Fix scrolling

submodules/Display/Source/ListView.swift

@@ -4,7 +4,6 @@ import SwiftSignalKit
 import UIKitRuntimeUtils
 import ObjCRuntimeUtils
 
-private let infiniteScrollSize: CGFloat = 10000.0
 private let insertionAnimationDuration: Double = 0.4
 
 private struct VisibleHeaderNodeId: Hashable {
@@ -161,6 +160,8 @@ open class ListView: ASDisplayNode, UIScrollViewAccessibilityDelegate, UIGesture
     private final var lastContentOffset: CGPoint = CGPoint()
     private final var lastContentOffsetTimestamp: CFAbsoluteTime = 0.0
     private final var ignoreScrollingEvents: Bool = false
+
+    private let infiniteScrollSize: CGFloat
     
     private final var displayLink: CADisplayLink!
     private final var needsAnimations = false
@@ -368,6 +369,8 @@ open class ListView: ASDisplayNode, UIScrollViewAccessibilityDelegate, UIGesture
         self.transactionQueue = ListViewTransactionQueue()
         
         self.scroller = ListViewScroller()
+
+        self.infiniteScrollSize = 10000.0
         
         super.init()
         
@@ -837,13 +840,7 @@ open class ListView: ASDisplayNode, UIScrollViewAccessibilityDelegate, UIGesture
                 print("Scrolling delta: \(delta)")
             }
         }
-        self.previousDidScrollTimestamp = timestamp
-
-        if let displayLink = self.scroller.getIvarValue("_scrollHeartbeat") as? CADisplayLink {
-            if #available(iOS 10.0, *) {
-                displayLink.preferredFramesPerSecond = 120
-            }
-        }*/
+        self.previousDidScrollTimestamp = timestamp*/
             
         //CATransaction.begin()
         //CATransaction.setDisableActions(true)
@@ -871,7 +868,7 @@ open class ListView: ASDisplayNode, UIScrollViewAccessibilityDelegate, UIGesture
             self.trackingOffset += -deltaY
         }
         
-        self.enqueueUpdateVisibleItems(synchronous: true)
+        self.enqueueUpdateVisibleItems(synchronous: false)
         
         var useScrollDynamics = false
         
@@ -1531,8 +1528,12 @@ open class ListView: ASDisplayNode, UIScrollViewAccessibilityDelegate, UIGesture
         else
         {
             self.scroller.contentSize = CGSize(width: self.visibleSize.width, height: infiniteScrollSize * 2.0)
-            self.lastContentOffset = CGPoint(x: 0.0, y: infiniteScrollSize)
-            self.scroller.contentOffset = self.lastContentOffset
+            if abs(self.scroller.contentOffset.y - infiniteScrollSize) > infiniteScrollSize / 2.0 {
+                self.lastContentOffset = CGPoint(x: 0.0, y: infiniteScrollSize)
+                self.scroller.contentOffset = self.lastContentOffset
+            } else {
+                self.lastContentOffset = self.scroller.contentOffset
+            }
         }
         self.ignoreScrollingEvents = wasIgnoringScrollingEvents
     }

submodules/ObjCRuntimeUtils/Source/ObjCRuntimeUtils/RuntimeUtils.m

@@ -98,6 +98,19 @@
     object_setClass(self, newClass);
 }
 
+- (NSNumber * _Nullable)floatValueForKeyPath:(NSString * _Nonnull)keyPath {
+    id value = [self valueForKeyPath:keyPath];
+    if (value != nil) {
+        if ([value respondsToSelector:@selector(floatValue)]) {
+            return @([value floatValue]);
+        } else {
+            return nil;
+        }
+    } else {
+        return nil;
+    }
+}
+
 + (NSArray<NSString *> * _Nonnull)getIvarList:(Class _Nonnull)classValue {
     NSMutableArray<NSString *> *result = [[NSMutableArray alloc] init];