From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 7 Feb 2021 14:36:12 +0000 (+0200)
Subject: Add some state checking to ImageLoader
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=2ebdf45974a0a7649b3488f9da4b8cf90a1db584;p=libs%2Fgui.git

Add some state checking to ImageLoader

Reject attemps to call load again on the same loader
---

diff --git a/source/graphics/bmploader.cpp b/source/graphics/bmploader.cpp
index f711dc1..39629f7 100644
--- a/source/graphics/bmploader.cpp
+++ b/source/graphics/bmploader.cpp
@@ -44,7 +44,7 @@ bool BmpLoader::detect(const std::string &sig)
 	return !sig.compare(0, sizeof(bmp_sig), bmp_sig, sizeof(bmp_sig));
 }
 
-void BmpLoader::load(Image::Data &data)
+void BmpLoader::load_(Image::Data &data)
 {
 	char bm_header[14];
 	read_full(io, bm_header+sig_bytes, sizeof(bm_header)-sig_bytes);
diff --git a/source/graphics/bmploader.h b/source/graphics/bmploader.h
index 273e104..9ae8f4e 100644
--- a/source/graphics/bmploader.h
+++ b/source/graphics/bmploader.h
@@ -18,7 +18,7 @@ public:
 	static unsigned get_signature_size() { return 2; }
 	static bool detect(const std::string &);
 
-	virtual void load(Image::Data &);
+	virtual void load_(Image::Data &);
 };
 
 } // namespace Graphics
diff --git a/source/graphics/devil/devilloader.cpp b/source/graphics/devil/devilloader.cpp
index e837154..423b108 100644
--- a/source/graphics/devil/devilloader.cpp
+++ b/source/graphics/devil/devilloader.cpp
@@ -101,7 +101,7 @@ bool DevilLoader::detect(const string &sig)
 	return type!=IL_TYPE_UNKNOWN;
 }
 
-void DevilLoader::load(Image::Data &data)
+void DevilLoader::load_(Image::Data &data)
 {
 	ilSetRead(0, 0, eof, get, read, seek, tell);
 	ilBindImage(id);
diff --git a/source/graphics/devil/devilloader.h b/source/graphics/devil/devilloader.h
index 42ac2b2..3cba0d5 100644
--- a/source/graphics/devil/devilloader.h
+++ b/source/graphics/devil/devilloader.h
@@ -19,7 +19,7 @@ public:
 	static unsigned get_signature_size() { return 128; }
 	static bool detect(const std::string &);
 
-	virtual void load(Image::Data &);
+	virtual void load_(Image::Data &);
 };
 
 } // namespace Graphics
diff --git a/source/graphics/imageloader.cpp b/source/graphics/imageloader.cpp
index b2a126e..2c6ce21 100644
--- a/source/graphics/imageloader.cpp
+++ b/source/graphics/imageloader.cpp
@@ -22,7 +22,8 @@ namespace Msp {
 namespace Graphics {
 
 ImageLoader::ImageLoader():
-	source(0)
+	source(0),
+	state(INITIAL)
 { }
 
 ImageLoader::~ImageLoader()
@@ -83,6 +84,15 @@ ImageLoader *ImageLoader::open_io(IO::Seekable &io)
 	return loader;
 }
 
+void ImageLoader::load(Image::Data &data)
+{
+	if(state>=FINISHED)
+		throw logic_error("already loaded");
+
+	load_(data);
+	state = FINISHED;
+}
+
 ImageLoader::Registry &ImageLoader::get_registry()
 {
 	static Registry registry;
diff --git a/source/graphics/imageloader.h b/source/graphics/imageloader.h
index 9dc1726..cb3f54a 100644
--- a/source/graphics/imageloader.h
+++ b/source/graphics/imageloader.h
@@ -23,6 +23,13 @@ public:
 
 class ImageLoader
 {
+public:
+	enum State
+	{
+		INITIAL,
+		FINISHED
+	};
+
 protected:
 	class RegisterBase
 	{
@@ -56,6 +63,7 @@ protected:
 
 private:
 	IO::Base *source;
+	State state;
 
 protected:
 	ImageLoader();
@@ -65,7 +73,12 @@ public:
 	static ImageLoader *open_file(const std::string &);
 	static ImageLoader *open_io(IO::Seekable &);
 
-	virtual void load(Image::Data &) = 0;
+	virtual void load(Image::Data &);
+protected:
+	virtual void load_(Image::Data &) = 0;
+
+public:
+	State get_state() const { return state; }
 
 	template<typename T>
 	static void register_loader();
diff --git a/source/graphics/jpeg/jpegloader.cpp b/source/graphics/jpeg/jpegloader.cpp
index 9b7150d..f61f651 100644
--- a/source/graphics/jpeg/jpegloader.cpp
+++ b/source/graphics/jpeg/jpegloader.cpp
@@ -119,7 +119,7 @@ bool JpegLoader::detect(const string &sig)
 	return !sig.compare(0, sizeof(jpeg_sig), jpeg_sig, sizeof(jpeg_sig));
 }
 
-void JpegLoader::load(Image::Data &data)
+void JpegLoader::load_(Image::Data &data)
 {
 	if(setjmp(priv->err_mgr.jmp))
 		throw bad_image_data(priv->err_mgr.message);
diff --git a/source/graphics/jpeg/jpegloader.h b/source/graphics/jpeg/jpegloader.h
index 04e8917..bf902d6 100644
--- a/source/graphics/jpeg/jpegloader.h
+++ b/source/graphics/jpeg/jpegloader.h
@@ -20,7 +20,7 @@ public:
 	static unsigned get_signature_size() { return 3; }
 	static bool detect(const std::string &);
 
-	virtual void load(Image::Data &);
+	virtual void load_(Image::Data &);
 };
 
 } // namespace Graphics
diff --git a/source/graphics/png/pngloader.cpp b/source/graphics/png/pngloader.cpp
index 537dcc1..16ad36b 100644
--- a/source/graphics/png/pngloader.cpp
+++ b/source/graphics/png/pngloader.cpp
@@ -54,7 +54,7 @@ bool PngLoader::detect(const std::string &sig)
 	return !png_sig_cmp(reinterpret_cast<png_byte *>(const_cast<char*>(sig.data())), 0, sig.size());
 }
 
-void PngLoader::load(Image::Data &data)
+void PngLoader::load_(Image::Data &data)
 {
 	png_byte **rows = 0;
 
diff --git a/source/graphics/png/pngloader.h b/source/graphics/png/pngloader.h
index 6ed57cc..21c1c72 100644
--- a/source/graphics/png/pngloader.h
+++ b/source/graphics/png/pngloader.h
@@ -20,7 +20,7 @@ public:
 	static unsigned get_signature_size() { return 8; }
 	static bool detect(const std::string &);
 
-	virtual void load(Image::Data &);
+	virtual void load_(Image::Data &);
 };
 
 } // namespace Graphics
diff --git a/source/graphics/quartz/quartzloader.cpp b/source/graphics/quartz/quartzloader.cpp
index 5493e45..472e066 100644
--- a/source/graphics/quartz/quartzloader.cpp
+++ b/source/graphics/quartz/quartzloader.cpp
@@ -81,7 +81,7 @@ bool QuartzLoader::detect(const string &sig)
 	return status==kCGImageStatusIncomplete || status==kCGImageStatusReadingHeader;
 }
 
-void QuartzLoader::load(Image::Data &data)
+void QuartzLoader::load_(Image::Data &data)
 {
 	CGImageRef image = CGImageSourceCreateImageAtIndex(priv->source, 0, 0);
 	if(!image)
diff --git a/source/graphics/quartz/quartzloader.h b/source/graphics/quartz/quartzloader.h
index 4885ff5..cf4a447 100644
--- a/source/graphics/quartz/quartzloader.h
+++ b/source/graphics/quartz/quartzloader.h
@@ -22,7 +22,7 @@ public:
 	static unsigned get_signature_size() { return 12; }
 	static bool detect(const std::string &);
 
-	virtual void load(Image::Data &);
+	virtual void load_(Image::Data &);
 };
 
 } // namespace Graphics