Compiler message:
file:///Users/nealyang/development/flutter/.pub-cache/hosted/pub.flutter-io.cn/zefyr-0.5.0/lib/src/widgets/selection.dart:42:7: Error: The non-abstract class '_ZefyrSelectionOverlayState' is missing implementations for these members:
 - TextSelectionDelegate.copyEnabled
 - TextSelectionDelegate.cutEnabled
 - TextSelectionDelegate.pasteEnabled
 - TextSelectionDelegate.selectAllEnabled
Try to either
 - provide an implementation,
 - inherit an implementation from a superclass or mixin,
 - mark the class as abstract, or
 - provide a 'noSuchMethod' implementation.

class _ZefyrSelectionOverlayState extends State<ZefyrSelectionOverlay>
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^
file:///Users/nealyang/development/flutter/packages/flutter/lib/src/services/text_input.dart:596:12: Context: 'TextSelectionDelegate.copyEnabled' is defined here.
  bool get copyEnabled => true;
           ^^^^^^^^^^^
file:///Users/nealyang/development/flutter/packages/flutter/lib/src/services/text_input.dart:593:12: Context: 'TextSelectionDelegate.cutEnabled' is defined here.
  bool get cutEnabled => true;
           ^^^^^^^^^^
file:///Users/nealyang/development/flutter/packages/flutter/lib/src/services/text_input.dart:599:12: Context: 'TextSelectionDelegate.pasteEnabled' is defined here.
  bool get pasteEnabled => true;
           ^^^^^^^^^^^^
file:///Users/nealyang/development/flutter/packages/flutter/lib/src/services/text_input.dart:602:12: Context: 'TextSelectionDelegate.selectAllEnabled' is defined here.
  bool get selectAllEnabled => true;
           ^^^^^^^^^^^^^^^^
file:///Users/nealyang/development/flutter/.pub-cache/hosted/pub.flutter-io.cn/zefyr-0.5.0/lib/src/widgets/rich_text.dart:184:26: Error: The parameter 'value' of the method 'RenderZefyrParagraph.text' has type 'TextSpan', which does not match the corresponding type, 'InlineSpan', in the overridden method, 'RenderParagraph.text'.
 - 'TextSpan' is from 'package:flutter/src/painting/text_span.dart' ('file:///Users/nealyang/development/flutter/packages/flutter/lib/src/painting/text_span.dart').
 - 'InlineSpan' is from 'package:flutter/src/painting/inline_span.dart' ('file:///Users/nealyang/development/flutter/packages/flutter/lib/src/painting/inline_span.dart').
Change to a supertype of 'InlineSpan', or, for a covariant parameter, a subtype.
  void set text(TextSpan value) {
                         ^
file:///Users/nealyang/development/flutter/packages/flutter/lib/src/rendering/paragraph.dart:115:7: Context: This is the overridden method ('text').
  set text(InlineSpan value) {
      ^
file:///Users/nealyang/development/flutter/.pub-cache/hosted/pub.flutter-io.cn/zefyr-0.5.0/lib/src/widgets/editable_text.dart:102:28: Error: The method 'reparentIfNeeded' isn't defined for the class 'FocusScopeNode'.
 - 'FocusScopeNode' is from 'package:flutter/src/widgets/focus_manager.dart' ('file:///Users/nealyang/development/flutter/packages/flutter/lib/src/widgets/focus_manager.dart').
Try correcting the name to the name of an existing method, or defining a method named 'reparentIfNeeded'.
    FocusScope.of(context).reparentIfNeeded(focusNode);
                           ^^^^^^^^^^^^^^^^
file:///Users/nealyang/development/flutter/.pub-cache/hosted/pub.flutter-io.cn/zefyr-0.5.0/lib/src/widgets/selection.dart:483:22: Error: Too few positional arguments: 6 required, 4 given.
        .buildToolbar(context, editingRegion, midpoint, widget.delegate);
                     ^
file:///Users/nealyang/development/flutter/.pub-cache/hosted/pub.flutter-io.cn/zefyr-0.5.0/lib/src/widgets/input.dart:153:18: Error: The argument type 'String' can't be assigned to the parameter type 'DiagnosticsNode'.
 - 'DiagnosticsNode' is from 'package:flutter/src/foundation/diagnostics.dart' ('file:///Users/nealyang/development/flutter/packages/flutter/lib/src/foundation/diagnostics.dart').
Try changing the type of the parameter, or casting the argument to 'DiagnosticsNode'.
        context: 'while updating editing value',

Flutter 1.7.12-pre.40 • channel master • https://github.com/flutter/flutter.git
Framework • revision 3badcf51a4 (7 hours ago) • 2019-06-28 15:14:03 -0700
Engine • revision e96900df2f
Tools • Dart 2.4.0