presenter.rs

  1use crate::{
  2    app::{AppContext, MutableAppContext, WindowInvalidation},
  3    elements::Element,
  4    font_cache::FontCache,
  5    json::{self, ToJson},
  6    platform::Event,
  7    text_layout::TextLayoutCache,
  8    Action, AnyAction, AssetCache, ElementBox, FontSystem, Scene,
  9};
 10use pathfinder_geometry::vector::{vec2f, Vector2F};
 11use serde_json::json;
 12use std::{
 13    collections::{HashMap, HashSet},
 14    ops::{Deref, DerefMut},
 15    sync::Arc,
 16};
 17
 18pub struct Presenter {
 19    window_id: usize,
 20    rendered_views: HashMap<usize, ElementBox>,
 21    parents: HashMap<usize, usize>,
 22    font_cache: Arc<FontCache>,
 23    text_layout_cache: TextLayoutCache,
 24    asset_cache: Arc<AssetCache>,
 25    last_mouse_moved_event: Option<Event>,
 26    titlebar_height: f32,
 27}
 28
 29impl Presenter {
 30    pub fn new(
 31        window_id: usize,
 32        titlebar_height: f32,
 33        font_cache: Arc<FontCache>,
 34        text_layout_cache: TextLayoutCache,
 35        asset_cache: Arc<AssetCache>,
 36        cx: &mut MutableAppContext,
 37    ) -> Self {
 38        Self {
 39            window_id,
 40            rendered_views: cx.render_views(window_id, titlebar_height),
 41            parents: HashMap::new(),
 42            font_cache,
 43            text_layout_cache,
 44            asset_cache,
 45            last_mouse_moved_event: None,
 46            titlebar_height,
 47        }
 48    }
 49
 50    pub fn dispatch_path(&self, app: &AppContext) -> Vec<usize> {
 51        let mut view_id = app.focused_view_id(self.window_id).unwrap();
 52        let mut path = vec![view_id];
 53        while let Some(parent_id) = self.parents.get(&view_id).copied() {
 54            path.push(parent_id);
 55            view_id = parent_id;
 56        }
 57        path.reverse();
 58        path
 59    }
 60
 61    pub fn invalidate(&mut self, mut invalidation: WindowInvalidation, cx: &mut MutableAppContext) {
 62        for view_id in invalidation.removed {
 63            invalidation.updated.remove(&view_id);
 64            self.rendered_views.remove(&view_id);
 65            self.parents.remove(&view_id);
 66        }
 67        for view_id in invalidation.updated {
 68            self.rendered_views.insert(
 69                view_id,
 70                cx.render_view(self.window_id, view_id, self.titlebar_height, false)
 71                    .unwrap(),
 72            );
 73        }
 74    }
 75
 76    pub fn refresh(
 77        &mut self,
 78        invalidation: Option<WindowInvalidation>,
 79        cx: &mut MutableAppContext,
 80    ) {
 81        if let Some(invalidation) = invalidation {
 82            for view_id in invalidation.removed {
 83                self.rendered_views.remove(&view_id);
 84                self.parents.remove(&view_id);
 85            }
 86        }
 87
 88        for (view_id, view) in &mut self.rendered_views {
 89            *view = cx
 90                .render_view(self.window_id, *view_id, self.titlebar_height, true)
 91                .unwrap();
 92        }
 93    }
 94
 95    pub fn build_scene(
 96        &mut self,
 97        window_size: Vector2F,
 98        scale_factor: f32,
 99        cx: &mut MutableAppContext,
100    ) -> Scene {
101        let mut scene = Scene::new(scale_factor);
102
103        if let Some(root_view_id) = cx.root_view_id(self.window_id) {
104            self.layout(window_size, cx);
105            let mut paint_cx = PaintContext {
106                scene: &mut scene,
107                font_cache: &self.font_cache,
108                text_layout_cache: &self.text_layout_cache,
109                rendered_views: &mut self.rendered_views,
110                app: cx.as_ref(),
111            };
112            paint_cx.paint(root_view_id, Vector2F::zero());
113            self.text_layout_cache.finish_frame();
114
115            if let Some(event) = self.last_mouse_moved_event.clone() {
116                self.dispatch_event(event, cx)
117            }
118        } else {
119            log::error!("could not find root_view_id for window {}", self.window_id);
120        }
121
122        scene
123    }
124
125    fn layout(&mut self, size: Vector2F, cx: &mut MutableAppContext) {
126        if let Some(root_view_id) = cx.root_view_id(self.window_id) {
127            self.build_layout_context(cx)
128                .layout(root_view_id, SizeConstraint::strict(size));
129        }
130    }
131
132    pub fn build_layout_context<'a>(
133        &'a mut self,
134        cx: &'a mut MutableAppContext,
135    ) -> LayoutContext<'a> {
136        LayoutContext {
137            rendered_views: &mut self.rendered_views,
138            parents: &mut self.parents,
139            font_cache: &self.font_cache,
140            font_system: cx.platform().fonts(),
141            text_layout_cache: &self.text_layout_cache,
142            asset_cache: &self.asset_cache,
143            view_stack: Vec::new(),
144            app: cx,
145        }
146    }
147
148    pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) {
149        if let Some(root_view_id) = cx.root_view_id(self.window_id) {
150            match event {
151                Event::MouseMoved { .. } => {
152                    self.last_mouse_moved_event = Some(event.clone());
153                }
154                Event::LeftMouseDragged { position } => {
155                    self.last_mouse_moved_event = Some(Event::MouseMoved {
156                        position,
157                        left_mouse_down: true,
158                    });
159                }
160                _ => {}
161            }
162
163            let mut event_cx = EventContext {
164                rendered_views: &mut self.rendered_views,
165                dispatched_actions: Default::default(),
166                font_cache: &self.font_cache,
167                text_layout_cache: &self.text_layout_cache,
168                view_stack: Default::default(),
169                invalidated_views: Default::default(),
170                app: cx,
171            };
172            event_cx.dispatch_event(root_view_id, &event);
173
174            let invalidated_views = event_cx.invalidated_views;
175            let dispatch_directives = event_cx.dispatched_actions;
176
177            for view_id in invalidated_views {
178                cx.notify_view(self.window_id, view_id);
179            }
180            for directive in dispatch_directives {
181                cx.dispatch_action_any(self.window_id, &directive.path, directive.action.as_ref());
182            }
183        }
184    }
185
186    pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
187        cx.root_view_id(self.window_id)
188            .and_then(|root_view_id| self.rendered_views.get(&root_view_id))
189            .map(|root_element| {
190                root_element.debug(&DebugContext {
191                    rendered_views: &self.rendered_views,
192                    font_cache: &self.font_cache,
193                    app: cx,
194                })
195            })
196    }
197}
198
199pub struct DispatchDirective {
200    pub path: Vec<usize>,
201    pub action: Box<dyn AnyAction>,
202}
203
204pub struct LayoutContext<'a> {
205    rendered_views: &'a mut HashMap<usize, ElementBox>,
206    parents: &'a mut HashMap<usize, usize>,
207    view_stack: Vec<usize>,
208    pub font_cache: &'a Arc<FontCache>,
209    pub font_system: Arc<dyn FontSystem>,
210    pub text_layout_cache: &'a TextLayoutCache,
211    pub asset_cache: &'a AssetCache,
212    pub app: &'a mut MutableAppContext,
213}
214
215impl<'a> LayoutContext<'a> {
216    fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
217        if let Some(parent_id) = self.view_stack.last() {
218            self.parents.insert(view_id, *parent_id);
219        }
220        self.view_stack.push(view_id);
221        let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
222        let size = rendered_view.layout(constraint, self);
223        self.rendered_views.insert(view_id, rendered_view);
224        self.view_stack.pop();
225        size
226    }
227}
228
229pub struct PaintContext<'a> {
230    rendered_views: &'a mut HashMap<usize, ElementBox>,
231    pub scene: &'a mut Scene,
232    pub font_cache: &'a FontCache,
233    pub text_layout_cache: &'a TextLayoutCache,
234    pub app: &'a AppContext,
235}
236
237impl<'a> PaintContext<'a> {
238    fn paint(&mut self, view_id: usize, origin: Vector2F) {
239        if let Some(mut tree) = self.rendered_views.remove(&view_id) {
240            tree.paint(origin, self);
241            self.rendered_views.insert(view_id, tree);
242        }
243    }
244}
245
246pub struct EventContext<'a> {
247    rendered_views: &'a mut HashMap<usize, ElementBox>,
248    dispatched_actions: Vec<DispatchDirective>,
249    pub font_cache: &'a FontCache,
250    pub text_layout_cache: &'a TextLayoutCache,
251    pub app: &'a mut MutableAppContext,
252    view_stack: Vec<usize>,
253    invalidated_views: HashSet<usize>,
254}
255
256impl<'a> EventContext<'a> {
257    fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
258        if let Some(mut element) = self.rendered_views.remove(&view_id) {
259            self.view_stack.push(view_id);
260            let result = element.dispatch_event(event, self);
261            self.view_stack.pop();
262            self.rendered_views.insert(view_id, element);
263            result
264        } else {
265            false
266        }
267    }
268
269    pub fn dispatch_action<A: Action>(&mut self, action: A) {
270        self.dispatched_actions.push(DispatchDirective {
271            path: self.view_stack.clone(),
272            action: Box::new(action),
273        });
274    }
275
276    pub fn notify(&mut self) {
277        self.invalidated_views
278            .insert(*self.view_stack.last().unwrap());
279    }
280}
281
282impl<'a> Deref for EventContext<'a> {
283    type Target = MutableAppContext;
284
285    fn deref(&self) -> &Self::Target {
286        self.app
287    }
288}
289
290impl<'a> DerefMut for EventContext<'a> {
291    fn deref_mut(&mut self) -> &mut Self::Target {
292        self.app
293    }
294}
295
296pub struct DebugContext<'a> {
297    rendered_views: &'a HashMap<usize, ElementBox>,
298    pub font_cache: &'a FontCache,
299    pub app: &'a AppContext,
300}
301
302#[derive(Clone, Copy, Debug, Eq, PartialEq)]
303pub enum Axis {
304    Horizontal,
305    Vertical,
306}
307
308impl Axis {
309    pub fn invert(self) -> Self {
310        match self {
311            Self::Horizontal => Self::Vertical,
312            Self::Vertical => Self::Horizontal,
313        }
314    }
315}
316
317impl ToJson for Axis {
318    fn to_json(&self) -> serde_json::Value {
319        match self {
320            Axis::Horizontal => json!("horizontal"),
321            Axis::Vertical => json!("vertical"),
322        }
323    }
324}
325
326pub trait Vector2FExt {
327    fn along(self, axis: Axis) -> f32;
328}
329
330impl Vector2FExt for Vector2F {
331    fn along(self, axis: Axis) -> f32 {
332        match axis {
333            Axis::Horizontal => self.x(),
334            Axis::Vertical => self.y(),
335        }
336    }
337}
338
339#[derive(Copy, Clone, Debug)]
340pub struct SizeConstraint {
341    pub min: Vector2F,
342    pub max: Vector2F,
343}
344
345impl SizeConstraint {
346    pub fn new(min: Vector2F, max: Vector2F) -> Self {
347        Self { min, max }
348    }
349
350    pub fn strict(size: Vector2F) -> Self {
351        Self {
352            min: size,
353            max: size,
354        }
355    }
356
357    pub fn strict_along(axis: Axis, max: f32) -> Self {
358        match axis {
359            Axis::Horizontal => Self {
360                min: vec2f(max, 0.0),
361                max: vec2f(max, f32::INFINITY),
362            },
363            Axis::Vertical => Self {
364                min: vec2f(0.0, max),
365                max: vec2f(f32::INFINITY, max),
366            },
367        }
368    }
369
370    pub fn max_along(&self, axis: Axis) -> f32 {
371        match axis {
372            Axis::Horizontal => self.max.x(),
373            Axis::Vertical => self.max.y(),
374        }
375    }
376
377    pub fn min_along(&self, axis: Axis) -> f32 {
378        match axis {
379            Axis::Horizontal => self.min.x(),
380            Axis::Vertical => self.min.y(),
381        }
382    }
383}
384
385impl ToJson for SizeConstraint {
386    fn to_json(&self) -> serde_json::Value {
387        json!({
388            "min": self.min.to_json(),
389            "max": self.max.to_json(),
390        })
391    }
392}
393
394pub struct ChildView {
395    view_id: usize,
396}
397
398impl ChildView {
399    pub fn new(view_id: usize) -> Self {
400        Self { view_id }
401    }
402}
403
404impl Element for ChildView {
405    type LayoutState = ();
406    type PaintState = ();
407
408    fn layout(
409        &mut self,
410        constraint: SizeConstraint,
411        cx: &mut LayoutContext,
412    ) -> (Vector2F, Self::LayoutState) {
413        let size = cx.layout(self.view_id, constraint);
414        (size, ())
415    }
416
417    fn paint(
418        &mut self,
419        bounds: pathfinder_geometry::rect::RectF,
420        _: &mut Self::LayoutState,
421        cx: &mut PaintContext,
422    ) -> Self::PaintState {
423        cx.paint(self.view_id, bounds.origin());
424    }
425
426    fn dispatch_event(
427        &mut self,
428        event: &Event,
429        _: pathfinder_geometry::rect::RectF,
430        _: &mut Self::LayoutState,
431        _: &mut Self::PaintState,
432        cx: &mut EventContext,
433    ) -> bool {
434        cx.dispatch_event(self.view_id, event)
435    }
436
437    fn debug(
438        &self,
439        bounds: pathfinder_geometry::rect::RectF,
440        _: &Self::LayoutState,
441        _: &Self::PaintState,
442        cx: &DebugContext,
443    ) -> serde_json::Value {
444        json!({
445            "type": "ChildView",
446            "view_id": self.view_id,
447            "bounds": bounds.to_json(),
448            "child": if let Some(view) = cx.rendered_views.get(&self.view_id) {
449                view.debug(cx)
450            } else {
451                json!(null)
452            }
453        })
454    }
455}
456
457#[cfg(test)]
458mod tests {
459    // #[test]
460    // fn test_responder_chain() {
461    //     let settings = settings_rx(None);
462    //     let mut app = App::new().unwrap();
463    //     let workspace = app.add_model(|cx| Workspace::new(Vec::new(), cx));
464    //     let (window_id, workspace_view) =
465    //         app.add_window(|cx| WorkspaceView::new(workspace.clone(), settings, cx));
466
467    //     let invalidations = Rc::new(RefCell::new(Vec::new()));
468    //     let invalidations_ = invalidations.clone();
469    //     app.on_window_invalidated(window_id, move |invalidation, _| {
470    //         invalidations_.borrow_mut().push(invalidation)
471    //     });
472
473    //     let active_pane_id = workspace_view.update(&mut app, |view, cx| {
474    //         cx.focus(view.active_pane());
475    //         view.active_pane().id()
476    //     });
477
478    //     app.update(|app| {
479    //         let mut presenter = Presenter::new(
480    //             window_id,
481    //             Rc::new(FontCache::new()),
482    //             Rc::new(AssetCache::new()),
483    //             app,
484    //         );
485    //         for invalidation in invalidations.borrow().iter().cloned() {
486    //             presenter.update(vec2f(1024.0, 768.0), 2.0, Some(invalidation), app);
487    //         }
488
489    //         assert_eq!(
490    //             presenter.responder_chain(app.cx()).unwrap(),
491    //             vec![workspace_view.id(), active_pane_id]
492    //         );
493    //     });
494    // }
495}