1use core::ops::Drop;
2
3use crate::forest::Forest;
4use crate::geometry::Size;
5use crate::id::{self, NodeId};
6use crate::number::Number;
7use crate::result::Layout;
8use crate::style::*;
9use crate::sys;
10use crate::Error;
11
12pub enum MeasureFunc {
13 Raw(fn(Size<Number>) -> Size<f32>),
14 #[cfg(any(feature = "std", feature = "alloc"))]
15 Boxed(sys::Box<dyn Fn(Size<Number>) -> Size<f32>>),
16}
17
18lazy_static! {
19 /// Global stretch instance id allocator.
20 static ref INSTANCE_ALLOCATOR: id::Allocator = id::Allocator::new();
21}
22
23#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
24#[cfg_attr(not(any(feature = "std", feature = "alloc")), derive(hash32_derive::Hash32))]
25pub struct Node {
26 instance: id::Id,
27 local: id::Id,
28}
29
30pub struct Stretch {
31 id: id::Id,
32 nodes: id::Allocator,
33 nodes_to_ids: crate::sys::Map<Node, NodeId>,
34 ids_to_nodes: crate::sys::Map<NodeId, Node>,
35 forest: Forest,
36}
37
38impl Default for Stretch {
39 fn default() -> Self {
40 Stretch::with_capacity(16)
41 }
42}
43
44impl Stretch {
45 pub fn new() -> Self {
46 Default::default()
47 }
48
49 pub fn with_capacity(capacity: usize) -> Self {
50 Stretch {
51 id: INSTANCE_ALLOCATOR.allocate(),
52 nodes: id::Allocator::new(),
53 nodes_to_ids: crate::sys::new_map_with_capacity(capacity),
54 ids_to_nodes: crate::sys::new_map_with_capacity(capacity),
55 forest: Forest::with_capacity(capacity),
56 }
57 }
58
59 fn allocate_node(&mut self) -> Node {
60 let local = self.nodes.allocate();
61 Node { instance: self.id, local }
62 }
63
64 fn add_node(&mut self, node: Node, id: NodeId) {
65 let _ = self.nodes_to_ids.insert(node, id);
66 let _ = self.ids_to_nodes.insert(id, node);
67 }
68
69 // Find node in the forest.
70 fn find_node(&self, node: Node) -> Result<NodeId, Error> {
71 match self.nodes_to_ids.get(&node) {
72 Some(id) => Ok(*id),
73 None => Err(Error::InvalidNode(node)),
74 }
75 }
76
77 pub fn new_leaf(&mut self, style: Style, measure: MeasureFunc) -> Result<Node, Error> {
78 let node = self.allocate_node();
79 let id = self.forest.new_leaf(style, measure);
80 self.add_node(node, id);
81 Ok(node)
82 }
83
84 pub fn new_node(&mut self, style: Style, children: &[Node]) -> Result<Node, Error> {
85 let node = self.allocate_node();
86 let children =
87 children.iter().map(|child| self.find_node(*child)).collect::<Result<sys::ChildrenVec<_>, Error>>()?;
88 let id = self.forest.new_node(style, children);
89 self.add_node(node, id);
90 Ok(node)
91 }
92
93 /// Removes all nodes.
94 ///
95 /// All associated nodes will be invalid.
96 pub fn clear(&mut self) {
97 for node in self.nodes_to_ids.keys() {
98 self.nodes.free(&[node.local]);
99 }
100 self.nodes_to_ids.clear();
101 self.ids_to_nodes.clear();
102 self.forest.clear();
103 }
104
105 /// Remove nodes.
106 pub fn remove(&mut self, node: Node) {
107 let id = if let Ok(id) = self.find_node(node) { id } else { return };
108
109 self.nodes_to_ids.remove(&node);
110 self.ids_to_nodes.remove(&id);
111
112 if let Some(new_id) = self.forest.swap_remove(id) {
113 let new = self.ids_to_nodes.remove(&new_id).unwrap();
114 let _ = self.nodes_to_ids.insert(new, id);
115 let _ = self.ids_to_nodes.insert(id, new);
116 }
117 }
118
119 pub fn set_measure(&mut self, node: Node, measure: Option<MeasureFunc>) -> Result<(), Error> {
120 let id = self.find_node(node)?;
121 self.forest.nodes[id].measure = measure;
122 self.forest.mark_dirty(id);
123 Ok(())
124 }
125
126 pub fn add_child(&mut self, node: Node, child: Node) -> Result<(), Error> {
127 let node_id = self.find_node(node)?;
128 let child_id = self.find_node(child)?;
129
130 self.forest.add_child(node_id, child_id);
131 Ok(())
132 }
133
134 pub fn set_children(&mut self, node: Node, children: &[Node]) -> Result<(), Error> {
135 let node_id = self.find_node(node)?;
136 let children_id =
137 children.iter().map(|child| self.find_node(*child)).collect::<Result<sys::ChildrenVec<_>, _>>()?;
138
139 // Remove node as parent from all its current children.
140 for child in &self.forest.children[node_id] {
141 self.forest.parents[*child].retain(|p| *p != node_id);
142 }
143
144 // Build up relation node <-> child
145 for child in &children_id {
146 self.forest.parents[*child].push(node_id);
147 }
148 self.forest.children[node_id] = children_id;
149
150 self.forest.mark_dirty(node_id);
151 Ok(())
152 }
153
154 pub fn remove_child(&mut self, node: Node, child: Node) -> Result<Node, Error> {
155 let node_id = self.find_node(node)?;
156 let child_id = self.find_node(child)?;
157
158 let prev_id = unsafe { self.forest.remove_child(node_id, child_id) };
159 Ok(self.ids_to_nodes[&prev_id])
160 }
161
162 pub fn remove_child_at_index(&mut self, node: Node, index: usize) -> Result<Node, Error> {
163 let node_id = self.find_node(node)?;
164 // TODO: index check
165
166 let prev_id = self.forest.remove_child_at_index(node_id, index);
167 Ok(self.ids_to_nodes[&prev_id])
168 }
169
170 pub fn replace_child_at_index(&mut self, node: Node, index: usize, child: Node) -> Result<Node, Error> {
171 let node_id = self.find_node(node)?;
172 let child_id = self.find_node(child)?;
173 // TODO: index check
174
175 self.forest.parents[child_id].push(node_id);
176 let old_child = core::mem::replace(&mut self.forest.children[node_id][index], child_id);
177 self.forest.parents[old_child].retain(|p| *p != node_id);
178
179 self.forest.mark_dirty(node_id);
180
181 Ok(self.ids_to_nodes[&old_child])
182 }
183
184 pub fn children(&self, node: Node) -> Result<sys::Vec<Node>, Error> {
185 let id = self.find_node(node)?;
186 Ok(self.forest.children[id].iter().map(|child| self.ids_to_nodes[child]).collect())
187 }
188
189 pub fn child_at_index(&self, node: Node, index: usize) -> Result<Node, Error> {
190 let id = self.find_node(node)?;
191 Ok(self.ids_to_nodes[&self.forest.children[id][index]])
192 }
193
194 pub fn child_count(&self, node: Node) -> Result<usize, Error> {
195 let id = self.find_node(node)?;
196 Ok(self.forest.children[id].len())
197 }
198
199 pub fn set_style(&mut self, node: Node, style: Style) -> Result<(), Error> {
200 let id = self.find_node(node)?;
201 self.forest.nodes[id].style = style;
202 self.forest.mark_dirty(id);
203 Ok(())
204 }
205
206 pub fn style(&self, node: Node) -> Result<&Style, Error> {
207 let id = self.find_node(node)?;
208 Ok(&self.forest.nodes[id].style)
209 }
210
211 pub fn layout(&self, node: Node) -> Result<&Layout, Error> {
212 let id = self.find_node(node)?;
213 Ok(&self.forest.nodes[id].layout)
214 }
215
216 pub fn mark_dirty(&mut self, node: Node) -> Result<(), Error> {
217 let id = self.find_node(node)?;
218 self.forest.mark_dirty(id);
219 Ok(())
220 }
221
222 pub fn dirty(&self, node: Node) -> Result<bool, Error> {
223 let id = self.find_node(node)?;
224 Ok(self.forest.nodes[id].is_dirty)
225 }
226
227 pub fn compute_layout(&mut self, node: Node, size: Size<Number>) -> Result<(), Error> {
228 let id = self.find_node(node)?;
229 self.forest.compute_layout(id, size);
230 Ok(())
231 }
232}
233
234impl Drop for Stretch {
235 fn drop(&mut self) {
236 INSTANCE_ALLOCATOR.free(&[self.id]);
237 }
238}