From ad2784a67eb4436826edbc08a2c4b84e820fa2a2 Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Sun, 6 Feb 2022 21:16:35 +0100
Subject: [PATCH] Automatically update all elements when changing a ui system's
 viewport

---
 CHANGELOG.md        |  1 +
 MLEM.Ui/UiSystem.cs | 14 ++++++++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5cbdb0..56940ba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,7 @@ Improvements
 - Allow setting a default text alignment for paragraphs in UiStyle
 - Made custom values of Element.Style persist when a new ui style is set
 - Update elements less aggressively when changing a ui system's style
+- Automatically update all elements when changing a ui system's viewport
 
 Fixes
 - Fixed paragraph links having incorrect hover locations when using special text alignments
diff --git a/MLEM.Ui/UiSystem.cs b/MLEM.Ui/UiSystem.cs
index 08f2a0c..596861d 100644
--- a/MLEM.Ui/UiSystem.cs
+++ b/MLEM.Ui/UiSystem.cs
@@ -23,9 +23,16 @@ namespace MLEM.Ui {
 
         /// <summary>
         /// The viewport that this ui system is rendering inside of.
-        /// This is automatically updated during <see cref="GameWindow.ClientSizeChanged"/>
+        /// This is automatically updated during <see cref="GameWindow.ClientSizeChanged"/> by default.
         /// </summary>
-        public Rectangle Viewport;
+        public Rectangle Viewport {
+            get => this.viewport;
+            set {
+                this.viewport = value;
+                foreach (var root in this.rootElements)
+                    root.Element.ForceUpdateArea();
+            }
+        }
         /// <summary>
         /// Set this field to true to cause the ui system and all of its elements to automatically scale up or down with greater and lower resolution, respectively.
         /// If this field is true, <see cref="AutoScaleReferenceSize"/> is used as the size that uses default <see cref="GlobalScale"/>
@@ -181,6 +188,7 @@ namespace MLEM.Ui {
         private float globalScale = 1;
         private bool drewEarly;
         private UiStyle style;
+        private Rectangle viewport;
 
         /// <summary>
         /// Creates a new ui system with the given settings.
@@ -228,8 +236,6 @@ namespace MLEM.Ui {
                 this.AutoScaleReferenceSize = this.Viewport.Size;
                 game.Window.ClientSizeChanged += (sender, args) => {
                     this.Viewport = new Rectangle(Point.Zero, game.Window.ClientBounds.Size);
-                    foreach (var root in this.rootElements)
-                        root.Element.ForceUpdateArea();
                 };
             }