aboutsummaryrefslogtreecommitdiff
path: root/helix-term/src/compositor.rs
blob: 971dc52d4ac287eef395d45a9b4bc327cc0220df (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
// Each component declares it's own size constraints and gets fitted based on it's parent.
// 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};

#[cfg(feature = "integration")]
use tui::backend::TestBackend;
use tui::buffer::Buffer as Surface;

pub type Callback = Box<dyn FnOnce(&mut Compositor, &mut Context)>;

// Cursive-inspired
pub enum EventResult {
    Ignored(Option<Callback>),
    Consumed(Option<Callback>),
}

use crate::job::Jobs;
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 {
    /// Process input events, return true if handled.
    fn handle_event(&mut self, _event: &Event, _ctx: &mut Context) -> EventResult {
        EventResult::Ignored(None)
    }
    // , 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
    }
}

use anyhow::Context as AnyhowContext;
use tui::backend::Backend;

#[cfg(not(feature = "integration"))]
use tui::backend::CrosstermBackend;

#[cfg(not(feature = "integration"))]
use std::io::stdout;

#[cfg(not(feature = "integration"))]
type Terminal = tui::terminal::Terminal<CrosstermBackend<std::io::Stdout>>;

#[cfg(feature = "integration")]
type Terminal = tui::terminal::Terminal<TestBackend>;

pub struct Compositor {
    layers: Vec<Box<dyn Component>>,
    terminal: Terminal,

    pub(crate) last_picker: Option<Box<dyn Component>>,
}

impl Compositor {
    pub fn new() -> anyhow::Result<Self> {
        #[cfg(not(feature = "integration"))]
        let backend = CrosstermBackend::new(stdout());

        #[cfg(feature = "integration")]
        let backend = TestBackend::new(120, 150);

        let terminal = Terminal::new(backend).context("build terminal")?;
        Ok(Self {
            layers: Vec::new(),
            terminal,
            last_picker: None,
        })
    }

    pub fn size(&self) -> Rect {
        self.terminal.size().expect("couldn't get terminal size")
    }

    pub fn resize(&mut self, width: u16, height: u16) {
        self.terminal
            .resize(Rect::new(0, 0, width, height))
            .expect("Unable to resize terminal")
    }

    pub fn save_cursor(&mut self) {
        if self.terminal.cursor_kind() == CursorKind::Hidden {
            self.terminal
                .backend_mut()
                .show_cursor(CursorKind::Block)
                .ok();
        }
    }

    pub fn load_cursor(&mut self) {
        if self.terminal.cursor_kind() == CursorKind::Hidden {
            self.terminal.backend_mut().hide_cursor().ok();
        }
    }

    pub fn push(&mut self, mut layer: Box<dyn Component>) {
        let size = self.size();
        // trigger required_size on init
        layer.required_size((size.width, size.height));
        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()
    }

    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)
        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) => {}
            };
        }

        for callback in callbacks {
            callback(self, cx)
        }

        consumed
    }

    pub fn render(&mut self, cx: &mut Context) {
        self.terminal
            .autoresize()
            .expect("Unable to determine terminal size");

        // TODO: need to recalculate view tree if necessary

        let surface = self.terminal.current_buffer_mut();

        let area = *surface.area();

        for layer in &mut self.layers {
            layer.render(area, surface, cx);
        }

        let (pos, kind) = self.cursor(area, cx.editor);
        let pos = pos.map(|pos| (pos.col as u16, pos.row as u16));

        self.terminal.draw(pos, kind).unwrap();
    }

    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>()
    }
}