T16 Finance: market charts with kinds, volume, profile, studies, drawings, compare, alerts and sync (T16a–b); quotes, book, tape and DOM (T16c); order entry, blotter, risk, options and payoff (T16d); markets, calendars, portfolio and wallet (T16e); typography::Ellipsis ends lines that gpui's truncate clipped; chart notes stack and ticks label round values

src/typography/fit.rs

@@ -1,7 +1,7 @@
 use gpui::{
     App, ElementId, InteractiveElement, IntoElement, ParentElement, Pixels, RenderOnce, ShapedLine,
     SharedString, StatefulInteractiveElement, Styled, TextRun, Window, canvas, div, prelude::*,
-    relative,
+    relative, transparent_black,
 };
 
 use crate::{
@@ -21,6 +21,23 @@ fn elide(chars: &[char], kept: usize) -> String {
     out
 }
 
+/// How wide `text` sets at `size` in the text style around it.
+pub(crate) fn text_width(text: &str, size: Pixels, window: &Window) -> Pixels {
+    let style = window.text_style();
+    let run = TextRun {
+        len: text.len(),
+        font: style.font(),
+        color: style.color,
+        background_color: None,
+        underline: None,
+        strikethrough: None,
+    };
+    window
+        .text_system()
+        .shape_line(SharedString::from(text.to_string()), size, &[run], None)
+        .width
+}
+
 fn shape(text: &str, window: &mut Window) -> ShapedLine {
     let style = window.text_style();
     let run = TextRun {
@@ -62,6 +79,76 @@ fn fit_middle(text: &str, width: Pixels, window: &mut Window) -> String {
     elide(&chars, low)
 }
 
+/// Longest front that fits `width` with an ellipsis after it.
+fn fit_end(text: &str, width: Pixels, window: &mut Window) -> String {
+    if width_of(text, window) <= width {
+        return text.to_string();
+    }
+    if width_of("…", window) > width {
+        return String::new();
+    }
+    let chars: Vec<char> = text.chars().collect();
+    let cut = |kept: usize| {
+        let front: String = chars[..kept].iter().collect();
+        let mut out: String = front
+            .trim_end_matches(|ch: char| ch.is_whitespace() || matches!(ch, '.' | ',' | ';' | ':'))
+            .into();
+        out.push('…');
+        out
+    };
+    let (mut low, mut high) = (0, chars.len());
+    while low < high {
+        let mid = (low + high).div_ceil(2);
+        if width_of(&cut(mid), window) <= width {
+            low = mid;
+        } else {
+            high = mid - 1;
+        }
+    }
+    cut(low)
+}
+
+/// One line in the text style around it, cut at the end with an ellipsis when its box is too narrow. gpui 0.2.2 keeps a line's first measure, so its own `truncate` clips instead in flex boxes.
+#[derive(IntoElement)]
+pub struct Ellipsis {
+    text: SharedString,
+}
+
+impl Ellipsis {
+    pub fn new(text: impl Into<SharedString>) -> Self {
+        Self { text: text.into() }
+    }
+}
+
+impl RenderOnce for Ellipsis {
+    fn render(self, _: &mut Window, _: &mut App) -> impl IntoElement {
+        let text = self.text.clone();
+        div()
+            .relative()
+            .min_w_0()
+            .overflow_hidden()
+            .whitespace_nowrap()
+            .child(div().text_color(transparent_black()).child(self.text))
+            .child(
+                canvas(
+                    move |bounds, window, _| {
+                        shape(&fit_end(&text, bounds.size.width, window), window)
+                    },
+                    |bounds, shaped, window, cx| {
+                        let line = window.text_style().line_height_in_pixels(window.rem_size());
+                        shaped
+                            .paint(bounds.origin, line, window, cx)
+                            .expect("an ellipsis line paints");
+                    },
+                )
+                .absolute()
+                .top_0()
+                .left_0()
+                .size_full(),
+            )
+    }
+}
+
 /// Shortens in the middle, keeping both ends. Paths, hashes.
 #[derive(IntoElement)]
 pub struct MiddleEllipsis {
@@ -176,3 +263,35 @@ mod tests {
         assert_eq!(elide(&wide, 4), "路径…rs");
     }
 }
+
+#[cfg(all(test, feature = "test-support"))]
+mod fits {
+    use gpui::{Pixels, TestAppContext};
+
+    use super::{fit_end, width_of};
+
+    #[gpui::test]
+    fn an_ellipsis_keeps_the_longest_front_that_fits(cx: &mut TestAppContext) {
+        let cx = cx.add_empty_window();
+        cx.update(|window, _| {
+            let text = "Good interfaces. Quiet ones";
+            let whole = width_of(text, window);
+            assert_eq!(
+                fit_end(text, whole, window),
+                text,
+                "a line that fits stays whole"
+            );
+            let room = width_of("Good interfaces.…", window);
+            assert_eq!(
+                fit_end(text, room, window),
+                "Good interfaces…",
+                "no stop or space before the ellipsis"
+            );
+            assert_eq!(
+                fit_end(text, Pixels::ZERO, window),
+                "",
+                "no room shows nothing"
+            );
+        });
+    }
+}

src/typography/mod.rs

@@ -15,8 +15,8 @@ mod text;
 pub use copy::CopyableText;
 pub use effects::{GradientText, ShimmerText, Typewriter};
 pub use emoji::Emoji;
-pub(crate) use fit::LEADING;
-pub use fit::{EllipsisTooltip, MiddleEllipsis};
+pub use fit::{Ellipsis, EllipsisTooltip, MiddleEllipsis};
+pub(crate) use fit::{LEADING, text_width};
 pub use format::DurationStyle;
 pub use formatted::{
     CurrencyText, DateTimeText, DurationText, FileSizeText, NumberText, PercentText, PluralText,