((_) => widget.onScaled?.call(entry));
             _applyingScale = false;
           });
         }
@@ -200,7 +201,7 @@ class _ScaleOverlayState extends State<ScaleOverlay> {
                     ],
                   ),
                 ),
-          duration: const Duration(milliseconds: 200),
+          duration: Durations.collectionScalingBackgroundAnimation,
           child: ValueListenableBuilder<double>(
             valueListenable: widget.scaledExtentNotifier,
             builder: (context, extent, child) {

lib/widgets/album/search/expandable_filter_row.dart

@@ -1,5 +1,6 @@
 import 'package:aves/model/filters/filters.dart';
 import 'package:aves/utils/constants.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_filter_chip.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:flutter/material.dart';
@@ -95,7 +96,7 @@ class ExpandableFilterRow extends StatelessWidget {
             children: [
               titleRow,
               AnimatedSwitcher(
-                duration: const Duration(milliseconds: 300),
+                duration: Durations.filterRowExpandAnimation,
                 child: filterChips,
                 layoutBuilder: (currentChild, previousChildren) => Stack(
                   children: [

lib/widgets/album/thumbnail/overlay.dart

@@ -2,10 +2,10 @@ import 'dart:math';
 
 import 'package:aves/model/collection_lens.dart';
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/fx/sweeper.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/scheduler.dart';
 import 'package:provider/provider.dart';
 
 class ThumbnailEntryOverlay extends StatelessWidget {
@@ -57,7 +57,7 @@ class ThumbnailSelectionOverlay extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final duration = Duration(milliseconds: (200 * timeDilation).toInt());
+    final duration = Durations.thumbnailOverlayAnimation;
     final fontSize = min(14.0, (extent / 8)).roundToDouble();
     final iconSize = fontSize * 2;
     final collection = Provider.of<CollectionLens>(context);

lib/widgets/album/thumbnail/raster.dart

@@ -1,6 +1,7 @@
 import 'dart:math';
 
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/image_providers/thumbnail_provider.dart';
 import 'package:aves/widgets/common/image_providers/uri_image_provider.dart';
 import 'package:aves/widgets/common/transition_image.dart';
@@ -93,7 +94,7 @@ class _ThumbnailRasterImageState extends State<ThumbnailRasterImage> {
             frameBuilder: (context, child, frame, wasSynchronouslyLoaded) {
               if (wasSynchronouslyLoaded) return child;
               return AnimatedSwitcher(
-                duration: const Duration(milliseconds: 200),
+                duration: Durations.thumbnailTransition,
                 transitionBuilder: (child, animation) {
                   var shouldFade = true;
                   if (child is Image && child.image == _fastThumbnailProvider) {

lib/widgets/album/thumbnail_collection.dart

@@ -4,6 +4,7 @@ import 'package:aves/model/collection_lens.dart';
 import 'package:aves/model/filters/favourite.dart';
 import 'package:aves/model/filters/mime.dart';
 import 'package:aves/model/mime_types.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/app_bar.dart';
 import 'package:aves/widgets/album/empty.dart';
 import 'package:aves/widgets/album/grid/list_section_layout.dart';
@@ -220,7 +221,7 @@ class _CollectionScrollViewState extends State<CollectionScrollView> {
   void _onScrollChange() {
     widget.isScrollingNotifier.value = true;
     _stopScrollMonitoringTimer();
-    _scrollMonitoringTimer = Timer(const Duration(milliseconds: 100), () {
+    _scrollMonitoringTimer = Timer(Durations.collectionScrollMonitoringTimerDelay, () {
       widget.isScrollingNotifier.value = false;
     });
   }

lib/widgets/common/action_delegates/create_album_dialog.dart

@@ -53,14 +53,14 @@ class _CreateAlbumDialogState extends State<CreateAlbumDialog> {
                   isExpanded: true,
                   items: allVolumes
                       .map((volume) => DropdownMenuItem(
-                    value: volume,
+                            value: volume,
-                    child: Text(
+                            child: Text(
-                      volume.description,
+                              volume.description,
-                      softWrap: false,
+                              softWrap: false,
-                      overflow: TextOverflow.fade,
+                              overflow: TextOverflow.fade,
-                      maxLines: 1,
+                              maxLines: 1,
-                    ),
+                            ),
-                  ))
+                          ))
                       .toList(),
                   value: selectedVolume,
                   onChanged: (volume) => setState(() => selectedVolume = volume),

lib/widgets/common/action_delegates/feedback.dart

@@ -1,5 +1,7 @@
+import 'package:aves/utils/durations.dart';
 import 'package:flushbar/flushbar.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 
 mixin FeedbackMixin {
   void showFeedback(BuildContext context, String message) {
@@ -9,9 +11,9 @@ mixin FeedbackMixin {
       borderRadius: 8,
       borderColor: Colors.white30,
       borderWidth: 0.5,
-      duration: const Duration(seconds: 2),
+      duration: Durations.opToastDisplay * timeDilation,
       flushbarPosition: FlushbarPosition.TOP,
-      animationDuration: const Duration(milliseconds: 600),
+      animationDuration: Durations.opToastAnimation,
     ).show(context);
   }
 }

lib/widgets/common/action_delegates/selection_action_delegate.dart

@@ -7,6 +7,7 @@ import 'package:aves/model/image_entry.dart';
 import 'package:aves/model/metadata_db.dart';
 import 'package:aves/services/android_app_service.dart';
 import 'package:aves/services/image_file_service.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/app_bar.dart';
 import 'package:aves/widgets/album/empty.dart';
 import 'package:aves/widgets/common/action_delegates/create_album_dialog.dart';
@@ -18,6 +19,7 @@ import 'package:aves/widgets/filter_grid_page.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:flutter/widgets.dart';
 import 'package:intl/intl.dart';
 import 'package:percent_indicator/circular_percent_indicator.dart';
@@ -221,8 +223,6 @@ class SelectionActionDelegate with FeedbackMixin, PermissionAwareMixin {
 
   OverlayEntry _opReportOverlayEntry;
 
-  static const _overlayAnimationDuration = Duration(milliseconds: 300);
-
   void _showOpReport<T extends ImageOpEvent>({
     @required BuildContext context,
     @required List<ImageEntry> selection,
@@ -260,7 +260,7 @@ class SelectionActionDelegate with FeedbackMixin, PermissionAwareMixin {
                 );
               }
               return AnimatedSwitcher(
-                duration: _overlayAnimationDuration,
+                duration: Durations.collectionOpOverlayAnimation,
                 child: child,
               );
             });
@@ -270,7 +270,7 @@ class SelectionActionDelegate with FeedbackMixin, PermissionAwareMixin {
   }
 
   Future<void> _hideOpReportOverlay() async {
-    await Future.delayed(_overlayAnimationDuration);
+    await Future.delayed(Durations.collectionOpOverlayAnimation * timeDilation);
     _opReportOverlayEntry.remove();
     _opReportOverlayEntry = null;
   }

lib/widgets/common/fx/sweeper.dart

@@ -1,5 +1,6 @@
 import 'dart:math';
 
+import 'package:aves/utils/durations.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
@@ -34,14 +35,11 @@ class _SweeperState extends State<Sweeper> with SingleTickerProviderStateMixin {
 
   bool get isToggled => widget.toggledNotifier.value;
 
-  static const opacityAnimationDurationMillis = 150;
-  static const sweepingDurationMillis = 650;
-
   @override
   void initState() {
     super.initState();
     _angleAnimationController = AnimationController(
-      duration: const Duration(milliseconds: sweepingDurationMillis),
+      duration: Durations.sweepingAnimation,
       vsync: this,
     );
     final startAngle = widget.startAngle;
@@ -86,7 +84,7 @@ class _SweeperState extends State<Sweeper> with SingleTickerProviderStateMixin {
     return IgnorePointer(
       child: AnimatedOpacity(
         opacity: isToggled && (_isAppearing || _angleAnimationController.status == AnimationStatus.forward) ? 1 : 0,
-        duration: const Duration(milliseconds: opacityAnimationDurationMillis),
+        duration: Durations.sweeperOpacityAnimation,
         child: ValueListenableBuilder<double>(
             valueListenable: _angleAnimationController,
             builder: (context, value, child) {
@@ -113,7 +111,7 @@ class _SweeperState extends State<Sweeper> with SingleTickerProviderStateMixin {
     if (isToggled) {
       _isAppearing = true;
       setState(() {});
-      await Future.delayed(Duration(milliseconds: (opacityAnimationDurationMillis * timeDilation).toInt()));
+      await Future.delayed(Durations.sweeperOpacityAnimation * timeDilation);
       _isAppearing = false;
       if (mounted) {
         _angleAnimationController.reset();

lib/widgets/filter_grid_page.dart

@@ -7,6 +7,7 @@ import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/model/settings.dart';
 import 'package:aves/utils/android_file_utils.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/collection_page.dart';
 import 'package:aves/widgets/album/thumbnail/raster.dart';
 import 'package:aves/widgets/album/thumbnail/vector.dart';
@@ -115,7 +116,8 @@ class FilterGridPage extends StatelessWidget {
                                   return AnimationConfiguration.staggeredGrid(
                                     position: i,
                                     columnCount: columnCount,
-                                    duration: const Duration(milliseconds: 375),
+                                    duration: Durations.staggeredAnimation,
+                                    delay: Durations.staggeredAnimationDelay,
                                     child: SlideAnimation(
                                       verticalOffset: 50.0,
                                       child: FadeInAnimation(

lib/widgets/fullscreen/fullscreen_body.dart

@@ -5,6 +5,7 @@ import 'package:aves/model/collection_lens.dart';
 import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/utils/change_notifier.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/album/collection_page.dart';
 import 'package:aves/widgets/common/action_delegates/entry_action_delegate.dart';
 import 'package:aves/widgets/common/image_providers/thumbnail_provider.dart';
@@ -73,7 +74,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
     _horizontalPager = PageController(initialPage: _currentHorizontalPage);
     _verticalPager = PageController(initialPage: _currentVerticalPage.value)..addListener(_onVerticalPageControllerChange);
     _overlayAnimationController = AnimationController(
-      duration: const Duration(milliseconds: 200),
+      duration: Durations.fullscreenOverlayAnimation,
       vsync: this,
     );
     _topOverlayScale = CurvedAnimation(
@@ -97,8 +98,8 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
     );
     WidgetsBinding.instance.addObserver(this);
     _initVideoController();
-    _initOverlay();
     _registerWidget(widget);
+    WidgetsBinding.instance.addPostFrameCallback((_) => _initOverlay());
   }
 
   @override
@@ -283,7 +284,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
   Future<void> _goToVerticalPage(int page) {
     return _verticalPager.animateToPage(
       page,
-      duration: Duration(milliseconds: (300 * timeDilation).toInt()),
+      duration: Durations.fullscreenPageAnimation,
       curve: Curves.easeInOut,
     );
   }
@@ -321,18 +322,18 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
     _showSystemUI();
   }
 
-// system UI
+  // system UI
 
   static void _showSystemUI() => SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values);
 
   static void _hideSystemUI() => SystemChrome.setEnabledSystemUIOverlays([]);
 
-// overlay
+  // overlay
 
   Future<void> _initOverlay() async {
     // wait for MaterialPageRoute.transitionDuration
     // to show overlay after hero animation is complete
-    await Future.delayed(Duration(milliseconds: (300 * timeDilation).toInt()));
+    await Future.delayed(ModalRoute.of(context).transitionDuration * timeDilation);
     await _onOverlayVisibleChange();
   }
 

lib/widgets/fullscreen/info/info_page.dart

@@ -1,6 +1,7 @@
 import 'package:aves/model/collection_lens.dart';
 import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_filter_chip.dart';
 import 'package:aves/widgets/common/data_providers/media_query_data_provider.dart';
 import 'package:aves/widgets/common/icons.dart';
@@ -8,7 +9,6 @@ import 'package:aves/widgets/fullscreen/info/basic_section.dart';
 import 'package:aves/widgets/fullscreen/info/location_section.dart';
 import 'package:aves/widgets/fullscreen/info/metadata_section.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/scheduler.dart';
 import 'package:provider/provider.dart';
 import 'package:tuple/tuple.dart';
 
@@ -177,7 +177,7 @@ class InfoPageState extends State<InfoPage> {
     BackUpNotification().dispatch(context);
     _scrollController.animateTo(
       0,
-      duration: Duration(milliseconds: (300 * timeDilation).toInt()),
+      duration: Durations.fullscreenPageAnimation,
       curve: Curves.easeInOut,
     );
   }

lib/widgets/fullscreen/overlay/video.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/services/android_app_service.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/utils/time_utils.dart';
 import 'package:aves/widgets/common/fx/blurred.dart';
 import 'package:aves/widgets/common/icons.dart';
@@ -61,7 +62,7 @@ class VideoControlOverlayState extends State<VideoControlOverlay> with SingleTic
   void initState() {
     super.initState();
     _playPauseAnimation = AnimationController(
-      duration: const Duration(milliseconds: 300),
+      duration: Durations.iconAnimation,
       vsync: this,
     );
     _registerWidget(widget);
@@ -220,9 +221,7 @@ class VideoControlOverlayState extends State<VideoControlOverlay> with SingleTic
   void _startTimer() {
     if (controller.textureId == null) return;
     _progressTimer?.cancel();
-    _progressTimer = Timer.periodic(const Duration(milliseconds: 300), (timer) {
+    _progressTimer = Timer.periodic(Durations.videoProgressTimerInterval, (_) => controller.refreshVideoInfo());
-      controller.refreshVideoInfo();
-    });
   }
 
   void _stopTimer() {

lib/widgets/welcome.dart

@@ -1,6 +1,7 @@
 import 'package:aves/main.dart';
 import 'package:aves/model/settings.dart';
 import 'package:aves/model/terms.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_logo.dart';
 import 'package:aves/widgets/common/labeled_checkbox.dart';
 import 'package:flutter/material.dart';
@@ -28,7 +29,8 @@ class _WelcomePageState extends State<WelcomePage> {
           child: Column(
             mainAxisSize: MainAxisSize.min,
             children: _toStaggeredList(
-              duration: const Duration(milliseconds: 375),
+              duration: Durations.staggeredAnimation,
+              delay: Durations.staggeredAnimationDelay,
               childAnimationBuilder: (child) => SlideAnimation(
                 verticalOffset: 50.0,
                 child: FadeInAnimation(