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Diffstat (limited to 'widget/src/pane_grid/state.rs')
| -rw-r--r-- | widget/src/pane_grid/state.rs | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/widget/src/pane_grid/state.rs b/widget/src/pane_grid/state.rs new file mode 100644 index 00000000..6fd15890 --- /dev/null +++ b/widget/src/pane_grid/state.rs @@ -0,0 +1,447 @@ +//! The state of a [`PaneGrid`]. +//! +//! [`PaneGrid`]: crate::widget::PaneGrid +use crate::core::{Point, Size}; +use crate::pane_grid::{ + Axis, Configuration, Direction, Edge, Node, Pane, Region, Split, Target, +}; + +use std::collections::HashMap; + +/// The state of a [`PaneGrid`]. +/// +/// It keeps track of the state of each [`Pane`] and the position of each +/// [`Split`]. +/// +/// The [`State`] needs to own any mutable contents a [`Pane`] may need. This is +/// why this struct is generic over the type `T`. Values of this type are +/// provided to the view function of [`PaneGrid::new`] for displaying each +/// [`Pane`]. +/// +/// [`PaneGrid`]: crate::widget::PaneGrid +/// [`PaneGrid::new`]: crate::widget::PaneGrid::new +#[derive(Debug, Clone)] +pub struct State<T> { + /// The panes of the [`PaneGrid`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub panes: HashMap<Pane, T>, + + /// The internal state of the [`PaneGrid`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub internal: Internal, + + /// The maximized [`Pane`] of the [`PaneGrid`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub(super) maximized: Option<Pane>, +} + +impl<T> State<T> { + /// Creates a new [`State`], initializing the first pane with the provided + /// state. + /// + /// Alongside the [`State`], it returns the first [`Pane`] identifier. + pub fn new(first_pane_state: T) -> (Self, Pane) { + ( + Self::with_configuration(Configuration::Pane(first_pane_state)), + Pane(0), + ) + } + + /// Creates a new [`State`] with the given [`Configuration`]. + pub fn with_configuration(config: impl Into<Configuration<T>>) -> Self { + let mut panes = HashMap::new(); + + let internal = + Internal::from_configuration(&mut panes, config.into(), 0); + + State { + panes, + internal, + maximized: None, + } + } + + /// Returns the total amount of panes in the [`State`]. + pub fn len(&self) -> usize { + self.panes.len() + } + + /// Returns `true` if the amount of panes in the [`State`] is 0. + pub fn is_empty(&self) -> bool { + self.len() == 0 + } + + /// Returns the internal state of the given [`Pane`], if it exists. + pub fn get(&self, pane: &Pane) -> Option<&T> { + self.panes.get(pane) + } + + /// Returns the internal state of the given [`Pane`] with mutability, if it + /// exists. + pub fn get_mut(&mut self, pane: &Pane) -> Option<&mut T> { + self.panes.get_mut(pane) + } + + /// Returns an iterator over all the panes of the [`State`], alongside its + /// internal state. + pub fn iter(&self) -> impl Iterator<Item = (&Pane, &T)> { + self.panes.iter() + } + + /// Returns a mutable iterator over all the panes of the [`State`], + /// alongside its internal state. + pub fn iter_mut(&mut self) -> impl Iterator<Item = (&Pane, &mut T)> { + self.panes.iter_mut() + } + + /// Returns the layout of the [`State`]. + pub fn layout(&self) -> &Node { + &self.internal.layout + } + + /// Returns the adjacent [`Pane`] of another [`Pane`] in the given + /// direction, if there is one. + pub fn adjacent(&self, pane: &Pane, direction: Direction) -> Option<Pane> { + let regions = self + .internal + .layout + .pane_regions(0.0, Size::new(4096.0, 4096.0)); + + let current_region = regions.get(pane)?; + + let target = match direction { + Direction::Left => { + Point::new(current_region.x - 1.0, current_region.y + 1.0) + } + Direction::Right => Point::new( + current_region.x + current_region.width + 1.0, + current_region.y + 1.0, + ), + Direction::Up => { + Point::new(current_region.x + 1.0, current_region.y - 1.0) + } + Direction::Down => Point::new( + current_region.x + 1.0, + current_region.y + current_region.height + 1.0, + ), + }; + + let mut colliding_regions = + regions.iter().filter(|(_, region)| region.contains(target)); + + let (pane, _) = colliding_regions.next()?; + + Some(*pane) + } + + /// Splits the given [`Pane`] into two in the given [`Axis`] and + /// initializing the new [`Pane`] with the provided internal state. + pub fn split( + &mut self, + axis: Axis, + pane: &Pane, + state: T, + ) -> Option<(Pane, Split)> { + self.split_node(axis, Some(pane), state, false) + } + + /// Split a target [`Pane`] with a given [`Pane`] on a given [`Region`]. + /// + /// Panes will be swapped by default for [`Region::Center`]. + pub fn split_with(&mut self, target: &Pane, pane: &Pane, region: Region) { + match region { + Region::Center => self.swap(pane, target), + Region::Edge(edge) => match edge { + Edge::Top => { + self.split_and_swap(Axis::Horizontal, target, pane, true) + } + Edge::Bottom => { + self.split_and_swap(Axis::Horizontal, target, pane, false) + } + Edge::Left => { + self.split_and_swap(Axis::Vertical, target, pane, true) + } + Edge::Right => { + self.split_and_swap(Axis::Vertical, target, pane, false) + } + }, + } + } + + /// Drops the given [`Pane`] into the provided [`Target`]. + pub fn drop(&mut self, pane: &Pane, target: Target) { + match target { + Target::Edge(edge) => self.move_to_edge(pane, edge), + Target::Pane(target, region) => { + self.split_with(&target, pane, region) + } + } + } + + fn split_node( + &mut self, + axis: Axis, + pane: Option<&Pane>, + state: T, + inverse: bool, + ) -> Option<(Pane, Split)> { + let node = if let Some(pane) = pane { + self.internal.layout.find(pane)? + } else { + // Major node + &mut self.internal.layout + }; + + let new_pane = { + self.internal.last_id = self.internal.last_id.checked_add(1)?; + + Pane(self.internal.last_id) + }; + + let new_split = { + self.internal.last_id = self.internal.last_id.checked_add(1)?; + + Split(self.internal.last_id) + }; + + if inverse { + node.split_inverse(new_split, axis, new_pane); + } else { + node.split(new_split, axis, new_pane); + } + + let _ = self.panes.insert(new_pane, state); + let _ = self.maximized.take(); + + Some((new_pane, new_split)) + } + + fn split_and_swap( + &mut self, + axis: Axis, + target: &Pane, + pane: &Pane, + swap: bool, + ) { + if let Some((state, _)) = self.close(pane) { + if let Some((new_pane, _)) = self.split(axis, target, state) { + if swap { + self.swap(target, &new_pane); + } + } + } + } + + /// Move [`Pane`] to an [`Edge`] of the [`PaneGrid`]. + pub fn move_to_edge(&mut self, pane: &Pane, edge: Edge) { + match edge { + Edge::Top => { + self.split_major_node_and_swap(Axis::Horizontal, pane, true) + } + Edge::Bottom => { + self.split_major_node_and_swap(Axis::Horizontal, pane, false) + } + Edge::Left => { + self.split_major_node_and_swap(Axis::Vertical, pane, true) + } + Edge::Right => { + self.split_major_node_and_swap(Axis::Vertical, pane, false) + } + } + } + + fn split_major_node_and_swap( + &mut self, + axis: Axis, + pane: &Pane, + swap: bool, + ) { + if let Some((state, _)) = self.close(pane) { + let _ = self.split_node(axis, None, state, swap); + } + } + + /// Swaps the position of the provided panes in the [`State`]. + /// + /// If you want to swap panes on drag and drop in your [`PaneGrid`], you + /// will need to call this method when handling a [`DragEvent`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + /// [`DragEvent`]: crate::widget::pane_grid::DragEvent + pub fn swap(&mut self, a: &Pane, b: &Pane) { + self.internal.layout.update(&|node| match node { + Node::Split { .. } => {} + Node::Pane(pane) => { + if pane == a { + *node = Node::Pane(*b); + } else if pane == b { + *node = Node::Pane(*a); + } + } + }); + } + + /// Resizes two panes by setting the position of the provided [`Split`]. + /// + /// The ratio is a value in [0, 1], representing the exact position of a + /// [`Split`] between two panes. + /// + /// If you want to enable resize interactions in your [`PaneGrid`], you will + /// need to call this method when handling a [`ResizeEvent`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + /// [`ResizeEvent`]: crate::widget::pane_grid::ResizeEvent + pub fn resize(&mut self, split: &Split, ratio: f32) { + let _ = self.internal.layout.resize(split, ratio); + } + + /// Closes the given [`Pane`] and returns its internal state and its closest + /// sibling, if it exists. + pub fn close(&mut self, pane: &Pane) -> Option<(T, Pane)> { + if self.maximized == Some(*pane) { + let _ = self.maximized.take(); + } + + if let Some(sibling) = self.internal.layout.remove(pane) { + self.panes.remove(pane).map(|state| (state, sibling)) + } else { + None + } + } + + /// Maximize the given [`Pane`]. Only this pane will be rendered by the + /// [`PaneGrid`] until [`Self::restore()`] is called. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub fn maximize(&mut self, pane: &Pane) { + self.maximized = Some(*pane); + } + + /// Restore the currently maximized [`Pane`] to it's normal size. All panes + /// will be rendered by the [`PaneGrid`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub fn restore(&mut self) { + let _ = self.maximized.take(); + } + + /// Returns the maximized [`Pane`] of the [`PaneGrid`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub fn maximized(&self) -> Option<Pane> { + self.maximized + } +} + +/// The internal state of a [`PaneGrid`]. +/// +/// [`PaneGrid`]: crate::widget::PaneGrid +#[derive(Debug, Clone)] +pub struct Internal { + layout: Node, + last_id: usize, +} + +impl Internal { + /// Initializes the [`Internal`] state of a [`PaneGrid`] from a + /// [`Configuration`]. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + pub fn from_configuration<T>( + panes: &mut HashMap<Pane, T>, + content: Configuration<T>, + next_id: usize, + ) -> Self { + let (layout, last_id) = match content { + Configuration::Split { axis, ratio, a, b } => { + let Internal { + layout: a, + last_id: next_id, + .. + } = Self::from_configuration(panes, *a, next_id); + + let Internal { + layout: b, + last_id: next_id, + .. + } = Self::from_configuration(panes, *b, next_id); + + ( + Node::Split { + id: Split(next_id), + axis, + ratio, + a: Box::new(a), + b: Box::new(b), + }, + next_id + 1, + ) + } + Configuration::Pane(state) => { + let id = Pane(next_id); + let _ = panes.insert(id, state); + + (Node::Pane(id), next_id + 1) + } + }; + + Self { layout, last_id } + } +} + +/// The current action of a [`PaneGrid`]. +/// +/// [`PaneGrid`]: crate::widget::PaneGrid +#[derive(Debug, Clone, Copy, PartialEq)] +pub enum Action { + /// The [`PaneGrid`] is idle. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + Idle, + /// A [`Pane`] in the [`PaneGrid`] is being dragged. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + Dragging { + /// The [`Pane`] being dragged. + pane: Pane, + /// The starting [`Point`] of the drag interaction. + origin: Point, + }, + /// A [`Split`] in the [`PaneGrid`] is being dragged. + /// + /// [`PaneGrid`]: crate::widget::PaneGrid + Resizing { + /// The [`Split`] being dragged. + split: Split, + /// The [`Axis`] of the [`Split`]. + axis: Axis, + }, +} + +impl Action { + /// Returns the current [`Pane`] that is being dragged, if any. + pub fn picked_pane(&self) -> Option<(Pane, Point)> { + match *self { + Action::Dragging { pane, origin, .. } => Some((pane, origin)), + _ => None, + } + } + + /// Returns the current [`Split`] that is being dragged, if any. + pub fn picked_split(&self) -> Option<(Split, Axis)> { + match *self { + Action::Resizing { split, axis, .. } => Some((split, axis)), + _ => None, + } + } +} + +impl Internal { + /// The layout [`Node`] of the [`Internal`] state + pub fn layout(&self) -> &Node { + &self.layout + } +} |