add GetResponsive

+import 'package:flutter/widgets.dart';
+
+import '../../../get.dart';
+import 'get_view.dart';
+
+abstract class GetResponsive<T> extends GetView<T> {
+  final ResponsiveScreen screen;
+  GetResponsive(ResponsiveScreenSettings settings, {Key key})
+      : screen = ResponsiveScreen(settings),
+        super(key: key);
+
+  Widget builder();
+  Widget mobile();
+  Widget tablet();
+  Widget desktop();
+  Widget watch();
+}
+
+class GetResponsiveView<T> extends GetResponsive<T> {
+  final bool alwaysUseBuilder = true;
+  GetResponsiveView(
+      {alwaysUseBuilder,
+      ResponsiveScreenSettings settings = const ResponsiveScreenSettings(),
+      Key key})
+      : super(settings, key: key);
+  @override
+  Widget build(BuildContext context) {
+    screen.context = context;
+    if (alwaysUseBuilder) {
+      return builder();
+    }
+    Widget widget;
+    if (screen.isDesktop) {
+      widget = desktop();
+      if (widget != null) return widget;
+    }
+    if (screen.isTablet) {
+      widget = tablet();
+      if (widget != null) return widget;
+    }
+    if (screen.isMobile) {
+      widget = mobile();
+      if (widget != null) return widget;
+    }
+    return watch();
+  }
+
+  @override
+  Widget builder() => null;
+
+  @override
+  Widget desktop() => null;
+
+  @override
+  Widget mobile() => null;
+
+  @override
+  Widget tablet() => null;
+
+  @override
+  Widget watch() => null;
+}
+
+class ResponsiveScreenSettings {
+  /// When the width is greater als this value
+  /// the display will be set as [ScreenType.Desktop]
+  final double desktopChangePoint;
+
+  /// When the width is greater als this value
+  /// the display will be set as [ScreenType.Tablet]
+  /// or when width greater als [watchChangePoint] and smaller als this value
+  /// the display will be [ScreenType.Mobile]
+  final double tabletChangePoint;
+
+  /// When the width is smaller als this value
+  /// the display will be set as [ScreenType.Watch]
+  /// or when width greater als this value and smaller als [tabletChangePoint]
+  /// the display will be [ScreenType.Mobile]
+  final double watchChangePoint;
+
+  const ResponsiveScreenSettings(
+      {this.desktopChangePoint = 1200,
+      this.tabletChangePoint = 600,
+      this.watchChangePoint = 300});
+}
+
+class ResponsiveScreen {
+  BuildContext context;
+  final ResponsiveScreenSettings settings;
+
+  bool _isPaltformDesktop;
+  ResponsiveScreen(this.settings) {
+    _isPaltformDesktop = GetPlatform.isDesktop;
+  }
+
+  double get height => context.height;
+  double get width => context.width;
+
+  /// Is [screenType] [ScreenType.Desktop]
+  bool get isDesktop => (screenType == ScreenType.Desktop);
+
+  /// Is [screenType] [ScreenType.Tablet]
+  bool get isTablet => (screenType == ScreenType.Tablet);
+
+  /// Is [screenType] [ScreenType.Mobile]
+  bool get isMobile => (screenType == ScreenType.Mobile);
+
+  /// Is [screenType] [ScreenType.Watch]
+  bool get isWatch => (screenType == ScreenType.Watch);
+
+  double get _getdeviceWidth {
+    if (_isPaltformDesktop) {
+      return width;
+    }
+    return context.mediaQueryShortestSide;
+  }
+
+  ScreenType get screenType {
+    final deviceWidth = _getdeviceWidth;
+    if (deviceWidth >= settings.desktopChangePoint) return ScreenType.Desktop;
+    if (deviceWidth >= settings.tabletChangePoint) return ScreenType.Tablet;
+    if (deviceWidth < settings.watchChangePoint) return ScreenType.Watch;
+    return ScreenType.Mobile;
+  }
+
+  /// Return widget according to screen type
+  /// if the [screenType] is [ScreenType.Desktop] and
+  /// `desktop` object is null the `tablet` object will be returned
+  /// and if `tablet` object is null the `mobile` object will be returned
+  /// and if `mobile` object is null the `watch` object will be returned
+  ///  also when it is null.
+  T responsiveValue<T>({
+    T mobile,
+    T tablet,
+    T desktop,
+    T watch,
+  }) {
+    if (isDesktop && desktop != null) return desktop;
+    if (isTablet && tablet != null) return tablet;
+    if (isMobile && mobile != null) return mobile;
+    return watch;
+  }
+}
+
+enum ScreenType {
+  Watch,
+  Mobile,
+  Tablet,
+  Desktop,
+}