script/dom/node/
nodelist.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use std::cell::RefCell;
6
7use dom_struct::dom_struct;
8use js::context::JSContext;
9use script_bindings::reflector::{Reflector, reflect_dom_object_with_cx};
10use stylo_atoms::Atom;
11
12use crate::dom::ChildrenMutation;
13use crate::dom::bindings::codegen::Bindings::NodeListBinding::NodeListMethods;
14use crate::dom::bindings::root::{Dom, DomRoot};
15use crate::dom::bindings::str::DOMString;
16use crate::dom::document::Document;
17use crate::dom::html::htmlelement::HTMLElement;
18use crate::dom::html::htmlformelement::HTMLFormElement;
19use crate::dom::node::Node;
20use crate::dom::window::Window;
21
22#[derive(JSTraceable, MallocSizeOf)]
23#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
24pub(crate) enum NodeListType {
25    Simple(Vec<Dom<Node>>),
26    Children(ChildrenList),
27    Labels(LabelsList),
28    Radio(RadioList),
29    ElementsByName(ElementsByNameList),
30}
31
32// https://dom.spec.whatwg.org/#interface-nodelist
33#[dom_struct]
34pub(crate) struct NodeList {
35    reflector_: Reflector,
36    list_type: NodeListType,
37}
38
39impl NodeList {
40    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
41    pub(crate) fn new_inherited(list_type: NodeListType) -> NodeList {
42        NodeList {
43            reflector_: Reflector::new(),
44            list_type,
45        }
46    }
47
48    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
49    pub(crate) fn new(
50        cx: &mut JSContext,
51        window: &Window,
52        list_type: NodeListType,
53    ) -> DomRoot<NodeList> {
54        reflect_dom_object_with_cx(Box::new(NodeList::new_inherited(list_type)), window, cx)
55    }
56
57    pub(crate) fn new_simple_list<T>(
58        cx: &mut JSContext,
59        window: &Window,
60        iter: T,
61    ) -> DomRoot<NodeList>
62    where
63        T: Iterator<Item = DomRoot<Node>>,
64    {
65        NodeList::new(
66            cx,
67            window,
68            NodeListType::Simple(iter.map(|r| Dom::from_ref(&*r)).collect()),
69        )
70    }
71
72    pub(crate) fn new_simple_list_slice(
73        cx: &mut JSContext,
74        window: &Window,
75        slice: &[&Node],
76    ) -> DomRoot<NodeList> {
77        NodeList::new(
78            cx,
79            window,
80            NodeListType::Simple(slice.iter().map(|r| Dom::from_ref(*r)).collect()),
81        )
82    }
83
84    pub(crate) fn new_child_list(
85        cx: &mut JSContext,
86        window: &Window,
87        node: &Node,
88    ) -> DomRoot<NodeList> {
89        NodeList::new(cx, window, NodeListType::Children(ChildrenList::new(node)))
90    }
91
92    pub(crate) fn new_labels_list(
93        cx: &mut JSContext,
94        window: &Window,
95        element: &HTMLElement,
96    ) -> DomRoot<NodeList> {
97        NodeList::new(cx, window, NodeListType::Labels(LabelsList::new(element)))
98    }
99
100    pub(crate) fn new_elements_by_name_list(
101        cx: &mut JSContext,
102        window: &Window,
103        document: &Document,
104        name: DOMString,
105    ) -> DomRoot<NodeList> {
106        NodeList::new(
107            cx,
108            window,
109            NodeListType::ElementsByName(ElementsByNameList::new(document, name)),
110        )
111    }
112
113    pub(crate) fn empty(cx: &mut JSContext, window: &Window) -> DomRoot<NodeList> {
114        NodeList::new(cx, window, NodeListType::Simple(vec![]))
115    }
116}
117
118impl NodeListMethods<crate::DomTypeHolder> for NodeList {
119    /// <https://dom.spec.whatwg.org/#dom-nodelist-length>
120    fn Length(&self) -> u32 {
121        match self.list_type {
122            NodeListType::Simple(ref elems) => elems.len() as u32,
123            NodeListType::Children(ref list) => list.len(),
124            NodeListType::Labels(ref list) => list.len(),
125            NodeListType::Radio(ref list) => list.len(),
126            NodeListType::ElementsByName(ref list) => list.len(),
127        }
128    }
129
130    /// <https://dom.spec.whatwg.org/#dom-nodelist-item>
131    fn Item(&self, index: u32) -> Option<DomRoot<Node>> {
132        match self.list_type {
133            NodeListType::Simple(ref elems) => elems
134                .get(index as usize)
135                .map(|node| DomRoot::from_ref(&**node)),
136            NodeListType::Children(ref list) => list.item(index),
137            NodeListType::Labels(ref list) => list.item(index),
138            NodeListType::Radio(ref list) => list.item(index),
139            NodeListType::ElementsByName(ref list) => list.item(index),
140        }
141    }
142
143    /// <https://dom.spec.whatwg.org/#dom-nodelist-item>
144    fn IndexedGetter(&self, index: u32) -> Option<DomRoot<Node>> {
145        self.Item(index)
146    }
147}
148
149impl NodeList {
150    pub(crate) fn as_children_list(&self) -> &ChildrenList {
151        if let NodeListType::Children(ref list) = self.list_type {
152            list
153        } else {
154            panic!("called as_children_list() on a non-children node list")
155        }
156    }
157
158    pub(crate) fn iter(&self) -> impl Iterator<Item = DomRoot<Node>> + '_ {
159        let len = self.Length();
160        // There is room for optimization here in non-simple cases,
161        // as calling Item repeatedly on a live list can involve redundant work.
162        (0..len).flat_map(move |i| self.Item(i))
163    }
164}
165
166#[derive(JSTraceable, MallocSizeOf)]
167#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
168pub(crate) struct ChildrenList {
169    node: Dom<Node>,
170    cached_children: RefCell<Option<Vec<Dom<Node>>>>,
171}
172
173impl ChildrenList {
174    pub(crate) fn new(node: &Node) -> ChildrenList {
175        ChildrenList {
176            node: Dom::from_ref(node),
177            cached_children: RefCell::new(None),
178        }
179    }
180
181    pub(crate) fn len(&self) -> u32 {
182        self.node.children_count()
183    }
184
185    pub(crate) fn item(&self, index: u32) -> Option<DomRoot<Node>> {
186        self.cached_children
187            .borrow_mut()
188            .get_or_insert_with(|| {
189                self.node
190                    .children()
191                    .map(|child| Dom::from_ref(&*child))
192                    .collect()
193            })
194            .get(index as usize)
195            .map(|child| DomRoot::from_ref(&**child))
196    }
197
198    pub(crate) fn children_changed(&self, mutation: &ChildrenMutation) {
199        match mutation {
200            ChildrenMutation::Append { .. } |
201            ChildrenMutation::Insert { .. } |
202            ChildrenMutation::Prepend { .. } |
203            ChildrenMutation::Replace { .. } |
204            ChildrenMutation::ReplaceAll { .. } => *self.cached_children.borrow_mut() = None,
205            ChildrenMutation::ChangeText => {},
206        }
207    }
208}
209
210// Labels lists: There might be room for performance optimization
211// analogous to the ChildrenMutation case of a children list,
212// in which we can keep information from an older access live
213// if we know nothing has happened that would change it.
214// However, label relationships can happen from further away
215// in the DOM than parent-child relationships, so it's not as simple,
216// and it's possible that tracking label moves would end up no faster
217// than recalculating labels.
218#[derive(JSTraceable, MallocSizeOf)]
219#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
220pub(crate) struct LabelsList {
221    element: Dom<HTMLElement>,
222}
223
224impl LabelsList {
225    pub(crate) fn new(element: &HTMLElement) -> LabelsList {
226        LabelsList {
227            element: Dom::from_ref(element),
228        }
229    }
230
231    pub(crate) fn len(&self) -> u32 {
232        self.element.labels_count()
233    }
234
235    pub(crate) fn item(&self, index: u32) -> Option<DomRoot<Node>> {
236        self.element.label_at(index)
237    }
238}
239
240// Radio node lists: There is room for performance improvement here;
241// a form is already aware of changes to its set of controls,
242// so a radio list can cache and cache-invalidate its contents
243// just by hooking into what the form already knows without a
244// separate mutation observer. FIXME #25482
245#[derive(Clone, Copy, JSTraceable, MallocSizeOf)]
246pub(crate) enum RadioListMode {
247    ControlsExceptImageInputs,
248    Images,
249}
250
251#[derive(JSTraceable, MallocSizeOf)]
252#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
253pub(crate) struct RadioList {
254    form: Dom<HTMLFormElement>,
255    mode: RadioListMode,
256    #[no_trace]
257    name: Atom,
258}
259
260impl RadioList {
261    pub(crate) fn new(form: &HTMLFormElement, mode: RadioListMode, name: Atom) -> RadioList {
262        RadioList {
263            form: Dom::from_ref(form),
264            mode,
265            name,
266        }
267    }
268
269    pub(crate) fn len(&self) -> u32 {
270        self.form.count_for_radio_list(self.mode, &self.name)
271    }
272
273    pub(crate) fn item(&self, index: u32) -> Option<DomRoot<Node>> {
274        self.form.nth_for_radio_list(index, self.mode, &self.name)
275    }
276}
277
278#[derive(JSTraceable, MallocSizeOf)]
279#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
280pub(crate) struct ElementsByNameList {
281    document: Dom<Document>,
282    name: DOMString,
283}
284
285impl ElementsByNameList {
286    pub(crate) fn new(document: &Document, name: DOMString) -> ElementsByNameList {
287        ElementsByNameList {
288            document: Dom::from_ref(document),
289            name,
290        }
291    }
292
293    pub(crate) fn len(&self) -> u32 {
294        self.document.elements_by_name_count(&self.name)
295    }
296
297    pub(crate) fn item(&self, index: u32) -> Option<DomRoot<Node>> {
298        self.document
299            .nth_element_by_name(index, &self.name)
300            .map(|n| DomRoot::from_ref(&*n))
301    }
302}
script/dom/node/nodelist.rs

script/dom/node/
nodelist.rs
