add DraggableScrollableSheet+Loadmore example

README.md

@@ -114,9 +114,9 @@ finally,[here](https://github.com/peng8350/flutter_pulltorefresh/tree/master/exa
 |:---:|:---:|:---:|
 |art| ![](arts/example5.gif) | ![](arts/example6.gif) |
 
-|Style| [ simple custom header(使用SpinKit)](example/lib/ui/example/useStage/custom_header.dart)|
+|Style| [ simple custom header(使用SpinKit)](example/lib/ui/example/useStage/custom_header.dart)| [dragableScrollSheet+LoadMore](example/lib/ui/example/otherwidget/draggable_bottomsheet_loadmore.dart)|
 |:---:|:---:|
-|art| ![](arts/example7.gif) |
+|art| ![](arts/example7.gif) | ![](arts/example8.gif) |
 
 
 ### Indicator

README_CN.md

@@ -100,9 +100,9 @@ header和footer的重复性的工作,在RefreshConfiguration子树下的SmartRef
 |:---:|:---:|:---:|
 |art| ![](arts/example5.gif) | ![](arts/example6.gif) |
 
-|Style| [简单自定义刷新指示器(使用SpinKit)](example/lib/ui/example/useStage/custom_header.dart)|
-|:---:|:---:|
-|art| ![](arts/example7.gif) |
+|Style| [简单自定义刷新指示器(使用SpinKit)](example/lib/ui/example/useStage/custom_header.dart)| [dragableScrollSheet+LoadMore](example/lib/ui/example/otherwidget/draggable_bottomsheet_loadmore.dart)|
+|:---:|:---:|:---:|
+|art| ![](arts/example7.gif) | ![](arts/example8.gif) |
 
 ### 各种指示器
 

example/lib/ui/example/ExamplePage.dart

@@ -16,6 +16,7 @@ import 'package:example/ui/example/otherwidget/refresh_pageView_example.dart';
 import 'package:example/ui/example/useStage/link_header_example.dart';
 import 'package:example/ui/example/useStage/twolevel_refresh.dart';
 import 'otherwidget/refresh_recordable_listview_example.dart';
+import 'otherwidget/draggable_bottomsheet_loadmore.dart';
 
 class ExamplePage extends StatefulWidget {
   @override
@@ -167,6 +168,16 @@ class _ExamplePageState extends State<ExamplePage>
               );
             }));
           }),
+      ExampleItem(
+          title: "loadmore+draggablesheet",
+          onClick: () {
+            Navigator.of(context).push(MaterialPageRoute(builder: (context) {
+              return Scaffold(
+                appBar: AppBar(),
+                body: DraggableLoadingBottomSheet(),
+              );
+            }));
+          }),
       ExampleItem(
           title: "pageView共用SmartRefresher",
           onClick: () {

example/lib/ui/example/otherwidget/draggable_bottomsheet_loadmore.dart

@@ -0,0 +1,100 @@
+/*
+ * Author: Jpeng
+ * Email: [email protected]
+ * Time:  2019-07-03 17:24
+ */
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import '../../Item.dart';
+import 'package:pull_to_refresh/pull_to_refresh.dart';
+
+/*
+  notice that,If your combine with DraggableScrollSheet with SmartRefresher,
+  It not support enablePullDown,only support enablePullUp = true.
+  the second, the example has StatefulBuilder,just not setState(),it will never rebuild scrollSheet
+ */
+class DraggableLoadingBottomSheet extends StatefulWidget {
+  @override
+  State<StatefulWidget> createState() {
+    // TODO: implement createState
+    return _DraggableLoadingBottomSheetState();
+  }
+}
+
+class _DraggableLoadingBottomSheetState
+    extends State<DraggableLoadingBottomSheet> {
+  RefreshController _controller = RefreshController();
+
+  List<String> items = [];
+
+  @override
+  void initState() {
+    // TODO: implement initState
+    super.initState();
+    for (int i = 0; i < 15; i++) items.add("数据");
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    // TODO: implement build
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('DraggableScrollableSheet'),
+      ),
+      body: Container(
+        child: RaisedButton(
+          onPressed: () {
+            showModalBottomSheet(
+                backgroundColor: Colors.transparent,
+                context: context,
+                builder: (c) {
+                  return DraggableScrollableSheet(
+                    initialChildSize: 1.0,
+                    maxChildSize: 1.0,
+                    minChildSize: 0.5,
+                    builder: (BuildContext context,
+                        ScrollController scrollController) {
+                      return Container(
+                        color: Colors.blue[100],
+                        child: StatefulBuilder(
+                          builder: (BuildContext context2, setter) {
+                            return SmartRefresher(
+                              child: ListView.separated(
+                                controller: scrollController,
+                                separatorBuilder: (c, i) => Divider(),
+                                itemBuilder: (_, e) => Container(
+                                  child:
+                                      Center(child: Text("菜单" + e.toString())),
+                                  height: 40.0,
+                                ),
+                                physics: ClampingScrollPhysics(),
+                                itemCount: items.length,
+                              ),
+                              controller: _controller,
+                              onLoading: () async {
+                                await Future.delayed(
+                                    Duration(milliseconds: 1000));
+                                _controller.loadComplete();
+                                for (int i = 0; i < 15; i++) {
+                                  items.add("1");
+                                }
+
+                                setter(() {});
+                              },
+                              enablePullUp: true,
+                              enablePullDown: false,
+                            );
+                          },
+                        ),
+                      );
+                    },
+                  );
+                });
+          },
+          child: Text("点击打开滑动BottomSheet"),
+        ),
+      ),
+    );
+  }
+}

lib/src/internals/refresh_physics.dart

@@ -202,7 +202,7 @@ class RefreshPhysics extends ScrollPhysics {
         spring: spring,
         position: position.pixels,
         // -1.0 avoid stop springing back ,and release gesture
-        velocity: velocity,
+        velocity: -1.0,
         // TODO(abarth): We should move this constant closer to the drag end.
         leadingExtent: position.minScrollExtent,
         trailingExtent: headerMode.value == RefreshStatus.twoLeveling