1use crate::{
  2    AnyElement, Element, IntoAnyElement, Layout, LayoutId, Line, Pixels, Result, Size, ViewContext,
  3};
  4use parking_lot::Mutex;
  5use std::{marker::PhantomData, sync::Arc};
  6use util::{arc_cow::ArcCow, ResultExt};
  7
  8impl<S: 'static> IntoAnyElement<S> for ArcCow<'static, str> {
  9    fn into_any(self) -> AnyElement<S> {
 10        Text {
 11            text: self,
 12            state_type: PhantomData,
 13        }
 14        .into_any()
 15    }
 16}
 17
 18impl<V: 'static> IntoAnyElement<V> for &'static str {
 19    fn into_any(self) -> AnyElement<V> {
 20        Text {
 21            text: ArcCow::from(self),
 22            state_type: PhantomData,
 23        }
 24        .into_any()
 25    }
 26}
 27
 28pub struct Text<S> {
 29    text: ArcCow<'static, str>,
 30    state_type: PhantomData<S>,
 31}
 32
 33impl<S: 'static> Element for Text<S> {
 34    type State = S;
 35    type FrameState = Arc<Mutex<Option<TextFrameState>>>;
 36
 37    fn layout(
 38        &mut self,
 39        _view: &mut S,
 40        cx: &mut ViewContext<S>,
 41    ) -> Result<(LayoutId, Self::FrameState)> {
 42        dbg!("layout text");
 43
 44        let text_system = cx.text_system().clone();
 45        let text_style = cx.text_style();
 46        let font_size = text_style.font_size * cx.rem_size();
 47        let line_height = text_style
 48            .line_height
 49            .to_pixels(font_size.into(), cx.rem_size());
 50        let text = self.text.clone();
 51        let paint_state = Arc::new(Mutex::new(None));
 52
 53        let rem_size = cx.rem_size();
 54        let layout_id = cx.request_measured_layout(Default::default(), rem_size, {
 55            let frame_state = paint_state.clone();
 56            move |_, _| {
 57                let Some(line_layout) = text_system
 58                    .layout_line(
 59                        text.as_ref(),
 60                        font_size,
 61                        &[(text.len(), text_style.to_run())],
 62                    )
 63                    .log_err()
 64                else {
 65                    return Size::default();
 66                };
 67
 68                let size = Size {
 69                    width: line_layout.width(),
 70                    height: line_height,
 71                };
 72
 73                frame_state.lock().replace(TextFrameState {
 74                    line: Arc::new(line_layout),
 75                    line_height,
 76                });
 77
 78                size
 79            }
 80        });
 81
 82        Ok((layout_id?, paint_state))
 83    }
 84
 85    fn paint<'a>(
 86        &mut self,
 87        layout: Layout,
 88        _: &mut Self::State,
 89        frame_state: &mut Self::FrameState,
 90        cx: &mut ViewContext<S>,
 91    ) -> Result<()> {
 92        let line;
 93        let line_height;
 94        {
 95            let frame_state = frame_state.lock();
 96            let frame_state = frame_state
 97                .as_ref()
 98                .expect("measurement has not been performed");
 99            line = frame_state.line.clone();
100            line_height = frame_state.line_height;
101        }
102
103        // todo!("We haven't added visible bounds to the new element system yet, so this is a placeholder.");
104        let visible_bounds = layout.bounds;
105        line.paint(&layout, visible_bounds, line_height, cx)?;
106
107        Ok(())
108    }
109}
110
111pub struct TextFrameState {
112    line: Arc<Line>,
113    line_height: Pixels,
114}