Flutter: Dynamic Dark/Light Theme with Provider

We all love themes in apps. Especially the so-called dark theme. A dark theme has now become an essential part of mobile applications. All major applications support the dark theme and some apps even have dark theme as default.

Dark themes reduce the luminance emitted by device screens, while still meeting minimum color contrast ratios. They help improve visual ergonomics by reducing eye strain, adjusting brightness to current lighting conditions, and facilitating screen use in dark environments — all while conserving battery power. Devices with OLED screens benefit from the ability to turn off black pixels at any time of day.

Well, we know the power of the dark side, that’s why we are here! So let’s bring this power to flutter.

We will be using the provider package. Add the provider plugin to pubspec.yaml file.

dependencies:   
  provider: ^3.1.0

We will create two themes — a light theme and a dark theme. I’ve done it manually but you can use panache to create the theme.

import 'package:flutter/material.dart';

final darkTheme = ThemeData(
  primarySwatch: Colors.grey,
  primaryColor: Colors.black,
  brightness: Brightness.dark,
  backgroundColor: const Color(0xFF212121),
  accentColor: Colors.white,
  accentIconTheme: IconThemeData(color: Colors.black),
  dividerColor: Colors.black12,
);

final lightTheme = ThemeData(
  primarySwatch: Colors.grey,
  primaryColor: Colors.white,
  brightness: Brightness.light,
  backgroundColor: const Color(0xFFE5E5E5),
  accentColor: Colors.black,
  accentIconTheme: IconThemeData(color: Colors.white),
  dividerColor: Colors.white54,
);

When the themes are ready, we create a theme notifier class to notify us of a theme change:

import 'package:flutter/material.dart';

class ThemeNotifier with ChangeNotifier {
  ThemeData _themeData;

  ThemeNotifier(this._themeData);

  getTheme() => _themeData;

  setTheme(ThemeData themeData) async {
    _themeData = themeData;
    notifyListeners();
  }
}

Next we wrap our app with ChangeNotifierProvider. Then we can use ThemeNotifier to get the theme.

void main() => runApp(
      ChangeNotifierProvider<ThemeNotifier>(
        builder: (_) => ThemeNotifier(darkTheme),
        child: MyApp(),
      ),
    );

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final themeNotifier = Provider.of<ThemeNotifier>(context);
    return MaterialApp(
      title: 'Chitr',
      theme: themeNotifier.getTheme(),
      home: HomePage(),
    );
  }
}

chitr_theme_main.dart

It’s time to change the theme manually. We use [DayNightSwitch](https://pub.dev/packages/day_night_switch) to do this — it works just like the normal switch widget in Flutter. Inside the onChanged callback of [DayNightSwitch](https://pub.dev/packages/day_night_switch), we call theonThemeChanged method, which uses themeNotifier to set the theme and notify the whole app.

void main() => runApp(
      ChangeNotifierProvider<ThemeNotifier>(
        builder: (_) => ThemeNotifier(darkTheme),
        child: MyApp(),
      ),
    );

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final themeNotifier = Provider.of<ThemeNotifier>(context);
    return MaterialApp(
      title: 'Chitr',
      theme: themeNotifier.getTheme(),
      home: HomePage(),
    );
  }
}

That’s it. With just a few lines of code we can dynamically change the theme of our app. Let’s see what it looks like:

This is image title

It looks amazing but…

Our theme isn’t being saved — if we restart the app it goes back to default. So we use use SharedPreferences to store the current theme. Inside of theonThemeChanged method, we save the current theme.

void onThemeChanged(bool value, ThemeNotifier themeNotifier) async {
  (value)
      ? themeNotifier.setTheme(darkTheme)
      : themeNotifier.setTheme(lightTheme);
  var prefs = await SharedPreferences.getInstance();
  prefs.setBool('darkMode', value);
}

We use SharedPreferences value inside the main method:

SharedPreferences.getInstance().then((prefs) {
  var darkModeOn = prefs.getBool('darkMode') ?? true;
  runApp(
    ChangeNotifierProvider<ThemeNotifier>(
      builder: (_) => ThemeNotifier(darkModeOn ? darkTheme : lightTheme),
      child: MyApp(),
    ),
  );
});

You can check the full source code here.

#flutter #programming

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Flutter: Dynamic Dark/Light Theme with Provider

Destiny Volkman

1597014000

Google's Flutter 1.20 stable announced with new features - Navoki

Flutter Google cross-platform UI framework has released a new version 1.20 stable.

Flutter is Google’s UI framework to make apps for Android, iOS, Web, Windows, Mac, Linux, and Fuchsia OS. Since the last 2 years, the flutter Framework has already achieved popularity among mobile developers to develop Android and iOS apps. In the last few releases, Flutter also added the support of making web applications and desktop applications.

Last month they introduced the support of the Linux desktop app that can be distributed through Canonical Snap Store(Snapcraft), this enables the developers to publish there Linux desktop app for their users and publish on Snap Store. If you want to learn how to Publish Flutter Desktop app in Snap Store that here is the tutorial.

Flutter 1.20 Framework is built on Google’s made Dart programming language that is a cross-platform language providing native performance, new UI widgets, and other more features for the developer usage.

Here are the few key points of this release:

Performance improvements for Flutter and Dart

In this release, they have got multiple performance improvements in the Dart language itself. A new improvement is to reduce the app size in the release versions of the app. Another performance improvement is to reduce junk in the display of app animation by using the warm-up phase.

sksl_warm-up

If your app is junk information during the first run then the Skia Shading Language shader provides for pre-compilation as part of your app’s build. This can speed it up by more than 2x.

Added a better support of mouse cursors for web and desktop flutter app,. Now many widgets will show cursor on top of them or you can specify the type of supported cursor you want.

Autofill for mobile text fields

Autofill was already supported in native applications now its been added to the Flutter SDK. Now prefilled information stored by your OS can be used for autofill in the application. This feature will be available soon on the flutter web.

flutter_autofill

A new widget for interaction

InteractiveViewer is a new widget design for common interactions in your app like pan, zoom drag and drop for resizing the widget. Informations on this you can check more on this API documentation where you can try this widget on the DartPad. In this release, drag-drop has more features added like you can know precisely where the drop happened and get the position.

Updated Material Slider, RangeSlider, TimePicker, and DatePicker

In this new release, there are many pre-existing widgets that were updated to match the latest material guidelines, these updates include better interaction with Slider and RangeSlider, DatePicker with support for date range and time picker with the new style.

flutter_DatePicker

New `pubspec.yaml` format

Other than these widget updates there is some update within the project also like in pubspec.yaml file format. If you are a flutter plugin publisher then your old pubspec.yaml is no longer supported to publish a plugin as the older format does not specify for which platform plugin you are making. All existing plugin will continue to work with flutter apps but you should make a plugin update as soon as possible.

Preview of embedded Dart DevTools in Visual Studio Code

Visual Studio code flutter extension got an update in this release. You get a preview of new features where you can analyze that Dev tools in your coding workspace. Enable this feature in your vs code by _dart.previewEmbeddedDevTools_setting. Dart DevTools menu you can choose your favorite page embed on your code workspace.

Network tracking

The updated the Dev tools comes with the network page that enables network profiling. You can track the timings and other information like status and content type of your** network calls** within your app. You can also monitor gRPC traffic.

Generate type-safe platform channels for platform interop

Pigeon is a command-line tool that will generate types of safe platform channels without adding additional dependencies. With this instead of manually matching method strings on platform channel and serializing arguments, you can invoke native class and pass nonprimitive data objects by directly calling the Dartmethod.

There is still a long list of updates in the new version of Flutter 1.2 that we cannot cover in this blog. You can get more details you can visit the official site to know more. Also, you can subscribe to the Navoki newsletter to get updates on these features and upcoming new updates and lessons. In upcoming new versions, we might see more new features and improvements.

You can get more free Flutter tutorials you can follow these courses:

#dart #developers #flutter #app developed #dart devtools in visual studio code #firebase local emulator suite in flutter #flutter autofill #flutter date picker #flutter desktop linux app build and publish on snapcraft store #flutter pigeon #flutter range slider #flutter slider #flutter time picker #flutter tutorial #flutter widget #google flutter #linux #navoki #pubspec format #setup flutter desktop on windows

Terry Tremblay

1598396940

What is Flutter and why you should learn it?

Flutter is an open-source UI toolkit for mobile developers, so they can use it to build native-looking** Android and iOS** applications from the same code base for both platforms. Flutter is also working to make Flutter apps for Web, PWA (progressive Web-App) and Desktop platform (Windows,macOS,Linux).

flutter-mobile-desktop-web-embedded_min

Flutter was officially released in December 2018. Since then, it has gone a much stronger flutter community.

There has been much increase in flutter developers, flutter packages, youtube tutorials, blogs, flutter examples apps, official and private events, and more. Flutter is now on top software repos based and trending on GitHub.

Flutter meaning?

What is Flutter? this question comes to many new developer’s mind.

humming_bird_dart_flutter

Flutter means flying wings quickly, and lightly but obviously, this doesn’t apply in our SDK.

So Flutter was one of the companies that were acquired by **Google **for around $40 million. That company was based on providing gesture detection and recognition from a standard webcam. But later when the Flutter was going to release in alpha version for developer it’s name was Sky, but since Google already owned Flutter name, so they rename it to Flutter.

Where Flutter is used?

Flutter is used in many startup companies nowadays, and even some MNCs are also adopting Flutter as a mobile development framework. Many top famous companies are using their apps in Flutter. Some of them here are

Dream11

NuBank

Reflectly app

Abbey Road Studios

and many more other apps. Mobile development companies also adopted Flutter as a service for their clients. Even I was one of them who developed flutter apps as a freelancer and later as an IT company for mobile apps.

Flutter as a service

#dart #flutter #uncategorized #flutter framework #flutter jobs #flutter language #flutter meaning #flutter meaning in hindi #google flutter #how does flutter work #what is flutter

Lessie Fisher

1626859620

Flutter Dynamic Theme - Dark and Light Theme

Switch Between Dark and Light Theme in Flutter. Also implement a way of adapting theme based on system theme
Flutter Bootcamp - https://rebrand.ly/flutterbootcamp
Article - https://mightytechno.com/dark-light-theme-flutter-app/

#flutter #dark and light theme

Aliyah Satterfield

1591643580

Adobe XD plugin for Flutter with CodePen Tutorial

Recently Adobe XD releases a new version of the plugin that you can use to export designs directly into flutter widgets or screens. Yes, you read it right, now you can make and export your favorite design in Adobe XD and export all the design in the widget form or as a full-screen design, this can save you a lot of time required in designing.

What we will do?
I will make a simple design of a dialogue box with a card design with text over it as shown below. After you complete this exercise you can experiment with the UI. You can make your own components or import UI kits available with the Adobe XD.

#developers #flutter #adobe xd design export to flutter #adobe xd flutter code #adobe xd flutter code generator - plugin #adobe xd flutter plugin #adobe xd flutter plugin tutorial #adobe xd plugins #adobe xd to flutter #adobe xd tutorial #codepen for flutter.

Maida Ratke

1590832500

Themes in Flutter: Part 3

In the 1st part, we saw 15 parameters of ThemeData class. Those were brightness, visualDensity, primaryColor, primaryColorBrightness, primaryColorLight, primaryColorDark, canvasColor, ascentColor, ascentColorBrightness, scaffoldNBackgroundColor, bottomAppBarColor, cardColor, dividerColor, focusColor.
In the 2nd part, we saw 27 parameters of ThemeData class. Those were hoverColor, hightlightColor, splashColor, splashFactory, selectedRowColor, unselectedWidgetColor, disabledColor, buttonTheme, toggleButtonsTheme, buttonColor, secondaryHeaderColor, textSelectionColor, cursorColor, textSelectionHandleColor, backgroundColor, dialogBackgroundColor, indicatorColor, hintColor, errorColor, toggleableActiveColor, textTheme, primaryTextTheme, accentTextTheme, inputDecorationTheme, iconTheme, primaryIconTheme, accentIconTheme.
Let’s start with 3rd set fo ThemeData parameters.

#flutter #flutter-color #flutter-widget #flutter-theme #flutter-ui