Ribbon key tips: Alt shows codes on tabs, buttons and menu items

A lone Alt shows a code on every ribbon tab and quick-access button.
Typing a tab code opens the tab and shows the codes of its buttons,
dropdowns, slide-outs and collapsed panels; a button code runs it, a
dropdown or slide-out code opens it and shows its item codes, Esc goes
back one level. Codes follow the reference ribbon; buttons without a
reference counterpart get none and unnamed menu items are numbered.

Codes are drawn as accent pills over the widgets that reported their
bounds in the current frame, with a hint bar under the ribbon. While
the tips are open keys go to them only. The automation gets a keytips
action and read operation.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ui/ribbon/mod.rs

@@ -31,6 +31,12 @@ use widgets::{StyleContext, *};
 pub(crate) use widgets::{REDO_HISTORY_ID, UNDO_HISTORY_ID};
 mod collapse;
 mod locate;
+mod keytips;
+pub use keytips::{
+    active as keytips_active, key_pressed as keytip_key_pressed,
+    key_released as keytip_key_released, pointer_pressed as keytip_pointer_pressed, KeyTipInput,
+    KeyTipStep,
+};
 use crate::t;
 use crate::ui::wrap_bar::{PosReport, WrapBar, WrapFlow};
 pub use collapse::CollapseMode;
@@ -122,6 +128,8 @@ pub struct Ribbon {
     block_editing: Option<usize>,
     /// XDWGFADECTL as the Reference slide-out shows it (negative = off).
     pub xref_fade: i32,
+    /// Open key tips (Alt).
+    keytips: Option<keytips::State>,
 }
 
 /// Per-layer display data shown in the ribbon layer dropdown.
@@ -224,6 +232,7 @@ impl Ribbon {
             point_cloud_ctx: None,
             block_editing: None,
             xref_fade: 50,
+            keytips: None,
         }
     }
 
@@ -662,7 +671,7 @@ impl Ribbon {
                     },
                     ..Default::default()
                 });
-                acc.push(btn.into());
+                acc.push(keytips::anchor_with(|| format!("tab:{}", module.id()), btn));
                 acc
             },
         );
@@ -800,7 +809,7 @@ impl Ribbon {
             tool_bar
         };
 
-        column![tab_bar, tool_bar].into()
+        keytips::ribbon_area(column![tab_bar, tool_bar])
     }
 
     // ── Dropdown overlay ──────────────────────────────────────────────────
@@ -971,7 +980,7 @@ impl Ribbon {
                             .then_some(theme.palette().background.base.text.scale_alpha(0.72)),
                     });
 
-                button(
+                let item = button(
                     row![checkmark, icon_el, label_el]
                         .spacing(4)
                         .align_y(iced::Center),
@@ -982,8 +991,8 @@ impl Ribbon {
                 }))
                 .style(popup_row_style)
                 .width(Fill)
-                .padding([4, 10])
-                .into()
+                .padding([4, 10]);
+                keytips::anchor_with(|| keytips::item_anchor(dd_id, cmd), item)
             })
             .collect();
 
@@ -1571,7 +1580,10 @@ fn collapse_button<'a>(
         .style(opener_style(holds))
         .width(Fill)
         .padding([3, 5]);
-        return automatic_large_button(localized_title, content.into());
+        return keytips::anchor_with(
+            || keytips::collapsed_anchor(title),
+            automatic_large_button(localized_title, content.into()),
+        );
     }
 
     // Collapsed (not yet tight): a large representative-tool face — a live button
@@ -1636,7 +1648,10 @@ fn collapse_button<'a>(
     .style(opener_style(holds && !face_lit))
     .width(Fill)
     .padding([1, 4]);
-    let opener = automatic_large_button(localized_title, opener.into());
+    let opener = keytips::anchor_with(
+        || keytips::collapsed_anchor(title),
+        automatic_large_button(localized_title, opener.into()),
+    );
 
     // The large face fills a fixed slot so a collapsed panel is shorter than a full
     // 3-row panel, letting `CollapsePanels` shrink the ribbon row.