Fixes #37

ensure that we actually need to move it and save out original cords
jamesmontemagno · Feb 2, 2018 · 7c293c3 · 7c293c3
1 parent dc5ba9a
commit 7c293c3
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Showing 2 changed files with 38 additions and 8 deletions.
diff --git a/PullToRefresh/PullToRefresh.iOS/PullToRefreshLayoutRenderer.cs b/PullToRefresh/PullToRefresh.iOS/PullToRefreshLayoutRenderer.cs
@@ -78,26 +78,40 @@ protected override void OnElementChanged (ElementChangedEventArgs<Refractored.Xa
             UpdateIsSwipeToRefreshEnabled();
         }
 
+        bool set;
+        nfloat origininalY;
 
         bool TryOffsetRefresh(UIView view, bool refreshing, int index = 0)
         {
             if (view is UITableView)
             {
                 var uiTableView = view as UITableView;
+                if (!set)
+                {
+                    origininalY = uiTableView.ContentOffset.Y;
+                    set = true;
+                }
+
                 if (refreshing)
-                    uiTableView.SetContentOffset(new CoreGraphics.CGPoint(0, uiTableView.ContentOffset.Y - refreshControl.Frame.Size.Height), true);
+                    uiTableView.SetContentOffset(new CoreGraphics.CGPoint(0, origininalY - refreshControl.Frame.Size.Height), true);
                 else
-                    uiTableView.SetContentOffset(new CoreGraphics.CGPoint(0, uiTableView.ContentOffset.Y + refreshControl.Frame.Size.Height), true);
+                    uiTableView.SetContentOffset(new CoreGraphics.CGPoint(0, origininalY), true);
                 return true;
             }
 
             if (view is UICollectionView)
             {
+
                 var uiCollectionView = view as UICollectionView;
+                if (!set)
+                {
+                    origininalY = uiCollectionView.ContentOffset.Y;
+                    set = true;
+                }
                 if (refreshing)
-                    uiCollectionView.SetContentOffset(new CoreGraphics.CGPoint(0, uiCollectionView.ContentOffset.Y - refreshControl.Frame.Size.Height), true);
+                    uiCollectionView.SetContentOffset(new CoreGraphics.CGPoint(0, origininalY - refreshControl.Frame.Size.Height), true);
                 else
-                    uiCollectionView.SetContentOffset(new CoreGraphics.CGPoint(0, uiCollectionView.ContentOffset.Y + refreshControl.Frame.Size.Height), true);
+                    uiCollectionView.SetContentOffset(new CoreGraphics.CGPoint(0, origininalY), true);
                 return true;
             }
 
@@ -112,10 +126,16 @@ bool TryOffsetRefresh(UIView view, bool refreshing, int index = 0)
             if (view is UIScrollView)
             {
                 var uiScrollView = view as UIScrollView;
+
+                if (!set)
+                {
+                    origininalY = uiScrollView.ContentOffset.Y;
+                    set = true;
+                }
                 if (refreshing)
-                    uiScrollView.SetContentOffset(new CoreGraphics.CGPoint(0, uiScrollView.ContentOffset.Y - refreshControl.Frame.Size.Height), true);
+                    uiScrollView.SetContentOffset(new CoreGraphics.CGPoint(0, origininalY - refreshControl.Frame.Size.Height), true);
                 else
-                    uiScrollView.SetContentOffset(new CoreGraphics.CGPoint(0, uiScrollView.ContentOffset.Y + refreshControl.Frame.Size.Height), true);
+                    uiScrollView.SetContentOffset(new CoreGraphics.CGPoint(0, origininalY), true);
                 return true;
             }
 
@@ -250,14 +270,17 @@ public bool IsRefreshing
         {
             get { return isRefreshing;}
             set
-            { 
+            {
+                bool changed = IsRefreshing != value;
+
                 isRefreshing = value;
                 if (isRefreshing)
                     refreshControl.BeginRefreshing();
                 else
                     refreshControl.EndRefreshing();
 
-                TryOffsetRefresh(this, IsRefreshing);
+                if(changed)
+                    TryOffsetRefresh(this, IsRefreshing);
             }
         }
 

diff --git a/RefreshSample/Views/ScrollViewPageManual.cs b/RefreshSample/Views/ScrollViewPageManual.cs
@@ -29,6 +29,7 @@ public ScrollViewPageManual(bool insideLayout)
             BindingContext = new TestViewModel (this);
             var buttonStart = new Button { Text = "Start" };
             var buttonStop = new Button { Text = "Stop" };
+            var buttonStartStop = new Button { Text = "Start/Stop" };
 
             var grid = new Grid
                 {
@@ -80,6 +81,11 @@ public ScrollViewPageManual(bool insideLayout)
 
             buttonStart.Clicked += (sender, args) => refreshView.IsRefreshing = true;
             buttonStop.Clicked += (sender, args) => refreshView.IsRefreshing = false;
+            buttonStartStop.Clicked += (sender, args) =>
+            {
+                refreshView.IsRefreshing = true;
+                refreshView.IsRefreshing = false;
+            };
 
 
             if (insideLayout)
@@ -100,6 +106,7 @@ public ScrollViewPageManual(bool insideLayout)
                             },
                             buttonStart, 
                             buttonStop,
+                            buttonStartStop,
                             refreshView
                         }
                     };