Clamp AppBar scroll notifications when ClampOverscrolls is true (#4152)

ff1d3b81 · Hans Muller · 3b3db78f · ff1d3b81
Commit ff1d3b81 authored May 24, 2016 by Hans Muller
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Showing with 11 additions and 5 deletions

scaffold.dart packages/flutter/lib/src/material/scaffold.dart +11 -5

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--- a/packages/flutter/lib/src/material/scaffold.dart
+++ b/packages/flutter/lib/src/material/scaffold.dart
@@ -547,11 +547,17 @@ class ScaffoldState extends State<Scaffold> {
    final ScrollableState scrollable = notification.scrollable;
    if ((scrollable.config.scrollDirection == Axis.vertical) &&
        (config.scrollableKey == null || config.scrollableKey == scrollable.config.key)) {
-      final double newScrollOffset = scrollable.scrollOffset;
+      double newScrollOffset = scrollable.scrollOffset;
-      setState(() {
+      if (ClampOverscrolls.of(scrollable.context)) {
-        _scrollOffsetDelta = _scrollOffset - newScrollOffset;
+        ExtentScrollBehavior limits = scrollable.scrollBehavior;
-        _scrollOffset = newScrollOffset;
+        newScrollOffset = newScrollOffset.clamp(limits.minScrollOffset, limits.maxScrollOffset);
-      });
+      }
+      if (_scrollOffset != newScrollOffset) {
+        setState(() {
+          _scrollOffsetDelta = _scrollOffset - newScrollOffset;
+          _scrollOffset = newScrollOffset;
+        });
+      }
    }
    return false;
  }