packages/devtools_app/lib/src/shared/screen.dart - external/github.com/flutter/devtools - Git at Google

 // Copyright 2019 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:async';
 import 'dart:math' as math;

 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';

 import '../primitives/listenable.dart';
 import 'globals.dart';
 import 'theme.dart';
 import 'version.dart';

 /// Defines a page shown in the DevTools [TabBar].
 @immutable
 abstract class Screen {
   const Screen(
     this.screenId, {
     this.title = '',
     this.icon,
     this.tabKey,
     this.requiresLibrary,
     this.requiresDartVm = false,
     this.requiresDebugBuild = false,
     this.requiresVmDeveloperMode = false,
     this.worksOffline = false,
     this.shouldShowForFlutterVersion,
     this.showFloatingDebuggerControls = true,
   });

   const Screen.conditional({
     required String id,
     String? requiresLibrary,
     bool requiresDartVm = false,
     bool requiresDebugBuild = false,
     bool requiresVmDeveloperMode = false,
     bool worksOffline = false,
     bool Function(FlutterVersion? currentVersion)? shouldShowForFlutterVersion,
     bool showFloatingDebuggerControls = true,
     String title = '',
     IconData? icon,
     Key? tabKey,
   }) : this(
           id,
           requiresLibrary: requiresLibrary,
           requiresDartVm: requiresDartVm,
           requiresDebugBuild: requiresDebugBuild,
           requiresVmDeveloperMode: requiresVmDeveloperMode,
           worksOffline: worksOffline,
           shouldShowForFlutterVersion: shouldShowForFlutterVersion,
           showFloatingDebuggerControls: showFloatingDebuggerControls,
           title: title,
           icon: icon,
           tabKey: tabKey,
         );

   /// Whether to show floating debugger controls if the app is paused.
   ///
   /// If your page is negatively impacted by the app being paused you should
   /// show debugger controls.
   final bool showFloatingDebuggerControls;

   /// Whether to show the console for this screen.
   bool showConsole(bool embed) => false;

   /// Which keyboard shortcuts should be enabled for this screen.
   ShortcutsConfiguration buildKeyboardShortcuts(BuildContext context) =>
       ShortcutsConfiguration.empty();

   final String screenId;

   /// The user-facing name of the page.
   final String title;

   final IconData? icon;

   /// An optional key to use when creating the Tab widget (for use during
   /// testing).
   final Key? tabKey;

   /// Library uri that determines whether to include this screen in DevTools.
   ///
   /// This can either be a full library uri or it can be a prefix. If null, this
   /// screen will be shown if it meets all other criteria.
   ///
   /// Examples:
   ///  * 'package:provider/provider.dart'
   ///  * 'package:provider/'
   final String? requiresLibrary;

   /// Whether this screen should only be included when the app is running on the Dart VM.
   final bool requiresDartVm;

   /// Whether this screen should only be included when the app is debuggable.
   final bool requiresDebugBuild;

   /// Whether this screen should only be included when VM developer mode is enabled.
   final bool requiresVmDeveloperMode;

   /// Whether this screen works offline and should show in offline mode even if conditions are not met.
   final bool worksOffline;

   /// A callback that will determine whether or not this screen should be
   /// available for a given flutter version.
   final bool Function(FlutterVersion? currentFlutterVersion)?
       shouldShowForFlutterVersion;

   /// Whether this screen should display the isolate selector in the status
   /// line.
   ///
   /// Some screens act on all isolates; for these screens, displaying a
   /// selector doesn't make sense.
   ValueListenable<bool> get showIsolateSelector =>
       const FixedValueListenable<bool>(false);

   /// The id to use to synthesize a help URL.
   ///
   /// If the screen does not have a custom documentation page, this property
   /// should return `null`.
   String? get docPageId => null;

   int get badgeCount => 0;

   double approximateWidth(TextTheme textTheme) {
     final painter = TextPainter(
       text: TextSpan(
         text: title,
         style: textTheme.bodyText1,
       ),
       textDirection: TextDirection.ltr,
     )..layout();
     return painter.width + denseSpacing + defaultIconSize + defaultSpacing * 2;
   }

   /// Builds the tab to show for this screen in the [DevToolsScaffold]'s main
   /// navbar.
   ///
   /// This will not be used if the [Screen] is the only one shown in the
   /// scaffold.
   Widget buildTab(BuildContext context) {
     return ValueListenableBuilder<int>(
       valueListenable:
           serviceManager.errorBadgeManager.errorCountNotifier(screenId),
       builder: (context, count, _) {
         final tab = Tab(
           key: tabKey,
           child: Row(
             children: <Widget>[
               Icon(icon, size: defaultIconSize),
               Padding(
                 padding: const EdgeInsets.only(left: denseSpacing),
                 child: Text(title),
               ),
             ],
           ),
         );

         if (count > 0) {
           // Calculate the width of the title text so that we can provide an accurate
           // size for the [BadgePainter]
           final painter = TextPainter(
             text: TextSpan(
               text: title,
               style: Theme.of(context).regularTextStyle,
             ),
             textDirection: TextDirection.ltr,
           )..layout();
           final titleWidth = painter.width;

           return LayoutBuilder(
             builder: (context, constraints) {
               return Stack(
                 children: [
                   CustomPaint(
                     size: Size(defaultIconSize + denseSpacing + titleWidth, 0),
                     painter: BadgePainter(number: count),
                   ),
                   tab,
                 ],
               );
             },
           );
         }

         return tab;
       },
     );
   }

   /// Builds the body to display for this tab.
   Widget build(BuildContext context);

   /// Build a widget to display in the status line.
   ///
   /// If this method returns `null`, then no page specific status is displayed.
   Widget? buildStatus(BuildContext context) {
     return null;
   }
 }

 mixin OfflineScreenMixin<T extends StatefulWidget, U> on State<T> {
   bool get loadingOfflineData => _loadingOfflineData;
   bool _loadingOfflineData = false;

   bool shouldLoadOfflineData();

   FutureOr<void> processOfflineData(U offlineData);

   Future<void> loadOfflineData(U offlineData) async {
     setState(() {
       _loadingOfflineData = true;
     });
     await processOfflineData(offlineData);
     setState(() {
       _loadingOfflineData = false;
     });
   }
 }

 /// Check whether a screen should be shown in the UI.
 bool shouldShowScreen(Screen screen) {
   if (offlineController.offlineMode.value) {
     return screen.worksOffline;
   }
   // No sense in ever showing screens in non-offline mode unless the service
   // is available. This also avoids odd edge cases where we could show screens
   // while the ServiceManager is still initializing.
   if (!serviceManager.isServiceAvailable ||
       !serviceManager.connectedApp!.connectedAppInitialized) return false;

   if (screen.requiresLibrary != null) {
     if (serviceManager.isolateManager.mainIsolate.value == null ||
         !serviceManager.libraryUriAvailableNow(screen.requiresLibrary)) {
       return false;
     }
   }
   if (screen.requiresDartVm) {
     if (serviceManager.connectedApp!.isRunningOnDartVM != true) {
       return false;
     }
   }
   if (screen.requiresDebugBuild) {
     if (serviceManager.connectedApp!.isProfileBuildNow == true) {
       return false;
     }
   }
   if (screen.requiresVmDeveloperMode) {
     if (!preferences.vmDeveloperModeEnabled.value) {
       return false;
     }
   }
   if (screen.shouldShowForFlutterVersion != null) {
     if (serviceManager.connectedApp!.isFlutterAppNow == true &&
         !screen.shouldShowForFlutterVersion!(
           serviceManager.connectedApp!.flutterVersionNow,
         )) {
       return false;
     }
   }
   return true;
 }

 class BadgePainter extends CustomPainter {
   BadgePainter({required this.number});

   final int number;

   @override
   void paint(Canvas canvas, Size size) {
     final paint = Paint()
       ..color = devtoolsError
       ..style = PaintingStyle.fill;

     final countPainter = TextPainter(
       text: TextSpan(
         text: '$number',
         style: const TextStyle(
           color: Colors.white,
           fontWeight: FontWeight.bold,
         ),
       ),
       textDirection: TextDirection.ltr,
     )..layout();

     final badgeWidth = math.max(
       defaultIconSize,
       countPainter.width + denseSpacing,
     );
     canvas.drawOval(
       Rect.fromLTWH(size.width, 0, badgeWidth, defaultIconSize),
       paint,
     );

     countPainter.paint(
       canvas,
       Offset(size.width + (badgeWidth - countPainter.width) / 2, 0),
     );
   }

   @override
   bool shouldRepaint(covariant CustomPainter oldDelegate) {
     if (oldDelegate is BadgePainter) {
       return number != oldDelegate.number;
     }
     return true;
   }
 }

 class ShortcutsConfiguration {
   const ShortcutsConfiguration({
     required this.shortcuts,
     required this.actions,
   }) : assert(shortcuts.length == actions.length);

   factory ShortcutsConfiguration.empty() {
     return ShortcutsConfiguration(shortcuts: {}, actions: {});
   }

   final Map<ShortcutActivator, Intent> shortcuts;
   final Map<Type, Action<Intent>> actions;

   bool get isEmpty => shortcuts.isEmpty && actions.isEmpty;
 }
	// Copyright 2019 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:async';
	import 'dart:math' as math;

	import 'package:flutter/foundation.dart';
	import 'package:flutter/material.dart';

	import '../primitives/listenable.dart';
	import 'globals.dart';
	import 'theme.dart';
	import 'version.dart';

	/// Defines a page shown in the DevTools [TabBar].
	@immutable
	abstract class Screen {
	const Screen(
	this.screenId, {
	this.title = '',
	this.icon,
	this.tabKey,
	this.requiresLibrary,
	this.requiresDartVm = false,
	this.requiresDebugBuild = false,
	this.requiresVmDeveloperMode = false,
	this.worksOffline = false,
	this.shouldShowForFlutterVersion,
	this.showFloatingDebuggerControls = true,
	});

	const Screen.conditional({
	required String id,
	String? requiresLibrary,
	bool requiresDartVm = false,
	bool requiresDebugBuild = false,
	bool requiresVmDeveloperMode = false,
	bool worksOffline = false,
	bool Function(FlutterVersion? currentVersion)? shouldShowForFlutterVersion,
	bool showFloatingDebuggerControls = true,
	String title = '',
	IconData? icon,
	Key? tabKey,
	}) : this(
	id,
	requiresLibrary: requiresLibrary,
	requiresDartVm: requiresDartVm,
	requiresDebugBuild: requiresDebugBuild,
	requiresVmDeveloperMode: requiresVmDeveloperMode,
	worksOffline: worksOffline,
	shouldShowForFlutterVersion: shouldShowForFlutterVersion,
	showFloatingDebuggerControls: showFloatingDebuggerControls,
	title: title,
	icon: icon,
	tabKey: tabKey,
	);

	/// Whether to show floating debugger controls if the app is paused.
	///
	/// If your page is negatively impacted by the app being paused you should
	/// show debugger controls.
	final bool showFloatingDebuggerControls;

	/// Whether to show the console for this screen.
	bool showConsole(bool embed) => false;

	/// Which keyboard shortcuts should be enabled for this screen.
	ShortcutsConfiguration buildKeyboardShortcuts(BuildContext context) =>
	ShortcutsConfiguration.empty();

	final String screenId;

	/// The user-facing name of the page.
	final String title;

	final IconData? icon;

	/// An optional key to use when creating the Tab widget (for use during
	/// testing).
	final Key? tabKey;

	/// Library uri that determines whether to include this screen in DevTools.
	///
	/// This can either be a full library uri or it can be a prefix. If null, this
	/// screen will be shown if it meets all other criteria.
	///
	/// Examples:
	/// * 'package:provider/provider.dart'
	/// * 'package:provider/'
	final String? requiresLibrary;

	/// Whether this screen should only be included when the app is running on the Dart VM.
	final bool requiresDartVm;

	/// Whether this screen should only be included when the app is debuggable.
	final bool requiresDebugBuild;

	/// Whether this screen should only be included when VM developer mode is enabled.
	final bool requiresVmDeveloperMode;

	/// Whether this screen works offline and should show in offline mode even if conditions are not met.
	final bool worksOffline;

	/// A callback that will determine whether or not this screen should be
	/// available for a given flutter version.
	final bool Function(FlutterVersion? currentFlutterVersion)?
	shouldShowForFlutterVersion;

	/// Whether this screen should display the isolate selector in the status
	/// line.
	///
	/// Some screens act on all isolates; for these screens, displaying a
	/// selector doesn't make sense.
	ValueListenable<bool> get showIsolateSelector =>
	const FixedValueListenable<bool>(false);

	/// The id to use to synthesize a help URL.
	///
	/// If the screen does not have a custom documentation page, this property
	/// should return `null`.
	String? get docPageId => null;

	int get badgeCount => 0;

	double approximateWidth(TextTheme textTheme) {
	final painter = TextPainter(
	text: TextSpan(
	text: title,
	style: textTheme.bodyText1,
	),
	textDirection: TextDirection.ltr,
	)..layout();
	return painter.width + denseSpacing + defaultIconSize + defaultSpacing * 2;
	}

	/// Builds the tab to show for this screen in the [DevToolsScaffold]'s main
	/// navbar.
	///
	/// This will not be used if the [Screen] is the only one shown in the
	/// scaffold.
	Widget buildTab(BuildContext context) {
	return ValueListenableBuilder<int>(
	valueListenable:
	serviceManager.errorBadgeManager.errorCountNotifier(screenId),
	builder: (context, count, _) {
	final tab = Tab(
	key: tabKey,
	child: Row(
	children: <Widget>[
	Icon(icon, size: defaultIconSize),
	Padding(
	padding: const EdgeInsets.only(left: denseSpacing),
	child: Text(title),
	),
	],
	),
	);

	if (count > 0) {
	// Calculate the width of the title text so that we can provide an accurate
	// size for the [BadgePainter]
	final painter = TextPainter(
	text: TextSpan(
	text: title,
	style: Theme.of(context).regularTextStyle,
	),
	textDirection: TextDirection.ltr,
	)..layout();
	final titleWidth = painter.width;

	return LayoutBuilder(
	builder: (context, constraints) {
	return Stack(
	children: [
	CustomPaint(
	size: Size(defaultIconSize + denseSpacing + titleWidth, 0),
	painter: BadgePainter(number: count),
	),
	tab,
	],
	);
	},
	);
	}

	return tab;
	},
	);
	}

	/// Builds the body to display for this tab.
	Widget build(BuildContext context);

	/// Build a widget to display in the status line.
	///
	/// If this method returns `null`, then no page specific status is displayed.
	Widget? buildStatus(BuildContext context) {
	return null;
	}
	}

	mixin OfflineScreenMixin<T extends StatefulWidget, U> on State<T> {
	bool get loadingOfflineData => _loadingOfflineData;
	bool _loadingOfflineData = false;

	bool shouldLoadOfflineData();

	FutureOr<void> processOfflineData(U offlineData);

	Future<void> loadOfflineData(U offlineData) async {
	setState(() {
	_loadingOfflineData = true;
	});
	await processOfflineData(offlineData);
	setState(() {
	_loadingOfflineData = false;
	});
	}
	}

	/// Check whether a screen should be shown in the UI.
	bool shouldShowScreen(Screen screen) {
	if (offlineController.offlineMode.value) {
	return screen.worksOffline;
	}
	// No sense in ever showing screens in non-offline mode unless the service
	// is available. This also avoids odd edge cases where we could show screens
	// while the ServiceManager is still initializing.
	if (!serviceManager.isServiceAvailable \|\|
	!serviceManager.connectedApp!.connectedAppInitialized) return false;

	if (screen.requiresLibrary != null) {
	if (serviceManager.isolateManager.mainIsolate.value == null \|\|
	!serviceManager.libraryUriAvailableNow(screen.requiresLibrary)) {
	return false;
	}
	}
	if (screen.requiresDartVm) {
	if (serviceManager.connectedApp!.isRunningOnDartVM != true) {
	return false;
	}
	}
	if (screen.requiresDebugBuild) {
	if (serviceManager.connectedApp!.isProfileBuildNow == true) {
	return false;
	}
	}
	if (screen.requiresVmDeveloperMode) {
	if (!preferences.vmDeveloperModeEnabled.value) {
	return false;
	}
	}
	if (screen.shouldShowForFlutterVersion != null) {
	if (serviceManager.connectedApp!.isFlutterAppNow == true &&
	!screen.shouldShowForFlutterVersion!(
	serviceManager.connectedApp!.flutterVersionNow,
	)) {
	return false;
	}
	}
	return true;
	}

	class BadgePainter extends CustomPainter {
	BadgePainter({required this.number});

	final int number;

	@override
	void paint(Canvas canvas, Size size) {
	final paint = Paint()
	..color = devtoolsError
	..style = PaintingStyle.fill;

	final countPainter = TextPainter(
	text: TextSpan(
	text: '$number',
	style: const TextStyle(
	color: Colors.white,
	fontWeight: FontWeight.bold,
	),
	),
	textDirection: TextDirection.ltr,
	)..layout();

	final badgeWidth = math.max(
	defaultIconSize,
	countPainter.width + denseSpacing,
	);
	canvas.drawOval(
	Rect.fromLTWH(size.width, 0, badgeWidth, defaultIconSize),
	paint,
	);

	countPainter.paint(
	canvas,
	Offset(size.width + (badgeWidth - countPainter.width) / 2, 0),
	);
	}

	@override
	bool shouldRepaint(covariant CustomPainter oldDelegate) {
	if (oldDelegate is BadgePainter) {
	return number != oldDelegate.number;
	}
	return true;
	}
	}

	class ShortcutsConfiguration {
	const ShortcutsConfiguration({
	required this.shortcuts,
	required this.actions,
	}) : assert(shortcuts.length == actions.length);

	factory ShortcutsConfiguration.empty() {
	return ShortcutsConfiguration(shortcuts: {}, actions: {});
	}

	final Map<ShortcutActivator, Intent> shortcuts;
	final Map<Type, Action<Intent>> actions;

	bool get isEmpty => shortcuts.isEmpty && actions.isEmpty;
	}