Cut text at the available width instead of a character count

AGENTS.md

@@ -219,6 +219,9 @@ Layer 5 (binary):     code_assistant    — CLI, config, feature-gated frontend
 - GPUI frontend based on gpui-kit (gpui via `gpui_kit::*`, gpui-component via `gpui_kit::component`) with custom components
 - GPUI API reference (contexts, entities, tasks, elements, actions, events):
   `docs/gpui-reference.md`
+- Text is cut at the available width, never at a character count: `.truncate()`
+  or `.line_clamp(n).text_ellipsis()`, with `min_w_0()` on flex items around it
+  and `shared::text::single_line` for text that may hold line breaks
 - The right panel shows the agent's browser live (CDP screencast, feature
   `browser-panel`, default): `docs/browser-panel-plan.md`. GPUI must not run
   inside a tokio `block_on` (tokio's cooperation budget would never renew on

crates/ui_gpui/src/blocks/render.rs

@@ -5,6 +5,7 @@
 //! thinking, tool-use, compaction, image).
 
 use super::{BlockData, BlockView, ToolBlockState, ToolUseBlock};
+use crate::shared::text::single_line;
 use crate::shared::{file_icons, frame_profile};
 use code_assistant_core::ui::ToolStatus;
 
@@ -106,7 +107,7 @@ impl BlockView {
         };
         let header_text_color = theme.muted_foreground;
         let icon = file_icons::get().get_tool_icon(&block.name);
-        let label = renderer.describe(block);
+        let label = single_line(&renderer.describe(block));
 
         div()
             .w_full()
@@ -131,6 +132,8 @@ impl BlockView {
                     ))
                     .child(
                         div()
+                            .min_w_0()
+                            .truncate()
                             .text_size(rems(0.75))
                             .text_color(header_text_color)
                             .child(label),
@@ -171,15 +174,13 @@ impl BlockView {
         };
 
         // Description text
-        let description = if block.status == ToolStatus::Error {
-            if let Some(ref msg) = block.status_message {
-                format!("{} — {}", renderer.describe(block), msg)
-            } else {
-                renderer.describe(block)
-            }
-        } else {
-            renderer.describe(block)
-        };
+        let description = single_line(&renderer.describe(block));
+        // Its own element, so a long description can't push it out of view.
+        let error_message = block
+            .status_message
+            .as_deref()
+            .filter(|_| block.status == ToolStatus::Error)
+            .map(|message| format!("— {}", single_line(message)));
 
         // Optional right-aligned pill (e.g. the MCP server name).
         let header_tag = renderer.header_tag(block);
@@ -283,14 +284,22 @@ impl BlockView {
                     // Description text
                     .child(
                         div()
+                            .min_w_0()
+                            .truncate()
                             .text_size(rems(0.8125))
                             .text_color(desc_color)
-                            .overflow_hidden()
-                            .text_overflow(gpui_kit::TextOverflow::Truncate(SharedString::from(
-                                "…",
-                            )))
                             .child(description),
-                    ),
+                    )
+                    .when_some(error_message, |d, message| {
+                        d.child(
+                            div()
+                                .min_w_0()
+                                .truncate()
+                                .text_size(rems(0.8125))
+                                .text_color(desc_color)
+                                .child(message),
+                        )
+                    }),
             )
             // Optional pill (e.g. MCP server name), right-aligned before the
             // chevron.
@@ -399,6 +408,8 @@ impl BlockView {
             .child(
                 div()
                     .flex_1()
+                    .min_w_0()
+                    .truncate()
                     .text_size(rems(0.8125))
                     .text_color(color)
                     .child(label),
@@ -665,10 +676,8 @@ impl BlockView {
                                     .text_size(rems(0.8125))
                                     .italic()
                                     .text_color(muted)
-                                    .overflow_hidden()
-                                    .text_overflow(gpui_kit::TextOverflow::Truncate(
-                                        SharedString::from("…"),
-                                    ))
+                                    .min_w_0()
+                                    .truncate()
                                     .child(header_text),
                             ),
                     )
@@ -996,13 +1005,15 @@ impl BlockView {
             .hover(|s| s.text_color(theme.foreground))
             .child(
                 gpui_kit::svg()
+                    .flex_none()
                     .size(px(14.))
                     .path("icons/message_bubbles.svg")
                     .text_color(theme.muted_foreground),
             )
-            .child(label)
+            .child(div().min_w_0().truncate().child(label))
             .child(
                 gpui_kit::svg()
+                    .flex_none()
                     .size(px(10.))
                     .path(if expanded {
                         "icons/chevron_down.svg"

crates/ui_gpui/src/diff/render.rs

@@ -46,15 +46,14 @@ pub(crate) fn render_diff_chunk(
         return rows;
     }
     let (_, ctx_color) = unchanged_row_colors(theme);
-    let separator = div().w_full().flex().text_color(ctx_color.opacity(0.5));
+    let separator = div().w_full().text_color(ctx_color.opacity(0.5));
     let separator = match header {
+        // Not a flex container: text directly in one doesn't shrink.
         Some(header) => separator
             .px_3()
-            .overflow_hidden()
-            .whitespace_nowrap()
-            .text_ellipsis()
+            .truncate()
             .child(SharedString::from(format!("⋯  {header}"))),
-        None => separator.justify_center().child("⋯"),
+        None => separator.flex().justify_center().child("⋯"),
     };
     div()
         .flex()

crates/ui_gpui/src/input/attachment.rs

@@ -103,7 +103,7 @@ impl AttachmentView {
                     div()
                         .text_xs()
                         .text_color(cx.theme().muted_foreground)
-                        .text_ellipsis()
+                        .truncate()
                         .w_full()
                         .text_center()
                         .child(filename.clone()),

crates/ui_gpui/src/input/comments.rs

@@ -8,6 +8,7 @@
 
 use super::{InputArea, InputAreaEvent};
 use crate::shared::dismiss::dismiss_layer;
+use crate::shared::text::single_line;
 use code_assistant_core::line_comments::LineComment;
 use code_assistant_core::persistence::DraftAttachment;
 use gpui_kit::component::{ActiveTheme, Icon, Sizable, Size, ThemeStyled};
@@ -17,9 +18,6 @@ use gpui_kit::{
 };
 use std::collections::BTreeSet;
 
-/// Characters of a comment's text shown in the chip.
-const PREVIEW_CHARS: usize = 40;
-
 impl InputArea {
     /// The draft's line comments, in the order they were made.
     pub fn comments(&self) -> &[LineComment] {
@@ -96,13 +94,7 @@ impl InputArea {
         match comments {
             [] => String::new(),
             [c] => {
-                let text: String = c.text.chars().take(PREVIEW_CHARS).collect();
-                let ellipsis = if c.text.chars().count() > PREVIEW_CHARS {
-                    "…"
-                } else {
-                    ""
-                };
-                format!("{} · {text}{ellipsis}", c.location_label())
+                format!("{} · {}", c.location_label(), single_line(&c.text))
             }
             _ if comments.iter().any(|c| c.on_message) => {
                 format!("{} comments", comments.len())
@@ -161,9 +153,7 @@ impl InputArea {
                         .child(
                             div()
                                 .min_w_0()
-                                .overflow_hidden()
-                                .whitespace_nowrap()
-                                .text_ellipsis()
+                                .truncate()
                                 .text_xs()
                                 .text_color(theme.foreground)
                                 .child(label),
@@ -248,9 +238,7 @@ impl InputArea {
                             )
                             .child(
                                 div()
-                                    .overflow_hidden()
-                                    .whitespace_nowrap()
-                                    .text_ellipsis()
+                                    .truncate()
                                     .text_xs()
                                     .font_family("Menlo")
                                     .text_color(theme.muted_foreground)
@@ -346,8 +334,10 @@ mod tests {
             InputArea::comments_label(&[comment("/p/src/lib.rs", "no unwrap here")]),
             "lib.rs:3-5 · no unwrap here"
         );
-        let long = "a".repeat(50);
-        assert!(InputArea::comments_label(&[comment("/p/a.rs", &long)]).ends_with("a…"));
+        assert_eq!(
+            InputArea::comments_label(&[comment("/p/src/lib.rs", "first\nsecond")]),
+            "lib.rs:3-5 · first second"
+        );
         assert_eq!(
             InputArea::comments_label(&[comment("/p/a.rs", "x"), comment("/p/a.rs", "y")]),
             "2 comments in a.rs"

crates/ui_gpui/src/input/mod.rs

@@ -728,13 +728,16 @@ impl InputArea {
                     }))
                     .child(
                         div()
+                            .min_w_0()
                             .flex()
                             .items_baseline()
                             .gap_2()
                             .text_sm()
-                            .child(item.label.clone())
+                            .child(div().flex_none().child(item.label.clone()))
                             .child(
                                 div()
+                                    .min_w_0()
+                                    .truncate()
                                     .text_xs()
                                     .text_color(cx.theme().muted_foreground)
                                     .child(item.detail.clone()),

crates/ui_gpui/src/input/model_selector.rs

@@ -90,7 +90,7 @@ impl SelectItem for ModelItem {
                 .min_w_0()
                 .flex()
                 .items_center()
-                .child(div().min_w_0().text_ellipsis().child(self.name.clone())),
+                .child(div().min_w_0().truncate().child(self.name.clone())),
         );
 
         Some(row.into_any_element())

crates/ui_gpui/src/main_screen/agents_panel.rs

@@ -182,9 +182,7 @@ fn sub_agent_row(
             div()
                 .flex_1()
                 .min_w_0()
-                .overflow_hidden()
-                .text_ellipsis()
-                .whitespace_nowrap()
+                .truncate()
                 .text_size(rems(0.8125))
                 .text_color(foreground)
                 .child(agent.title.clone()),
@@ -208,9 +206,7 @@ fn sub_agent_row(
             div()
                 .flex_none()
                 .w(px(160.))
-                .overflow_hidden()
-                .text_ellipsis()
-                .whitespace_nowrap()
+                .truncate()
                 .text_size(rems(0.75))
                 .text_color(muted)
                 .map(|column| {

crates/ui_gpui/src/main_screen/mod.rs

@@ -1469,6 +1469,7 @@ impl MainScreen {
                                         .text_xs()
                                         .text_color(cx.theme().muted_foreground)
                                         .line_clamp(4)
+                                        .text_ellipsis()
                                         .child(request.summary.clone()),
                                 ),
                         )

crates/ui_gpui/src/main_screen/project_dialog.rs

@@ -185,8 +185,7 @@ impl Render for NewProjectDialog {
                         div()
                             .text_xs()
                             .text_color(cx.theme().danger.opacity(0.8))
-                            .overflow_hidden()
-                            .text_ellipsis()
+                            .truncate()
                             .child(SharedString::from(existing_path.clone())),
                     ),
             ),
@@ -236,8 +235,7 @@ impl Render for NewProjectDialog {
                         div()
                             .text_xs()
                             .text_color(cx.theme().muted_foreground)
-                            .overflow_hidden()
-                            .text_ellipsis()
+                            .truncate()
                             .child(SharedString::from(path_display)),
                     )
                     // Name input

crates/ui_gpui/src/main_screen/right_panel/browser/toolbar.rs

@@ -3,6 +3,7 @@
 
 use super::BrowserPanel;
 use crate::Gpui;
+use crate::shared::text::single_line;
 use code_assistant_core::session::browsers::BrowserKey;
 use gpui_kit::component::button::{Button, ButtonVariants};
 use gpui_kit::component::input::{Input, InputEvent, InputState};
@@ -49,7 +50,7 @@ impl BrowserPanel {
                     let label = if t.title.is_empty() { &t.url } else { &t.title };
                     chip(
                         SharedString::from(format!("tab-{}", t.id)),
-                        truncate(label, 28),
+                        single_line(label),
                         Some(t.id.as_str()) == watched_tab,
                         cx,
                     )
@@ -84,9 +85,7 @@ impl BrowserPanel {
                 .bg(theme.muted)
                 .text_xs()
                 .text_color(theme.foreground)
-                .overflow_hidden()
-                .whitespace_nowrap()
-                .text_ellipsis()
+                .truncate()
                 .when(in_control, |el| el.cursor_text())
                 .on_click(cx.listener(|this, _, window, cx| this.edit_address(window, cx)))
                 .child(tab.map(|t| t.url.clone()).unwrap_or_default())
@@ -246,6 +245,8 @@ fn chip(
     let theme = cx.theme();
     div()
         .id(id)
+        .max_w(px(220.))
+        .truncate()
         .px_2()
         .py_0p5()
         .rounded(px(4.))
@@ -269,14 +270,6 @@ fn browser_label(key: &BrowserKey) -> String {
     }
 }
 
-fn truncate(text: &str, max: usize) -> String {
-    if text.chars().count() <= max {
-        return text.to_string();
-    }
-    let cut: String = text.chars().take(max.saturating_sub(1)).collect();
-    format!("{cut}…")
-}
-
 /// What the user typed as an address, with `https://` when it has no scheme.
 fn with_scheme(typed: &str) -> String {
     if typed.contains("://") || typed.starts_with("about:") || typed.starts_with("data:") {

crates/ui_gpui/src/main_screen/right_panel/file_renderers/raster.rs

@@ -175,6 +175,7 @@ impl Render for RasterPreview {
         let muted = theme.muted_foreground;
         let notice = move |text: String| {
             div()
+                .min_w_0()
                 .text_sm()
                 .text_color(muted)
                 .child(text)

crates/ui_gpui/src/main_screen/right_panel/file_renderers/svg.rs

@@ -224,6 +224,7 @@ impl Render for SvgPreview {
         let themed = self.themed_background;
         let notice = |text: String| {
             div()
+                .min_w_0()
                 .text_sm()
                 .text_color(muted)
                 .child(text)

crates/ui_gpui/src/main_screen/right_panel/file_viewer.rs

@@ -765,7 +765,7 @@ impl FileViewer {
                 .bg(theme.warning.opacity(0.12))
                 .text_xs()
                 .text_color(theme.foreground)
-                .child(div().flex_1().child(text))
+                .child(div().flex_1().min_w_0().child(text))
                 .when(actions, |d| {
                     d.child(
                         Button::new("file-reload-disk")