From bf5e8f54d1878ef12d7c25623959d7eb96b57d6a Mon Sep 17 00:00:00 2001
From: unknown <michaelsa@ftlms-z420.eng.citrite.net>
Date: Wed, 16 Mar 2016 12:32:33 -0400
Subject: [PATCH] Add a persist mode that will keep the right / left content
 visible until it is dismissed.

---
 .../SwipeListBehavior.cs                      |  5 ++
 .../SwipeListViewItem.cs                      | 53 +++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/Runtime/Universal.UI.Xaml.Controls/SwipeListBehavior.cs b/Runtime/Universal.UI.Xaml.Controls/SwipeListBehavior.cs
index cff9433..63c0849 100644
--- a/Runtime/Universal.UI.Xaml.Controls/SwipeListBehavior.cs
+++ b/Runtime/Universal.UI.Xaml.Controls/SwipeListBehavior.cs
@@ -18,6 +18,11 @@ public enum SwipeListBehavior
         /// </summary>
         Collapse,
 
+        /// <summary>
+        /// Triggered when swipe reaches 2/5 of the width of the item. Once triggered side menu will continue to stay open, <see cref="SwipeListViewItem"/> state is not restored.
+        /// </summary>
+        Persist,
+
         /// <summary>
         /// Swipe is disabled.
         /// </summary>
diff --git a/Runtime/Universal.UI.Xaml.Controls/SwipeListViewItem.cs b/Runtime/Universal.UI.Xaml.Controls/SwipeListViewItem.cs
index 626b6b8..f48bc5b 100644
--- a/Runtime/Universal.UI.Xaml.Controls/SwipeListViewItem.cs
+++ b/Runtime/Universal.UI.Xaml.Controls/SwipeListViewItem.cs
@@ -229,6 +229,8 @@ protected override void OnManipulationCompleted(ManipulationCompletedRoutedEvent
             {
                 if (LeftBehavior == SwipeListBehavior.Collapse)
                     currentAnim = CollapseAnimation(SwipeListDirection.Left, true);
+                else if (LeftBehavior == SwipeListBehavior.Persist)
+                    currentAnim = PersistAnimation(SwipeListDirection.Left, target);
                 else
                     currentAnim = ExpandAnimation(SwipeListDirection.Left);
             }
@@ -236,6 +238,8 @@ protected override void OnManipulationCompleted(ManipulationCompletedRoutedEvent
             {
                 if (RightBehavior == SwipeListBehavior.Collapse)
                     currentAnim = CollapseAnimation(SwipeListDirection.Right, true);
+                else if (RightBehavior == SwipeListBehavior.Persist)
+                    currentAnim = PersistAnimation(SwipeListDirection.Right, target);
                 else
                     currentAnim = ExpandAnimation(SwipeListDirection.Right);
             }
@@ -329,6 +333,48 @@ private Storyboard ExpandAnimation(SwipeListDirection direction)
             return currentAnim;
         }
 
+
+
+        private Storyboard PersistAnimation(SwipeListDirection direction, double target)
+        {
+            var currentAnim = new Storyboard();
+            if (direction == SwipeListDirection.Left)
+            {
+                var animDrag = CreateDouble(target, 300, ContentDragTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+                var animClip = CreateDouble(target, 300, DragClipTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+                var animLeft = CreateDouble(-LeftContainer.ActualWidth + target, 300, LeftTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+                var animRight = CreateDouble((RightContainer.ActualWidth + target), 300, RightTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+
+                currentAnim.Children.Add(animDrag);
+                currentAnim.Children.Add(animClip);
+                currentAnim.Children.Add(animLeft);
+                currentAnim.Children.Add(animRight);
+            }
+            else if (direction == SwipeListDirection.Right)
+            {
+                var animDrag = CreateDouble(-target, 300, ContentDragTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+                var animClip = CreateDouble(-target, 300, DragClipTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+                var animLeft = CreateDouble(-LeftContainer.ActualWidth - target, 300, LeftTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+                var animRight = CreateDouble((RightContainer.ActualWidth - target), 300, RightTransform, "TranslateTransform.X", new ExponentialEase { EasingMode = EasingMode.EaseOut });
+
+                currentAnim.Children.Add(animDrag);
+                currentAnim.Children.Add(animClip);
+                currentAnim.Children.Add(animLeft);
+                currentAnim.Children.Add(animRight);
+            }
+
+            currentAnim.Completed += (s, args) =>
+            {
+                if (ItemSwipe != null)
+                    ItemSwipe(this, new ItemSwipeEventArgs(Content, direction));
+
+                if (_parent != null)
+                    _parent.RaiseItemSwipe(new ItemSwipeEventArgs(Content, direction));
+            };
+
+            return currentAnim;
+        }
+
         private DoubleAnimation CreateDouble(double to, int duration, DependencyObject target, string path, EasingFunctionBase easing)
         {
             var anim = new DoubleAnimation();
@@ -346,6 +392,13 @@ private DoubleAnimation CreateDouble(double to, int duration, DependencyObject t
             return anim;
         }
 
+
+        public void CollapseSwipeContent()
+        {
+            var animation = CollapseAnimation(SwipeListDirection.Left, false);
+            animation.Begin();
+        }
+
         /// <summary>
         /// Occurs when the item is swiped from left or right.
         /// </summary>