StickeyHeader added

README.md

@@ -1,6 +1,5 @@
 [![pub package](https://img.shields.io/pub/v/getwidget.svg)](https://pub.dartlang.org/packages/getwidget) [![Build Status](https://travis-ci.org/ionicfirebaseapp/getwidget.svg?branch=master)](https://travis-ci.com/ionicfirebaseapp/getwidget) [![Open Source Love](https://badges.frapsoft.com/os/v1/open-source.svg?v=102)](https://opensource.org/licenses/MIT) [![License](https://img.shields.io/badge/license-MIT-orange.svg)](https://github.com/ionicfirebaseapp/getwidget/blob/master/LICENSE) [![Twitter Follow](https://img.shields.io/twitter/follow/getwidgetdev.svg?style=social)](https://twitter.com/getwidgetdev)
 
-
 <p align="center">
   <a href="https://docs.getwidget.dev/" target="_blank">
     <img src="https://ik.imagekit.io/ionicfirebaseapp/logo.black_iOBoLWdj2I.png" alt="GetWidget">
@@ -28,6 +27,7 @@
 </p>
 
 
+
 ## Quick start
 
 Read the [Getting started page](https://docs.getwidget.dev) 

lib/components/sticky_header/gf_sticky_header.dart

@@ -0,0 +1,63 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:meta/meta.dart';
+import 'package:getwidget/getwidget.dart';
+
+/// Place this widget inside a [ListView], [GridView], [CustomScrollView], [SingleChildScrollView] or similar.
+
+class GFStickyHeader extends MultiChildRenderObjectWidget {
+  GFStickyHeader(
+      {Key key,
+      @required this.stickyContent,
+      @required this.content,
+      this.direction = Axis.vertical,
+      this.enableHeaderOverlap = false,
+      this.callback,
+      this.stickyContentPosition = GFPosition.start})
+      : assert(direction != null),
+        super(
+            key: key,
+            children: stickyContentPosition == GFPosition.start &&
+                    direction == Axis.horizontal
+                ? [stickyContent, content]
+                : stickyContentPosition == GFPosition.start &&
+                        direction == Axis.vertical
+                    ? [content, stickyContent]
+                    : [content, stickyContent]);
+
+  /// widget can be used to define [stickyContent].
+  final Widget stickyContent;
+
+  /// widget can be used to define [content].
+  final Widget content;
+
+  /// On state true, the [stickyContent] will overlap the [content].
+  /// Only works when direction is [Axis.vertical]. Default set to false.
+  final bool enableHeaderOverlap;
+
+  /// [GFPosition] allows to [stickyContentPosition] to stick at top in [Axis.vertical] and stick at start in [Axis.horizontal]
+  /// Defaults to [GFPosition.start]
+  final GFPosition stickyContentPosition;
+
+  /// Allows to add custom stickyHeader stuck offset value
+  final RenderGFStickyHeaderCallback callback;
+
+  ///  [direction] allows children to align in vertical / horizontal way
+  ///  Defaults to [Axis.vertical]
+  final Axis direction;
+
+  @override
+  RenderGFStickyHeader createRenderObject(BuildContext context) {
+    final scrollable = Scrollable.of(context);
+    assert(scrollable != null);
+    return RenderGFStickyHeader(
+      direction: direction,
+      scrollable: scrollable,
+      enableHeaderOverlap: enableHeaderOverlap,
+      callback: callback,
+      stickyContentPosition: stickyContentPosition,
+    );
+  }
+}

lib/components/sticky_header/gf_sticky_header_builder.dart

@@ -0,0 +1,71 @@
+import 'package:flutter/material.dart';
+import 'package:getwidget/getwidget.dart';
+
+typedef StickyHeaderWidgetBuilder = Widget Function(
+    BuildContext context, double stuckValue);
+
+/// Place this widget inside a [ListView], [GridView], [CustomScrollView], [SingleChildScrollView] or similar.
+
+class GFStickyHeaderBuilder extends StatefulWidget {
+  /// Constructs a new [GFStickyHeaderBuilder] widget.
+  const GFStickyHeaderBuilder({
+    Key key,
+    @required this.stickyContentBuilder,
+    @required this.content,
+    this.direction = Axis.vertical,
+    this.enableHeaderOverlap = false,
+    this.callback,
+    this.stickyContentPosition = GFPosition.start,
+  })  : assert(direction != null),
+        super(key: key);
+
+  /// widget can be used to define [stickyContentBuilder].
+  final StickyHeaderWidgetBuilder stickyContentBuilder;
+
+  /// widget can be used to define [content].
+  final Widget content;
+
+  /// On state true, the [stickyContentBuilder] will overlap the [content].
+  /// Only works when direction is [Axis.vertical]. Default set to false.
+  final bool enableHeaderOverlap;
+
+  /// [GFPosition] allows to [stickyContentPosition] to stick at top in [Axis.vertical] and stick at start in [Axis.horizontal]
+  /// Defaults to [GFPosition.start]
+  final GFPosition stickyContentPosition;
+
+  /// Allows to add custom stickyHeader stuck offset value
+  final RenderGFStickyHeaderCallback callback;
+
+  ///  [direction] allows children to align in vertical / horizontal way
+  ///  Defaults to [Axis.vertical]
+  final Axis direction;
+
+  @override
+  _GFStickyHeaderBuilderState createState() => _GFStickyHeaderBuilderState();
+}
+
+class _GFStickyHeaderBuilderState extends State<GFStickyHeaderBuilder> {
+  double _stuckValue;
+
+  @override
+  Widget build(BuildContext context) => GFStickyHeader(
+        enableHeaderOverlap: widget.enableHeaderOverlap,
+        direction: widget.direction,
+        stickyContentPosition: widget.stickyContentPosition,
+        stickyContent: LayoutBuilder(
+          builder: (context, _) =>
+              widget.stickyContentBuilder(context, _stuckValue ?? 0.0),
+        ),
+        content: widget.content,
+        callback: (double stuckValue) {
+          if (_stuckValue != stuckValue) {
+            _stuckValue = stuckValue;
+            WidgetsBinding.instance.endOfFrame.then((_) {
+              if (mounted) {
+                setState(() {});
+              }
+            });
+          }
+        },
+      );
+}