LibWeb: Allow HTMLObjectElement to convert a Resource to ImageResource

HTMLObjectElement, when implemented according to the spec, does not know
the resource type specified by the 'data' attribute until after it has
actually loaded (i.e. it may be an image, XML document, etc.). Currently
we always use ImageLoader within HTMLObjectElement to load the object,
but will need to use ResourceLoader instead to generically load data.

However, ImageLoader / ImageResource have image-specific functionality
that HTMLObjectElement still needs if the resource turns out to be an
image. This patch will allow (only) HTMLObjectElement to convert the
generic Resource to an ImageResource as needed.

Userland/Libraries/LibWeb/Loader/ImageLoader.cpp

@@ -20,6 +20,12 @@ ImageLoader::ImageLoader(DOM::Element& owner_element)
 {
 }
 
+void ImageLoader::adopt_object_resource(Badge<HTML::HTMLObjectElement>, Resource& resource)
+{
+    auto image_resource = ImageResource::convert_from_resource(resource);
+    set_resource(image_resource);
+}
+
 void ImageLoader::load(const AK::URL& url)
 {
     m_redirects_count = 0;

Userland/Libraries/LibWeb/Loader/ImageLoader.h

@@ -16,6 +16,8 @@ class ImageLoader : public ImageResourceClient {
 public:
     ImageLoader(DOM::Element& owner_element);
 
+    void adopt_object_resource(Badge<HTML::HTMLObjectElement>, Resource&);
+
     void load(const AK::URL&);
 
     const Gfx::Bitmap* bitmap(size_t index) const;

Userland/Libraries/LibWeb/Loader/ImageResource.cpp

@@ -10,11 +10,21 @@
 
 namespace Web {
 
+NonnullRefPtr<ImageResource> ImageResource::convert_from_resource(Resource& resource)
+{
+    return adopt_ref(*new ImageResource(resource));
+}
+
 ImageResource::ImageResource(const LoadRequest& request)
     : Resource(Type::Image, request)
 {
 }
 
+ImageResource::ImageResource(Resource& resource)
+    : Resource(Type::Image, resource)
+{
+}
+
 ImageResource::~ImageResource() = default;
 
 int ImageResource::frame_duration(size_t frame_index) const

Userland/Libraries/LibWeb/Loader/ImageResource.h

@@ -14,6 +14,8 @@ class ImageResource final : public Resource {
     friend class Resource;
 
 public:
+    static NonnullRefPtr<ImageResource> convert_from_resource(Resource&);
+
     virtual ~ImageResource() override;
 
     struct Frame {
@@ -43,6 +45,7 @@ public:
 
 private:
     explicit ImageResource(const LoadRequest&);
+    explicit ImageResource(Resource&);
 
     void decode_if_needed() const;
 

Userland/Libraries/LibWeb/Loader/Resource.cpp

@@ -27,6 +27,20 @@ Resource::Resource(Type type, const LoadRequest& request)
 {
 }
 
+Resource::Resource(Type type, Resource& resource)
+    : m_request(resource.m_request)
+    , m_encoded_data(move(resource.m_encoded_data))
+    , m_type(type)
+    , m_loaded(resource.m_loaded)
+    , m_failed(resource.m_failed)
+    , m_error(move(resource.m_error))
+    , m_encoding(move(resource.m_encoding))
+    , m_mime_type(move(resource.m_mime_type))
+    , m_response_headers(move(resource.m_response_headers))
+    , m_status_code(move(resource.m_status_code))
+{
+}
+
 Resource::~Resource() = default;
 
 void Resource::for_each_client(Function<void(ResourceClient&)> callback)

Userland/Libraries/LibWeb/Loader/Resource.h

@@ -65,6 +65,7 @@ public:
 
 protected:
     explicit Resource(Type, const LoadRequest&);
+    Resource(Type, Resource&);
 
 private:
     LoadRequest m_request;