Enable plain clicks on transcript links and style bare URLs (#46884)

## Why

Transcript links required a modified click to open, and bare URLs lacked the visual styling of explicit Markdown links.

## What changed

- Open links on release after an unmodified, stationary left click. Cancel activation after dragging, scrolling, or releasing elsewhere so text selection remains usable.
- Apply Markdown link styling to bare URLs while preserving surrounding prose, existing emphasis, Unicode, and table wrapping.

## Testing

Add gesture tests for bare and Markdown links at narrow and wide widths, drag and scroll cancellation, and existing modified-click behavior. Add styling tests and snapshots covering punctuation, emphasis, tabs, Unicode, and wrapped table URLs.

GitOrigin-RevId: 23d12c901932d7e3586d841e5a0ece00e422fccd

codex-rs/tui/src/transcript_view/input.rs

@@ -1,4 +1,5 @@
 //! Transcript gestures leave ordinary typing and composer editing with the existing input path.
+//! Stationary link clicks open on release; dragging or scrolling keeps the gesture in selection.
 
 use crate::key_hint::KeyBindingListExt;
 use crossterm::event::KeyCode;
@@ -206,6 +207,27 @@ impl TranscriptView {
                 self.extend_selection(event.column, event.row);
             }
             MouseEventKind::Up(MouseButton::Left) if dragging => {
+                // Open only a stationary click. Dragging back to the origin is still selection,
+                // and wheel scrolling clears the pointer even when it cannot move the viewport.
+                let link = self.selection.as_mut().and_then(|selection| {
+                    (inside
+                        && !selection.moved
+                        && selection.pointer == Some(ScreenPosition::new(event.column, event.row))
+                        && event.modifiers.is_empty())
+                    .then(|| selection.pressed_link.take())
+                    .flatten()
+                });
+                let link = link.filter(|destination| {
+                    self.visible
+                        .get(usize::from(event.row - self.area.y))
+                        .and_then(|visible| {
+                            visible
+                                .layout
+                                .link_at(visible.row, event.column - self.area.x)
+                        })
+                        .as_ref()
+                        == Some(destination)
+                });
                 if self
                     .selection
                     .as_ref()
@@ -217,6 +239,9 @@ impl TranscriptView {
                 if self.selected_text(cells).is_none() {
                     self.end_selection(cells);
                 }
+                if let Some(link) = link {
+                    return Some(ViewAction::OpenLink(link));
+                }
             }
             _ => return None,
         }
@@ -317,7 +342,21 @@ impl TranscriptView {
         {
             return None;
         }
+        let link = (clicks == 1 && event.modifiers.is_empty())
+            .then(|| {
+                visible
+                    .layout
+                    .link_at(visible.row, event.column.saturating_sub(self.area.x))
+            })
+            .flatten();
         self.begin_selection(cells, event.column, event.row, clicks);
+        if let Some(selection) = &mut self.selection {
+            selection.pressed_link = link;
+        }
         Some(ViewAction::Changed)
     }
 }
+
+#[cfg(test)]
+#[path = "input_tests.rs"]
+mod tests;

codex-rs/tui/src/transcript_view/input_tests.rs

@@ -0,0 +1,173 @@
+//! Link activation shares pointer gestures with selection without opening after a drag or scroll.
+
+use super::*;
+use crate::history_cell::AgentMarkdownCell;
+use pretty_assertions::assert_eq;
+
+fn transcript(markdown: &str, width: u16) -> (TranscriptView, Vec<Arc<dyn HistoryCell>>) {
+    let cells: Vec<Arc<dyn HistoryCell>> = vec![Arc::new(AgentMarkdownCell::new(
+        markdown.into(),
+        std::path::Path::new("/"),
+    ))];
+    let mut view = TranscriptView::default();
+    let area = Rect::new(/*x*/ 2, /*y*/ 1, width, /*height*/ 8);
+    view.render(area, &mut Buffer::empty(area), &cells);
+    (view, cells)
+}
+
+fn mouse(kind: MouseEventKind, column: u16, row: u16) -> MouseEvent {
+    MouseEvent {
+        kind,
+        column,
+        row,
+        modifiers: KeyModifiers::NONE,
+    }
+}
+
+#[test]
+fn ordinary_click_opens_bare_and_markdown_links_on_release() {
+    for markdown in [
+        "https://example.com/docs",
+        "[docs](https://example.com/docs)",
+    ] {
+        for width in [12, 60] {
+            let (mut view, cells) = transcript(markdown, width);
+            let down = mouse(
+                MouseEventKind::Down(MouseButton::Left),
+                /*column*/ 4,
+                /*row*/ 1,
+            );
+            assert!(matches!(
+                view.handle_mouse(down, &cells),
+                Some(ViewAction::Changed)
+            ));
+            // Match the app's redraw before dispatching the next mouse event.
+            let area = view.area;
+            view.render(area, &mut Buffer::empty(area), &cells);
+            let up = MouseEvent {
+                kind: MouseEventKind::Up(MouseButton::Left),
+                ..down
+            };
+            let Some(ViewAction::OpenLink(url)) = view.handle_mouse(up, &cells) else {
+                panic!("click should open {markdown}");
+            };
+            assert_eq!(
+                (
+                    url.as_str(),
+                    view.selected_text(&cells),
+                    view.is_following()
+                ),
+                ("https://example.com/docs", None, true)
+            );
+            assert!(view.handle_mouse(up, &cells).is_none());
+        }
+    }
+}
+
+#[test]
+fn dragging_a_link_selects_text_and_never_opens_it() {
+    for return_to_origin in [false, true] {
+        let (mut view, cells) = transcript(
+            "[documentation](https://example.com/docs)",
+            /*width*/ 60,
+        );
+        view.handle_mouse(
+            mouse(
+                MouseEventKind::Down(MouseButton::Left),
+                /*column*/ 4,
+                /*row*/ 1,
+            ),
+            &cells,
+        );
+        view.handle_mouse(
+            mouse(
+                MouseEventKind::Drag(MouseButton::Left),
+                /*column*/ 7,
+                /*row*/ 1,
+            ),
+            &cells,
+        );
+        assert_eq!(view.selected_text(&cells).as_deref(), Some("doc"));
+        let column = if return_to_origin { 4 } else { 7 };
+        let action = view.handle_mouse(
+            mouse(
+                MouseEventKind::Up(MouseButton::Left),
+                column,
+                /*row*/ 1,
+            ),
+            &cells,
+        );
+        assert!(matches!(action, Some(ViewAction::Changed)));
+        assert_eq!(
+            view.selected_text(&cells).as_deref(),
+            (!return_to_origin).then_some("doc")
+        );
+    }
+}
+
+#[test]
+fn scrolling_or_releasing_elsewhere_cancels_link_activation() {
+    for interruption in [
+        mouse(MouseEventKind::ScrollUp, /*column*/ 4, /*row*/ 1),
+        mouse(
+            MouseEventKind::ScrollDown,
+            /*column*/ 4,
+            /*row*/ 1,
+        ),
+        mouse(
+            MouseEventKind::Up(MouseButton::Left),
+            /*column*/ 5,
+            /*row*/ 1,
+        ),
+        mouse(
+            MouseEventKind::Up(MouseButton::Left),
+            /*column*/ 0,
+            /*row*/ 0,
+        ),
+    ] {
+        let (mut view, cells) = transcript("[docs](https://example.com/docs)", /*width*/ 60);
+        view.handle_mouse(
+            mouse(
+                MouseEventKind::Down(MouseButton::Left),
+                /*column*/ 4,
+                /*row*/ 1,
+            ),
+            &cells,
+        );
+        assert!(!matches!(
+            view.handle_mouse(interruption, &cells),
+            Some(ViewAction::OpenLink(_))
+        ));
+        assert!(!matches!(
+            view.handle_mouse(
+                mouse(
+                    MouseEventKind::Up(MouseButton::Left),
+                    /*column*/ 4,
+                    /*row*/ 1
+                ),
+                &cells
+            ),
+            Some(ViewAction::OpenLink(_))
+        ));
+    }
+}
+
+#[test]
+fn modified_clicks_still_open_immediately() {
+    for modifiers in [KeyModifiers::CONTROL, KeyModifiers::SUPER] {
+        let (mut view, cells) = transcript("[docs](https://example.com/docs)", /*width*/ 60);
+        let event = MouseEvent {
+            modifiers,
+            ..mouse(
+                MouseEventKind::Down(MouseButton::Left),
+                /*column*/ 4,
+                /*row*/ 1,
+            )
+        };
+        let Some(ViewAction::OpenLink(url)) = view.handle_mouse(event, &cells) else {
+            panic!("modified click should open link");
+        };
+        assert_eq!(url, "https://example.com/docs");
+        assert!(view.selection.is_none());
+    }
+}

codex-rs/tui/src/transcript_view/selection.rs

@@ -16,6 +16,7 @@ pub(super) struct Selection {
     pub(super) moved: bool,
     pub(super) resume_on_empty: bool,
     pub(super) pointer: Option<ScreenPosition>,
+    pub(super) pressed_link: Option<String>,
     origin: (Anchor, Anchor),
     unit: SelectionUnit,
     preferred_column: Option<u16>,
@@ -57,6 +58,7 @@ impl TranscriptView {
             moved: false,
             resume_on_empty: was_following,
             pointer: Some(ScreenPosition::new(column, row)),
+            pressed_link: None,
         });
         if was_following {
             self.hold_position();