use crate::{View, ViewId}; use slotmap::HopSlotMap; use tui::layout::Rect; // the dimensions are recomputed on windo resize/tree change. // pub struct Tree { root: ViewId, // (container, index inside the container) pub focus: ViewId, // fullscreen: bool, area: Rect, nodes: HopSlotMap, // used for traversals stack: Vec<(ViewId, Rect)>, } pub struct Node { parent: ViewId, content: Content, } pub enum Content { View(Box), Container(Box), } impl Node { pub fn container(layout: Layout) -> Self { Self { parent: ViewId::default(), content: Content::Container(Box::new(Container::new(layout))), } } pub fn view(view: View) -> Self { Self { parent: ViewId::default(), content: Content::View(Box::new(view)), } } } // TODO: screen coord to container + container coordinate helpers #[derive(PartialEq, Eq)] pub enum Layout { Horizontal, Vertical, // could explore stacked/tabbed } pub struct Container { layout: Layout, children: Vec, area: Rect, } impl Container { pub fn new(layout: Layout) -> Self { Self { layout, children: Vec::new(), area: Rect::default(), } } } impl Default for Container { fn default() -> Self { Self::new(Layout::Vertical) } } impl Tree { pub fn new(area: Rect) -> Self { let root = Node::container(Layout::Vertical); let mut nodes = HopSlotMap::with_key(); 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) -> ViewId { 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 split(&mut self, view: View, layout: Layout) -> ViewId { let focus = self.focus; let parent = self.nodes[focus].parent; let node = Node::view(view); 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!(), }; if container.layout == layout { // 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); self.nodes[node].parent = parent; } else { let mut split = Node::container(layout); split.parent = parent; let split = self.nodes.insert(split); let container = match &mut self.nodes[split] { Node { content: Content::Container(container), .. } => container, _ => unreachable!(), }; container.children.push(focus); container.children.push(node); self.nodes[focus].parent = split; self.nodes[node].parent = split; let container = match &mut self.nodes[parent] { Node { content: Content::Container(container), .. } => container, _ => unreachable!(), }; let pos = container .children .iter() .position(|&child| child == focus) .unwrap(); // replace focus on parent with split container.children[pos] = split; } // focus the new node self.focus = node; // recalculate all the sizes self.recalculate(); node } pub fn remove(&mut self, index: ViewId) { 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(&self) -> impl Iterator { let focus = self.focus; self.nodes.iter().filter_map(move |(key, node)| match node { Node { content: Content::View(view), .. } => Some((view.as_ref(), focus == key)), _ => None, }) } pub fn views_mut(&mut self) -> impl Iterator { 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: ViewId) -> &View { match &self.nodes[index] { Node { content: Content::View(view), .. } => view, _ => unreachable!(), } } pub fn get_mut(&mut self, index: ViewId) -> &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::Horizontal => { 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::Vertical => { 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 if let Some((key, _)) = iter.next() { self.focus = key; } else { // 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, // 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 = (ViewId, &'a View); fn next(&mut self) -> Option { 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()); } } } } }