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[green] keep iPad keyboard palette clear of editing controls
Signed-off-by: Viwat Vchirawongkwin <viwat.v@chula.ac.th>
1 parent bd36731 commit bef67bd

4 files changed

Lines changed: 346 additions & 1 deletion

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‎app/ios/Runner/AppDelegate.swift‎

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Original file line numberDiff line numberDiff line change
@@ -6,6 +6,8 @@ import UIKit
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@main
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@objc class AppDelegate: FlutterAppDelegate, FlutterImplicitEngineDelegate {
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private var keyboardInsets: PybleKeyboardInsets?
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override func application(
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_ application: UIApplication,
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didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
@@ -17,6 +19,7 @@ import UIKit
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GeneratedPluginRegistrant.register(with: engineBridge.pluginRegistry)
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guard let registrar = engineBridge.pluginRegistry.registrar(forPlugin: "PybleKeyboardDismissal")
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else { return }
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keyboardInsets = PybleKeyboardInsets(registrar: registrar)
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let keyboard = FlutterMethodChannel(
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name: "dev.pyble/keyboard", binaryMessenger: registrar.messenger())
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keyboard.setMethodCallHandler { [weak registrar] call, result in
@@ -31,3 +34,108 @@ import UIKit
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}
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}
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}
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/// Measures the current Flutter view's public layout guide instead of keyboard
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/// notification frames, which can be offscreen after an iPad palette transition.
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private final class PybleKeyboardInsets {
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private weak var registrar: FlutterPluginRegistrar?
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private let channel: FlutterMethodChannel
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private var observer: PybleKeyboardGuideView?
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private var generation: Int?
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private var lastBottom: CGFloat?
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init(registrar: FlutterPluginRegistrar) {
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self.registrar = registrar
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channel = FlutterMethodChannel(
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name: "dev.pyble/keyboard/insets", binaryMessenger: registrar.messenger())
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channel.setMethodCallHandler { [weak self] call, result in
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guard let self = self, let epoch = call.arguments as? Int else {
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result(FlutterMethodNotImplemented)
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return
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}
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switch call.method {
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case "observe":
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self.observe(generation: epoch)
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result(nil)
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case "stop":
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if self.generation == epoch { self.stop() }
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result(nil)
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default:
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result(FlutterMethodNotImplemented)
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}
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}
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}
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private func observe(generation: Int) {
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if self.generation != generation {
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stop()
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self.generation = generation
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}
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guard let view = registrar?.viewController?.viewIfLoaded else {
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observer?.removeFromSuperview()
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observer = nil
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publish(0)
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return
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}
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if observer?.superview !== view {
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observer?.removeFromSuperview()
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let guideView = PybleKeyboardGuideView()
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guideView.translatesAutoresizingMaskIntoConstraints = false
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guideView.isUserInteractionEnabled = false
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guideView.accessibilityElementsHidden = true
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guideView.backgroundColor = .clear
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guideView.changed = { [weak self] bottom in self?.publish(bottom) }
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observer = guideView
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view.addSubview(guideView)
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NSLayoutConstraint.activate([
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guideView.topAnchor.constraint(equalTo: view.keyboardLayoutGuide.topAnchor),
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guideView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
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guideView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
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guideView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
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])
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view.layoutIfNeeded()
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}
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// An explicit refresh must return a snapshot even if UIKit has not moved:
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// Dart may have rejected the previous value while its window size lagged.
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lastBottom = nil
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observer?.reportOverlap()
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}
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private func publish(_ bottom: CGFloat) {
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guard let generation = generation, bottom != lastBottom else { return }
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lastBottom = bottom
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channel.invokeMethod("inset", arguments: ["generation": generation, "bottom": bottom])
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}
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private func stop() {
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generation = nil
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observer?.removeFromSuperview()
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observer = nil
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lastBottom = nil
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}
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}
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private final class PybleKeyboardGuideView: UIView {
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var changed: ((CGFloat) -> Void)?
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override func layoutSubviews() {
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super.layoutSubviews()
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reportOverlap()
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}
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override func didMoveToWindow() {
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super.didMoveToWindow()
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reportOverlap()
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}
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func reportOverlap() {
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guard let owner = superview, window != nil else {
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changed?(0)
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return
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}
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// On iOS 15/16 a hidden/undocked guide ends at the safe-area bottom.
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// A real docked keyboard or input palette reports its full overlap.
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let overlap = min(owner.bounds.height, max(0, bounds.height))
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changed?(overlap <= owner.safeAreaInsets.bottom + 0.5 ? 0 : overlap)
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}
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}

‎app/lib/app/app.dart‎

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Original file line numberDiff line numberDiff line change
@@ -19,6 +19,7 @@ import 'package:pyble/editor/recovery_gate.dart';
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import 'package:pyble/theme/theme.dart';
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import 'shell.dart';
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import 'keyboard_insets.dart';
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/// Navigator used by explicit user confirmations, never by local recovery itself.
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final GlobalKey<NavigatorState> appNavigatorKey = GlobalKey<NavigatorState>();
@@ -45,6 +46,8 @@ class PybleApp extends StatelessWidget {
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highContrastDarkTheme: PybleTheme.highContrastDark,
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themeMode: ThemeMode.system,
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debugShowCheckedModeBanner: false,
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builder: (BuildContext context, Widget? child) =>
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KeyboardInsets(child: child ?? const SizedBox.shrink()),
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home: const RecoveryGate(child: PybleShell()),
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);
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}

‎app/lib/app/keyboard_insets.dart‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,131 @@
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// SPDX-License-Identifier: MIT
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// Part of PyBLE (https://pyble.dev) — see /LICENSE.
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import 'dart:async';
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import 'dart:math' as math;
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import 'package:flutter/foundation.dart';
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import 'package:flutter/services.dart';
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import 'package:flutter/widgets.dart';
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const MethodChannel _channel = MethodChannel('dev.pyble/keyboard/insets');
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/// Supplements notification-derived iOS metrics with the current window's
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/// keyboard layout guide. UIKit points and Flutter logical pixels coincide.
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class KeyboardInsets extends StatefulWidget {
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const KeyboardInsets({required this.child, super.key});
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final Widget child;
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@override
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State<KeyboardInsets> createState() => _KeyboardInsetsState();
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}
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class _KeyboardInsetsState extends State<KeyboardInsets>
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with WidgetsBindingObserver {
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static int _nextGeneration = 0;
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late final bool _enabled =
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!kIsWeb && defaultTargetPlatform == TargetPlatform.iOS;
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int? _generation;
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double _nativeBottom = 0;
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double _viewHeight = 0;
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bool _refreshScheduled = false;
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@override
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void initState() {
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super.initState();
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if (!_enabled) return;
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_channel.setMethodCallHandler(_handleInset);
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WidgetsBinding.instance.addObserver(this);
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_generation = ++_nextGeneration;
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_refreshAfterFrame();
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}
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Future<void> _handleInset(MethodCall call) async {
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final Object? arguments = call.arguments;
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if (!mounted ||
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_generation == null ||
48+
call.method != 'inset' ||
49+
arguments is! Map ||
50+
arguments['generation'] != _generation) {
51+
return;
52+
}
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final Object? raw = arguments['bottom'];
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if (raw is! num) return;
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final double bottom = raw.toDouble();
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if (!bottom.isFinite || bottom < 0 || bottom > _viewHeight) return;
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if (_nativeBottom != bottom) setState(() => _nativeBottom = bottom);
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}
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Future<void> _request(String method, int generation) async {
61+
try {
62+
await _channel.invokeMethod<void>(method, generation);
63+
} on MissingPluginException {
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// Host-only widget tests have no UIKit registrar. Flutter's ordinary
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// metrics remain usable; the shipping iOS runner registers this channel.
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}
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}
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void _refreshAfterFrame() {
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if (_refreshScheduled || _generation == null) return;
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_refreshScheduled = true;
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WidgetsBinding.instance.addPostFrameCallback((_) {
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_refreshScheduled = false;
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final int? generation = _generation;
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if (mounted && generation != null) {
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unawaited(_request('observe', generation));
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}
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});
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}
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@override
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void didChangeMetrics() => _refreshAfterFrame();
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@override
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void didChangeAppLifecycleState(AppLifecycleState state) {
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if (state == AppLifecycleState.paused ||
87+
state == AppLifecycleState.detached) {
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_stop();
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if (_nativeBottom != 0) setState(() => _nativeBottom = 0);
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} else if (state == AppLifecycleState.resumed) {
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_generation ??= ++_nextGeneration;
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_refreshAfterFrame();
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}
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}
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void _stop() {
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final int? generation = _generation;
98+
_generation = null;
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if (generation != null) unawaited(_request('stop', generation));
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}
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@override
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void dispose() {
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if (_enabled) {
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_stop();
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WidgetsBinding.instance.removeObserver(this);
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_channel.setMethodCallHandler(null);
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}
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super.dispose();
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}
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@override
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Widget build(BuildContext context) {
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if (!_enabled) return widget.child;
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final MediaQueryData original = MediaQuery.of(context);
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_viewHeight = original.size.height;
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final double bottom = math.max(
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original.viewInsets.bottom,
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_nativeBottom.clamp(0, _viewHeight),
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);
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return MediaQuery(
122+
data: original.copyWith(
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viewInsets: original.viewInsets.copyWith(bottom: bottom),
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padding: original.padding.copyWith(
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bottom: math.max(0, original.viewPadding.bottom - bottom),
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),
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),
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child: widget.child,
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);
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}
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}

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