LibWeb: Start fleshing out HTML "image requests" and "image data"

This patch adds HTML::ImageRequest and HTML::DecodedImageData. The latter had to use a different name than "ImageData", as there is already an IDL-exposed ImageData class in HTML.
2025-06-30 05:32:07 +00:00 · 2023-05-10 19:36:43 +02:00 · 2023-05-10 19:36:43 +02:00 · 596eabe9e6
commit 596eabe9e6
parent 420952a433
6 changed files with 281 additions and 0 deletions
--- a/Userland/Libraries/LibWeb/HTML/ImageRequest.cpp
+++ b/Userland/Libraries/LibWeb/HTML/ImageRequest.cpp
@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2023, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibGfx/Bitmap.h>
+#include <LibWeb/Fetch/Infrastructure/FetchController.h>
+#include <LibWeb/HTML/DecodedImageData.h>
+#include <LibWeb/HTML/ImageRequest.h>
+
+namespace Web::HTML {
+
+ErrorOr<NonnullRefPtr<ImageRequest>> ImageRequest::create()
+{
+    return adopt_nonnull_ref_or_enomem(new (nothrow) ImageRequest);
+}
+
+ImageRequest::ImageRequest() = default;
+
+ImageRequest::~ImageRequest() = default;
+
+// https://html.spec.whatwg.org/multipage/images.html#img-available
+bool ImageRequest::is_available() const
+{
+    // When an image request's state is either partially available or completely available, the image request is said to be available.
+    return m_state == State::PartiallyAvailable || m_state == State::CompletelyAvailable;
+}
+
+ImageRequest::State ImageRequest::state() const
+{
+    return m_state;
+}
+
+void ImageRequest::set_state(State state)
+{
+    m_state = state;
+}
+
+AK::URL const& ImageRequest::current_url() const
+{
+    return m_current_url;
+}
+
+void ImageRequest::set_current_url(AK::URL url)
+{
+    m_current_url = move(url);
+}
+
+// https://html.spec.whatwg.org/multipage/images.html#abort-the-image-request
+void ImageRequest::abort(JS::Realm& realm)
+{
+    // 1. Forget image request's image data, if any.
+    m_image_data = nullptr;
+
+    // 2. Abort any instance of the fetching algorithm for image request,
+    //    discarding any pending tasks generated by that algorithm.
+    if (m_fetch_controller)
+        m_fetch_controller->abort(realm, {});
+
+    m_fetch_controller = nullptr;
+}
+
+RefPtr<DecodedImageData const> ImageRequest::image_data() const
+{
+    return m_image_data;
+}
+
+void ImageRequest::set_image_data(RefPtr<DecodedImageData const> data)
+{
+    m_image_data = move(data);
+}
+
+// https://html.spec.whatwg.org/multipage/images.html#prepare-an-image-for-presentation
+void ImageRequest::prepare_for_presentation(HTMLImageElement&)
+{
+    // FIXME: 1. Let exifTagMap be the EXIF tags obtained from req's image data, as defined by the relevant codec. [EXIF]
+    // FIXME: 2. Let physicalWidth and physicalHeight be the width and height obtained from req's image data, as defined by the relevant codec.
+    // FIXME: 3. Let dimX be the value of exifTagMap's tag 0xA002 (PixelXDimension).
+    // FIXME: 4. Let dimY be the value of exifTagMap's tag 0xA003 (PixelYDimension).
+    // FIXME: 5. Let resX be the value of exifTagMap's tag 0x011A (XResolution).
+    // FIXME: 6. Let resY be the value of exifTagMap's tag 0x011B (YResolution).
+    // FIXME: 7. Let resUnit be the value of exifTagMap's tag 0x0128 (ResolutionUnit).
+    // FIXME: 8. If either dimX or dimY is not a positive integer, then return.
+    // FIXME: 9. If either resX or resY is not a positive floating-point number, then return.
+    // FIXME: 10. If resUnit is not equal to 2 (Inch), then return.
+    // FIXME: 11. Let widthFromDensity be the value of physicalWidth, multiplied by 72 and divided by resX.
+    // FIXME: 12. Let heightFromDensity be the value of physicalHeight, multiplied by 72 and divided by resY.
+    // FIXME: 13. If widthFromDensity is not equal to dimX or heightFromDensity is not equal to dimY, then return.
+    // FIXME: 14. If req's image data is CORS-cross-origin, then set img's intrinsic dimensions to dimX and dimY, scale img's pixel data accordingly, and return.
+    // FIXME: 15. Set req's preferred density-corrected dimensions to a struct with its width set to dimX and its height set to dimY.
+    // FIXME: 16. Update req's img element's presentation appropriately.
+}
+
+void ImageRequest::set_fetch_controller(JS::GCPtr<Fetch::Infrastructure::FetchController> fetch_controller)
+{
+    m_fetch_controller = move(fetch_controller);
+}
+
+}