Tinkering with transitions more.

include/ui/ControlGuide.hpp

@@ -0,0 +1,51 @@
+#pragma once
+#include "sdl.hpp"
+#include "ui/Element.hpp"
+#include "ui/Transition.hpp"
+
+namespace ui
+{
+    class ControlGuide final : public ui::Element
+    {
+        public:
+            /// @brief Creates a new control guide.
+            /// @param string Pointer to the control guide string to render.
+            ControlGuide(const char *guide);
+
+            static inline std::shared_ptr<ControlGuide> create(const char *guide)
+            {
+                return std::make_shared<ControlGuide>(guide);
+            }
+
+            /// @brief Update routine. Opens the guide.
+            void update(bool hasFocus) override;
+
+            /// @brief Sub update routine. Handles hiding the control guide.
+            void sub_update();
+
+            /// @brief Renders the control guide. Both arguments are ignored in this case.
+            void render(sdl::SharedTexture &target, bool hasFocus) override;
+
+        private:
+            /// @brief Stores the pointer to the guide string.
+            const char *m_guide{};
+
+            /// @brief Width of the control guide text.
+            int m_textWidth{};
+
+            /// @brief This stores the target X coordinate of the guide.
+            int m_targetX{};
+
+            /// @brief Width of the guide.
+            int m_guideWidth{};
+
+            /// @brief Transition for the guide string.
+            ui::Transition m_transition{};
+
+            /// @brief This is shared by all instances.
+            static inline sdl::SharedTexture sm_controlCap{};
+
+            /// @brief Ensures the control guide cap is loaded for all instances.
+            void initialize_static_members();
+    };
+}