From 66f4e7fee6b900cc7008cb5ed62f7b30fe425e64 Mon Sep 17 00:00:00 2001
From: Suphon Thanakornpakapong <paphonb@gmail.com>
Date: Tue, 12 Oct 2021 22:54:38 +0700
Subject: [PATCH] Reverse edge effects when dragging in opposite direction

---
 .../components/NestedScrollStretch.kt         | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/lawnchair/src/app/lawnchair/ui/preferences/components/NestedScrollStretch.kt b/lawnchair/src/app/lawnchair/ui/preferences/components/NestedScrollStretch.kt
index bf88598f65..4458c9d4d8 100644
--- a/lawnchair/src/app/lawnchair/ui/preferences/components/NestedScrollStretch.kt
+++ b/lawnchair/src/app/lawnchair/ui/preferences/components/NestedScrollStretch.kt
@@ -81,6 +81,26 @@ private class NestedScrollStretchConnection(context: Context, invalidate: Runnab
     val topEdgeEffect = StretchEdgeEffect(context, invalidate, invalidate)
     val bottomEdgeEffect = StretchEdgeEffect(context, invalidate, invalidate)
 
+    override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
+        val availableY = available.y
+        when {
+            source != NestedScrollSource.Drag || height == 0 -> return Offset.Zero
+            availableY != 0f -> {
+                if (availableY < 0f) {
+                    val consumed = topEdgeEffect.onPullDistance(availableY / height, 0f)
+                    if (topEdgeEffect.distance == 0f) topEdgeEffect.onRelease()
+                    return Offset(0f, consumed * height)
+                }
+                if (availableY > 0f) {
+                    val consumed = bottomEdgeEffect.onPullDistance(-availableY / height, 0f)
+                    if (bottomEdgeEffect.distance == 0f) bottomEdgeEffect.onRelease()
+                    return Offset(0f, -consumed * height)
+                }
+            }
+        }
+        return Offset.Zero
+    }
+
     override fun onPostScroll(
         consumed: Offset,
         available: Offset,
@@ -89,7 +109,7 @@ private class NestedScrollStretchConnection(context: Context, invalidate: Runnab
         val availableY = available.y
         when {
             source != NestedScrollSource.Drag || height == 0 -> return Offset.Zero
-            availableY != 0F -> {
+            availableY != 0f -> {
                 if (availableY > 0f) {
                     topEdgeEffect.onPull(availableY / height)
                 } else {