inicia separação dos componentes

lib/animeted_focus_light.dart

@@ -0,0 +1,14 @@
+
+import 'package:flutter/widgets.dart';
+
+class AnimetedFocusLight extends StatefulWidget {
+  @override
+  _AnimetedFocusLightState createState() => _AnimetedFocusLightState();
+}
+
+class _AnimetedFocusLightState extends State<AnimetedFocusLight> {
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}

lib/content_target.dart

@@ -0,0 +1,17 @@
+
+import 'package:flutter/widgets.dart';
+
+enum AlignContent{
+  top,
+  bottom,
+  left,
+  right
+}
+
+class ContentTarget{
+
+  final AlignContent align;
+  final Widget child;
+
+  ContentTarget({this.align = AlignContent.bottom, this.child}):assert(child != null);
+}

lib/light_paint.dart

@@ -0,0 +1,43 @@
+ import 'dart:math';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+
+class LightPaint extends CustomPainter {
+
+  final double progress;
+  final Offset positioned;
+  final double sizeCircle;
+
+  Paint _paintFocus;
+
+  LightPaint(this.progress, this.positioned, this.sizeCircle){
+    _paintFocus = Paint()
+      ..color = Colors.transparent
+      ..blendMode = BlendMode.clear;
+  }
+
+  @override
+  void paint(Canvas canvas, Size size) {
+
+    canvas.saveLayer(Offset.zero & size, Paint());
+    canvas.drawColor(Colors.black.withOpacity(0.8), BlendMode.dstATop);
+
+    double sizeFocus = (size.height * 1.4) * (1-progress) + sizeCircle;
+    double radius  = min(sizeFocus,sizeFocus);
+
+    canvas.drawCircle(
+        positioned,
+        radius,
+        _paintFocus
+    );
+    canvas.restore();
+
+  }
+
+  @override
+  bool shouldRepaint(LightPaint oldDelegate) {
+    return oldDelegate.progress != progress;
+  }
+
+ }

lib/target_focus.dart

@@ -0,0 +1,13 @@
+import 'package:flutter/widgets.dart';
+import 'package:tutorial_coach_mark/content_target.dart';
+import 'package:tutorial_coach_mark/target_position.dart';
+
+class TargetFocus{
+
+  final GlobalKey keyTarget;
+  final TargetPosition targetPosition;
+  final List<ContentTarget> contents;
+
+  TargetFocus({this.keyTarget, this.targetPosition, this.contents}):assert(keyTarget != null || targetPosition != null);
+
+}

lib/target_position.dart

@@ -0,0 +1,9 @@
+
+import 'dart:ui';
+
+class TargetPosition{
+  final Size size;
+  final Offset offset;
+
+  TargetPosition(this.size, this.offset);
+}

lib/tutorial_coach_mark.dart

@@ -1,7 +1,30 @@
 library tutorial_coach_mark;
+import 'package:flutter/material.dart';
+import 'package:tutorial_coach_mark/tutorial_coach_mark_widget.dart';
 
-/// A Calculator.
-class Calculator {
-  /// Returns [value] plus 1.
-  int addOne(int value) => value + 1;
+class TutorialCoachMark {
+  final BuildContext _context;
+
+  OverlayEntry _overlayEntry;
+
+  TutorialCoachMark(
+      this._context,);
+
+  OverlayEntry _buildOverlay() {
+    return OverlayEntry(builder: (context) {
+      return TutorialCoachMarkWidget();
+    });
+  }
+
+  void show() {
+    if (_overlayEntry == null) {
+      _overlayEntry = _buildOverlay();
+      Overlay.of(_context).insert(_overlayEntry);
+    }
+  }
+
+  void _hide() {
+    _overlayEntry?.remove();
+    _overlayEntry = null;
+  }
 }