script/dom/html/
htmllabelelement.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 dom_struct::dom_struct;
6use html5ever::{LocalName, Prefix, local_name};
7use js::rust::HandleObject;
8use style::attr::AttrValue;
9
10use crate::dom::activation::Activatable;
11use crate::dom::attr::Attr;
12use crate::dom::bindings::codegen::Bindings::AttrBinding::AttrMethods;
13use crate::dom::bindings::codegen::Bindings::ElementBinding::ElementMethods;
14use crate::dom::bindings::codegen::Bindings::HTMLElementBinding::HTMLElementMethods;
15use crate::dom::bindings::codegen::Bindings::HTMLLabelElementBinding::HTMLLabelElementMethods;
16use crate::dom::bindings::codegen::Bindings::NodeBinding::{GetRootNodeOptions, NodeMethods};
17use crate::dom::bindings::inheritance::Castable;
18use crate::dom::bindings::root::DomRoot;
19use crate::dom::bindings::str::DOMString;
20use crate::dom::document::Document;
21use crate::dom::element::{AttributeMutation, Element};
22use crate::dom::event::Event;
23use crate::dom::eventtarget::EventTarget;
24use crate::dom::html::htmlelement::HTMLElement;
25use crate::dom::html::htmlformelement::{FormControl, FormControlElementHelpers, HTMLFormElement};
26use crate::dom::node::{Node, ShadowIncluding};
27use crate::dom::virtualmethods::VirtualMethods;
28use crate::script_runtime::CanGc;
29
30#[dom_struct]
31pub(crate) struct HTMLLabelElement {
32    htmlelement: HTMLElement,
33}
34
35impl HTMLLabelElement {
36    fn new_inherited(
37        local_name: LocalName,
38        prefix: Option<Prefix>,
39        document: &Document,
40    ) -> HTMLLabelElement {
41        HTMLLabelElement {
42            htmlelement: HTMLElement::new_inherited(local_name, prefix, document),
43        }
44    }
45
46    pub(crate) fn new(
47        local_name: LocalName,
48        prefix: Option<Prefix>,
49        document: &Document,
50        proto: Option<HandleObject>,
51        can_gc: CanGc,
52    ) -> DomRoot<HTMLLabelElement> {
53        Node::reflect_node_with_proto(
54            Box::new(HTMLLabelElement::new_inherited(
55                local_name, prefix, document,
56            )),
57            document,
58            proto,
59            can_gc,
60        )
61    }
62}
63
64impl Activatable for HTMLLabelElement {
65    fn as_element(&self) -> &Element {
66        self.upcast::<Element>()
67    }
68
69    fn is_instance_activatable(&self) -> bool {
70        true
71    }
72
73    // https://html.spec.whatwg.org/multipage/#the-label-element:activation_behaviour
74    // Basically this is telling us that if activation bubbles up to the label
75    // at all, we are free to do an implementation-dependent thing;
76    // firing a click event is an example, and the precise details of that
77    // click event (e.g. isTrusted) are not specified.
78    fn activation_behavior(&self, _event: &Event, _target: &EventTarget, can_gc: CanGc) {
79        if let Some(e) = self.GetControl() {
80            e.Click(can_gc);
81        }
82    }
83}
84
85impl HTMLLabelElementMethods<crate::DomTypeHolder> for HTMLLabelElement {
86    /// <https://html.spec.whatwg.org/multipage/#dom-fae-form>
87    fn GetForm(&self) -> Option<DomRoot<HTMLFormElement>> {
88        self.form_owner()
89    }
90
91    // https://html.spec.whatwg.org/multipage/#dom-label-htmlfor
92    make_getter!(HtmlFor, "for");
93
94    // https://html.spec.whatwg.org/multipage/#dom-label-htmlfor
95    make_atomic_setter!(SetHtmlFor, "for");
96
97    /// <https://html.spec.whatwg.org/multipage/#dom-label-control>
98    fn GetControl(&self) -> Option<DomRoot<HTMLElement>> {
99        let for_attr = match self.upcast::<Element>().get_attribute(&local_name!("for")) {
100            Some(for_attr) => for_attr,
101            None => return self.first_labelable_descendant(),
102        };
103
104        let for_value = for_attr.Value();
105
106        // "If the attribute is specified and there is an element in the tree
107        // whose ID is equal to the value of the for attribute, and the first
108        // such element in tree order is a labelable element, then that
109        // element is the label element's labeled control."
110        // Two subtle points here: we need to search the _tree_, which is
111        // not necessarily the document if we're detached from the document,
112        // and we only consider one element even if a later element with
113        // the same ID is labelable.
114
115        let maybe_found = self
116            .upcast::<Node>()
117            .GetRootNode(&GetRootNodeOptions::empty())
118            .traverse_preorder(ShadowIncluding::No)
119            .find_map(|e| {
120                if let Some(htmle) = e.downcast::<HTMLElement>() {
121                    if htmle.upcast::<Element>().Id() == for_value {
122                        Some(DomRoot::from_ref(htmle))
123                    } else {
124                        None
125                    }
126                } else {
127                    None
128                }
129            });
130        // We now have the element that we would return, but only return it
131        // if it's labelable.
132        if let Some(ref maybe_labelable) = maybe_found {
133            if maybe_labelable.is_labelable_element() {
134                return maybe_found;
135            }
136        }
137        None
138    }
139}
140
141impl VirtualMethods for HTMLLabelElement {
142    fn super_type(&self) -> Option<&dyn VirtualMethods> {
143        Some(self.upcast::<HTMLElement>() as &dyn VirtualMethods)
144    }
145
146    fn parse_plain_attribute(&self, name: &LocalName, value: DOMString) -> AttrValue {
147        match name {
148            &local_name!("for") => AttrValue::from_atomic(value.into()),
149            _ => self
150                .super_type()
151                .unwrap()
152                .parse_plain_attribute(name, value),
153        }
154    }
155
156    fn attribute_mutated(&self, attr: &Attr, mutation: AttributeMutation, can_gc: CanGc) {
157        self.super_type()
158            .unwrap()
159            .attribute_mutated(attr, mutation, can_gc);
160        if *attr.local_name() == local_name!("form") {
161            self.form_attribute_mutated(mutation, can_gc);
162        }
163    }
164}
165
166impl HTMLLabelElement {
167    pub(crate) fn first_labelable_descendant(&self) -> Option<DomRoot<HTMLElement>> {
168        self.upcast::<Node>()
169            .traverse_preorder(ShadowIncluding::No)
170            .filter_map(DomRoot::downcast::<HTMLElement>)
171            .find(|elem| elem.is_labelable_element())
172    }
173}
174
175impl FormControl for HTMLLabelElement {
176    fn form_owner(&self) -> Option<DomRoot<HTMLFormElement>> {
177        self.GetControl()
178            .map(DomRoot::upcast::<Element>)
179            .and_then(|elem| {
180                elem.as_maybe_form_control()
181                    .and_then(|control| control.form_owner())
182            })
183    }
184
185    fn set_form_owner(&self, _: Option<&HTMLFormElement>) {
186        // Label is a special case for form owner, it reflects its control's
187        // form owner. Therefore it doesn't hold form owner itself.
188    }
189
190    fn to_element(&self) -> &Element {
191        self.upcast::<Element>()
192    }
193}
script/dom/html/htmllabelelement.rs

script/dom/html/
htmllabelelement.rs
