From 0885a7e155653acbbc1b15eff590feabbb6f00d9 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 19 Dec 2014 05:24:52 +0200
Subject: [PATCH] Add a helper class for registering image loaders

---
 source/graphics/devil/devilloader.cpp   |  2 --
 source/graphics/devil/devilloader.h     |  4 +--
 source/graphics/imageloader.h           | 34 +++++++++++++++++--------
 source/graphics/jpeg/jpegloader.cpp     |  2 --
 source/graphics/jpeg/jpegloader.h       |  4 +--
 source/graphics/png/pngloader.cpp       |  1 -
 source/graphics/png/pngloader.h         |  4 +--
 source/graphics/quartz/quartzloader.cpp |  2 --
 source/graphics/quartz/quartzloader.h   |  4 +--
 9 files changed, 27 insertions(+), 30 deletions(-)

diff --git a/source/graphics/devil/devilloader.cpp b/source/graphics/devil/devilloader.cpp
index 131b6ba..ab962d1 100644
--- a/source/graphics/devil/devilloader.cpp
+++ b/source/graphics/devil/devilloader.cpp
@@ -74,8 +74,6 @@ std::string error_string(ILenum err)
 namespace Msp {
 namespace Graphics {
 
-ImageLoader::Register<DevilLoader> DevilLoader::reg;
-
 DevilLoader::DevilLoader(IO::Seekable &i):
 	io(i)
 {
diff --git a/source/graphics/devil/devilloader.h b/source/graphics/devil/devilloader.h
index daab2a2..e94a31b 100644
--- a/source/graphics/devil/devilloader.h
+++ b/source/graphics/devil/devilloader.h
@@ -6,14 +6,12 @@
 namespace Msp {
 namespace Graphics {
 
-class DevilLoader: public ImageLoader
+class DevilLoader: public RegisteredImageLoader<DevilLoader>
 {
 private:
 	IO::Base &io;
 	unsigned id;
 
-	static Register<DevilLoader> reg;
-
 public:
 	DevilLoader(IO::Seekable &);
 	virtual ~DevilLoader();
diff --git a/source/graphics/imageloader.h b/source/graphics/imageloader.h
index c06a759..85e6b52 100644
--- a/source/graphics/imageloader.h
+++ b/source/graphics/imageloader.h
@@ -23,7 +23,7 @@ public:
 
 class ImageLoader
 {
-private:
+protected:
 	class RegisterBase
 	{
 	protected:
@@ -36,16 +36,6 @@ private:
 		virtual ImageLoader *create(IO::Seekable &) const = 0;
 	};
 
-protected:
-	template<typename T>
-	class Register: RegisterBase
-	{
-	public:
-		virtual unsigned get_signature_size() const { return T::get_signature_size(); }
-		virtual bool detect(const std::string &s) const { return T::detect(s); }
-		virtual T *create(IO::Seekable &io) const { return new T(io); }
-	};
-
 private:
 	IO::Base *source;
 
@@ -64,6 +54,28 @@ public:
 	virtual void load(Image::Data &) = 0;
 };
 
+
+template<typename T>
+class RegisteredImageLoader: public ImageLoader
+{
+private:
+	class Register: public RegisterBase
+	{
+	public:
+		virtual unsigned get_signature_size() const { return T::get_signature_size(); }
+		virtual bool detect(const std::string &s) const { return T::detect(s); }
+		virtual ImageLoader *create(IO::Seekable &io) const { return new T(io); }
+	};
+
+	static Register reg;
+
+protected:
+	RegisteredImageLoader() { (void)reg; }
+};
+
+template<typename T>
+typename RegisteredImageLoader<T>::Register RegisteredImageLoader<T>::reg;
+
 } // namespace Graphics
 } // namespace Msp
 
diff --git a/source/graphics/jpeg/jpegloader.cpp b/source/graphics/jpeg/jpegloader.cpp
index 9aadcb9..844446c 100644
--- a/source/graphics/jpeg/jpegloader.cpp
+++ b/source/graphics/jpeg/jpegloader.cpp
@@ -84,8 +84,6 @@ struct JpegLoader::Private
 };
 
 
-ImageLoader::Register<JpegLoader> JpegLoader::reg;
-
 JpegLoader::JpegLoader(IO::Seekable &io):
 	priv(new Private)
 {
diff --git a/source/graphics/jpeg/jpegloader.h b/source/graphics/jpeg/jpegloader.h
index d45e599..b93d5bc 100644
--- a/source/graphics/jpeg/jpegloader.h
+++ b/source/graphics/jpeg/jpegloader.h
@@ -6,15 +6,13 @@
 namespace Msp {
 namespace Graphics {
 
-class JpegLoader: public ImageLoader
+class JpegLoader: public RegisteredImageLoader<JpegLoader>
 {
 private:
 	struct Private;
 
 	Private *priv;
 
-	static Register<JpegLoader> reg;
-
 public:
 	JpegLoader(IO::Seekable &);
 	virtual ~JpegLoader();
diff --git a/source/graphics/png/pngloader.cpp b/source/graphics/png/pngloader.cpp
index 35e6a97..ede91b0 100644
--- a/source/graphics/png/pngloader.cpp
+++ b/source/graphics/png/pngloader.cpp
@@ -31,7 +31,6 @@ struct PngLoader::Private
 	png_info *info;
 };
 
-ImageLoader::Register<PngLoader> PngLoader::reg;
 
 PngLoader::PngLoader(IO::Base &io, unsigned sig_bytes):
 	priv(new Private)
diff --git a/source/graphics/png/pngloader.h b/source/graphics/png/pngloader.h
index 683f4d3..de8b535 100644
--- a/source/graphics/png/pngloader.h
+++ b/source/graphics/png/pngloader.h
@@ -6,15 +6,13 @@
 namespace Msp {
 namespace Graphics {
 
-class PngLoader: public ImageLoader
+class PngLoader: public RegisteredImageLoader<PngLoader>
 {
 private:
 	struct Private;
 
 	Private *priv;
 
-	static Register<PngLoader> reg;
-
 public:
 	PngLoader(IO::Base &, unsigned = 0);
 	virtual ~PngLoader();
diff --git a/source/graphics/quartz/quartzloader.cpp b/source/graphics/quartz/quartzloader.cpp
index d1baaef..2821190 100644
--- a/source/graphics/quartz/quartzloader.cpp
+++ b/source/graphics/quartz/quartzloader.cpp
@@ -55,8 +55,6 @@ struct QuartzLoader::Private
 };
 
 
-ImageLoader::Register<QuartzLoader> QuartzLoader::reg;
-
 QuartzLoader::QuartzLoader(IO::Seekable &io):
 	priv(new Private)
 {
diff --git a/source/graphics/quartz/quartzloader.h b/source/graphics/quartz/quartzloader.h
index d3bef7b..963e45c 100644
--- a/source/graphics/quartz/quartzloader.h
+++ b/source/graphics/quartz/quartzloader.h
@@ -6,15 +6,13 @@
 namespace Msp {
 namespace Graphics {
 
-class QuartzLoader: public ImageLoader
+class QuartzLoader: public RegisteredImageLoader<QuartzLoader>
 {
 private:
 	struct Private;
 
 	Private *priv;
 
-	static Register<QuartzLoader> reg;
-
 public:
 	QuartzLoader(IO::Seekable &);
 	virtual ~QuartzLoader();
-- 
2.43.0