ImageIO provider: Retrieve supported image sources file extensions during runtime (#8623)

* ImageIO provider: Get supported sources file extensions during runtime

* Remove visionOS as is not available on older XCode versions. * will be enough as this API is supported from visionOS 1.0 onwards

kivy/core/image/img_imageio.pyx

@@ -1,3 +1,5 @@
+# distutils: language = c++
+
 '''
 ImageIO OSX framework
 =====================
@@ -140,6 +142,16 @@ cdef extern from "Accelerate/Accelerate.h" nogil:
             int flags)
 
 
+cdef extern from "img_imageio_implem.mm":
+    cppclass KivyImageIOProviderSupportedExtensionList:
+        int count()
+        char* get(int index)
+
+    cppclass KivyImageIOProvider:
+        KivyImageIOProvider()
+        KivyImageIOProviderSupportedExtensionList* supported_source_image_extensions
+
+
 def load_image_data(bytes _url, bytes _data=None):
     cdef size_t width, height
     cdef char *r_data = NULL
@@ -310,19 +322,36 @@ def save_image(filenm, width, height, fmt, data, flipped):
     free(pixels)
 
 
+
+cdef class _ImageIOInterface:
+    cdef KivyImageIOProvider* _provider
+
+    def __cinit__(self):
+        self._provider = new KivyImageIOProvider()
+
+    def __dealloc__(self):
+        del self._provider
+
+    cdef list get_supported_source_extensions(self):
+        cdef list ret = []
+        for i in range(self._provider.supported_source_image_extensions.count()):
+            ret.append(self._provider.supported_source_image_extensions.get(i).decode('utf-8'))
+        return ret
+
+# A list of the supported source extensions is served by the static method
+# extensions() of the ImageLoaderImageIO class.
+# To avoid the creation of a new _ImageIOInterface object each time we need to
+# get the list of supported extensions, we create a single use object and get
+# the list of supported extensions at the module level.
+cdef list _supported_source_extensions = _ImageIOInterface().get_supported_source_extensions()
+
 class ImageLoaderImageIO(ImageLoaderBase):
     '''Image loader based on ImageIO OS X Framework
     '''
 
     @staticmethod
     def extensions():
-        # FIXME check which one are available on osx
-        return ('bmp', 'bufr', 'cur', 'dcx', 'fits', 'fl', 'fpx', 'gbr',
-                'gd', 'grib', 'hdf5', 'ico', 'im', 'imt', 'iptc',
-                'jpeg', 'jpg', 'jpe', 'mcidas', 'mic', 'mpeg', 'msp',
-                'pcd', 'pcx', 'pixar', 'png', 'ppm', 'psd', 'sgi',
-                'spider', 'tga', 'tiff', 'wal', 'wmf', 'xbm', 'xpm',
-                'xv', 'icns')
+        return _supported_source_extensions
 
     def load(self, filename):
         # FIXME: if the filename is unicode, the loader is failing.

kivy/core/image/img_imageio_implem.h

@@ -0,0 +1,23 @@
+#include <Foundation/Foundation.h>
+#include <UniformTypeIdentifiers/UniformTypeIdentifiers.h>
+
+class KivyImageIOProviderSupportedExtensionList {
+    public:
+        KivyImageIOProviderSupportedExtensionList();
+        ~KivyImageIOProviderSupportedExtensionList();
+        void add(NSString* extension);
+        char* get(int index);
+        int count();
+        void clear();
+    private:
+        NSMutableArray* extensions;
+};
+
+class KivyImageIOProvider {
+    public:
+        KivyImageIOProvider();
+        ~KivyImageIOProvider();
+        KivyImageIOProviderSupportedExtensionList* supported_source_image_extensions;
+    private:
+        void load_supported_source_extensions();
+};

kivy/core/image/img_imageio_implem.mm

@@ -0,0 +1,84 @@
+#include "img_imageio_implem.h"
+
+/*
+* KivyImageIOProviderSupportedExtensionList
+*/
+
+KivyImageIOProviderSupportedExtensionList::KivyImageIOProviderSupportedExtensionList()
+{
+    this->extensions = [[NSMutableArray alloc] init];
+}
+
+KivyImageIOProviderSupportedExtensionList::~KivyImageIOProviderSupportedExtensionList()
+{
+}
+
+void KivyImageIOProviderSupportedExtensionList::add(NSString *extension)
+{
+    if (![this->extensions containsObject:extension])
+    {
+        [this->extensions addObject:extension];
+    }
+}
+
+int KivyImageIOProviderSupportedExtensionList::count()
+{
+    return [this->extensions count];
+}
+
+char *KivyImageIOProviderSupportedExtensionList::get(int index)
+{
+    NSString *extension = [this->extensions objectAtIndex:index];
+    return (char *)[extension UTF8String];
+}
+
+void KivyImageIOProviderSupportedExtensionList::clear()
+{
+    [this->extensions removeAllObjects];
+}
+
+/*
+* KivyImageIOProvider
+*/
+
+KivyImageIOProvider::KivyImageIOProvider()
+{
+    this->supported_source_image_extensions = new KivyImageIOProviderSupportedExtensionList();
+    this->load_supported_source_extensions();
+}
+
+KivyImageIOProvider::~KivyImageIOProvider()
+{
+    delete this->supported_source_image_extensions;
+}
+
+void KivyImageIOProvider::load_supported_source_extensions()
+{
+    this->supported_source_image_extensions->clear();
+
+    CFArrayRef type_identifiers = CGImageSourceCopyTypeIdentifiers();
+
+    for (CFIndex i = 0; i < CFArrayGetCount(type_identifiers); i++)
+    {
+        CFStringRef uti = (CFStringRef)CFArrayGetValueAtIndex(type_identifiers, i);
+        NSArray *uti_extensions;
+
+        if (@available(macOS 11.0, iOS 14.0, tvOS 14.0, watchOS 7.0, *))
+        {
+            UTType *uttype = [UTType typeWithIdentifier:(NSString *)uti];
+            uti_extensions = uttype.tags[@"public.filename-extension"];
+        }
+        else
+        {
+            // UTTypeCopyAllTagsWithClass is deprecated, we're leaving this here
+            // for compatibility with older versions of macOS and iOS
+            uti_extensions = CFBridgingRelease(
+                UTTypeCopyAllTagsWithClass(uti, kUTTagClassFilenameExtension));
+        }
+
+        for (NSString *extension in uti_extensions)
+        {
+            this->supported_source_image_extensions->add(extension);
+        }
+    }
+}

setup.py

@@ -974,6 +974,7 @@ if platform in ('darwin', 'ios'):
     else:
         osx_flags = {'extra_link_args': [
             '-framework', 'ApplicationServices']}
+    osx_flags['extra_compile_args'] = ['-ObjC++']
     sources['core/image/img_imageio.pyx'] = merge(
         base_flags, osx_flags)