/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use std::cell::Cell;
use std::collections::HashSet;
use std::default::Default;
use std::rc::Rc;
use std::sync::Arc;
use std::{char, mem};
use app_units::{AU_PER_PX, Au};
use content_security_policy as csp;
use cssparser::{Parser, ParserInput};
use dom_struct::dom_struct;
use euclid::Point2D;
use html5ever::{LocalName, Prefix, QualName, local_name, ns};
use js::jsapi::JSAutoRealm;
use js::rust::HandleObject;
use mime::{self, Mime};
use net_traits::http_status::HttpStatus;
use net_traits::image_cache::{
Image, ImageCache, ImageCacheResult, ImageLoadListener, ImageOrMetadataAvailable,
ImageResponse, PendingImageId, UsePlaceholder,
};
use net_traits::request::{Destination, Initiator, RequestId};
use net_traits::{
FetchMetadata, FetchResponseListener, FetchResponseMsg, NetworkError, ReferrerPolicy,
ResourceFetchTiming, ResourceTimingType,
};
use num_traits::ToPrimitive;
use pixels::{CorsStatus, ImageMetadata};
use servo_url::ServoUrl;
use servo_url::origin::MutableOrigin;
use style::attr::{AttrValue, LengthOrPercentageOrAuto, parse_integer, parse_length};
use style::context::QuirksMode;
use style::parser::ParserContext;
use style::stylesheets::{CssRuleType, Origin};
use style::values::specified::AbsoluteLength;
use style::values::specified::length::{Length, NoCalcLength};
use style::values::specified::source_size_list::SourceSizeList;
use style_traits::ParsingMode;
use url::Url;
use super::domexception::DOMErrorName;
use super::types::DOMException;
use crate::document_loader::{LoadBlocker, LoadType};
use crate::dom::activation::Activatable;
use crate::dom::attr::Attr;
use crate::dom::bindings::cell::{DomRefCell, RefMut};
use crate::dom::bindings::codegen::Bindings::DOMRectBinding::DOMRect_Binding::DOMRectMethods;
use crate::dom::bindings::codegen::Bindings::ElementBinding::Element_Binding::ElementMethods;
use crate::dom::bindings::codegen::Bindings::HTMLImageElementBinding::HTMLImageElementMethods;
use crate::dom::bindings::codegen::Bindings::MouseEventBinding::MouseEventMethods;
use crate::dom::bindings::codegen::Bindings::NodeBinding::Node_Binding::NodeMethods;
use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
use crate::dom::bindings::error::{Error, Fallible};
use crate::dom::bindings::inheritance::Castable;
use crate::dom::bindings::refcounted::Trusted;
use crate::dom::bindings::reflector::DomGlobal;
use crate::dom::bindings::root::{DomRoot, LayoutDom, MutNullableDom};
use crate::dom::bindings::str::{DOMString, USVString};
use crate::dom::document::{Document, determine_policy_for_token};
use crate::dom::element::{
AttributeMutation, CustomElementCreationMode, Element, ElementCreator, LayoutElementHelpers,
cors_setting_for_element, referrer_policy_for_element, reflect_cross_origin_attribute,
reflect_referrer_policy_attribute, set_cross_origin_attribute,
};
use crate::dom::event::Event;
use crate::dom::eventtarget::EventTarget;
use crate::dom::globalscope::GlobalScope;
use crate::dom::htmlareaelement::HTMLAreaElement;
use crate::dom::htmlelement::HTMLElement;
use crate::dom::htmlformelement::{FormControl, HTMLFormElement};
use crate::dom::htmlmapelement::HTMLMapElement;
use crate::dom::htmlpictureelement::HTMLPictureElement;
use crate::dom::htmlsourceelement::HTMLSourceElement;
use crate::dom::mouseevent::MouseEvent;
use crate::dom::node::{BindContext, Node, NodeDamage, NodeTraits, ShadowIncluding, UnbindContext};
use crate::dom::performanceresourcetiming::InitiatorType;
use crate::dom::promise::Promise;
use crate::dom::values::UNSIGNED_LONG_MAX;
use crate::dom::virtualmethods::VirtualMethods;
use crate::dom::window::Window;
use crate::fetch::create_a_potential_cors_request;
use crate::microtask::{Microtask, MicrotaskRunnable};
use crate::network_listener::{self, PreInvoke, ResourceTimingListener};
use crate::realms::enter_realm;
use crate::script_runtime::CanGc;
use crate::script_thread::ScriptThread;
#[derive(Clone, Copy, Debug)]
enum ParseState {
InDescriptor,
InParens,
AfterDescriptor,
}
#[derive(MallocSizeOf)]
pub(crate) struct SourceSet {
image_sources: Vec<ImageSource>,
source_size: SourceSizeList,
}
impl SourceSet {
fn new() -> SourceSet {
SourceSet {
image_sources: Vec::new(),
source_size: SourceSizeList::empty(),
}
}
}
#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
pub struct ImageSource {
pub url: String,
pub descriptor: Descriptor,
}
#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
pub struct Descriptor {
pub width: Option<u32>,
pub density: Option<f64>,
}
#[derive(Clone, Copy, JSTraceable, MallocSizeOf)]
#[allow(dead_code)]
enum State {
Unavailable,
PartiallyAvailable,
CompletelyAvailable,
Broken,
}
#[derive(Clone, Copy, JSTraceable, MallocSizeOf)]
enum ImageRequestPhase {
Pending,
Current,
}
#[derive(JSTraceable, MallocSizeOf)]
#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
struct ImageRequest {
state: State,
#[no_trace]
parsed_url: Option<ServoUrl>,
source_url: Option<USVString>,
blocker: DomRefCell<Option<LoadBlocker>>,
#[no_trace]
image: Option<Image>,
#[no_trace]
metadata: Option<ImageMetadata>,
#[no_trace]
final_url: Option<ServoUrl>,
current_pixel_density: Option<f64>,
}
#[dom_struct]
pub(crate) struct HTMLImageElement {
htmlelement: HTMLElement,
image_request: Cell<ImageRequestPhase>,
current_request: DomRefCell<ImageRequest>,
pending_request: DomRefCell<ImageRequest>,
form_owner: MutNullableDom<HTMLFormElement>,
generation: Cell<u32>,
source_set: DomRefCell<SourceSet>,
last_selected_source: DomRefCell<Option<USVString>>,
#[ignore_malloc_size_of = "promises are hard"]
image_decode_promises: DomRefCell<Vec<Rc<Promise>>>,
}
impl HTMLImageElement {
pub(crate) fn get_url(&self) -> Option<ServoUrl> {
self.current_request.borrow().parsed_url.clone()
}
// https://html.spec.whatwg.org/multipage/#check-the-usability-of-the-image-argument
pub(crate) fn is_usable(&self) -> Fallible<bool> {
// If image has an intrinsic width or intrinsic height (or both) equal to zero, then return bad.
if let Some(image) = &self.current_request.borrow().image {
let intrinsic_size = image.metadata();
if intrinsic_size.width == 0 || intrinsic_size.height == 0 {
return Ok(false);
}
}
match self.current_request.borrow().state {
// If image's current request's state is broken, then throw an "InvalidStateError" DOMException.
State::Broken => Err(Error::InvalidState),
State::CompletelyAvailable => Ok(true),
// If image is not fully decodable, then return bad.
State::PartiallyAvailable | State::Unavailable => Ok(false),
}
}
pub(crate) fn image_data(&self) -> Option<Image> {
self.current_request.borrow().image.clone()
}
}
/// The context required for asynchronously loading an external image.
struct ImageContext {
/// Reference to the script thread image cache.
image_cache: Arc<dyn ImageCache>,
/// Indicates whether the request failed, and why
status: Result<(), NetworkError>,
/// The cache ID for this request.
id: PendingImageId,
/// Used to mark abort
aborted: bool,
/// The document associated with this request
doc: Trusted<Document>,
/// timing data for this resource
resource_timing: ResourceFetchTiming,
url: ServoUrl,
}
impl FetchResponseListener for ImageContext {
fn process_request_body(&mut self, _: RequestId) {}
fn process_request_eof(&mut self, _: RequestId) {}
fn process_response(
&mut self,
request_id: RequestId,
metadata: Result<FetchMetadata, NetworkError>,
) {
debug!("got {:?} for {:?}", metadata.as_ref().map(|_| ()), self.url);
self.image_cache.notify_pending_response(
self.id,
FetchResponseMsg::ProcessResponse(request_id, metadata.clone()),
);
let metadata = metadata.ok().map(|meta| match meta {
FetchMetadata::Unfiltered(m) => m,
FetchMetadata::Filtered { unsafe_, .. } => unsafe_,
});
// Step 14.5 of https://html.spec.whatwg.org/multipage/#img-environment-changes
if let Some(metadata) = metadata.as_ref() {
if let Some(ref content_type) = metadata.content_type {
let mime: Mime = content_type.clone().into_inner().into();
if mime.type_() == mime::MULTIPART && mime.subtype().as_str() == "x-mixed-replace" {
self.aborted = true;
}
}
}
let status = metadata
.as_ref()
.map(|m| m.status.clone())
.unwrap_or_else(HttpStatus::new_error);
self.status = {
if status.is_error() {
Err(NetworkError::Internal(
"No http status code received".to_owned(),
))
} else if status.is_success() {
Ok(())
} else {
Err(NetworkError::Internal(format!(
"HTTP error code {}",
status.code()
)))
}
};
}
fn process_response_chunk(&mut self, request_id: RequestId, payload: Vec<u8>) {
if self.status.is_ok() {
self.image_cache.notify_pending_response(
self.id,
FetchResponseMsg::ProcessResponseChunk(request_id, payload),
);
}
}
fn process_response_eof(
&mut self,
request_id: RequestId,
response: Result<ResourceFetchTiming, NetworkError>,
) {
self.image_cache.notify_pending_response(
self.id,
FetchResponseMsg::ProcessResponseEOF(request_id, response),
);
}
fn resource_timing_mut(&mut self) -> &mut ResourceFetchTiming {
&mut self.resource_timing
}
fn resource_timing(&self) -> &ResourceFetchTiming {
&self.resource_timing
}
fn submit_resource_timing(&mut self) {
network_listener::submit_timing(self, CanGc::note())
}
fn process_csp_violations(&mut self, _request_id: RequestId, violations: Vec<csp::Violation>) {
let global = &self.resource_timing_global();
global.report_csp_violations(violations, None);
}
}
impl ResourceTimingListener for ImageContext {
fn resource_timing_information(&self) -> (InitiatorType, ServoUrl) {
(
InitiatorType::LocalName("img".to_string()),
self.url.clone(),
)
}
fn resource_timing_global(&self) -> DomRoot<GlobalScope> {
self.doc.root().global()
}
}
impl PreInvoke for ImageContext {
fn should_invoke(&self) -> bool {
!self.aborted
}
}
#[allow(non_snake_case)]
impl HTMLImageElement {
/// Update the current image with a valid URL.
fn fetch_image(&self, img_url: &ServoUrl, can_gc: CanGc) {
let window = self.owner_window();
let cache_result = window.image_cache().get_cached_image_status(
img_url.clone(),
window.origin().immutable().clone(),
cors_setting_for_element(self.upcast()),
UsePlaceholder::Yes,
);
match cache_result {
ImageCacheResult::Available(ImageOrMetadataAvailable::ImageAvailable {
image,
url,
is_placeholder,
}) => {
if is_placeholder {
if let Some(raster_image) = image.as_raster_image() {
self.process_image_response(
ImageResponse::PlaceholderLoaded(raster_image, url),
can_gc,
)
}
} else {
self.process_image_response(ImageResponse::Loaded(image, url), can_gc)
}
},
ImageCacheResult::Available(ImageOrMetadataAvailable::MetadataAvailable(
metadata,
id,
)) => {
self.process_image_response(ImageResponse::MetadataLoaded(metadata), can_gc);
self.register_image_cache_callback(id, ChangeType::Element);
},
ImageCacheResult::Pending(id) => {
self.register_image_cache_callback(id, ChangeType::Element);
},
ImageCacheResult::ReadyForRequest(id) => {
self.fetch_request(img_url, id);
self.register_image_cache_callback(id, ChangeType::Element);
},
ImageCacheResult::LoadError => self.process_image_response(ImageResponse::None, can_gc),
};
}
fn register_image_cache_callback(&self, id: PendingImageId, change_type: ChangeType) {
let trusted_node = Trusted::new(self);
let generation = self.generation_id();
let window = self.owner_window();
let sender = window.register_image_cache_listener(id, move |response| {
let trusted_node = trusted_node.clone();
let window = trusted_node.root().owner_window();
let callback_type = change_type.clone();
window
.as_global_scope()
.task_manager()
.networking_task_source()
.queue(task!(process_image_response: move || {
let element = trusted_node.root();
// Ignore any image response for a previous request that has been discarded.
if generation != element.generation_id() {
return;
}
match callback_type {
ChangeType::Element => {
element.process_image_response(response.response, CanGc::note());
}
ChangeType::Environment { selected_source, selected_pixel_density } => {
element.process_image_response_for_environment_change(
response.response, selected_source, generation, selected_pixel_density, CanGc::note()
);
}
}
}));
});
window
.image_cache()
.add_listener(ImageLoadListener::new(sender, window.pipeline_id(), id));
}
fn fetch_request(&self, img_url: &ServoUrl, id: PendingImageId) {
let document = self.owner_document();
let window = self.owner_window();
let context = ImageContext {
image_cache: window.image_cache(),
status: Ok(()),
id,
aborted: false,
doc: Trusted::new(&document),
resource_timing: ResourceFetchTiming::new(ResourceTimingType::Resource),
url: img_url.clone(),
};
// https://html.spec.whatwg.org/multipage/#update-the-image-data steps 17-20
// This function is also used to prefetch an image in `script::dom::servoparser::prefetch`.
let global = document.global();
let mut request = create_a_potential_cors_request(
Some(window.webview_id()),
img_url.clone(),
Destination::Image,
cors_setting_for_element(self.upcast()),
None,
global.get_referrer(),
document.insecure_requests_policy(),
document.has_trustworthy_ancestor_or_current_origin(),
global.policy_container(),
)
.origin(document.origin().immutable().clone())
.pipeline_id(Some(document.global().pipeline_id()))
.referrer_policy(referrer_policy_for_element(self.upcast()));
if Self::uses_srcset_or_picture(self.upcast()) {
request = request.initiator(Initiator::ImageSet);
}
// This is a background load because the load blocker already fulfills the
// purpose of delaying the document's load event.
document.fetch_background(request, context);
}
// Steps common to when an image has been loaded.
fn handle_loaded_image(&self, image: Image, url: ServoUrl, can_gc: CanGc) {
self.current_request.borrow_mut().metadata = Some(image.metadata());
self.current_request.borrow_mut().final_url = Some(url);
self.current_request.borrow_mut().image = Some(image);
self.current_request.borrow_mut().state = State::CompletelyAvailable;
LoadBlocker::terminate(&self.current_request.borrow().blocker, can_gc);
// Mark the node dirty
self.upcast::<Node>().dirty(NodeDamage::Other);
self.resolve_image_decode_promises(can_gc);
}
/// Step 24 of <https://html.spec.whatwg.org/multipage/#update-the-image-data>
fn process_image_response(&self, image: ImageResponse, can_gc: CanGc) {
// TODO: Handle multipart/x-mixed-replace
let (trigger_image_load, trigger_image_error) = match (image, self.image_request.get()) {
(ImageResponse::Loaded(image, url), ImageRequestPhase::Current) => {
self.handle_loaded_image(image, url, can_gc);
(true, false)
},
(ImageResponse::PlaceholderLoaded(image, url), ImageRequestPhase::Current) => {
self.handle_loaded_image(Image::Raster(image), url, can_gc);
(false, true)
},
(ImageResponse::Loaded(image, url), ImageRequestPhase::Pending) => {
self.abort_request(State::Unavailable, ImageRequestPhase::Pending, can_gc);
self.image_request.set(ImageRequestPhase::Current);
self.handle_loaded_image(image, url, can_gc);
(true, false)
},
(ImageResponse::PlaceholderLoaded(image, url), ImageRequestPhase::Pending) => {
self.abort_request(State::Unavailable, ImageRequestPhase::Pending, can_gc);
self.image_request.set(ImageRequestPhase::Current);
self.handle_loaded_image(Image::Raster(image), url, can_gc);
(false, true)
},
(ImageResponse::MetadataLoaded(meta), ImageRequestPhase::Current) => {
self.current_request.borrow_mut().state = State::PartiallyAvailable;
self.current_request.borrow_mut().metadata = Some(meta);
(false, false)
},
(ImageResponse::MetadataLoaded(_), ImageRequestPhase::Pending) => {
self.pending_request.borrow_mut().state = State::PartiallyAvailable;
(false, false)
},
(ImageResponse::None, ImageRequestPhase::Current) => {
self.abort_request(State::Broken, ImageRequestPhase::Current, can_gc);
(false, true)
},
(ImageResponse::None, ImageRequestPhase::Pending) => {
self.abort_request(State::Broken, ImageRequestPhase::Current, can_gc);
self.abort_request(State::Broken, ImageRequestPhase::Pending, can_gc);
self.image_request.set(ImageRequestPhase::Current);
(false, true)
},
};
// Fire image.onload and loadend
if trigger_image_load {
// TODO: https://html.spec.whatwg.org/multipage/#fire-a-progress-event-or-event
self.upcast::<EventTarget>()
.fire_event(atom!("load"), can_gc);
self.upcast::<EventTarget>()
.fire_event(atom!("loadend"), can_gc);
}
// Fire image.onerror
if trigger_image_error {
self.upcast::<EventTarget>()
.fire_event(atom!("error"), can_gc);
self.upcast::<EventTarget>()
.fire_event(atom!("loadend"), can_gc);
}
self.upcast::<Node>().dirty(NodeDamage::Other);
}
fn process_image_response_for_environment_change(
&self,
image: ImageResponse,
src: USVString,
generation: u32,
selected_pixel_density: f64,
can_gc: CanGc,
) {
match image {
ImageResponse::Loaded(image, url) => {
self.pending_request.borrow_mut().metadata = Some(image.metadata());
self.pending_request.borrow_mut().final_url = Some(url);
self.pending_request.borrow_mut().image = Some(image);
self.finish_reacting_to_environment_change(src, generation, selected_pixel_density);
},
ImageResponse::PlaceholderLoaded(image, url) => {
let image = Image::Raster(image);
self.pending_request.borrow_mut().metadata = Some(image.metadata());
self.pending_request.borrow_mut().final_url = Some(url);
self.pending_request.borrow_mut().image = Some(image);
self.finish_reacting_to_environment_change(src, generation, selected_pixel_density);
},
ImageResponse::MetadataLoaded(meta) => {
self.pending_request.borrow_mut().metadata = Some(meta);
},
ImageResponse::None => {
self.abort_request(State::Unavailable, ImageRequestPhase::Pending, can_gc);
},
};
}
/// <https://html.spec.whatwg.org/multipage/#abort-the-image-request>
fn abort_request(&self, state: State, request: ImageRequestPhase, can_gc: CanGc) {
let mut request = match request {
ImageRequestPhase::Current => self.current_request.borrow_mut(),
ImageRequestPhase::Pending => self.pending_request.borrow_mut(),
};
LoadBlocker::terminate(&request.blocker, can_gc);
request.state = state;
request.image = None;
request.metadata = None;
if matches!(state, State::Broken) {
self.reject_image_decode_promises(can_gc);
} else if matches!(state, State::CompletelyAvailable) {
self.resolve_image_decode_promises(can_gc);
}
}
/// <https://html.spec.whatwg.org/multipage/#update-the-source-set>
fn update_source_set(&self) {
// Step 1
*self.source_set.borrow_mut() = SourceSet::new();
// Step 2
let elem = self.upcast::<Element>();
let parent = elem.upcast::<Node>().GetParentElement();
let nodes;
let elements = match parent.as_ref() {
Some(p) => {
if p.is::<HTMLPictureElement>() {
nodes = p.upcast::<Node>().children();
nodes
.filter_map(DomRoot::downcast::<Element>)
.map(|n| DomRoot::from_ref(&*n))
.collect()
} else {
vec![DomRoot::from_ref(elem)]
}
},
None => vec![DomRoot::from_ref(elem)],
};
// Step 3
let width = match elem.get_attribute(&ns!(), &local_name!("width")) {
Some(x) => match parse_length(&x.value()) {
LengthOrPercentageOrAuto::Length(x) => {
let abs_length = AbsoluteLength::Px(x.to_f32_px());
Some(Length::NoCalc(NoCalcLength::Absolute(abs_length)))
},
_ => None,
},
None => None,
};
// Step 4
for element in &elements {
// Step 4.1
if *element == DomRoot::from_ref(elem) {
let mut source_set = SourceSet::new();
// Step 4.1.1
if let Some(x) = element.get_attribute(&ns!(), &local_name!("srcset")) {
source_set.image_sources = parse_a_srcset_attribute(&x.value());
}
// Step 4.1.2
if let Some(x) = element.get_attribute(&ns!(), &local_name!("sizes")) {
source_set.source_size =
parse_a_sizes_attribute(DOMString::from_string(x.value().to_string()));
}
// Step 4.1.3
let src_attribute = element.get_string_attribute(&local_name!("src"));
let is_src_empty = src_attribute.is_empty();
let no_density_source_of_1 = source_set
.image_sources
.iter()
.all(|source| source.descriptor.density != Some(1.));
let no_width_descriptor = source_set
.image_sources
.iter()
.all(|source| source.descriptor.width.is_none());
if !is_src_empty && no_density_source_of_1 && no_width_descriptor {
source_set.image_sources.push(ImageSource {
url: src_attribute.to_string(),
descriptor: Descriptor {
width: None,
density: None,
},
})
}
// Step 4.1.4
self.normalise_source_densities(&mut source_set, width);
// Step 4.1.5
*self.source_set.borrow_mut() = source_set;
// Step 4.1.6
return;
}
// Step 4.2
if !element.is::<HTMLSourceElement>() {
continue;
}
// Step 4.3 - 4.4
let mut source_set = SourceSet::new();
match element.get_attribute(&ns!(), &local_name!("srcset")) {
Some(x) => {
source_set.image_sources = parse_a_srcset_attribute(&x.value());
},
_ => continue,
}
// Step 4.5
if source_set.image_sources.is_empty() {
continue;
}
// Step 4.6
if let Some(x) = element.get_attribute(&ns!(), &local_name!("media")) {
if !elem.matches_environment(&x.value()) {
continue;
}
}
// Step 4.7
if let Some(x) = element.get_attribute(&ns!(), &local_name!("sizes")) {
source_set.source_size =
parse_a_sizes_attribute(DOMString::from_string(x.value().to_string()));
}
// Step 4.8
if let Some(x) = element.get_attribute(&ns!(), &local_name!("type")) {
// TODO Handle unsupported mime type
let mime = x.value().parse::<Mime>();
match mime {
Ok(m) => match m.type_() {
mime::IMAGE => (),
_ => continue,
},
_ => continue,
}
}
// Step 4.9
self.normalise_source_densities(&mut source_set, width);
// Step 4.10
*self.source_set.borrow_mut() = source_set;
return;
}
}
fn evaluate_source_size_list(
&self,
source_size_list: &mut SourceSizeList,
_width: Option<Length>,
) -> Au {
let document = self.owner_document();
let quirks_mode = document.quirks_mode();
let result = source_size_list.evaluate(document.window().layout().device(), quirks_mode);
result
}
/// <https://html.spec.whatwg.org/multipage/#normalise-the-source-densities>
fn normalise_source_densities(&self, source_set: &mut SourceSet, width: Option<Length>) {
// Step 1
let source_size = &mut source_set.source_size;
// Find source_size_length for Step 2.2
let source_size_length = self.evaluate_source_size_list(source_size, width);
// Step 2
for imgsource in &mut source_set.image_sources {
// Step 2.1
if imgsource.descriptor.density.is_some() {
continue;
}
// Step 2.2
if imgsource.descriptor.width.is_some() {
let wid = imgsource.descriptor.width.unwrap();
imgsource.descriptor.density = Some(wid as f64 / source_size_length.to_f64_px());
} else {
//Step 2.3
imgsource.descriptor.density = Some(1_f64);
}
}
}
/// <https://html.spec.whatwg.org/multipage/#select-an-image-source>
fn select_image_source(&self) -> Option<(USVString, f64)> {
// Step 1, 3
self.update_source_set();
let source_set = &*self.source_set.borrow_mut();
let len = source_set.image_sources.len();
// Step 2
if len == 0 {
return None;
}
// Step 4
let mut repeat_indices = HashSet::new();
for outer_index in 0..len {
if repeat_indices.contains(&outer_index) {
continue;
}
let imgsource = &source_set.image_sources[outer_index];
let pixel_density = imgsource.descriptor.density.unwrap();
for inner_index in (outer_index + 1)..len {
let imgsource2 = &source_set.image_sources[inner_index];
if pixel_density == imgsource2.descriptor.density.unwrap() {
repeat_indices.insert(inner_index);
}
}
}
let mut max = (0f64, 0);
let img_sources = &mut vec![];
for (index, image_source) in source_set.image_sources.iter().enumerate() {
if repeat_indices.contains(&index) {
continue;
}
let den = image_source.descriptor.density.unwrap();
if max.0 < den {
max = (den, img_sources.len());
}
img_sources.push(image_source);
}
// Step 5
let mut best_candidate = max;
let device_pixel_ratio = self
.owner_document()
.window()
.viewport_details()
.hidpi_scale_factor
.get() as f64;
for (index, image_source) in img_sources.iter().enumerate() {
let current_den = image_source.descriptor.density.unwrap();
if current_den < best_candidate.0 && current_den >= device_pixel_ratio {
best_candidate = (current_den, index);
}
}
let selected_source = img_sources.remove(best_candidate.1).clone();
Some((
USVString(selected_source.url),
selected_source.descriptor.density.unwrap(),
))
}
fn init_image_request(
&self,
request: &mut RefMut<ImageRequest>,
url: &ServoUrl,
src: &USVString,
can_gc: CanGc,
) {
request.parsed_url = Some(url.clone());
request.source_url = Some(src.clone());
request.image = None;
request.metadata = None;
let document = self.owner_document();
LoadBlocker::terminate(&request.blocker, can_gc);
*request.blocker.borrow_mut() =
Some(LoadBlocker::new(&document, LoadType::Image(url.clone())));
}
/// Step 13-17 of html.spec.whatwg.org/multipage/#update-the-image-data
fn prepare_image_request(
&self,
url: &ServoUrl,
src: &USVString,
selected_pixel_density: f64,
can_gc: CanGc,
) {
match self.image_request.get() {
ImageRequestPhase::Pending => {
if let Some(pending_url) = self.pending_request.borrow().parsed_url.clone() {
// Step 13
if pending_url == *url {
return;
}
}
},
ImageRequestPhase::Current => {
let mut current_request = self.current_request.borrow_mut();
let mut pending_request = self.pending_request.borrow_mut();
// step 16, create a new "image_request"
match (current_request.parsed_url.clone(), current_request.state) {
(Some(parsed_url), State::PartiallyAvailable) => {
// Step 14
if parsed_url == *url {
// Step 15 abort pending request
pending_request.image = None;
pending_request.parsed_url = None;
LoadBlocker::terminate(&pending_request.blocker, can_gc);
// TODO: queue a task to restart animation, if restart-animation is set
return;
}
pending_request.current_pixel_density = Some(selected_pixel_density);
self.image_request.set(ImageRequestPhase::Pending);
self.init_image_request(&mut pending_request, url, src, can_gc);
},
(_, State::Broken) | (_, State::Unavailable) => {
// Step 17
current_request.current_pixel_density = Some(selected_pixel_density);
self.init_image_request(&mut current_request, url, src, can_gc);
},
(_, _) => {
// step 17
pending_request.current_pixel_density = Some(selected_pixel_density);
self.image_request.set(ImageRequestPhase::Pending);
self.init_image_request(&mut pending_request, url, src, can_gc);
},
}
},
}
self.fetch_image(url, can_gc);
}
/// Step 8-12 of html.spec.whatwg.org/multipage/#update-the-image-data
fn update_the_image_data_sync_steps(&self, can_gc: CanGc) {
let document = self.owner_document();
let global = self.owner_global();
let task_manager = global.task_manager();
let task_source = task_manager.dom_manipulation_task_source();
let this = Trusted::new(self);
let (src, pixel_density) = match self.select_image_source() {
// Step 8
Some(data) => data,
None => {
self.abort_request(State::Broken, ImageRequestPhase::Current, can_gc);
self.abort_request(State::Broken, ImageRequestPhase::Pending, can_gc);
// Step 9.
task_source.queue(task!(image_null_source_error: move || {
let this = this.root();
{
let mut current_request =
this.current_request.borrow_mut();
current_request.source_url = None;
current_request.parsed_url = None;
}
let elem = this.upcast::<Element>();
let src_present = elem.has_attribute(&local_name!("src"));
if src_present || Self::uses_srcset_or_picture(elem) {
this.upcast::<EventTarget>().fire_event(atom!("error"), CanGc::note());
}
}));
return;
},
};
// Step 11
let base_url = document.base_url();
let parsed_url = base_url.join(&src.0);
match parsed_url {
Ok(url) => {
// Step 13-17
self.prepare_image_request(&url, &src, pixel_density, can_gc);
},
Err(_) => {
self.abort_request(State::Broken, ImageRequestPhase::Current, can_gc);
self.abort_request(State::Broken, ImageRequestPhase::Pending, can_gc);
// Step 12.1-12.5.
let src = src.0;
task_source.queue(task!(image_selected_source_error: move || {
let this = this.root();
{
let mut current_request =
this.current_request.borrow_mut();
current_request.source_url = Some(USVString(src))
}
this.upcast::<EventTarget>().fire_event(atom!("error"), CanGc::note());
}));
},
}
}
/// <https://html.spec.whatwg.org/multipage/#update-the-image-data>
pub(crate) fn update_the_image_data(&self, can_gc: CanGc) {
let document = self.owner_document();
let window = document.window();
let elem = self.upcast::<Element>();
let src = elem.get_url_attribute(&local_name!("src"));
let base_url = document.base_url();
// https://html.spec.whatwg.org/multipage/#reacting-to-dom-mutations
// Always first set the current request to unavailable,
// ensuring img.complete is false.
{
let mut current_request = self.current_request.borrow_mut();
current_request.state = State::Unavailable;
}
if !document.is_active() {
// Step 1 (if the document is inactive)
// TODO: use GlobalScope::enqueue_microtask,
// to queue micro task to come back to this algorithm
}
// Step 2 abort if user-agent does not supports images
// NOTE: Servo only supports images, skipping this step
// Step 3, 4
let mut selected_source = None;
let mut pixel_density = None;
let src_set = elem.get_url_attribute(&local_name!("srcset"));
let is_parent_picture = elem
.upcast::<Node>()
.GetParentElement()
.is_some_and(|p| p.is::<HTMLPictureElement>());
if src_set.is_empty() && !is_parent_picture && !src.is_empty() {
selected_source = Some(src.clone());
pixel_density = Some(1_f64);
};
// Step 5
self.last_selected_source
.borrow_mut()
.clone_from(&selected_source);
// Step 6, check the list of available images
if let Some(src) = selected_source {
if let Ok(img_url) = base_url.join(&src) {
let image_cache = window.image_cache();
let response = image_cache.get_image(
img_url.clone(),
window.origin().immutable().clone(),
cors_setting_for_element(self.upcast()),
);
if let Some(image) = response {
// Cancel any outstanding tasks that were queued before the src was
// set on this element.
self.generation.set(self.generation.get() + 1);
// Step 6.3
let metadata = image.metadata();
// Step 6.3.2 abort requests
self.abort_request(
State::CompletelyAvailable,
ImageRequestPhase::Current,
can_gc,
);
self.abort_request(State::Unavailable, ImageRequestPhase::Pending, can_gc);
let mut current_request = self.current_request.borrow_mut();
current_request.final_url = Some(img_url.clone());
current_request.image = Some(image);
current_request.metadata = Some(metadata);
// Step 6.3.6
current_request.current_pixel_density = pixel_density;
let this = Trusted::new(self);
let src = src.0;
self.owner_global()
.task_manager()
.dom_manipulation_task_source()
.queue(task!(image_load_event: move || {
let this = this.root();
{
let mut current_request =
this.current_request.borrow_mut();
current_request.parsed_url = Some(img_url);
current_request.source_url = Some(USVString(src));
}
// TODO: restart animation, if set.
this.upcast::<EventTarget>().fire_event(atom!("load"), CanGc::note());
}));
return;
}
}
}
// step 7, await a stable state.
self.generation.set(self.generation.get() + 1);
let task = ImageElementMicrotask::StableStateUpdateImageData {
elem: DomRoot::from_ref(self),
generation: self.generation.get(),
};
ScriptThread::await_stable_state(Microtask::ImageElement(task));
}
/// <https://html.spec.whatwg.org/multipage/#img-environment-changes>
pub(crate) fn react_to_environment_changes(&self) {
// Step 1
let task = ImageElementMicrotask::EnvironmentChanges {
elem: DomRoot::from_ref(self),
generation: self.generation.get(),
};
ScriptThread::await_stable_state(Microtask::ImageElement(task));
}
/// Step 2-12 of <https://html.spec.whatwg.org/multipage/#img-environment-changes>
fn react_to_environment_changes_sync_steps(&self, generation: u32, can_gc: CanGc) {
let elem = self.upcast::<Element>();
let document = elem.owner_document();
let has_pending_request = matches!(self.image_request.get(), ImageRequestPhase::Pending);
// Step 2
if !document.is_active() || !Self::uses_srcset_or_picture(elem) || has_pending_request {
return;
}
// Steps 3-4
let (selected_source, selected_pixel_density) = match self.select_image_source() {
Some(selected) => selected,
None => return,
};
// Step 5
let same_source = match *self.last_selected_source.borrow() {
Some(ref last_src) => *last_src == selected_source,
_ => false,
};
let same_selected_pixel_density = match self.current_request.borrow().current_pixel_density
{
Some(den) => selected_pixel_density == den,
_ => false,
};
if same_source && same_selected_pixel_density {
return;
}
let base_url = document.base_url();
// Step 6
let img_url = match base_url.join(&selected_source.0) {
Ok(url) => url,
Err(_) => return,
};
// Step 12
self.image_request.set(ImageRequestPhase::Pending);
self.init_image_request(
&mut self.pending_request.borrow_mut(),
&img_url,
&selected_source,
can_gc,
);
// Step 14
let window = self.owner_window();
let cache_result = window.image_cache().get_cached_image_status(
img_url.clone(),
window.origin().immutable().clone(),
cors_setting_for_element(self.upcast()),
UsePlaceholder::No,
);
let change_type = ChangeType::Environment {
selected_source: selected_source.clone(),
selected_pixel_density,
};
match cache_result {
ImageCacheResult::Available(ImageOrMetadataAvailable::ImageAvailable { .. }) => {
// Step 15
self.finish_reacting_to_environment_change(
selected_source,
generation,
selected_pixel_density,
)
},
ImageCacheResult::Available(ImageOrMetadataAvailable::MetadataAvailable(m, id)) => {
self.process_image_response_for_environment_change(
ImageResponse::MetadataLoaded(m),
selected_source,
generation,
selected_pixel_density,
can_gc,
);
self.register_image_cache_callback(id, change_type);
},
ImageCacheResult::LoadError => {
self.process_image_response_for_environment_change(
ImageResponse::None,
selected_source,
generation,
selected_pixel_density,
can_gc,
);
},
ImageCacheResult::ReadyForRequest(id) => {
self.fetch_request(&img_url, id);
self.register_image_cache_callback(id, change_type);
},
ImageCacheResult::Pending(id) => {
self.register_image_cache_callback(id, change_type);
},
}
}
// Step 2 for <https://html.spec.whatwg.org/multipage/#dom-img-decode>
fn react_to_decode_image_sync_steps(&self, promise: Rc<Promise>, can_gc: CanGc) {
let document = self.owner_document();
// Step 2.1 of <https://html.spec.whatwg.org/multipage/#dom-img-decode>
if !document.is_fully_active() ||
matches!(self.current_request.borrow().state, State::Broken)
{
promise.reject_native(
&DOMException::new(&document.global(), DOMErrorName::EncodingError, can_gc),
can_gc,
);
} else if matches!(
self.current_request.borrow().state,
State::CompletelyAvailable
) {
// this doesn't follow the spec, but it's been discussed in <https://github.com/whatwg/html/issues/4217>
promise.resolve_native(&(), can_gc);
} else {
self.image_decode_promises
.borrow_mut()
.push(promise.clone());
}
}
fn resolve_image_decode_promises(&self, can_gc: CanGc) {
for promise in self.image_decode_promises.borrow().iter() {
promise.resolve_native(&(), can_gc);
}
self.image_decode_promises.borrow_mut().clear();
}
fn reject_image_decode_promises(&self, can_gc: CanGc) {
let document = self.owner_document();
for promise in self.image_decode_promises.borrow().iter() {
promise.reject_native(
&DOMException::new(&document.global(), DOMErrorName::EncodingError, can_gc),
can_gc,
);
}
self.image_decode_promises.borrow_mut().clear();
}
/// Step 15 for <https://html.spec.whatwg.org/multipage/#img-environment-changes>
fn finish_reacting_to_environment_change(
&self,
src: USVString,
generation: u32,
selected_pixel_density: f64,
) {
let this = Trusted::new(self);
let src = src.0;
self.owner_global().task_manager().dom_manipulation_task_source().queue(
task!(image_load_event: move || {
let this = this.root();
let relevant_mutation = this.generation.get() != generation;
// Step 15.1
if relevant_mutation {
this.abort_request(State::Unavailable, ImageRequestPhase::Pending, CanGc::note());
return;
}
// Step 15.2
*this.last_selected_source.borrow_mut() = Some(USVString(src));
{
let mut pending_request = this.pending_request.borrow_mut();
pending_request.current_pixel_density = Some(selected_pixel_density);
// Step 15.3
pending_request.state = State::CompletelyAvailable;
// Step 15.4
// Already a part of the list of available images due to Step 14
// Step 15.5
mem::swap(&mut this.current_request.borrow_mut(), &mut pending_request);
}
this.abort_request(State::Unavailable, ImageRequestPhase::Pending, CanGc::note());
// Step 15.6
this.upcast::<Node>().dirty(NodeDamage::Other);
// Step 15.7
this.upcast::<EventTarget>().fire_event(atom!("load"), CanGc::note());
})
);
}
fn uses_srcset_or_picture(elem: &Element) -> bool {
let has_src = elem.has_attribute(&local_name!("srcset"));
let is_parent_picture = elem
.upcast::<Node>()
.GetParentElement()
.is_some_and(|p| p.is::<HTMLPictureElement>());
has_src || is_parent_picture
}
fn new_inherited(
local_name: LocalName,
prefix: Option<Prefix>,
document: &Document,
) -> HTMLImageElement {
HTMLImageElement {
htmlelement: HTMLElement::new_inherited(local_name, prefix, document),
image_request: Cell::new(ImageRequestPhase::Current),
current_request: DomRefCell::new(ImageRequest {
state: State::Unavailable,
parsed_url: None,
source_url: None,
image: None,
metadata: None,
blocker: DomRefCell::new(None),
final_url: None,
current_pixel_density: None,
}),
pending_request: DomRefCell::new(ImageRequest {
state: State::Unavailable,
parsed_url: None,
source_url: None,
image: None,
metadata: None,
blocker: DomRefCell::new(None),
final_url: None,
current_pixel_density: None,
}),
form_owner: Default::default(),
generation: Default::default(),
source_set: DomRefCell::new(SourceSet::new()),
last_selected_source: DomRefCell::new(None),
image_decode_promises: DomRefCell::new(vec![]),
}
}
#[cfg_attr(crown, allow(crown::unrooted_must_root))]
pub(crate) fn new(
local_name: LocalName,
prefix: Option<Prefix>,
document: &Document,
proto: Option<HandleObject>,
can_gc: CanGc,
) -> DomRoot<HTMLImageElement> {
Node::reflect_node_with_proto(
Box::new(HTMLImageElement::new_inherited(
local_name, prefix, document,
)),
document,
proto,
can_gc,
)
}
pub(crate) fn areas(&self) -> Option<Vec<DomRoot<HTMLAreaElement>>> {
let elem = self.upcast::<Element>();
let usemap_attr = elem.get_attribute(&ns!(), &local_name!("usemap"))?;
let value = usemap_attr.value();
if value.len() == 0 || !value.is_char_boundary(1) {
return None;
}
let (first, last) = value.split_at(1);
if first != "#" || last.is_empty() {
return None;
}
let useMapElements = self
.owner_document()
.upcast::<Node>()
.traverse_preorder(ShadowIncluding::No)
.filter_map(DomRoot::downcast::<HTMLMapElement>)
.find(|n| {
n.upcast::<Element>()
.get_name()
.is_some_and(|n| *n == *last)
});
useMapElements.map(|mapElem| mapElem.get_area_elements())
}
pub(crate) fn same_origin(&self, origin: &MutableOrigin) -> bool {
if let Some(ref image) = self.current_request.borrow().image {
return image.cors_status() == CorsStatus::Safe;
}
self.current_request
.borrow()
.final_url
.as_ref()
.is_some_and(|url| url.scheme() == "data" || url.origin().same_origin(origin))
}
fn generation_id(&self) -> u32 {
self.generation.get()
}
}
#[derive(JSTraceable, MallocSizeOf)]
pub(crate) enum ImageElementMicrotask {
StableStateUpdateImageData {
elem: DomRoot<HTMLImageElement>,
generation: u32,
},
EnvironmentChanges {
elem: DomRoot<HTMLImageElement>,
generation: u32,
},
Decode {
elem: DomRoot<HTMLImageElement>,
#[ignore_malloc_size_of = "promises are hard"]
promise: Rc<Promise>,
},
}
impl MicrotaskRunnable for ImageElementMicrotask {
fn handler(&self, can_gc: CanGc) {
match *self {
ImageElementMicrotask::StableStateUpdateImageData {
ref elem,
ref generation,
} => {
// Step 7 of https://html.spec.whatwg.org/multipage/#update-the-image-data,
// stop here if other instances of this algorithm have been scheduled
if elem.generation.get() == *generation {
elem.update_the_image_data_sync_steps(can_gc);
}
},
ImageElementMicrotask::EnvironmentChanges {
ref elem,
ref generation,
} => {
elem.react_to_environment_changes_sync_steps(*generation, can_gc);
},
ImageElementMicrotask::Decode {
ref elem,
ref promise,
} => {
elem.react_to_decode_image_sync_steps(promise.clone(), can_gc);
},
}
}
fn enter_realm(&self) -> JSAutoRealm {
match self {
&ImageElementMicrotask::StableStateUpdateImageData { ref elem, .. } |
&ImageElementMicrotask::EnvironmentChanges { ref elem, .. } |
&ImageElementMicrotask::Decode { ref elem, .. } => enter_realm(&**elem),
}
}
}
pub(crate) trait LayoutHTMLImageElementHelpers {
fn image_url(self) -> Option<ServoUrl>;
fn image_density(self) -> Option<f64>;
fn image_data(self) -> (Option<Image>, Option<ImageMetadata>);
fn get_width(self) -> LengthOrPercentageOrAuto;
fn get_height(self) -> LengthOrPercentageOrAuto;
}
impl<'dom> LayoutDom<'dom, HTMLImageElement> {
#[allow(unsafe_code)]
fn current_request(self) -> &'dom ImageRequest {
unsafe { self.unsafe_get().current_request.borrow_for_layout() }
}
}
impl LayoutHTMLImageElementHelpers for LayoutDom<'_, HTMLImageElement> {
fn image_url(self) -> Option<ServoUrl> {
self.current_request().parsed_url.clone()
}
fn image_data(self) -> (Option<Image>, Option<ImageMetadata>) {
let current_request = self.current_request();
(current_request.image.clone(), current_request.metadata)
}
fn image_density(self) -> Option<f64> {
self.current_request().current_pixel_density
}
fn get_width(self) -> LengthOrPercentageOrAuto {
self.upcast::<Element>()
.get_attr_for_layout(&ns!(), &local_name!("width"))
.map(AttrValue::as_dimension)
.cloned()
.unwrap_or(LengthOrPercentageOrAuto::Auto)
}
fn get_height(self) -> LengthOrPercentageOrAuto {
self.upcast::<Element>()
.get_attr_for_layout(&ns!(), &local_name!("height"))
.map(AttrValue::as_dimension)
.cloned()
.unwrap_or(LengthOrPercentageOrAuto::Auto)
}
}
//https://html.spec.whatwg.org/multipage/#parse-a-sizes-attribute
pub(crate) fn parse_a_sizes_attribute(value: DOMString) -> SourceSizeList {
let mut input = ParserInput::new(&value);
let mut parser = Parser::new(&mut input);
let url_data = Url::parse("about:blank").unwrap().into();
let context = ParserContext::new(
Origin::Author,
&url_data,
Some(CssRuleType::Style),
// FIXME(emilio): why ::empty() instead of ::DEFAULT? Also, what do
// browsers do regarding quirks-mode in a media list?
ParsingMode::empty(),
QuirksMode::NoQuirks,
/* namespaces = */ Default::default(),
None,
None,
);
SourceSizeList::parse(&context, &mut parser)
}
fn get_correct_referrerpolicy_from_raw_token(token: &DOMString) -> DOMString {
if token == "" {
// Empty token is treated as the default referrer policy inside determine_policy_for_token,
// so it should remain unchanged.
DOMString::new()
} else {
let policy = determine_policy_for_token(token);
if policy == ReferrerPolicy::EmptyString {
return DOMString::new();
}
DOMString::from_string(policy.to_string())
}
}
#[allow(non_snake_case)]
impl HTMLImageElementMethods<crate::DomTypeHolder> for HTMLImageElement {
// https://html.spec.whatwg.org/multipage/#dom-image
fn Image(
window: &Window,
proto: Option<HandleObject>,
can_gc: CanGc,
width: Option<u32>,
height: Option<u32>,
) -> Fallible<DomRoot<HTMLImageElement>> {
let element = Element::create(
QualName::new(None, ns!(html), local_name!("img")),
None,
&window.Document(),
ElementCreator::ScriptCreated,
CustomElementCreationMode::Synchronous,
proto,
can_gc,
);
let image = DomRoot::downcast::<HTMLImageElement>(element).unwrap();
if let Some(w) = width {
image.SetWidth(w, can_gc);
}
if let Some(h) = height {
image.SetHeight(h, can_gc);
}
// run update_the_image_data when the element is created.
// https://html.spec.whatwg.org/multipage/#when-to-obtain-images
image.update_the_image_data(can_gc);
Ok(image)
}
// https://html.spec.whatwg.org/multipage/#dom-img-alt
make_getter!(Alt, "alt");
// https://html.spec.whatwg.org/multipage/#dom-img-alt
make_setter!(SetAlt, "alt");
// https://html.spec.whatwg.org/multipage/#dom-img-src
make_url_getter!(Src, "src");
// https://html.spec.whatwg.org/multipage/#dom-img-src
make_url_setter!(SetSrc, "src");
// https://html.spec.whatwg.org/multipage/#dom-img-srcset
make_url_getter!(Srcset, "srcset");
// https://html.spec.whatwg.org/multipage/#dom-img-src
make_url_setter!(SetSrcset, "srcset");
// https://html.spec.whatwg.org/multipage/#dom-img-crossOrigin
fn GetCrossOrigin(&self) -> Option<DOMString> {
reflect_cross_origin_attribute(self.upcast::<Element>())
}
// https://html.spec.whatwg.org/multipage/#dom-img-crossOrigin
fn SetCrossOrigin(&self, value: Option<DOMString>, can_gc: CanGc) {
set_cross_origin_attribute(self.upcast::<Element>(), value, can_gc);
}
// https://html.spec.whatwg.org/multipage/#dom-img-usemap
make_getter!(UseMap, "usemap");
// https://html.spec.whatwg.org/multipage/#dom-img-usemap
make_setter!(SetUseMap, "usemap");
// https://html.spec.whatwg.org/multipage/#dom-img-ismap
make_bool_getter!(IsMap, "ismap");
// https://html.spec.whatwg.org/multipage/#dom-img-ismap
make_bool_setter!(SetIsMap, "ismap");
// https://html.spec.whatwg.org/multipage/#dom-img-width
fn Width(&self, can_gc: CanGc) -> u32 {
let node = self.upcast::<Node>();
match node.bounding_content_box(can_gc) {
Some(rect) => rect.size.width.to_px() as u32,
None => self.NaturalWidth(),
}
}
// https://html.spec.whatwg.org/multipage/#dom-img-width
fn SetWidth(&self, value: u32, can_gc: CanGc) {
image_dimension_setter(self.upcast(), local_name!("width"), value, can_gc);
}
// https://html.spec.whatwg.org/multipage/#dom-img-height
fn Height(&self, can_gc: CanGc) -> u32 {
let node = self.upcast::<Node>();
match node.bounding_content_box(can_gc) {
Some(rect) => rect.size.height.to_px() as u32,
None => self.NaturalHeight(),
}
}
// https://html.spec.whatwg.org/multipage/#dom-img-height
fn SetHeight(&self, value: u32, can_gc: CanGc) {
image_dimension_setter(self.upcast(), local_name!("height"), value, can_gc);
}
// https://html.spec.whatwg.org/multipage/#dom-img-naturalwidth
fn NaturalWidth(&self) -> u32 {
let request = self.current_request.borrow();
let pixel_density = request.current_pixel_density.unwrap_or(1f64);
match request.metadata {
Some(ref metadata) => (metadata.width as f64 / pixel_density) as u32,
None => 0,
}
}
// https://html.spec.whatwg.org/multipage/#dom-img-naturalheight
fn NaturalHeight(&self) -> u32 {
let request = self.current_request.borrow();
let pixel_density = request.current_pixel_density.unwrap_or(1f64);
match request.metadata {
Some(ref metadata) => (metadata.height as f64 / pixel_density) as u32,
None => 0,
}
}
// https://html.spec.whatwg.org/multipage/#dom-img-complete
fn Complete(&self) -> bool {
let elem = self.upcast::<Element>();
let srcset_absent = !elem.has_attribute(&local_name!("srcset"));
if !elem.has_attribute(&local_name!("src")) && srcset_absent {
return true;
}
let src = elem.get_string_attribute(&local_name!("src"));
if srcset_absent && src.is_empty() {
return true;
}
let request = self.current_request.borrow();
let request_state = request.state;
match request_state {
State::CompletelyAvailable | State::Broken => true,
State::PartiallyAvailable | State::Unavailable => false,
}
}
// https://html.spec.whatwg.org/multipage/#dom-img-currentsrc
fn CurrentSrc(&self) -> USVString {
let current_request = self.current_request.borrow();
let url = ¤t_request.parsed_url;
match *url {
Some(ref url) => USVString(url.clone().into_string()),
None => {
let unparsed_url = ¤t_request.source_url;
match *unparsed_url {
Some(ref url) => url.clone(),
None => USVString("".to_owned()),
}
},
}
}
/// <https://html.spec.whatwg.org/multipage/#dom-img-referrerpolicy>
fn ReferrerPolicy(&self) -> DOMString {
reflect_referrer_policy_attribute(self.upcast::<Element>())
}
// https://html.spec.whatwg.org/multipage/#dom-img-referrerpolicy
fn SetReferrerPolicy(&self, value: DOMString, can_gc: CanGc) {
let referrerpolicy_attr_name = local_name!("referrerpolicy");
let element = self.upcast::<Element>();
let previous_correct_attribute_value = get_correct_referrerpolicy_from_raw_token(
&element.get_string_attribute(&referrerpolicy_attr_name),
);
let correct_value_or_empty_string = get_correct_referrerpolicy_from_raw_token(&value);
if previous_correct_attribute_value != correct_value_or_empty_string {
// Setting the attribute to the same value will update the image.
// We don't want to start an update if referrerpolicy is set to the same value.
element.set_string_attribute(
&referrerpolicy_attr_name,
correct_value_or_empty_string,
can_gc,
);
}
}
/// <https://html.spec.whatwg.org/multipage/#dom-img-decode>
fn Decode(&self, can_gc: CanGc) -> Rc<Promise> {
// Step 1
let promise = Promise::new(&self.global(), can_gc);
// Step 2
let task = ImageElementMicrotask::Decode {
elem: DomRoot::from_ref(self),
promise: promise.clone(),
};
ScriptThread::await_stable_state(Microtask::ImageElement(task));
// Step 3
promise
}
// https://html.spec.whatwg.org/multipage/#dom-img-name
make_getter!(Name, "name");
// https://html.spec.whatwg.org/multipage/#dom-img-name
make_atomic_setter!(SetName, "name");
// https://html.spec.whatwg.org/multipage/#dom-img-align
make_getter!(Align, "align");
// https://html.spec.whatwg.org/multipage/#dom-img-align
make_setter!(SetAlign, "align");
// https://html.spec.whatwg.org/multipage/#dom-img-hspace
make_uint_getter!(Hspace, "hspace");
// https://html.spec.whatwg.org/multipage/#dom-img-hspace
make_uint_setter!(SetHspace, "hspace");
// https://html.spec.whatwg.org/multipage/#dom-img-vspace
make_uint_getter!(Vspace, "vspace");
// https://html.spec.whatwg.org/multipage/#dom-img-vspace
make_uint_setter!(SetVspace, "vspace");
// https://html.spec.whatwg.org/multipage/#dom-img-longdesc
make_getter!(LongDesc, "longdesc");
// https://html.spec.whatwg.org/multipage/#dom-img-longdesc
make_setter!(SetLongDesc, "longdesc");
// https://html.spec.whatwg.org/multipage/#dom-img-border
make_getter!(Border, "border");
// https://html.spec.whatwg.org/multipage/#dom-img-border
make_setter!(SetBorder, "border");
}
impl VirtualMethods for HTMLImageElement {
fn super_type(&self) -> Option<&dyn VirtualMethods> {
Some(self.upcast::<HTMLElement>() as &dyn VirtualMethods)
}
fn adopting_steps(&self, old_doc: &Document, can_gc: CanGc) {
self.super_type().unwrap().adopting_steps(old_doc, can_gc);
self.update_the_image_data(can_gc);
}
fn attribute_mutated(&self, attr: &Attr, mutation: AttributeMutation, can_gc: CanGc) {
self.super_type()
.unwrap()
.attribute_mutated(attr, mutation, can_gc);
match attr.local_name() {
&local_name!("src") |
&local_name!("srcset") |
&local_name!("width") |
&local_name!("crossorigin") |
&local_name!("sizes") |
&local_name!("referrerpolicy") => self.update_the_image_data(can_gc),
_ => {},
}
}
fn parse_plain_attribute(&self, name: &LocalName, value: DOMString) -> AttrValue {
match name {
&local_name!("width") | &local_name!("height") => {
AttrValue::from_dimension(value.into())
},
&local_name!("hspace") | &local_name!("vspace") => AttrValue::from_u32(value.into(), 0),
_ => self
.super_type()
.unwrap()
.parse_plain_attribute(name, value),
}
}
fn handle_event(&self, event: &Event, can_gc: CanGc) {
if event.type_() != atom!("click") {
return;
}
let area_elements = self.areas();
let elements = match area_elements {
Some(x) => x,
None => return,
};
// Fetch click coordinates
let mouse_event = match event.downcast::<MouseEvent>() {
Some(x) => x,
None => return,
};
let point = Point2D::new(
mouse_event.ClientX().to_f32().unwrap(),
mouse_event.ClientY().to_f32().unwrap(),
);
let bcr = self.upcast::<Element>().GetBoundingClientRect(can_gc);
let bcr_p = Point2D::new(bcr.X() as f32, bcr.Y() as f32);
// Walk HTMLAreaElements
for element in elements {
let shape = element.get_shape_from_coords();
let shp = match shape {
Some(x) => x.absolute_coords(bcr_p),
None => return,
};
if shp.hit_test(&point) {
element.activation_behavior(event, self.upcast(), can_gc);
return;
}
}
}
fn bind_to_tree(&self, context: &BindContext, can_gc: CanGc) {
if let Some(s) = self.super_type() {
s.bind_to_tree(context, can_gc);
}
let document = self.owner_document();
if context.tree_connected {
document.register_responsive_image(self);
}
// The element is inserted into a picture parent element
// https://html.spec.whatwg.org/multipage/#relevant-mutations
if let Some(parent) = self.upcast::<Node>().GetParentElement() {
if parent.is::<HTMLPictureElement>() {
self.update_the_image_data(can_gc);
}
}
}
fn unbind_from_tree(&self, context: &UnbindContext, can_gc: CanGc) {
self.super_type().unwrap().unbind_from_tree(context, can_gc);
let document = self.owner_document();
document.unregister_responsive_image(self);
// The element is removed from a picture parent element
// https://html.spec.whatwg.org/multipage/#relevant-mutations
if context.parent.is::<HTMLPictureElement>() {
self.update_the_image_data(can_gc);
}
}
}
impl FormControl for HTMLImageElement {
fn form_owner(&self) -> Option<DomRoot<HTMLFormElement>> {
self.form_owner.get()
}
fn set_form_owner(&self, form: Option<&HTMLFormElement>) {
self.form_owner.set(form);
}
fn to_element(&self) -> &Element {
self.upcast::<Element>()
}
fn is_listed(&self) -> bool {
false
}
}
fn image_dimension_setter(element: &Element, attr: LocalName, value: u32, can_gc: CanGc) {
// This setter is a bit weird: the IDL type is unsigned long, but it's parsed as
// a dimension for rendering.
let value = if value > UNSIGNED_LONG_MAX { 0 } else { value };
// FIXME: There are probably quite a few more cases of this. This is the
// only overflow that was hitting on automation, but we should consider what
// to do in the general case case.
//
// See <https://github.com/servo/app_units/issues/22>
let pixel_value = if value > (i32::MAX / AU_PER_PX) as u32 {
0
} else {
value
};
let dim = LengthOrPercentageOrAuto::Length(Au::from_px(pixel_value as i32));
let value = AttrValue::Dimension(value.to_string(), dim);
element.set_attribute(&attr, value, can_gc);
}
/// Collect sequence of code points
pub(crate) fn collect_sequence_characters(
s: &str,
mut predicate: impl FnMut(&char) -> bool,
) -> (&str, &str) {
let i = s.find(|ch| !predicate(&ch)).unwrap_or(s.len());
(&s[0..i], &s[i..])
}
/// Parse an `srcset` attribute:
/// <https://html.spec.whatwg.org/multipage/#parsing-a-srcset-attribute>.
pub fn parse_a_srcset_attribute(input: &str) -> Vec<ImageSource> {
// > 1. Let input be the value passed to this algorithm.
// > 2. Let position be a pointer into input, initially pointing at the start of the string.
let mut current_index = 0;
// > 3. Let candidates be an initially empty source set.
let mut candidates = vec![];
while current_index < input.len() {
let remaining_string = &input[current_index..];
// > 4. Splitting loop: Collect a sequence of code points that are ASCII whitespace or
// > U+002C COMMA characters from input given position. If any U+002C COMMA
// > characters were collected, that is a parse error.
let mut collected_comma = false;
let (collected_characters, string_after_whitespace) =
collect_sequence_characters(remaining_string, |character| {
if *character == ',' {
collected_comma = true;
}
*character == ',' || character.is_ascii_whitespace()
});
if collected_comma {
return Vec::new();
}
// Add the length of collected whitespace, to find the start of the URL we are going
// to parse.
current_index += collected_characters.len();
// > 5. If position is past the end of input, return candidates.
if string_after_whitespace.is_empty() {
return candidates;
}
// 6. Collect a sequence of code points that are not ASCII whitespace from input
// given position, and let that be url.
let (url, _) =
collect_sequence_characters(string_after_whitespace, |c| !char::is_ascii_whitespace(c));
// Add the length of `url` that we will parse to advance the index of the next part
// of the string to prase.
current_index += url.len();
// 7. Let descriptors be a new empty list.
let mut descriptors = Vec::new();
// > 8. If url ends with U+002C (,), then:
// > 1. Remove all trailing U+002C COMMA characters from url. If this removed
// > more than one character, that is a parse error.
if url.ends_with(',') {
let image_source = ImageSource {
url: url.trim_end_matches(',').into(),
descriptor: Descriptor {
width: None,
density: None,
},
};
candidates.push(image_source);
continue;
}
// Otherwise:
// > 8.1. Descriptor tokenizer: Skip ASCII whitespace within input given position.
let descriptors_string = &input[current_index..];
let (spaces, descriptors_string) =
collect_sequence_characters(descriptors_string, |character| {
character.is_ascii_whitespace()
});
current_index += spaces.len();
// > 8.2. Let current descriptor be the empty string.
let mut current_descriptor = String::new();
// > 8.3. Let state be "in descriptor".
let mut state = ParseState::InDescriptor;
// > 8.4. Let c be the character at position. Do the following depending on the value of
// > state. For the purpose of this step, "EOF" is a special character representing
// > that position is past the end of input.
let mut characters = descriptors_string.chars();
let mut character = characters.next();
if let Some(character) = character {
current_index += character.len_utf8();
}
loop {
match (state, character) {
(ParseState::InDescriptor, Some(character)) if character.is_ascii_whitespace() => {
// > If current descriptor is not empty, append current descriptor to
// > descriptors and let current descriptor be the empty string. Set
// > state to after descriptor.
if !current_descriptor.is_empty() {
descriptors.push(current_descriptor);
current_descriptor = String::new();
state = ParseState::AfterDescriptor;
}
},
(ParseState::InDescriptor, Some(',')) => {
// > Advance position to the next character in input. If current descriptor
// > is not empty, append current descriptor to descriptors. Jump to the
// > step labeled descriptor parser.
if !current_descriptor.is_empty() {
descriptors.push(current_descriptor);
}
break;
},
(ParseState::InDescriptor, Some('(')) => {
// > Append c to current descriptor. Set state to in parens.
current_descriptor.push('(');
state = ParseState::InParens;
},
(ParseState::InDescriptor, Some(character)) => {
// > Append c to current descriptor.
current_descriptor.push(character);
},
(ParseState::InDescriptor, None) => {
// > If current descriptor is not empty, append current descriptor to
// > descriptors. Jump to the step labeled descriptor parser.
if !current_descriptor.is_empty() {
descriptors.push(current_descriptor);
}
break;
},
(ParseState::InParens, Some(')')) => {
// > Append c to current descriptor. Set state to in descriptor.
current_descriptor.push(')');
state = ParseState::InDescriptor;
},
(ParseState::InParens, Some(character)) => {
// Append c to current descriptor.
current_descriptor.push(character);
},
(ParseState::InParens, None) => {
// > Append current descriptor to descriptors. Jump to the step
// > labeled descriptor parser.
descriptors.push(current_descriptor);
break;
},
(ParseState::AfterDescriptor, Some(character))
if character.is_ascii_whitespace() =>
{
// > Stay in this state.
},
(ParseState::AfterDescriptor, Some(_)) => {
// > Set state to in descriptor. Set position to the previous
// > character in input.
state = ParseState::InDescriptor;
continue;
},
(ParseState::AfterDescriptor, None) => {
// > Jump to the step labeled descriptor parser.
break;
},
}
character = characters.next();
if let Some(character) = character {
current_index += character.len_utf8();
}
}
// > 9. Descriptor parser: Let error be no.
let mut error = false;
// > 10. Let width be absent.
let mut width: Option<u32> = None;
// > 11. Let density be absent.
let mut density: Option<f64> = None;
// > 12. Let future-compat-h be absent.
let mut future_compat_h: Option<u32> = None;
// > 13. For each descriptor in descriptors, run the appropriate set of steps from
// > the following list:
for descriptor in descriptors.into_iter() {
let Some(last_character) = descriptor.chars().last() else {
break;
};
let first_part_of_string = &descriptor[0..descriptor.len() - last_character.len_utf8()];
match last_character {
// > If the descriptor consists of a valid non-negative integer followed by a
// > U+0077 LATIN SMALL LETTER W character
// > 1. If the user agent does not support the sizes attribute, let error be yes.
// > 2. If width and density are not both absent, then let error be yes.
// > 3. Apply the rules for parsing non-negative integers to the descriptor.
// > If the result is 0, let error be yes. Otherwise, let width be the result.
'w' if density.is_none() && width.is_none() => {
match parse_integer(first_part_of_string.chars()) {
Ok(number) if number > 0 => {
width = Some(number as u32);
continue;
},
_ => error = true,
}
},
// > If the descriptor consists of a valid floating-point number followed by a
// > U+0078 LATIN SMALL LETTER X character
// > 1. If width, density and future-compat-h are not all absent, then let
// > error be yes.
// > 2. Apply the rules for parsing floating-point number values to the
// > descriptor. If the result is less than 0, let error be yes. Otherwise, let
// > density be the result.
//
// The HTML specification has a procedure for parsing floats that is different enough from
// the one that stylo uses, that it's better to use Rust's float parser here. This is
// what Gecko does, but it also checks to see if the number is a valid HTML-spec compliant
// number first. Not doing that means that we might be parsing numbers that otherwise
// wouldn't parse.
// TODO: Do what Gecko does and first validate the number passed to the Rust float parser.
'x' if width.is_none() && density.is_none() && future_compat_h.is_none() => {
match first_part_of_string.parse::<f64>() {
Ok(number) if number.is_normal() && number > 0. => {
density = Some(number);
continue;
},
_ => error = true,
}
},
// > If the descriptor consists of a valid non-negative integer followed by a
// > U+0068 LATIN SMALL LETTER H character
// > This is a parse error.
// > 1. If future-compat-h and density are not both absent, then let error be
// > yes.
// > 2. Apply the rules for parsing non-negative integers to the descriptor.
// > If the result is 0, let error be yes. Otherwise, let future-compat-h be the
// > result.
'h' if future_compat_h.is_none() && density.is_none() => {
match parse_integer(first_part_of_string.chars()) {
Ok(number) if number > 0 => {
future_compat_h = Some(number as u32);
continue;
},
_ => error = true,
}
},
// > Anything else
// > Let error be yes.
_ => error = true,
}
if error {
break;
}
}
// > 14. If future-compat-h is not absent and width is absent, let error be yes.
if future_compat_h.is_some() && width.is_none() {
error = true;
}
if !error {
let image_source = ImageSource {
url: url.into(),
descriptor: Descriptor { width, density },
};
candidates.push(image_source);
}
}
candidates
}
#[derive(Clone)]
enum ChangeType {
Environment {
selected_source: USVString,
selected_pixel_density: f64,
},
Element,
}