From e8997e1de9448aecf6e3ef44d9928738a8a54465 Mon Sep 17 00:00:00 2001
From: Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
Date: Sat, 23 Jan 2021 01:16:06 +0100
Subject: [PATCH] LibGfx: Implement Rect resizing around a fixed point

---
 Userland/Libraries/LibGfx/Rect.cpp | 10 ++++++++++
 Userland/Libraries/LibGfx/Rect.h   |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/Userland/Libraries/LibGfx/Rect.cpp b/Userland/Libraries/LibGfx/Rect.cpp
index 1f0d39d440..0a9ce4fc3b 100644
--- a/Userland/Libraries/LibGfx/Rect.cpp
+++ b/Userland/Libraries/LibGfx/Rect.cpp
@@ -141,6 +141,16 @@ void Rect<T>::align_within(const Rect<T>& other, TextAlignment alignment)
     }
 }
 
+template<typename T>
+void Rect<T>::set_size_around(const Size<T>& new_size, const Point<T>& fixed_point)
+{
+    const T new_x = fixed_point.x() - (T)(new_size.width() * ((float)(fixed_point.x() - x()) / width()));
+    const T new_y = fixed_point.y() - (T)(new_size.height() * ((float)(fixed_point.y() - y()) / height()));
+
+    set_location({ new_x, new_y });
+    set_size(new_size);
+}
+
 template<>
 String IntRect::to_string() const
 {
diff --git a/Userland/Libraries/LibGfx/Rect.h b/Userland/Libraries/LibGfx/Rect.h
index e9ad4b136e..a6997a4bc6 100644
--- a/Userland/Libraries/LibGfx/Rect.h
+++ b/Userland/Libraries/LibGfx/Rect.h
@@ -114,6 +114,8 @@ public:
         m_size = size;
     }
 
+    void set_size_around(const Size<T>&, const Point<T>& fixed_point);
+
     void set_size(T width, T height)
     {
         m_size.set_width(width);