Allow transcript selection and copying while bottom modals are open (#50564)

## Why

The plan confirmation prompt allowed transcript scrolling but blocked selecting and copying the visible plan text.

## What changed

Allow mouse selection and copying in the visible transcript while a bottom modal is open, preserving drags across redraws. Keep other keyboard input with the modal and suppress transcript link activation, disclosure toggles, and follow-control clicks during modal mouse handling.

## Testing

Extend the plan prompt test to cover selection, `Ctrl+Insert` copying, selection highlighting, and popup bounds. Add coverage confirming that ordinary and Control-clicks do not open links in selection-only mouse handling.

GitOrigin-RevId: 9e1fdfcb4bc18215e62a714f173bc8cb372b090a

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

@@ -26,6 +26,12 @@ pub(crate) enum ViewAction {
     OpenLink(String),
 }
 
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum MouseMode {
+    Interactive,
+    Selection,
+}
+
 /// Transcript jumps shared with input routing so legacy terminals preserve their Alt modifier.
 #[derive(Clone, Copy, PartialEq, Eq)]
 pub(crate) enum JumpTarget {
@@ -200,10 +206,31 @@ impl TranscriptView {
         event: MouseEvent,
         cells: &[Arc<dyn HistoryCell>],
     ) -> Option<ViewAction> {
-        if let Some(action) = self.handle_follow_control_mouse(event) {
+        self.handle_mouse_with_mode(event, cells, MouseMode::Interactive)
+    }
+
+    /// Handles selection and scrolling without activating transcript content.
+    pub(crate) fn handle_selection_mouse(
+        &mut self,
+        event: MouseEvent,
+        cells: &[Arc<dyn HistoryCell>],
+    ) -> Option<ViewAction> {
+        self.handle_mouse_with_mode(event, cells, MouseMode::Selection)
+    }
+
+    fn handle_mouse_with_mode(
+        &mut self,
+        event: MouseEvent,
+        cells: &[Arc<dyn HistoryCell>],
+        mode: MouseMode,
+    ) -> Option<ViewAction> {
+        if mode == MouseMode::Interactive
+            && let Some(action) = self.handle_follow_control_mouse(event)
+        {
             return Some(action);
         }
-        if event.kind == MouseEventKind::Down(MouseButton::Left)
+        if mode == MouseMode::Interactive
+            && event.kind == MouseEventKind::Down(MouseButton::Left)
             && event
                 .modifiers
                 .intersects(KeyModifiers::CONTROL | KeyModifiers::SUPER)
@@ -264,21 +291,28 @@ impl TranscriptView {
                     .filter(|text| !text.is_empty())
                     .map(ViewAction::Copy);
             }
-            MouseEventKind::Down(MouseButton::Left) => return self.pointer_down(event, cells),
+            MouseEventKind::Down(MouseButton::Left) => {
+                return self.pointer_down(event, cells, mode);
+            }
             MouseEventKind::Drag(MouseButton::Left) if dragging => {
                 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 = if mode == MouseMode::Interactive {
+                    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()
+                    })
+                } else {
+                    None
+                };
                 let link = link.filter(|destination| {
                     self.link_at(event.column, event.row).as_ref() == Some(destination)
                 });
@@ -385,17 +419,22 @@ impl TranscriptView {
         &mut self,
         event: MouseEvent,
         cells: &[Arc<dyn HistoryCell>],
+        mode: MouseMode,
     ) -> Option<ViewAction> {
-        if event.modifiers.is_empty() && self.toggle_disclosure_at(cells, event.column, event.row) {
+        if mode == MouseMode::Interactive
+            && event.modifiers.is_empty()
+            && self.toggle_disclosure_at(cells, event.column, event.row)
+        {
             return Some(ViewAction::Changed);
         }
         self.disclosure.focused = None;
         let visible = self
             .visible
             .get(usize::from(event.row.checked_sub(self.area.y)?))?;
-        if event
-            .modifiers
-            .intersects(KeyModifiers::CONTROL | KeyModifiers::SUPER)
+        if mode == MouseMode::Interactive
+            && event
+                .modifiers
+                .intersects(KeyModifiers::CONTROL | KeyModifiers::SUPER)
         {
             return self
                 .link_at(event.column, event.row)
@@ -420,7 +459,7 @@ impl TranscriptView {
         {
             return None;
         }
-        let link = (clicks == 1 && event.modifiers.is_empty())
+        let link = (mode == MouseMode::Interactive && clicks == 1 && event.modifiers.is_empty())
             .then(|| self.link_at(event.column, event.row))
             .flatten();
         self.begin_selection(cells, event.column, event.row, clicks);

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

@@ -306,6 +306,38 @@ fn ordinary_click_opens_bare_and_markdown_links_on_release() {
     }
 }
 
+#[test]
+fn selection_mouse_does_not_open_links() {
+    for modifiers in [KeyModifiers::NONE, KeyModifiers::CONTROL] {
+        let (mut view, cells) = transcript("[docs](https://example.com/docs)", /*width*/ 60);
+        let down = MouseEvent {
+            modifiers,
+            ..mouse(
+                MouseEventKind::Down(MouseButton::Left),
+                /*column*/ 4,
+                /*row*/ 1,
+            )
+        };
+        assert!(matches!(
+            view.handle_selection_mouse(down, &cells),
+            Some(ViewAction::Changed)
+        ));
+        let area = view.area;
+        view.render(area, &mut Buffer::empty(area), &cells);
+        assert!(matches!(
+            view.handle_selection_mouse(
+                MouseEvent {
+                    kind: MouseEventKind::Up(MouseButton::Left),
+                    ..down
+                },
+                &cells,
+            ),
+            Some(ViewAction::Changed)
+        ));
+        assert_eq!(view.selected_text(&cells), None);
+    }
+}
+
 #[test]
 fn dragging_a_link_selects_text_and_never_opens_it() {
     for return_to_origin in [false, true] {