harmony_flutter 自定义 toast

export default class FlutterToastPlugin implements FlutterPlugin {  private channel: MethodChannel | null = null;
  getUniqueClassName(): string {    return TAG;  }
  onAttachedToEngine(binding: FlutterPluginBinding): void {    this.setupChannel(binding.getBinaryMessenger());  }
  onDetachedFromEngine(binding: FlutterPluginBinding): void {    this.teardownChannel();  }
  private setupChannel(messenger: BinaryMessenger) {    this.channel = new MethodChannel(messenger, "PonnamKarthik/fluttertoast", StandardMethodCodec.INSTANCE);    let handler = new MethodCallHandlerImpl();    this.channel.setMethodCallHandler(handler);  }
  private teardownChannel() {    this.channel?.setMethodCallHandler(null)    this.channel = null  }}

export default class MethodCallHandlerImpl implements MethodCallHandler{  onMethodCall(call: MethodCall, result: MethodResult): void {    switch (call.method) {      case 'showToast': {        let msg: string = call.argument('msg');
        /* dart层传入时间单位为 s, promptAction.showToast 传入时间单位为ms */        let time: number = call.argument('time') * 1000;        let gravity: string = call.argument("gravity");        let bgcolor: number = call.argument("bgcolor");        let textcolor: number = call.argument("textcolor");        let textSize: number = call.argument("fontSize");
        try {          promptAction.showToast({message: msg, duration: time});        } catch (e) {          Log.e(TAG, "Show toast err " + e);        }
        result.success(true);      }      case 'cancel': {        result.success(true);      }      default: {        result.notImplemented();      }    }  }}

/// Toast Length/// Only for Android Platformenum Toast {  /// Show Short toast for 1 sec  LENGTH_SHORT,
  /// Show Long toast for 5 sec  LENGTH_LONG}
/// ToastGravity/// Used to define the position of the Toast on the screenenum ToastGravity { TOP, BOTTOM, CENTER, TOP_LEFT, TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT, CENTER_LEFT, CENTER_RIGHT, SNACKBAR, NONE }
/// Plugin to show a toast message on screen/// Only for android, ios and Web platformsclass Fluttertoast {  /// [MethodChannel] used to communicate with the platform side.  static const MethodChannel _channel = const MethodChannel('PonnamKarthik/fluttertoast');
  /// Let say you have an active show  /// Use this method to hide the toast immediately  static Future<bool?> cancel() async {    bool? res = await _channel.invokeMethod("cancel");    return res;  }
  /// Summons the platform's showToast which will display the message  ///  /// Wraps the platform's native Toast for android.  /// Wraps the Plugin https://github.com/scalessec/Toast for iOS  /// Wraps the https://github.com/apvarun/toastify-js for Web  ///  /// Parameter [msg] is required and all remaining are optional  static Future<bool?> showToast({    required String msg,    Toast? toastLength,    int timeInSecForIosWeb = 1,    double? fontSize,    ToastGravity? gravity,    Color? backgroundColor,    Color? textColor,    bool webShowClose = false,    webBgColor = "linear-gradient(to right, #00b09b, #96c93d)",    webPosition = "right",  }) async {    String toast = "short";    if (toastLength == Toast.LENGTH_LONG) {      toast = "long";    }
    String gravityToast = "bottom";    if (gravity == ToastGravity.TOP) {      gravityToast = "top";    } else if (gravity == ToastGravity.CENTER) {      gravityToast = "center";    } else {      gravityToast = "bottom";    }
//lines from 78 to 97 have been changed in order to solve issue #328    if (backgroundColor == null) {      backgroundColor = Colors.black;    }    if (textColor == null) {      textColor = Colors.white;    }    final Map<String, dynamic> params = <String, dynamic>{      'msg': msg,      'length': toast,      'time': timeInSecForIosWeb,      'gravity': gravityToast,      'bgcolor': backgroundColor.value,      'iosBgcolor': backgroundColor.value,      'textcolor': textColor.value,      'iosTextcolor': textColor.value,      'fontSize': fontSize,      'webShowClose': webShowClose,      'webBgColor': webBgColor,      'webPosition': webPosition    };
    bool? res = await _channel.invokeMethod('showToast', params);    return res;  }}
/// Signature for a function to buildCustom Toasttypedef PositionedToastBuilder = Widget Function(BuildContext context, Widget child);
/// Runs on dart side this has no interaction with the Native Side/// Works with all platforms just in two lines of code/// final fToast = FToast().init(context)/// fToast.showToast(child)///class FToast {  BuildContext? context;
  static final FToast _instance = FToast._internal();
  /// Prmary Constructor for FToast  factory FToast() {    return _instance;  }
  /// Take users Context and saves to avariable  FToast init(BuildContext context) {    _instance.context = context;    return _instance;  }
  FToast._internal();
  OverlayEntry? _entry;  List<_ToastEntry> _overlayQueue = [];  Timer? _timer;  Timer? _fadeTimer;
  /// Internal function which handles the adding  /// the overlay to the screen  ///  _showOverlay() {    if (_overlayQueue.length == 0) {      _entry = null;      return;    }    if (context == null) {      /// Need to clear queue      removeQueuedCustomToasts();      throw ("Error: Context is null, Please call init(context) before showing toast.");    }
    /// To prevent exception "Looking up a deactivated widget's ancestor is unsafe."    /// which can be thrown if context was unmounted (e.g. screen with given context was popped)    /// TODO: revert this change when envoirment will be Flutter >= 3.7.0    // if (context?.mounted != true) {    //   if (kDebugMode) {    //     print(    //         'FToast: Context was unmuted, can not show ${_overlayQueue.length} toast.');    //   }
    //   /// Need to clear queue    //   removeQueuedCustomToasts();    //   return; // Or maybe thrown error too    // }    var _overlay;    try {      _overlay = Overlay.of(context!);    } catch (err) {      removeQueuedCustomToasts();      throw ("""Error: Overlay is null.       Please don't use top of the widget tree context (such as Navigator or MaterialApp) or       create overlay manually in MaterialApp builder.      More information         - https://github.com/ponnamkarthik/FlutterToast/issues/393        - https://github.com/ponnamkarthik/FlutterToast/issues/234""");    }    if (_overlay == null) {      /// Need to clear queue      removeQueuedCustomToasts();      throw ("""Error: Overlay is null.       Please don't use top of the widget tree context (such as Navigator or MaterialApp) or       create overlay manually in MaterialApp builder.      More information         - https://github.com/ponnamkarthik/FlutterToast/issues/393        - https://github.com/ponnamkarthik/FlutterToast/issues/234""");    }
    /// Create entry only after all checks    _ToastEntry _toastEntry = _overlayQueue.removeAt(0);    _entry = _toastEntry.entry;    _overlay.insert(_entry!);
    _timer = Timer(_toastEntry.duration, () {      _fadeTimer = Timer(_toastEntry.fadeDuration, () {        removeCustomToast();      });    });  }
  /// If any active toast present  /// call removeCustomToast to hide the toast immediately  removeCustomToast() {    _timer?.cancel();    _fadeTimer?.cancel();    _timer = null;    _fadeTimer = null;    _entry?.remove();    _entry = null;    _showOverlay();  }
  /// FToast maintains a queue for every toast  /// if we called showToast for 3 times we all to queue  /// and show them one after another  ///  /// call removeCustomToast to hide the toast immediately  removeQueuedCustomToasts() {    _timer?.cancel();    _fadeTimer?.cancel();    _timer = null;    _fadeTimer = null;    _overlayQueue.clear();    _entry?.remove();    _entry = null;  }
  /// showToast accepts all the required paramenters and prepares the child  /// calls _showOverlay to display toast  ///  /// Paramenter [child] is requried  /// toastDuration default is 2 seconds  /// fadeDuration default is 350 milliseconds  void showToast({    required Widget child,    PositionedToastBuilder? positionedToastBuilder,    Duration toastDuration = const Duration(seconds: 2),    ToastGravity? gravity,    Duration fadeDuration = const Duration(milliseconds: 350),    bool ignorePointer = false,    bool isDismissable = false,  }) {    if (context == null) throw ("Error: Context is null, Please call init(context) before showing toast.");    Widget newChild = _ToastStateFul(        child,        toastDuration,        fadeDuration,        ignorePointer,        !isDismissable            ? null            : () {                removeCustomToast();              });
    /// Check for keyboard open    /// If open will ignore the gravity bottom and change it to center    if (gravity == ToastGravity.BOTTOM) {      if (MediaQuery.of(context!).viewInsets.bottom != 0) {        gravity = ToastGravity.CENTER;      }    }
    OverlayEntry newEntry = OverlayEntry(builder: (context) {      if (positionedToastBuilder != null) return positionedToastBuilder(context, newChild);      return _getPostionWidgetBasedOnGravity(newChild, gravity);    });    _overlayQueue.add(_ToastEntry(entry: newEntry, duration: toastDuration, fadeDuration: fadeDuration));    if (_timer == null) _showOverlay();  }
  /// _getPostionWidgetBasedOnGravity generates [Positioned] [Widget]  /// based on the gravity  [ToastGravity] provided by the user in  /// [showToast]  _getPostionWidgetBasedOnGravity(Widget child, ToastGravity? gravity) {    switch (gravity) {      case ToastGravity.TOP:        return Positioned(top: 100.0, left: 24.0, right: 24.0, child: child);      case ToastGravity.TOP_LEFT:        return Positioned(top: 100.0, left: 24.0, child: child);      case ToastGravity.TOP_RIGHT:        return Positioned(top: 100.0, right: 24.0, child: child);      case ToastGravity.CENTER:        return Positioned(top: 50.0, bottom: 50.0, left: 24.0, right: 24.0, child: child);      case ToastGravity.CENTER_LEFT:        return Positioned(top: 50.0, bottom: 50.0, left: 24.0, child: child);      case ToastGravity.CENTER_RIGHT:        return Positioned(top: 50.0, bottom: 50.0, right: 24.0, child: child);      case ToastGravity.BOTTOM_LEFT:        return Positioned(bottom: 50.0, left: 24.0, child: child);      case ToastGravity.BOTTOM_RIGHT:        return Positioned(bottom: 50.0, right: 24.0, child: child);      case ToastGravity.SNACKBAR:        return Positioned(bottom: MediaQuery.of(context!).viewInsets.bottom, left: 0, right: 0, child: child);      case ToastGravity.NONE:        return Positioned.fill(child: child);      case ToastGravity.BOTTOM:      default:        return Positioned(bottom: 50.0, left: 24.0, right: 24.0, child: child);    }  }}
/// Simple builder method to create a [TransitionBuilder]/// and for the use in MaterialApp builder method// ignore: non_constant_identifier_namesTransitionBuilder FToastBuilder() {  return (context, child) {    return _FToastHolder(      child: child!,    );  };}
/// Simple StatelessWidget which holds the child/// and creates an [Overlay] to display the toast/// which returns the Directionality widget with [TextDirection.ltr]/// and [Overlay] widgetclass _FToastHolder extends StatelessWidget {  const _FToastHolder({Key? key, required this.child}) : super(key: key);
  final Widget child;
  @override  Widget build(BuildContext context) {    final Overlay overlay = Overlay(      initialEntries: <OverlayEntry>[        OverlayEntry(          builder: (BuildContext ctx) {            return child;          },        ),      ],    );
    return Directionality(      textDirection: TextDirection.ltr,      child: overlay,    );  }}
/// internal class [_ToastEntry] which maintains/// each [OverlayEntry] and [Duration] for every toast user/// triggeredclass _ToastEntry {  final OverlayEntry entry;  final Duration duration;  final Duration fadeDuration;
  _ToastEntry({    required this.entry,    required this.duration,    required this.fadeDuration,  });}
/// internal [StatefulWidget] which handles the show and hide/// animations for [FToast]class _ToastStateFul extends StatefulWidget {  _ToastStateFul(this.child, this.duration, this.fadeDuration, this.ignorePointer, this.onDismiss, {Key? key}) : super(key: key);
  final Widget child;  final Duration duration;  final Duration fadeDuration;  final bool ignorePointer;  final VoidCallback? onDismiss;
  @override  ToastStateFulState createState() => ToastStateFulState();}
/// State for [_ToastStateFul]class ToastStateFulState extends State<_ToastStateFul> with SingleTickerProviderStateMixin {  /// Start the showing animations for the toast  showIt() {    _animationController!.forward();  }
  /// Start the hidding animations for the toast  hideIt() {    _animationController!.reverse();    _timer?.cancel();  }
  /// Controller to start and hide the animation  AnimationController? _animationController;  late Animation _fadeAnimation;
  Timer? _timer;
  @override  void initState() {    _animationController = AnimationController(      vsync: this,      duration: widget.fadeDuration,    );    _fadeAnimation = CurvedAnimation(parent: _animationController!, curve: Curves.easeIn);    super.initState();
    showIt();    _timer = Timer(widget.duration, () {      hideIt();    });  }
  @override  void deactivate() {    _timer?.cancel();    _animationController!.stop();    super.deactivate();  }
  @override  void dispose() {    _timer?.cancel();    _animationController?.dispose();    super.dispose();  }
  @override  Widget build(BuildContext context) {    return GestureDetector(      onTap: widget.onDismiss == null ? null : () => widget.onDismiss!(),      behavior: HitTestBehavior.translucent,      child: IgnorePointer(        ignoring: widget.ignorePointer,        child: FadeTransition(          opacity: _fadeAnimation as Animation<double>,          child: Center(            child: Material(              color: Colors.transparent,              child: widget.child,            ),          ),        ),      ),    );  }}

fToast = FToast();fToast.init(context);
fToast.showToast(    child: toast,    gravity: ToastGravity.BOTTOM,    toastDuration: Duration(seconds: 2),    positionedToastBuilder: (context, child) {      return Positioned(        child: child,        top: 16.0,        left: 16.0,      );    });