/* 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/. */
//! A gecko snapshot, that stores the element attributes and state before they
//! change in order to properly calculate restyle hints.
use crate::dom::TElement;
use crate::gecko::snapshot_helpers;
use crate::gecko::wrapper::GeckoElement;
use crate::gecko_bindings::bindings;
use crate::gecko_bindings::structs::ServoElementSnapshot;
use crate::gecko_bindings::structs::ServoElementSnapshotFlags as Flags;
use crate::gecko_bindings::structs::ServoElementSnapshotTable;
use crate::invalidation::element::element_wrapper::ElementSnapshot;
use crate::selector_parser::AttrValue;
use crate::string_cache::{Atom, Namespace};
use crate::values::{AtomIdent, AtomString};
use crate::LocalName;
use crate::WeakAtom;
use dom::ElementState;
use selectors::attr::{AttrSelectorOperation, CaseSensitivity, NamespaceConstraint};
/// A snapshot of a Gecko element.
pub type GeckoElementSnapshot = ServoElementSnapshot;
/// A map from elements to snapshots for Gecko's style back-end.
pub type SnapshotMap = ServoElementSnapshotTable;
impl SnapshotMap {
/// Gets the snapshot for this element, if any.
///
/// FIXME(emilio): The transmute() business we do here is kind of nasty, but
/// it's a consequence of the map being a OpaqueNode -> Snapshot table in
/// Servo and an Element -> Snapshot table in Gecko.
///
/// We should be able to make this a more type-safe with type annotations by
/// making SnapshotMap a trait and moving the implementations outside, but
/// that's a pain because it implies parameterizing SharedStyleContext.
pub fn get<E: TElement>(&self, element: &E) -> Option<&GeckoElementSnapshot> {
debug_assert!(element.has_snapshot());
unsafe {
let element = ::std::mem::transmute::<&E, &GeckoElement>(element);
bindings::Gecko_GetElementSnapshot(self, element.0).as_ref()
}
}
}
impl GeckoElementSnapshot {
#[inline]
fn has_any(&self, flags: Flags) -> bool {
(self.mContains as u8 & flags as u8) != 0
}
/// Returns true if the snapshot has stored state for pseudo-classes
/// that depend on things other than `ElementState`.
#[inline]
pub fn has_other_pseudo_class_state(&self) -> bool {
self.has_any(Flags::OtherPseudoClassState)
}
/// Returns true if the snapshot recorded an id change.
#[inline]
pub fn id_changed(&self) -> bool {
self.mIdAttributeChanged()
}
/// Returns true if the snapshot recorded a class attribute change.
#[inline]
pub fn class_changed(&self) -> bool {
self.mClassAttributeChanged()
}
/// Executes the callback once for each attribute that changed.
#[inline]
pub fn each_attr_changed<F>(&self, mut callback: F)
where
F: FnMut(&AtomIdent),
{
for attr in self.mChangedAttrNames.iter() {
unsafe { AtomIdent::with(attr.mRawPtr, &mut callback) }
}
}
/// selectors::Element::attr_matches
pub fn attr_matches(
&self,
ns: &NamespaceConstraint<&Namespace>,
local_name: &LocalName,
operation: &AttrSelectorOperation<&AttrValue>,
) -> bool {
snapshot_helpers::attr_matches(&self.mAttrs, ns, local_name, operation)
}
}
impl ElementSnapshot for GeckoElementSnapshot {
fn debug_list_attributes(&self) -> String {
use nsstring::nsCString;
let mut string = nsCString::new();
unsafe {
bindings::Gecko_Snapshot_DebugListAttributes(self, &mut string);
}
String::from_utf8_lossy(&*string).into_owned()
}
fn state(&self) -> Option<ElementState> {
if self.has_any(Flags::State) {
Some(ElementState::from_bits_retain(self.mState))
} else {
None
}
}
#[inline]
fn has_attrs(&self) -> bool {
self.has_any(Flags::Attributes)
}
#[inline]
fn id_attr(&self) -> Option<&WeakAtom> {
if !self.has_any(Flags::Id) {
return None;
}
snapshot_helpers::get_id(&*self.mAttrs)
}
#[inline]
fn is_part(&self, name: &AtomIdent) -> bool {
let attr = match snapshot_helpers::find_attr(&*self.mAttrs, &atom!("part")) {
Some(attr) => attr,
None => return false,
};
snapshot_helpers::has_class_or_part(name, CaseSensitivity::CaseSensitive, attr)
}
#[inline]
fn imported_part(&self, name: &AtomIdent) -> Option<AtomIdent> {
snapshot_helpers::imported_part(&*self.mAttrs, name)
}
#[inline]
fn has_class(&self, name: &AtomIdent, case_sensitivity: CaseSensitivity) -> bool {
if !self.has_any(Flags::MaybeClass) {
return false;
}
snapshot_helpers::has_class_or_part(name, case_sensitivity, &self.mClass)
}
#[inline]
fn each_class<F>(&self, callback: F)
where
F: FnMut(&AtomIdent),
{
if !self.has_any(Flags::MaybeClass) {
return;
}
snapshot_helpers::each_class_or_part(&self.mClass, callback)
}
#[inline]
fn lang_attr(&self) -> Option<AtomString> {
let ptr = unsafe { bindings::Gecko_SnapshotLangValue(self) };
if ptr.is_null() {
None
} else {
Some(AtomString(unsafe { Atom::from_addrefed(ptr) }))
}
}
/// Returns true if the snapshot has stored state for custom states
#[inline]
fn has_custom_states(&self) -> bool {
self.has_any(Flags::CustomState)
}
/// Returns true if the snapshot has a given CustomState
#[inline]
fn has_custom_state(&self, state: &AtomIdent) -> bool {
unsafe {
self.mCustomStates
.iter()
.any(|setstate| AtomIdent::with(setstate.mRawPtr, |setstate| state == setstate))
}
}
#[inline]
fn each_custom_state<F>(&self, mut callback: F)
where
F: FnMut(&AtomIdent),
{
unsafe {
for atom in self.mCustomStates.iter() {
AtomIdent::with(atom.mRawPtr, &mut callback)
}
}
}
}
