platty

Platform Conforming Widgets for Flutter!

Flutter makes no attempt to provide familiar widgets for a specific platform (unlike React Native, ionic, and other cross platform tooling). This has enormous benefits to unified rendering on all platforms, maximum flexibility, and eliminating a whole class of bugs and testing done for each platform. While this is great, many scenarios we want our apps to look and feel like an Android or iOS app. Platty allows you to render iOS (Cupertino) and Android (Material) like widgets with minimal effort and maximum control in a unified API.

No more checking for platform inside render blocks to render a CupertinoButton or FlatButton, let platty do the logic for you! Want to use bottom tabs in your app that resolve to platform specific UI? No problem!

Widgets

List of Widget Files:

Alerts

Back Button

Buttons

Navigation Bars

Progress

Routing

Scaffold

Slider

Switch

TabView

Getting Started

Use platty to unify render-specific APIs for you. The library utilizes the BuildContext theming APIs to propagate platform information into the Widgets.

By default, all widgets conform to the default TargetPlatform. It looks up the Theme.of(context).platform for its default. Also, all widgets provide a renderPlatform prop that allows you to choose which one to render (if you wish).

Replace MaterialApp and CupertinoApp with PlatformApp:


class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return PlatformApp(
      title: 'Flutter Demo',
      // specify our app theme here. We do the leg work of bridging it to Cupertino.
      unifiedTheme: ThemeData(
            primarySwatch: Colors.lightBlue,
            bottomAppBarColor: Colors.red,
          ),
      home: ExamplePage(),
    );
  }
}

PlatformApp unifies all of the same properties between MaterialApp and CupertinoApp to allow both instances of widgets in the hiearchy and switching styling based on platform.

Now you replace widgets that are included in this library with their "P" counterparts:

Button/CupertinoButton -> PButton

Material Raised Button Cupertino Button

Source

FlatButton/CupertinoButton -> PFlatButton

Material Flat Button Cupertino Flat Button

Source

AppBar/CupertinoNavigationBar -> PNavigationBar

Android Nav iOS Nav

Source

SliverAppBar/CupertinoSliverNavigationBar -> PSliverNavigationBar

Slider/CupertinoSlider -> PSlider

Sliders

Source

Switch/CupertinoSwitch -> PSwitch

Switch

Source

BottomNavigationBar/CupertinoTabBar -> PTabBar

Bottom Navigation Android Bottom Navigation iOS

Source

Scaffold/CupertinoScaffold -> PScaffold

CircularProgressIndicator/CupertinoActivityIndicator -> PActivityIndicator

Progress

Source

BackButton/CupertinoNavigationBarBackButton -> PBackButton

AlertDialog/CupertinoAlertDialog -> PAlertDialog

Android Alert Ios Alert

Source

Properties Specific to a platform have a prefix

Any widgets that have ios-only or android-only counterparts, they are prefixed to android/ios accordingly:

For example PButton, androidShape applies to RaisedButton.shape property. It does not exist on a CupertinoButton. However CupertinoButton has a borderRadius and pressedOpacity. Those two props become iosBorderRadius and iosPressedOpacity.

Helpers

This library bundles a few standard functions to easily return code that is unique for each platform. Instead of checking
and switching on the result of Theme.of(context).targetPlatform, utilize the following methods:

Specific Platform Instance

To have a specific P-Widget utilize a specific platform theme only, such as Material or Cupertino, you can wrap it in a PTheme instance:

PTheme(
  data: PThemeData(
    platform: TargetPlatform.android,  // or iOS
    child: child,
  ),
);

Or, more simply, utilize helper method:

PTheme.ios(child);
PTheme.android(child);

Also, all P-widgets and methods allow you to override the PTheme with a renderPlatform parameter in their constructor or calling method:

PButton("Hello Android", 
  renderPlatform: TargetPlatform.Android,
)

This will swap the rendering over to Material widgets for this specific widget.

Note: Wrapping a widget with the PTheme will propagate that instance down the widget hierarchy and is thus preferred than manually specifying the renderPlatform for each individual widget.

Creating Your Own Platform-Adapting Widgets

We can extend upon the logic included in this library to build our own, powerful platform-adapting widgets. Included in the library is the PlatformAdaptingWidget base class, which inherits from StatelessWidget.

class SamplePlatformWidget extends PlatformAdaptingWidget {
  final Color color;

  SamplePlatformWidget({Key key, @required this.color, TargetPlatform renderPlatform}) // should allow consumers to choose TargetPlatform
      : super(key: key, renderPlatform: renderPlatform);

  /// Render a material widget here. Most Material widgets require a Material Theme instance above it.
  @override
  get renderMaterial => (BuildContext context) {
        return BackButton(
          color: color,
        );
      };

  /// Render a cupertino widget here.
  @override
  get renderCupertino => (BuildContext context) {
        return CupertinoNavigationBarBackButton(
          color: color,
        );
      };
  
  /// Render a fuchsia widget here. (defaults to material)
    @override
    get renderFuchsia => (BuildContext context) {
          return BackButton(
            color: color,
          );
        };
}

Platform-specific logic

This library comes with a few standard ways to implement behavior based on platform. You can utilize platformWrap, which allows you to specify a child, and on 1 or all platforms, wrap it with another widget:

platformWrap(
      context,
      child: PButton(
        padding: EdgeInsets.all(0.0),
        child: Text(title),
        color: Colors.red,
        onPressed: () {
          Navigator.push(context, PlatformRoute.of(context, builder: page));
        },
      ),
      renderCupertino: (context, child) => Padding(
            padding: EdgeInsets.only(bottom: 8.0),
            child: child,
          ),
    );

You can specify any of renderCupertino, renderMaterial, or renderFuschia (or none). Any render methods not specified default to the child.

Also, platformSelect is a helper that enables returning different objects based on platform in a unified way. In our PlatformAdaptingWidget, we utilize it to return a different widget based on platform. You can use it to return any return type based on platform:


Column(
  children: [
    platformSelect(context, 
      renderMaterial: (context) => Text("I am android"),
      renderCupertino: (context) => Text("I am iOS"),
      renderFuchsia: (context) => Text("I am FUCHSIA")) 
  ],
),

renderMaterial and renderCupertino are required. renderFuchsia defaults to material.

or you can return a non-widget too:

Column(
  children: [
    Text(platformSelect(context, 
      renderMaterial: (context) => "I am android"),
      renderCupertino: (context) => "I am iOS",
      renderFuchsia: (context) => "I am FUCHSIA")) 
  ],
),

Libraries

platty
Flutter widget library utilize Platform-switching widgets. To use, import package:platty/platty.dart.

Dart

dart:ui
Built-in types and core primitives for a Flutter application. [...]

Core

dart:async
Support for asynchronous programming, with classes such as Future and Stream. [...]
dart:collection
Classes and utilities that supplement the collection support in dart:core. [...]
dart:convert
Encoders and decoders for converting between different data representations, including JSON and UTF-8. [...]
dart:core
Built-in types, collections, and other core functionality for every Dart program. [...]
dart:developer
Interact with developer tools such as the debugger and inspector. [...]
dart:math
Mathematical constants and functions, plus a random number generator. [...]
dart:typed_data
Lists that efficiently handle fixed sized data (for example, unsigned 8 byte integers) and SIMD numeric types. [...]

VM

dart:io
File, socket, HTTP, and other I/O support for non-web applications. [...]
dart:isolate
Concurrent programming using isolates: independent workers that are similar to threads but don't share memory, communicating only via messages. [...]