script/dom/execcommand/contenteditable/
text.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 script_bindings::cell::Ref;
6use script_bindings::inheritance::Castable;
7use style::computed_values::white_space_collapse::T as WhiteSpaceCollapse;
8
9use crate::dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
10use crate::dom::characterdata::CharacterData;
11use crate::dom::element::Element;
12use crate::dom::html::htmlbrelement::HTMLBRElement;
13use crate::dom::html::htmlimageelement::HTMLImageElement;
14use crate::dom::iterators::ShadowIncluding;
15use crate::dom::node::Node;
16use crate::dom::text::Text;
17
18impl Text {
19    /// <https://dom.spec.whatwg.org/#concept-cd-data>
20    pub(crate) fn data(&self) -> Ref<'_, String> {
21        self.upcast::<CharacterData>().data()
22    }
23
24    /// <https://w3c.github.io/editing/docs/execCommand/#whitespace-node>
25    pub(crate) fn is_whitespace_node(&self) -> bool {
26        // > A whitespace node is either a Text node whose data is the empty string;
27        let data = self.data();
28        if data.is_empty() {
29            return true;
30        }
31        // > or a Text node whose data consists only of one or more tabs (0x0009), line feeds (0x000A),
32        // > carriage returns (0x000D), and/or spaces (0x0020),
33        // > and whose parent is an Element whose resolved value for "white-space" is "normal" or "nowrap";
34        let Some(parent) = self.upcast::<Node>().GetParentElement() else {
35            return false;
36        };
37        // TODO: Optimize the below to only do a traversal once and in the match handle the expected collapse value
38        let Some(style) = parent.style() else {
39            return false;
40        };
41        let white_space_collapse = style.get_inherited_text().white_space_collapse;
42        if data
43            .bytes()
44            .all(|byte| matches!(byte, b'\t' | b'\n' | b'\r' | b' ')) &&
45            // Note that for "normal" and "nowrap", the longhand "white-space-collapse: collapse" applies
46            // https://www.w3.org/TR/css-text-4/#white-space-property
47            white_space_collapse == WhiteSpaceCollapse::Collapse
48        {
49            return true;
50        }
51        // > or a Text node whose data consists only of one or more tabs (0x0009), carriage returns (0x000D),
52        // > and/or spaces (0x0020), and whose parent is an Element whose resolved value for "white-space" is "pre-line".
53        data.bytes()
54            .all(|byte| matches!(byte, b'\t' | b'\r' | b' ')) &&
55            // Note that for "pre-line", the longhand "white-space-collapse: preserve-breaks" applies
56            // https://www.w3.org/TR/css-text-4/#white-space-property
57            white_space_collapse == WhiteSpaceCollapse::PreserveBreaks
58    }
59
60    /// <https://w3c.github.io/editing/docs/execCommand/#collapsed-whitespace-node>
61    pub(crate) fn is_collapsed_whitespace_node(&self) -> bool {
62        // Step 1. If node is not a whitespace node, return false.
63        if !self.is_whitespace_node() {
64            return false;
65        }
66        // Step 2. If node's data is the empty string, return true.
67        if self.data().is_empty() {
68            return true;
69        }
70        // Step 3. Let ancestor be node's parent.
71        let node = self.upcast::<Node>();
72        let Some(ancestor) = node.GetParentNode() else {
73            // Step 4. If ancestor is null, return true.
74            return true;
75        };
76        let mut resolved_ancestor = ancestor.clone();
77        for parent in ancestor.ancestors() {
78            // Step 5. If the "display" property of some ancestor of node has resolved value "none", return true.
79            if parent
80                .downcast::<Element>()
81                .is_some_and(Element::is_display_none)
82            {
83                return true;
84            }
85            // Step 6. While ancestor is not a block node and its parent is not null, set ancestor to its parent.
86            //
87            // Note that the spec is written as "while not". Since this is the end-condition, we need to invert
88            // the condition to decide when to stop.
89            if parent.is_block_node() {
90                break;
91            }
92            resolved_ancestor = parent;
93        }
94        // Step 7. Let reference be node.
95        // Step 8. While reference is a descendant of ancestor:
96        // Step 8.1. Let reference be the node before it in tree order.
97        for reference in node.preceding_nodes(&resolved_ancestor) {
98            // Step 8.2. If reference is a block node or a br, return true.
99            if reference.is_block_node() || reference.is::<HTMLBRElement>() {
100                return true;
101            }
102            // Step 8.3. If reference is a Text node that is not a whitespace node, or is an img, break from this loop.
103            if reference
104                .downcast::<Text>()
105                .is_some_and(|text| !text.is_whitespace_node()) ||
106                reference.is::<HTMLImageElement>()
107            {
108                break;
109            }
110        }
111        // Step 9. Let reference be node.
112        // Step 10. While reference is a descendant of ancestor:
113        // Step 10.1. Let reference be the node after it in tree order, or null if there is no such node.
114        for reference in node.following_nodes(&resolved_ancestor, ShadowIncluding::No) {
115            // Step 10.2. If reference is a block node or a br, return true.
116            if reference.is_block_node() || reference.is::<HTMLBRElement>() {
117                return true;
118            }
119            // Step 10.3. If reference is a Text node that is not a whitespace node, or is an img, break from this loop.
120            if reference
121                .downcast::<Text>()
122                .is_some_and(|text| !text.is_whitespace_node()) ||
123                reference.is::<HTMLImageElement>()
124            {
125                break;
126            }
127        }
128        // Step 11. Return false.
129        false
130    }
131
132    /// Part of <https://w3c.github.io/editing/docs/execCommand/#canonicalize-whitespace>
133    /// and deduplicated here, since we need to do this for both start and end nodes
134    pub(crate) fn has_whitespace_and_has_parent_with_whitespace_preserve(
135        &self,
136        offset: u32,
137        space_characters: &'static [&'static char],
138    ) -> bool {
139        // if node is a Text node and its parent's resolved value for "white-space" is neither "pre" nor "pre-wrap"
140        // and start offset is not zero and the (start offset − 1)st code unit of start node's data is a space (0x0020) or
141        // non-breaking space (0x00A0)
142        let has_preserve_space = self
143            .upcast::<Node>()
144            .GetParentNode()
145            .and_then(|parent_node| parent_node.downcast::<Element>().and_then(Element::style))
146            .is_some_and(|style| {
147                // Note that for "pre" and "pre-wrap", the longhand "white-space-collapse: preserve" applies
148                // https://www.w3.org/TR/css-text-4/#white-space-property
149                style.get_inherited_text().white_space_collapse != WhiteSpaceCollapse::Preserve
150            });
151        let has_space_character = self
152            .data()
153            .chars()
154            .nth(offset as usize)
155            .is_some_and(|c| space_characters.contains(&&c));
156        has_preserve_space && has_space_character
157    }
158}
script/dom/execcommand/contenteditable/text.rs

script/dom/execcommand/contenteditable/
text.rs
