Merge pull request #22 from jamesblasco/small_bug_fixes

Small bug fixes

@@ -18,7 +18,7 @@ class ModalInsideModal extends StatelessWidget {
         child: ListView(
           shrinkWrap: true,
           controller: scrollController,
-          physics: BouncingScrollPhysics(),
+          physics: ClampingScrollPhysics(),
           children: ListTile.divideTiles(
               context: context,
               tiles: List.generate(

@@ -13,7 +13,7 @@ import 'package:flutter/widgets.dart';
 
 const Duration _bottomSheetDuration = Duration(milliseconds: 400);
 const double _minFlingVelocity = 500.0;
-const double _closeProgressThreshold = 0.5;
+const double _closeProgressThreshold = 0.6;
 const double _willPopThreshold = 0.8;
 
 typedef ScrollWidgetBuilder = Widget Function(
@@ -243,14 +243,30 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
 
   void _handleScrollUpdate(ScrollNotification notification) {
     if (notification.metrics.pixels <= notification.metrics.minScrollExtent) {
-      //Check if listener is same from scrollController
       if (!_scrollController.hasClients) return;
 
-      if (_scrollController.position.pixels != notification.metrics.pixels) {
+      // Check if listener is same from scrollController.
+      // TODO: Improve the way it checks if it the same view controller
+      // Use PrimaryScrollController
+      if (_scrollController.position.pixels != notification.metrics.pixels &&
+          !(_scrollController.position.pixels == 0 &&
+              notification.metrics.pixels >= 0)) {
         return;
       }
+      // Clamping Scroll Physics end with a ScrollEndNotification with a DragEndDetail class
+      // while Bouncing Scroll Physics or other physics that Overflow don't return a drag end info
+
+      // We use the velocity from DragEndDetail in case it is available
+      if (notification is ScrollEndNotification &&
+          notification.dragDetails != null) {
+        _handleDragEnd(notification.dragDetails.primaryVelocity);
+        _velocityTracker = null;
+        _startTime = null;
+        return;
+      }
+      // Otherwise the calculate the velocity with a VelocityTracker
       DragUpdateDetails dragDetails;
-      if (notification is ScrollStartNotification) {
+      if (_velocityTracker == null) {
         _velocityTracker = VelocityTracker();
         _startTime = DateTime.now();
       }
@@ -262,11 +278,13 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
       }
       if (dragDetails != null) {
         final duration = _startTime.difference(DateTime.now());
-        final offset = Offset(0, _scrollController.offset);
+        final offset = Offset(0, notification.metrics.pixels);
         _velocityTracker.addPosition(duration, offset);
         _handleDragUpdate(dragDetails.primaryDelta);
       } else if (isDragging) {
         final velocity = _velocityTracker.getVelocity().pixelsPerSecond.dy;
+        _velocityTracker = null;
+        _startTime = null;
         _handleDragEnd(velocity);
       }
     }
@@ -285,7 +303,7 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
   Widget build(BuildContext context) {
     final bounceAnimation = CurvedAnimation(
       parent: _bounceDragController,
-      curve: widget.animationCurve ?? Curves.easeOutSine,
+      curve: Curves.easeOutSine,
     );
 
     var child = widget.builder(context, _scrollController);
@@ -299,17 +317,17 @@ class _ModalBottomSheetState extends State<ModalBottomSheet>
     }
 
     // Todo: Add curved Animation when push and pop without gesture
-    /* final Animation<double> containerAnimation = CurvedAnimation(
+    final Animation<double> containerAnimation = CurvedAnimation(
       parent: widget.animationController,
-      curve: Curves.easeOut,
-    );*/
+      curve: widget.animationCurve ?? Curves.linear,
+    );
 
     return AnimatedBuilder(
       animation: widget.animationController,
       builder: (context, _) => ClipRect(
         child: CustomSingleChildLayout(
           delegate: _ModalBottomSheetLayout(
-              widget.animationController.value, widget.expanded),
+              containerAnimation.value, widget.expanded),
           child: !widget.enableDrag
               ? child
               : KeyedSubtree(