div.rs

  1use crate::{
  2    AnyElement, Bounds, Element, Layout, LayoutId, Overflow, ParentElement, Pixels, Point,
  3    Refineable, RefinementCascade, Result, Style, StyleHelpers, Styled, ViewContext,
  4};
  5use smallvec::SmallVec;
  6use std::{cell::Cell, rc::Rc};
  7use util::ResultExt;
  8
  9pub struct Div<S: 'static> {
 10    styles: RefinementCascade<Style>,
 11    // handlers: InteractionHandlers<V>,
 12    children: SmallVec<[AnyElement<S>; 2]>,
 13    scroll_state: Option<ScrollState>,
 14}
 15
 16pub fn div<S>() -> Div<S> {
 17    Div {
 18        styles: Default::default(),
 19        // handlers: Default::default(),
 20        children: Default::default(),
 21        scroll_state: None,
 22    }
 23}
 24
 25impl<S: 'static> Element for Div<S> {
 26    type State = S;
 27    type FrameState = Vec<LayoutId>;
 28
 29    fn layout(
 30        &mut self,
 31        view: &mut S,
 32        cx: &mut ViewContext<S>,
 33    ) -> Result<(LayoutId, Self::FrameState)> {
 34        let style = self.computed_style();
 35        let pop_text_style = style
 36            .text_style(cx)
 37            .map(|style| cx.push_text_style(style))
 38            .is_some();
 39
 40        let children = self
 41            .children
 42            .iter_mut()
 43            .map(|child| child.layout(view, cx))
 44            .collect::<Result<Vec<LayoutId>>>()?;
 45
 46        if pop_text_style {
 47            cx.pop_text_style();
 48        }
 49
 50        Ok((cx.request_layout(style.into(), children.clone())?, children))
 51    }
 52
 53    fn paint(
 54        &mut self,
 55        layout: Layout,
 56        state: &mut S,
 57        child_layouts: &mut Self::FrameState,
 58        cx: &mut ViewContext<S>,
 59    ) -> Result<()> {
 60        let Layout { order, bounds } = layout;
 61
 62        let style = self.computed_style();
 63        let pop_text_style = style
 64            .text_style(cx)
 65            .map(|style| cx.push_text_style(style))
 66            .is_some();
 67        style.paint_background(bounds, cx);
 68        // self.interaction_handlers().paint(order, bounds, cx);
 69
 70        let scrolled_origin = bounds.origin - self.scroll_offset(&style.overflow);
 71
 72        // // TODO: Support only one dimension being hidden
 73        // let mut pop_layer = false;
 74        // if style.overflow.y != Overflow::Visible || style.overflow.x != Overflow::Visible {
 75        //     cx.scene().push_layer(Some(bounds));
 76        //     pop_layer = true;
 77        // }
 78
 79        for child in &mut self.children {
 80            child.paint(scrolled_origin, state, cx)?;
 81        }
 82
 83        // if pop_layer {
 84        //     cx.scene().pop_layer();
 85        // }
 86
 87        style.paint_foreground(bounds, cx);
 88        if pop_text_style {
 89            cx.pop_text_style();
 90        }
 91
 92        self.handle_scroll(order, bounds, style.overflow.clone(), child_layouts, cx);
 93
 94        // if cx.is_inspector_enabled() {
 95        //     self.paint_inspector(parent_origin, layout, cx);
 96        // }
 97        //
 98        Ok(())
 99    }
100}
101
102impl<V: 'static> Div<V> {
103    pub fn overflow_hidden(mut self) -> Self {
104        self.declared_style().overflow.x = Some(Overflow::Hidden);
105        self.declared_style().overflow.y = Some(Overflow::Hidden);
106        self
107    }
108
109    pub fn overflow_hidden_x(mut self) -> Self {
110        self.declared_style().overflow.x = Some(Overflow::Hidden);
111        self
112    }
113
114    pub fn overflow_hidden_y(mut self) -> Self {
115        self.declared_style().overflow.y = Some(Overflow::Hidden);
116        self
117    }
118
119    pub fn overflow_scroll(mut self, scroll_state: ScrollState) -> Self {
120        self.scroll_state = Some(scroll_state);
121        self.declared_style().overflow.x = Some(Overflow::Scroll);
122        self.declared_style().overflow.y = Some(Overflow::Scroll);
123        self
124    }
125
126    pub fn overflow_x_scroll(mut self, scroll_state: ScrollState) -> Self {
127        self.scroll_state = Some(scroll_state);
128        self.declared_style().overflow.x = Some(Overflow::Scroll);
129        self
130    }
131
132    pub fn overflow_y_scroll(mut self, scroll_state: ScrollState) -> Self {
133        self.scroll_state = Some(scroll_state);
134        self.declared_style().overflow.y = Some(Overflow::Scroll);
135        self
136    }
137
138    fn scroll_offset(&self, overflow: &Point<Overflow>) -> Point<Pixels> {
139        let mut offset = Point::default();
140        if overflow.y == Overflow::Scroll {
141            offset.y = self.scroll_state.as_ref().unwrap().y();
142        }
143        if overflow.x == Overflow::Scroll {
144            offset.x = self.scroll_state.as_ref().unwrap().x();
145        }
146
147        offset
148    }
149
150    fn handle_scroll(
151        &mut self,
152        order: u32,
153        bounds: Bounds<Pixels>,
154        overflow: Point<Overflow>,
155        child_layout_ids: &[LayoutId],
156        cx: &mut ViewContext<V>,
157    ) {
158        if overflow.y == Overflow::Scroll || overflow.x == Overflow::Scroll {
159            let mut scroll_max = Point::default();
160            for child_layout_id in child_layout_ids {
161                if let Some(child_layout) = cx.layout(*child_layout_id).log_err() {
162                    scroll_max = scroll_max.max(&child_layout.bounds.lower_right());
163                }
164            }
165            scroll_max -= bounds.size;
166
167            // let scroll_state = self.scroll_state.as_ref().unwrap().clone();
168            // cx.on_event(order, move |_, event: &ScrollWheelEvent, cx| {
169            //     if bounds.contains_point(event.position) {
170            //         let scroll_delta = match event.delta {
171            //             ScrollDelta::Pixels(delta) => delta,
172            //             ScrollDelta::Lines(delta) => cx.text_style().font_size * delta,
173            //         };
174            //         if overflow.x == Overflow::Scroll {
175            //             scroll_state.set_x(
176            //                 (scroll_state.x() - scroll_delta.x())
177            //                     .max(px(0.))
178            //                     .min(scroll_max.x),
179            //             );
180            //         }
181            //         if overflow.y == Overflow::Scroll {
182            //             scroll_state.set_y(
183            //                 (scroll_state.y() - scroll_delta.y())
184            //                     .max(px(0.))
185            //                     .min(scroll_max.y),
186            //             );
187            //         }
188            //         cx.repaint();
189            //     } else {
190            //         cx.bubble_event();
191            //     }
192            // })
193        }
194    }
195
196    fn paint_inspector(
197        &self,
198        parent_origin: Point<Pixels>,
199        layout: &Layout,
200        cx: &mut ViewContext<V>,
201    ) {
202        let style = self.styles.merged();
203        let bounds = layout.bounds;
204
205        let hovered = bounds.contains_point(cx.mouse_position());
206        if hovered {
207            let rem_size = cx.rem_size();
208            // cx.scene().push_quad(scene::Quad {
209            //     bounds,
210            //     background: Some(hsla(0., 0., 1., 0.05).into()),
211            //     border: gpui::Border {
212            //         color: hsla(0., 0., 1., 0.2).into(),
213            //         top: 1.,
214            //         right: 1.,
215            //         bottom: 1.,
216            //         left: 1.,
217            //     },
218            //     corner_radii: CornerRadii::default()
219            //         .refined(&style.corner_radii)
220            //         .to_gpui(bounds.size(), rem_size),
221            // })
222        }
223
224        // let pressed = Cell::new(hovered && cx.is_mouse_down(MouseButton::Left));
225        // cx.on_event(layout.order, move |_, event: &MouseButtonEvent, _| {
226        //     if bounds.contains_point(event.position) {
227        //         if event.is_down {
228        //             pressed.set(true);
229        //         } else if pressed.get() {
230        //             pressed.set(false);
231        //             eprintln!("clicked div {:?} {:#?}", bounds, style);
232        //         }
233        //     }
234        // });
235
236        // let hovered = Cell::new(hovered);
237        // cx.on_event(layout.order, move |_, event: &MouseMovedEvent, cx| {
238        //     cx.bubble_event();
239        //     let hovered_now = bounds.contains_point(event.position);
240        //     if hovered.get() != hovered_now {
241        //         hovered.set(hovered_now);
242        //         cx.repaint();
243        //     }
244        // });
245    }
246}
247
248impl<V> Styled for Div<V> {
249    type Style = Style;
250
251    fn style_cascade(&mut self) -> &mut RefinementCascade<Self::Style> {
252        &mut self.styles
253    }
254
255    fn declared_style(&mut self) -> &mut <Self::Style as Refineable>::Refinement {
256        self.styles.base()
257    }
258}
259
260impl<V> StyleHelpers for Div<V> {}
261
262// impl<V> Interactive<V> for Div<V> {
263//     fn interaction_handlers(&mut self) -> &mut InteractionHandlers<V> {
264//         &mut self.handlers
265//     }
266// }
267
268impl<V: 'static> ParentElement<V> for Div<V> {
269    fn children_mut(&mut self) -> &mut SmallVec<[AnyElement<V>; 2]> {
270        &mut self.children
271    }
272}
273
274#[derive(Default, Clone)]
275pub struct ScrollState(Rc<Cell<Point<Pixels>>>);
276
277impl ScrollState {
278    pub fn x(&self) -> Pixels {
279        self.0.get().x
280    }
281
282    pub fn set_x(&self, value: Pixels) {
283        let mut current_value = self.0.get();
284        current_value.x = value;
285        self.0.set(current_value);
286    }
287
288    pub fn y(&self) -> Pixels {
289        self.0.get().y
290    }
291
292    pub fn set_y(&self, value: Pixels) {
293        let mut current_value = self.0.get();
294        current_value.y = value;
295        self.0.set(current_value);
296    }
297}