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helix/helix-term/src/compositor.rs

282 lines
8.5 KiB
Rust

// Each component declares its own size constraints and gets fitted based on its parent.
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// Q: how does this work with popups?
// cursive does compositor.screen_mut().add_layer_at(pos::absolute(x, y), <component>)
use helix_core::Position;
use helix_view::graphics::{CursorKind, Rect};
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use tui::buffer::Buffer as Surface;
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pub type Callback = Box<dyn FnOnce(&mut Compositor, &mut Context)>;
pub type SyncCallback = Box<dyn FnOnce(&mut Compositor, &mut Context) + Sync>;
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// Cursive-inspired
pub enum EventResult {
Ignored(Option<Callback>),
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Consumed(Option<Callback>),
}
use crate::job::Jobs;
use crate::ui::picker;
use helix_view::Editor;
pub use helix_view::input::Event;
pub struct Context<'a> {
pub editor: &'a mut Editor,
pub scroll: Option<usize>,
pub jobs: &'a mut Jobs,
}
impl<'a> Context<'a> {
/// Waits on all pending jobs, and then tries to flush all pending write
/// operations for all documents.
pub fn block_try_flush_writes(&mut self) -> anyhow::Result<()> {
tokio::task::block_in_place(|| helix_lsp::block_on(self.jobs.finish(self.editor, None)))?;
tokio::task::block_in_place(|| helix_lsp::block_on(self.editor.flush_writes()))?;
Ok(())
}
}
pub trait Component: Any + AnyComponent {
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/// Process input events, return true if handled.
fn handle_event(&mut self, _event: &Event, _ctx: &mut Context) -> EventResult {
EventResult::Ignored(None)
}
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// , args: ()
/// Should redraw? Useful for saving redraw cycles if we know component didn't change.
fn should_update(&self) -> bool {
true
}
/// Render the component onto the provided surface.
fn render(&mut self, area: Rect, frame: &mut Surface, ctx: &mut Context);
/// Get cursor position and cursor kind.
fn cursor(&self, _area: Rect, _ctx: &Editor) -> (Option<Position>, CursorKind) {
(None, CursorKind::Hidden)
}
/// May be used by the parent component to compute the child area.
/// viewport is the maximum allowed area, and the child should stay within those bounds.
///
/// The returned size might be larger than the viewport if the child is too big to fit.
/// In this case the parent can use the values to calculate scroll.
fn required_size(&mut self, _viewport: (u16, u16)) -> Option<(u16, u16)> {
None
}
fn type_name(&self) -> &'static str {
std::any::type_name::<Self>()
}
fn id(&self) -> Option<&'static str> {
None
}
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}
pub struct Compositor {
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layers: Vec<Box<dyn Component>>,
area: Rect,
pub(crate) last_picker: Option<Box<dyn Component>>,
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}
impl Compositor {
pub fn new(area: Rect) -> Self {
Self {
layers: Vec::new(),
area,
last_picker: None,
}
}
pub fn size(&self) -> Rect {
self.area
}
pub fn resize(&mut self, area: Rect) {
self.area = area;
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}
/// Add a layer to be rendered in front of all existing layers.
pub fn push(&mut self, mut layer: Box<dyn Component>) {
// immediately clear last_picker field to avoid excessive memory
// consumption for picker with many items
if layer.id() == Some(picker::ID) {
self.last_picker = None;
}
let size = self.size();
// trigger required_size on init
layer.required_size((size.width, size.height));
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self.layers.push(layer);
}
/// Replace a component that has the given `id` with the new layer and if
/// no component is found, push the layer normally.
pub fn replace_or_push<T: Component>(&mut self, id: &'static str, layer: T) {
if let Some(component) = self.find_id(id) {
*component = layer;
} else {
self.push(Box::new(layer))
}
}
pub fn pop(&mut self) -> Option<Box<dyn Component>> {
self.layers.pop()
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}
pub fn remove(&mut self, id: &'static str) -> Option<Box<dyn Component>> {
let idx = self
.layers
.iter()
.position(|layer| layer.id() == Some(id))?;
Some(self.layers.remove(idx))
}
pub fn handle_event(&mut self, event: &Event, cx: &mut Context) -> bool {
// If it is a key event and a macro is being recorded, push the key event to the recording.
if let (Event::Key(key), Some((_, keys))) = (event, &mut cx.editor.macro_recording) {
keys.push(*key);
}
let mut callbacks = Vec::new();
let mut consumed = false;
// propagate events through the layers until we either find a layer that consumes it or we
// run out of layers (event bubbling), starting at the front layer and then moving to the
// background.
for layer in self.layers.iter_mut().rev() {
match layer.handle_event(event, cx) {
EventResult::Consumed(Some(callback)) => {
callbacks.push(callback);
consumed = true;
break;
}
EventResult::Consumed(None) => {
consumed = true;
break;
}
EventResult::Ignored(Some(callback)) => {
callbacks.push(callback);
}
EventResult::Ignored(None) => {}
};
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}
for callback in callbacks {
callback(self, cx)
}
consumed
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}
pub fn render(&mut self, area: Rect, surface: &mut Surface, cx: &mut Context) {
for layer in &mut self.layers {
layer.render(area, surface, cx);
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}
}
pub fn cursor(&self, area: Rect, editor: &Editor) -> (Option<Position>, CursorKind) {
for layer in self.layers.iter().rev() {
if let (Some(pos), kind) = layer.cursor(area, editor) {
return (Some(pos), kind);
}
}
(None, CursorKind::Hidden)
}
pub fn has_component(&self, type_name: &str) -> bool {
self.layers
.iter()
.any(|component| component.type_name() == type_name)
}
pub fn find<T: 'static>(&mut self) -> Option<&mut T> {
let type_name = std::any::type_name::<T>();
self.layers
.iter_mut()
.find(|component| component.type_name() == type_name)
.and_then(|component| component.as_any_mut().downcast_mut())
}
pub fn find_id<T: 'static>(&mut self, id: &'static str) -> Option<&mut T> {
self.layers
.iter_mut()
.find(|component| component.id() == Some(id))
.and_then(|component| component.as_any_mut().downcast_mut())
}
}
// View casting, taken straight from Cursive
use std::any::Any;
/// A view that can be downcasted to its concrete type.
///
/// This trait is automatically implemented for any `T: Component`.
pub trait AnyComponent {
/// Downcast self to a `Any`.
fn as_any(&self) -> &dyn Any;
/// Downcast self to a mutable `Any`.
fn as_any_mut(&mut self) -> &mut dyn Any;
/// Returns a boxed any from a boxed self.
///
/// Can be used before `Box::downcast()`.
///
/// # Examples
///
/// ```rust
/// use helix_term::{ui::Text, compositor::Component};
/// let boxed: Box<dyn Component> = Box::new(Text::new("text".to_string()));
/// let text: Box<Text> = boxed.as_boxed_any().downcast().unwrap();
/// ```
fn as_boxed_any(self: Box<Self>) -> Box<dyn Any>;
}
impl<T: Component> AnyComponent for T {
/// Downcast self to a `Any`.
fn as_any(&self) -> &dyn Any {
self
}
/// Downcast self to a mutable `Any`.
fn as_any_mut(&mut self) -> &mut dyn Any {
self
}
fn as_boxed_any(self: Box<Self>) -> Box<dyn Any> {
self
}
}
impl dyn AnyComponent {
/// Attempts to downcast `self` to a concrete type.
pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
self.as_any().downcast_ref()
}
/// Attempts to downcast `self` to a concrete type.
pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T> {
self.as_any_mut().downcast_mut()
}
/// Attempts to downcast `Box<Self>` to a concrete type.
pub fn downcast<T: Any>(self: Box<Self>) -> Result<Box<T>, Box<Self>> {
// Do the check here + unwrap, so the error
// value is `Self` and not `dyn Any`.
if self.as_any().is::<T>() {
Ok(self.as_boxed_any().downcast().unwrap())
} else {
Err(self)
}
}
/// Checks if this view is of type `T`.
pub fn is<T: Any>(&mut self) -> bool {
self.as_any().is::<T>()
}
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}