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 <[email protected]>

src/app/update/keytips.rs

@@ -0,0 +1,80 @@
+//! Ribbon key tips: a lone Alt opens them, typed codes walk the ribbon and
+//! Esc goes back one level.
+
+use iced::Task;
+
+use crate::app::{Message, OpenCADStudio};
+use crate::ui::ribbon::{KeyTipInput, KeyTipStep};
+
+impl OpenCADStudio {
+    pub(in crate::app) fn on_keytip(&mut self, input: KeyTipInput) -> Task<Message> {
+        match input {
+            KeyTipInput::AltTap if self.ribbon.keytips_active() => self.hide_keytips(),
+            KeyTipInput::AltTap => {
+                if self.active_modal.is_some() || self.clean_screen || self.ribbon_closed {
+                    return Task::none();
+                }
+                // A focused field other than the command line keeps Alt.
+                iced::advanced::widget::operate(
+                    iced::advanced::widget::operation::focusable::count(),
+                )
+                .then(|count| {
+                    if count.focused.is_none() {
+                        return Task::done(Message::KeyTip(KeyTipInput::Open { refocus: false }));
+                    }
+                    iced::widget::operation::is_focused(iced::widget::Id::new(
+                        crate::ui::command_line::CMD_INPUT_ID,
+                    ))
+                    .map(|command_line| {
+                        if command_line {
+                            Message::KeyTip(KeyTipInput::Open { refocus: true })
+                        } else {
+                            Message::Noop
+                        }
+                    })
+                })
+            }
+            KeyTipInput::Open { refocus } => {
+                self.ribbon.show_keytips(refocus);
+                // Typed codes must not reach the command line.
+                if refocus {
+                    self.unfocus_widgets()
+                } else {
+                    Task::none()
+                }
+            }
+            KeyTipInput::Hide => self.hide_keytips(),
+            KeyTipInput::Escape => {
+                if self.ribbon.keytip_escape() {
+                    Task::none()
+                } else {
+                    self.hide_keytips()
+                }
+            }
+            KeyTipInput::Char(_) | KeyTipInput::Enter => {
+                let ch = match &input {
+                    KeyTipInput::Char(ch) => Some(ch.as_str()),
+                    _ => None,
+                };
+                match self.ribbon.keytip_type(ch) {
+                    KeyTipStep::Ignore | KeyTipStep::Stay => Task::none(),
+                    KeyTipStep::Open(message) => self.update(message),
+                    KeyTipStep::Run(message) => {
+                        let refocus = self.hide_keytips();
+                        Task::batch([refocus, self.update(message)])
+                    }
+                }
+            }
+        }
+    }
+
+    /// Close the key tips, returning the focus to the command line if it had
+    /// it.
+    pub(in crate::app) fn hide_keytips(&mut self) -> Task<Message> {
+        if self.ribbon.hide_keytips() {
+            self.focus_cmd_input()
+        } else {
+            Task::none()
+        }
+    }
+}

src/app/update/mod.rs

@@ -102,6 +102,7 @@ mod dialog;
 mod dynamic;
 mod file;
 mod graphic_attributes;
+mod keytips;
 pub(in crate::app) use file::background_task;
 #[cfg(not(target_arch = "wasm32"))]
 pub(in crate::app) use file::native_paths_match;
@@ -621,6 +622,10 @@ impl OpenCADStudio {
                 if Some(id) == self.main_window {
                     self.spacemouse_focused = focused;
                 }
+                // Key tips close when the window loses the focus.
+                if !focused && self.ribbon.keytips_active() {
+                    return self.hide_keytips();
+                }
                 Task::none()
             }
             Message::SpaceMouseEnabled(enabled) => {
@@ -2277,6 +2282,7 @@ impl OpenCADStudio {
             Message::PcManager(message) => self.update_pc_manager(message),
             Message::Count(message) => self.on_count(message),
             Message::SheetSet(message) => self.on_sheet_set(message),
+            Message::KeyTip(input) => self.on_keytip(input),
             Message::RibbonSelectTab(idx) => {
                 self.ribbon.select(idx);
                 Task::none()