From 1885e14b0dfe7f7026de986aa807fd695d9c3c3f Mon Sep 17 00:00:00 2001
From: Bruno Van de Velde <vdv_b@tgui.eu>
Date: Sun, 22 Sep 2024 18:48:44 +0200
Subject: [PATCH] Layout with ratio can now also be created with RelativeValue
 object as alternative to a string containing a percentage

---
 include/TGUI/AbsoluteOrRelativeValue.hpp |  4 +++
 include/TGUI/Layout.hpp                  | 10 +++++++
 src/Layout.cpp                           |  9 +++++++
 tests/Layouts.cpp                        | 34 ++++++++++++++++++++++++
 4 files changed, 57 insertions(+)

diff --git a/include/TGUI/AbsoluteOrRelativeValue.hpp b/include/TGUI/AbsoluteOrRelativeValue.hpp
index 700cb9ac2..6a7ca147d 100644
--- a/include/TGUI/AbsoluteOrRelativeValue.hpp
+++ b/include/TGUI/AbsoluteOrRelativeValue.hpp
@@ -164,6 +164,10 @@ TGUI_MODULE_EXPORT namespace tgui
     /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     struct TGUI_API RelativeValue : AbsoluteOrRelativeValue
     {
+        /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+        /// @brief Default constructor that sets the given ratio
+        /// @param ratio  Ratio of the value relative to its parent size
+        /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
         explicit constexpr RelativeValue(float ratio)
         {
             m_constant = false;
diff --git a/include/TGUI/Layout.hpp b/include/TGUI/Layout.hpp
index ac3343024..0f41afbe3 100644
--- a/include/TGUI/Layout.hpp
+++ b/include/TGUI/Layout.hpp
@@ -27,6 +27,7 @@
 
 #include <TGUI/Config.hpp>
 #include <TGUI/Vector2.hpp>
+#include <TGUI/AbsoluteOrRelativeValue.hpp>
 
 #if !TGUI_EXPERIMENTAL_USE_STD_MODULE
     #include <type_traits>
@@ -141,6 +142,15 @@ TGUI_MODULE_EXPORT namespace tgui
         {
         }
 
+        /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+        /// @brief Constructs the layout from a ratio relative to the parent size
+        ///
+        /// @param ratio  Ratio to the size of the parent widget
+        ///
+        /// Layout(RelativeValue(0.3f)) is equivalent to Layout("30%")
+        /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+        Layout(RelativeValue ratio);
+
         /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
         /// @brief Constructs the layout based on a string which will be parsed to determine the value of the layout
         ///
diff --git a/src/Layout.cpp b/src/Layout.cpp
index b35cd8dc8..d58d9b368 100644
--- a/src/Layout.cpp
+++ b/src/Layout.cpp
@@ -60,6 +60,15 @@ namespace tgui
 
     /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
+    Layout::Layout(RelativeValue ratio) :
+        Layout{Layout::Operation::Multiplies,
+               std::make_unique<Layout>(ratio.getRatio()),
+               std::make_unique<Layout>(U"&.innersize")}
+    {
+    }
+
+    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
     Layout::Layout(String expression)
     {
         // Empty strings have value 0 (although this might indicate a mistake in the expression, it is valid for unary minus,
diff --git a/tests/Layouts.cpp b/tests/Layouts.cpp
index f759c7162..a93ed70c3 100644
--- a/tests/Layouts.cpp
+++ b/tests/Layouts.cpp
@@ -85,6 +85,40 @@ TEST_CASE("[Layouts]")
 
     SECTION("without strings")
     {
+        SECTION("relative values")
+        {
+            Layout layout{tgui::RelativeValue(1)};
+            REQUIRE(layout.toString() == "100%");
+
+            Layout layout2{tgui::RelativeValue(0.5f)};
+            REQUIRE(layout2.toString() == "50%");
+
+            REQUIRE(!layout.isConstant());
+
+            auto button = std::make_shared<tgui::Button>();
+            button->setPosition({tgui::RelativeValue(0.4f), tgui::RelativeValue(0.3f)});
+            button->setSize({tgui::RelativeValue(0.2f), tgui::RelativeValue(0.1f)});
+
+            REQUIRE(button->getSize() == tgui::Vector2f(0, 0));
+            REQUIRE(button->getPosition() == tgui::Vector2f(0, 0));
+
+            auto panel = std::make_shared<tgui::Panel>();
+            panel->setSize(400, 300);
+            panel->add(button);
+
+            REQUIRE(button->getSize() == tgui::Vector2f(80, 30));
+            REQUIRE(button->getPosition() == tgui::Vector2f(160, 90));
+
+            SECTION("Inner size is used")
+            {
+                panel->getRenderer()->setBorders({5, 10, 15, 20});
+                panel->getRenderer()->setPadding({25, 30, 35, 40});
+
+                REQUIRE(button->getSize() == tgui::Vector2f(0.2f * (400 - 5 - 15 - 25 - 35), 0.1f * (300 - 10 - 20 - 30 - 40)));
+                REQUIRE(button->getPosition() == tgui::Vector2f(0.4f * (400 - 5 - 15 - 25 - 35), 0.3f * (300 - 10 - 20 - 30 - 40)));
+            }
+        }
+
         SECTION("operators")
         {
             Layout l1{2};