From 80315e839a014c499402b46bd5a7dd5cfa462c91 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Wed, 6 Apr 2022 17:24:09 +0300
Subject: [PATCH] Add SDL2 cursor capabilities

---
 libs/sdl2/include/psemek/sdl2/cursor.hpp | 26 +++++++
 libs/sdl2/source/cursor.cpp              | 91 ++++++++++++++++++++++++
 2 files changed, 117 insertions(+)
 create mode 100644 libs/sdl2/include/psemek/sdl2/cursor.hpp
 create mode 100644 libs/sdl2/source/cursor.cpp

diff --git a/libs/sdl2/include/psemek/sdl2/cursor.hpp b/libs/sdl2/include/psemek/sdl2/cursor.hpp
new file mode 100644
index 00000000..1b0bf002
--- /dev/null
+++ b/libs/sdl2/include/psemek/sdl2/cursor.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+#include <memory>
+
+namespace psemek::sdl2
+{
+
+	struct cursor;
+
+	struct cursor_provider
+	{
+		virtual cursor const & arrow() const = 0;
+		virtual cursor const & beam() const = 0;
+		virtual cursor const & hand() const = 0;
+
+		virtual ~cursor_provider() {}
+	};
+
+	std::unique_ptr<cursor_provider> system_cursor_provider();
+
+	std::unique_ptr<cursor_provider> set_cursor_provider(std::unique_ptr<cursor_provider> new_provider);
+	cursor_provider const * get_cursor_provider();
+
+	void set_cursor(cursor const & c);
+
+}
diff --git a/libs/sdl2/source/cursor.cpp b/libs/sdl2/source/cursor.cpp
new file mode 100644
index 00000000..77b9631d
--- /dev/null
+++ b/libs/sdl2/source/cursor.cpp
@@ -0,0 +1,91 @@
+#include <psemek/sdl2/cursor.hpp>
+#include <psemek/log/log.hpp>
+
+#include <SDL2/SDL_mouse.h>
+
+#include <memory>
+
+namespace psemek::sdl2
+{
+
+	namespace
+	{
+
+		struct cursor_deleter
+		{
+			void operator() (SDL_Cursor * c) const
+			{
+				SDL_FreeCursor(c);
+			}
+		};
+
+		using cursor_ptr = std::unique_ptr<SDL_Cursor, cursor_deleter>;
+
+	}
+
+	struct cursor
+	{
+		cursor_ptr cursor;
+	};
+
+	namespace
+	{
+
+		SDL_Cursor * create_system_cursor(SDL_SystemCursor id)
+		{
+			auto cursor = SDL_CreateSystemCursor(id);
+			if (!cursor)
+				log::warning() << "Failed to create system cursor: " << SDL_GetError();
+			return cursor;
+		}
+
+		struct system_cursor_provider_impl
+			: cursor_provider
+		{
+			system_cursor_provider_impl()
+			{
+				arrow_.cursor.reset(create_system_cursor(SDL_SYSTEM_CURSOR_ARROW));
+				beam_.cursor.reset(create_system_cursor(SDL_SYSTEM_CURSOR_IBEAM));
+				hand_.cursor.reset(create_system_cursor(SDL_SYSTEM_CURSOR_HAND));
+			}
+
+			cursor const & arrow() const override { return arrow_; }
+			cursor const & beam() const override { return beam_; }
+			cursor const & hand() const override { return hand_; }
+
+		private:
+			cursor arrow_;
+			cursor beam_;
+			cursor hand_;
+		};
+
+	}
+
+	std::unique_ptr<cursor_provider> system_cursor_provider()
+	{
+		return std::make_unique<system_cursor_provider_impl>();
+	}
+
+	static std::unique_ptr<cursor_provider> current_provider;
+
+	std::unique_ptr<cursor_provider> set_cursor_provider(std::unique_ptr<cursor_provider> new_provider)
+	{
+		std::swap(current_provider, new_provider);
+		return new_provider;
+	}
+
+	cursor_provider const * get_cursor_provider()
+	{
+		static system_cursor_provider_impl const fallback;
+		if (!current_provider)
+			return &fallback;
+		return current_provider.get();
+	}
+
+	void set_cursor(cursor const & c)
+	{
+		SDL_SetCursor(c.cursor.get());
+	}
+
+
+}