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helix-plus/helix-view/src/tree.rs

377 lines
10 KiB
Rust

use crate::View;
use slotmap::{DefaultKey as Key, HopSlotMap};
use tui::layout::Rect;
// the dimensions are recomputed on windo resize/tree change.
//
pub struct Tree {
root: Key,
// (container, index inside the container)
pub focus: Key,
// fullscreen: bool,
area: Rect,
nodes: HopSlotMap<Key, Node>,
// used for traversals
stack: Vec<(Key, Rect)>,
}
pub struct Node {
parent: Key,
content: Content,
}
pub enum Content {
View(Box<View>),
Container(Box<Container>),
}
impl Node {
pub fn container() -> Self {
Node {
parent: Key::default(),
content: Content::Container(Box::new(Container::new())),
}
}
pub fn view(view: View) -> Self {
Node {
parent: Key::default(),
content: Content::View(Box::new(view)),
}
}
}
// TODO: screen coord to container + container coordinate helpers
pub enum Layout {
Horizontal,
Vertical,
// could explore stacked/tabbed
}
pub struct Container {
layout: Layout,
children: Vec<Key>,
area: Rect,
}
impl Container {
pub fn new() -> Self {
Self {
layout: Layout::Horizontal,
children: Vec::new(),
area: Rect::default(),
}
}
}
impl Default for Container {
fn default() -> Self {
Self::new()
}
}
impl Tree {
pub fn new(area: Rect) -> Self {
let root = Node::container();
let mut nodes = HopSlotMap::new();
let root = nodes.insert(root);
// root is it's own parent
nodes[root].parent = root;
Self {
root,
focus: root,
// fullscreen: false,
area,
nodes,
stack: Vec::new(),
}
}
pub fn insert(&mut self, view: View) -> Key {
let focus = self.focus;
let parent = self.nodes[focus].parent;
let mut node = Node::view(view);
node.parent = parent;
let node = self.nodes.insert(node);
self.get_mut(node).id = node;
let container = match &mut self.nodes[parent] {
Node {
content: Content::Container(container),
..
} => container,
_ => unreachable!(),
};
// insert node after the current item if there is children already
let pos = if container.children.is_empty() {
0
} else {
let pos = container
.children
.iter()
.position(|&child| child == focus)
.unwrap();
pos + 1
};
container.children.insert(pos, node);
// focus the new node
self.focus = node;
// recalculate all the sizes
self.recalculate();
node
}
pub fn remove(&mut self, index: Key) {
let mut stack = Vec::new();
if self.focus == index {
// focus on something else
self.focus_next();
}
stack.push(index);
while let Some(index) = stack.pop() {
let parent_id = self.nodes[index].parent;
if let Node {
content: Content::Container(container),
..
} = &mut self.nodes[parent_id]
{
if let Some(pos) = container.children.iter().position(|&child| child == index) {
container.children.remove(pos);
// TODO: if container now only has one child, remove it and place child in parent
if container.children.is_empty() && parent_id != self.root {
// if container now empty, remove it
stack.push(parent_id);
}
}
}
self.nodes.remove(index);
}
self.recalculate()
}
pub fn views(&mut self) -> impl Iterator<Item = (&mut View, bool)> {
let focus = self.focus;
self.nodes
.iter_mut()
.filter_map(move |(key, node)| match node {
Node {
content: Content::View(view),
..
} => Some((view.as_mut(), focus == key)),
_ => None,
})
}
pub fn get(&self, index: Key) -> &View {
match &self.nodes[index] {
Node {
content: Content::View(view),
..
} => view,
_ => unreachable!(),
}
}
pub fn get_mut(&mut self, index: Key) -> &mut View {
match &mut self.nodes[index] {
Node {
content: Content::View(view),
..
} => view,
_ => unreachable!(),
}
}
pub fn is_empty(&self) -> bool {
match &self.nodes[self.root] {
Node {
content: Content::Container(container),
..
} => container.children.is_empty(),
_ => unreachable!(),
}
}
pub fn resize(&mut self, area: Rect) {
self.area = area;
self.recalculate();
}
pub fn recalculate(&mut self) {
if self.is_empty() {
return;
}
self.stack.push((self.root, self.area));
// take the area
// fetch the node
// a) node is view, give it whole area
// b) node is container, calculate areas for each child and push them on the stack
while let Some((key, area)) = self.stack.pop() {
let node = &mut self.nodes[key];
match &mut node.content {
Content::View(view) => {
// debug!!("setting view area {:?}", area);
view.area = area;
} // TODO: call f()
Content::Container(container) => {
// debug!!("setting container area {:?}", area);
container.area = area;
match container.layout {
Layout::Vertical => {
let len = container.children.len();
let height = area.height / len as u16;
let mut child_y = area.y;
for (i, child) in container.children.iter().enumerate() {
let mut area = Rect::new(
container.area.x,
child_y,
container.area.width,
height,
);
child_y += height;
// last child takes the remaining width because we can get uneven
// space from rounding
if i == len - 1 {
area.height = container.area.y + container.area.height - area.y;
}
self.stack.push((*child, area));
}
}
Layout::Horizontal => {
let len = container.children.len();
let width = area.width / len as u16;
let mut child_x = area.x;
for (i, child) in container.children.iter().enumerate() {
let mut area = Rect::new(
child_x,
container.area.y,
width,
container.area.height,
);
child_x += width;
// last child takes the remaining width because we can get uneven
// space from rounding
if i == len - 1 {
area.width = container.area.x + container.area.width - area.x;
}
self.stack.push((*child, area));
}
}
}
}
}
}
}
pub fn traverse(&self) -> Traverse {
Traverse::new(self)
}
pub fn focus_next(&mut self) {
// This function is very dumb, but that's because we don't store any parent links.
// (we'd be able to go parent.next_sibling() recursively until we find something)
// For now that's okay though, since it's unlikely you'll be able to open a large enough
// number of splits to notice.
// current = focus
// let found = loop do {
// node = focus.parent;
// let found = node.next_sibling_of(current)
// if some {
// break found;
// }
// // else
// if node == root {
// return first child of root;
// };
// current = parent;
// }
// }
//
// use found next sibling
// loop do {
// if found = view -> focus = found, return
// if found = container -> found = first child
// }
let iter = self.traverse();
let mut iter = iter.skip_while(|&(key, _view)| key != self.focus);
iter.next(); // take the focused value
match iter.next() {
Some((key, _)) => {
self.focus = key;
}
None => {
// extremely crude, take the first item again
let (key, _) = self.traverse().next().unwrap();
self.focus = key;
}
}
}
}
pub struct Traverse<'a> {
tree: &'a Tree,
stack: Vec<Key>, // TODO: reuse the one we use on update
}
impl<'a> Traverse<'a> {
fn new(tree: &'a Tree) -> Self {
Self {
tree,
stack: vec![tree.root],
}
}
}
impl<'a> Iterator for Traverse<'a> {
type Item = (Key, &'a View);
fn next(&mut self) -> Option<Self::Item> {
loop {
let key = self.stack.pop()?;
let node = &self.tree.nodes[key];
match &node.content {
Content::View(view) => return Some((key, view)),
Content::Container(container) => {
self.stack.extend(container.children.iter().rev());
}
}
}
}
}