From 70bf73879b335ee85dfdae81dbfa3236f61779c9 Mon Sep 17 00:00:00 2001
From: Owen Mills <owenmills@live.ca>
Date: Thu, 30 Nov 2023 21:52:55 +0000
Subject: [PATCH] #1686: Use parent rect in ghostIsLast & ghostIsFirst

---
 src/Sortable.js | 17 ++++++++++-------
 src/utils.js    | 21 +++++++++++++++++++++
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/Sortable.js b/src/Sortable.js
index 7a8c779b8..8147c97d5 100644
--- a/src/Sortable.js
+++ b/src/Sortable.js
@@ -34,7 +34,8 @@ import {
 	throttle,
 	scrollBy,
 	clone,
-	expando
+	expando,
+	getContentRect
 } from './utils.js';
 
 
@@ -1788,21 +1789,23 @@ function _unsilent() {
 }
 
 function _ghostIsFirst(evt, vertical, sortable) {
-	let rect = getRect(getChild(sortable.el, 0, sortable.options, true));
+	let firstElRect = getRect(getChild(sortable.el, 0, sortable.options, true));
+	const sortableContentRect = getContentRect(sortable.el);
 	const spacer = 10;
 
 	return vertical ?
-		((evt.clientX < rect.left - spacer) || (evt.clientY < rect.top && evt.clientX < rect.right)) :
-		((evt.clientY < rect.top - spacer) || (evt.clientY < rect.bottom && evt.clientX < rect.left))
+		(evt.clientX < sortableContentRect.left - spacer || evt.clientY < firstElRect.top && evt.clientX < firstElRect.right) :
+		(evt.clientY < sortableContentRect.top - spacer || evt.clientY < firstElRect.bottom && evt.clientX < firstElRect.left)
 }
 
 function _ghostIsLast(evt, vertical, sortable) {
-	let rect = getRect(lastChild(sortable.el, sortable.options.draggable));
+	const lastElRect = getRect(lastChild(sortable.el, sortable.options.draggable));
+	const sortableContentRect = getContentRect(sortable.el);
 	const spacer = 10;
 
 	return vertical ?
-		(evt.clientX > rect.right + spacer || evt.clientX <= rect.right && evt.clientY > rect.bottom && evt.clientX >= rect.left) :
-		(evt.clientX > rect.right && evt.clientY > rect.top || evt.clientX <= rect.right && evt.clientY > rect.bottom + spacer);
+		(evt.clientX > sortableContentRect.right + spacer || evt.clientY > lastElRect.bottom && evt.clientX > lastElRect.left) :
+		(evt.clientY > sortableContentRect.bottom + spacer || evt.clientX > lastElRect.right && evt.clientY > lastElRect.top);
 }
 
 function _getSwapDirection(evt, target, targetRect, vertical, swapThreshold, invertedSwapThreshold, invertSwap, isLastTarget) {
diff --git a/src/utils.js b/src/utils.js
index cdb8cc774..b7649629e 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -254,6 +254,26 @@ function getRect(el, relativeToContainingBlock, relativeToNonStaticParent, undoS
 	};
 }
 
+/**
+ * Returns the content rect of the element (bounding rect minus border and padding)
+ * @param {HTMLElement} el 
+ */
+function getContentRect(el) {
+	let rect = getRect(el);
+	const paddingLeft = parseInt(css(el, 'padding-left')),
+		paddingTop = parseInt(css(el, 'padding-top')),
+		paddingRight = parseInt(css(el, 'padding-right')),
+		paddingBottom = parseInt(css(el, 'padding-bottom'));
+	rect.top += paddingTop + parseInt(css(el, 'border-top-width'));
+	rect.left += paddingLeft + parseInt(css(el, 'border-left-width'));
+	// Client Width/Height includes padding only
+	rect.width = el.clientWidth - paddingLeft - paddingRight;
+	rect.height = el.clientHeight - paddingTop - paddingBottom;
+	rect.bottom = rect.top + rect.height;
+	rect.right = rect.left + rect.width;
+	return rect;
+}
+
 /**
  * Checks if a side of an element is scrolled past a side of its parents
  * @param  {HTMLElement}  el           The element who's side being scrolled out of view is in question
@@ -552,5 +572,6 @@ export {
 	clone,
 	setRect,
 	unsetRect,
+	getContentRect,
 	expando
 };