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AhmedAmineZrAhmedAmineZr
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chore(A11Y): update accessibility Bottom Bar
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Lines changed: 291 additions & 106 deletions

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‎ouds_core/lib/components/navigation/internal/ouds_navigation_a11y.dart‎

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/*
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* // Software Name: OUDS Flutter
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* // SPDX-FileCopyrightText: Copyright (c) Orange SA
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* // SPDX-License-Identifier: MIT
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* //
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* // This software is distributed under the MIT license,
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* // the text of which is available at https://opensource.org/license/MIT/
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* // or see the "LICENSE" file for more details.
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* //
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* // Software description: Flutter library of reusable graphical components
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* //
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*/
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/// @nodoc
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library;
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import 'package:flutter/material.dart';
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/// Centralized accessibility utilities for OUDS Navigation components.
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///
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/// This class manages text scaling constraints for both [OudsNavigationBar] (Android/Material)
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/// and [OudsTabBar] (iOS/Cupertino) to ensure consistent accessibility behavior and prevent
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/// layout overflow when users enable zoom features.
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///
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/// ## Related Issues:
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/// - Issue #625: Android TalkBack inconsistent reading order with badges
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/// - Issue #627: iOS zoom overflow at 190-235% zoom levels
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class OudsNavigationA11y {
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/// Maximum text scale factor for navigation items (Issue #627).
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///
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/// Clamped to 108% to prevent item overflow that occurs between 190-235% zoom levels.
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/// This constraint applies to:
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/// - Icon scaling (26px icon → 28.08px at 108%)
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/// - Label text scaling
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/// - Badge size adjustments
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/// - Indicator visibility area
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///
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/// Rationale: At 108% zoom, all components remain within their allocated space without
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/// exceeding the navigation bar container boundaries, while still supporting the maximum
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/// accessibility zoom that users expect.
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static const double maxTextScaleFactor = 1.08;
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/// Wraps a navigation widget with accessibility text scaling constraints.
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///
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/// This helper method ensures consistent text and icon sizing across navigation items
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/// by limiting zoom enlargement to [maxTextScaleFactor]. Applied at the bar level
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/// (wrapping the entire [NavigationBar] or [CupertinoTabBar]) to work seamlessly with
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/// composite semantic labels and badge exclusion semantics.
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///
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/// Parameters:
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/// - [child]: The navigation widget to wrap (e.g., [NavigationBar], [CupertinoTabBar])
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///
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/// Returns:
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/// The widget wrapped with [MediaQuery.withClampedTextScaling], which enforces:
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/// - minScaleFactor: 1.0 (no minimum constraint, respects system defaults below 108%)
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/// - maxScaleFactor: 1.08 (108%, preventing overflow above this level)
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///
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/// Example:
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/// ```dart
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/// return OudsNavigationA11y.withA11yScaling(navigationBar);
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/// ```
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static Widget withA11yScaling(Widget child) {
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return MediaQuery.withClampedTextScaling(
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minScaleFactor: 1.0,
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maxScaleFactor: maxTextScaleFactor,
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child: child,
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);
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}
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}

‎ouds_core/lib/components/navigation/ouds_navigation_bar.dart‎

Lines changed: 78 additions & 47 deletions
Original file line numberDiff line numberDiff line change
@@ -15,6 +15,7 @@ library;
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import 'package:flutter/material.dart';
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import 'package:ouds_core/components/control/internal/interaction/ouds_inherited_interaction_model.dart';
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import 'package:ouds_core/components/navigation/internal/ouds_navigation_a11y.dart';
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import 'package:ouds_core/components/navigation/internal/ouds_navigation_bar_background_modifier.dart';
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import 'package:ouds_core/components/navigation/internal/ouds_navigation_bar_border_modifier.dart';
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import 'package:ouds_core/components/navigation/internal/ouds_navigation_bar_state.dart';
@@ -126,24 +127,39 @@ class _OudsNavigationBarState extends State<OudsNavigationBar> {
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@override
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void initState() {
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super.initState();
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_selectedIndex = widget.selectedIndex.clamp(0, widget.destinations.length - 1);
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_selectedIndex = widget.selectedIndex.clamp(
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0,
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widget.destinations.length - 1,
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);
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}
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/// Updates the selected index if [currentIndex] changes.
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@override
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void didUpdateWidget(covariant OudsNavigationBar oldWidget) {
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super.didUpdateWidget(oldWidget);
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if (widget.selectedIndex != oldWidget.selectedIndex) {
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_selectedIndex = widget.selectedIndex.clamp(0, widget.destinations.length - 1);
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_selectedIndex = widget.selectedIndex.clamp(
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0,
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widget.destinations.length - 1,
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);
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}
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}
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141148
/// Builds the navigation bar with dynamic label and icon colors and a custom indicator shape.
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@override
143150
Widget build(BuildContext context) {
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final interactionModelHover = OudsInheritedInteractionModel.of(context, InteractionAspect.hover);
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final interactionModelPressed = OudsInheritedInteractionModel.of(context, InteractionAspect.pressed);
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final interactionModelFocused = OudsInheritedInteractionModel.of(context, InteractionAspect.focused);
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final interactionModelHover = OudsInheritedInteractionModel.of(
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context,
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InteractionAspect.hover,
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);
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final interactionModelPressed = OudsInheritedInteractionModel.of(
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context,
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InteractionAspect.pressed,
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);
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final interactionModelFocused = OudsInheritedInteractionModel.of(
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context,
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InteractionAspect.focused,
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);
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final isHovered = interactionModelHover?.state.isHovered ?? false;
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final isPressed = interactionModelPressed?.state.isPressed ?? false;
@@ -158,57 +174,72 @@ class _OudsNavigationBarState extends State<OudsNavigationBar> {
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final barControlState = barStateDeterminer.determineControlState();
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final navigationBarModifier = OudsNavigationBarStatusModifier(context);
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final navigationBarBgModifier = OudsNavigationBarBackgroundColorModifier(context);
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final navigationBarBorderModifier = OudsNavigationBarBorderModifier(context);
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final navigationBarBgModifier = OudsNavigationBarBackgroundColorModifier(
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context,
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);
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final navigationBarBorderModifier = OudsNavigationBarBorderModifier(
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context,
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);
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final safeIndex = _selectedIndex.clamp(0, widget.destinations.length - 1);
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166-
return ClipRect(
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child: BackdropFilter(
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filter: navigationBarBorderModifier.getBlurNavigationBar(),
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child: Container(
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decoration: BoxDecoration(
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border: navigationBarBorderModifier.getBorderNavigationBar(),
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),
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child: NavigationBar(
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height: _oudsNavigationBarHeight,
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selectedIndex: safeIndex,
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// `indicatorColor` paints the Material 3 active indicator behind the selected destination.
177-
indicatorColor: navigationBarModifier.getMaterialIndicatorBarColor(
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barControlState,
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widget.onDestinationSelected != null,
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// Wrap the entire navigation bar with accessibility text scaling constraints
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// to prevent item overflow when zoom is enabled. The maxScaleFactor of 1.08 (108%) ensures
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// that the 26px icon scales to 28.08px at maximum zoom. This constraint is applied at the bar level
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// to ensure consistent scaling across all items and work seamlessly with composite semantic labels.
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return OudsNavigationA11y.withA11yScaling(
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ClipRect(
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child: BackdropFilter(
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filter: navigationBarBorderModifier.getBlurNavigationBar(),
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child: Container(
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decoration: BoxDecoration(
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border: navigationBarBorderModifier.getBorderNavigationBar(),
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),
181-
// `overlayColor` is the transient ink overlay used for interaction feedback (pressed/hovered/focused),
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// resolved per destination via `WidgetState`.
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overlayColor: WidgetStateProperty.resolveWith<Color>(
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(states) {
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child: NavigationBar(
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height: _oudsNavigationBarHeight,
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selectedIndex: safeIndex,
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indicatorColor: navigationBarModifier
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.getMaterialIndicatorBarColor(
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barControlState,
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widget.onDestinationSelected != null,
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),
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overlayColor: WidgetStateProperty.resolveWith<Color>((states) {
185207
final isSelected = states.contains(WidgetState.selected);
186-
return navigationBarModifier.getMaterialIndicatorBarColor(barControlState, isSelected);
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},
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),
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backgroundColor: navigationBarBgModifier.getBackgroundColor(widget.translucent),
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// Label text style resolved per destination via `WidgetState` (at minimum selected/unselected).
191-
labelTextStyle: WidgetStateProperty.resolveWith<TextStyle>(
192-
(states) {
208+
return navigationBarModifier.getMaterialIndicatorBarColor(
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barControlState,
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isSelected,
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);
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}),
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backgroundColor: navigationBarBgModifier.getBackgroundColor(
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widget.translucent,
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),
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labelTextStyle: WidgetStateProperty.resolveWith<TextStyle>((
217+
states,
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) {
193219
final isSelected = states.contains(WidgetState.selected);
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return OudsTheme.of(context).typographyTokens.typeLabelDefaultMedium(context).copyWith(
195-
color: navigationBarModifier.getTextIconItemColor(barControlState, isSelected),
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return OudsTheme.of(context).typographyTokens
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.typeLabelDefaultMedium(context)
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.copyWith(
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color: navigationBarModifier.getTextIconItemColor(
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barControlState,
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isSelected,
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),
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);
197-
},
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),
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destinations: List.generate(
200-
widget.destinations.length,
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(index) => widget.destinations[index].toNavigationDestination(
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context,
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barControlState,
204-
isSelected: index == safeIndex,
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}),
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destinations: List.generate(
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widget.destinations.length,
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(index) => widget.destinations[index].toNavigationDestination(
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context,
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barControlState,
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isSelected: index == safeIndex,
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),
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),
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onDestinationSelected: (index) {
238+
if (index == safeIndex) return;
239+
setState(() => _selectedIndex = index);
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widget.onDestinationSelected?.call(index);
241+
},
206242
),
207-
onDestinationSelected: (index) {
208-
if (index == safeIndex) return;
209-
setState(() => _selectedIndex = index);
210-
widget.onDestinationSelected?.call(index);
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},
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),
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),
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),

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