From f2939253b1934bdfbaff5590282e552644148823 Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Mon, 1 Nov 2021 13:39:37 +0100
Subject: [PATCH] Skip unnecessary area updates for elements with dirty parents

---
 CHANGELOG.md                | 1 +
 MLEM.Ui/Elements/Element.cs | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b435f63..5d36f01 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,7 @@ Improvements
 - Added style properties for a lot of hardcoded default element styles
 - Allow style properties to set style values with a higher priority, which allows elements to style their default children
 - Allow changing the entire ui style for a single element
+- Skip unnecessary area updates for elements with dirty parents
 
 Fixes
 - Fixed VerticalSpace height parameter being an integer
diff --git a/MLEM.Ui/Elements/Element.cs b/MLEM.Ui/Elements/Element.cs
index 19bfa3a..c468aaa 100644
--- a/MLEM.Ui/Elements/Element.cs
+++ b/MLEM.Ui/Elements/Element.cs
@@ -531,6 +531,12 @@ namespace MLEM.Ui.Elements {
             this.areaDirty = false;
             if (this.IsHidden)
                 return;
+            // if the parent's area is dirty, it would get updated anyway when querying its ChildPaddedArea,
+            // which would cause our ForceUpdateArea code to be run twice, so we only update our parent instead
+            if (this.Parent != null && this.Parent.areaDirty) {
+                this.Parent.ForceUpdateArea();
+                return;
+            }
 
             var parentArea = this.Parent != null ? this.Parent.ChildPaddedArea : (RectangleF) this.system.Viewport;
             var parentCenterX = parentArea.X + parentArea.Width / 2;