Redesign Select Color panel: index and true color tabs

Replace the old index page and the iced_aw ColorPicker popup with one
Select Color panel:

- Index Color tab: standard colors, ACI 10-249 grid, grays; arrow keys
  move through the palette.
- True Color tab: HSB, RGB and gradient-field modes built on two new
  widgets (GradientSlider, ColorArea) and iced_aw NumberInput boxes,
  an editable hex field and a nearest/exact index color button.
- Current/New swatch: clicking Current reverts. A mixed selection opens
  on the color of the most recently drawn object with *VARIES* on top.
- Color field accepts an index, a color name, r,g,b or hex.
- Enter confirms, Esc cancels, other keys stay in the panel.
- New labels translated in all 22 locales.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_013rGmDUNr1hUf4zo1X3dak8

src/app/update/mod.rs

@@ -377,6 +377,37 @@ impl OpenCADStudio {
         // closes it and every other keystroke-derived message is swallowed;
         // the modal's own text fields keep working because they emit their own
         // (non-blocked) messages. (#126)
+        // The Select Color panel can open on top of another dialog, so it
+        // takes the keyboard first: Esc cancels, Enter confirms, the arrows
+        // walk the index palette, and every other keystroke is swallowed.
+        if self.color_picker.is_some() {
+            use crate::ui::color_select::ColorPickerMsg;
+            let last_key = |key: &str| key.rsplit('+').next().map(str::to_owned);
+            match &msg {
+                Message::CommandEscape => {
+                    return self.update(Message::ColorPicker(ColorPickerMsg::Cancel));
+                }
+                Message::CommandFinalize => {
+                    return self.update(Message::ColorPicker(ColorPickerMsg::Ok));
+                }
+                Message::ShortcutPressed(key) => match last_key(key).as_deref() {
+                    Some("ESCAPE") => {
+                        return self.update(Message::ColorPicker(ColorPickerMsg::Cancel));
+                    }
+                    Some("ENTER" | "RETURN") => {
+                        return self.update(Message::ColorPicker(ColorPickerMsg::Ok));
+                    }
+                    _ => {}
+                },
+                Message::ArrowKeyPressed { direction, .. } => {
+                    return self.update(Message::ColorPicker(ColorPickerMsg::Arrow(*direction)));
+                }
+                _ => {}
+            }
+            if is_modal_blocked_key_msg(&msg) {
+                return Task::none();
+            }
+        }
         if self.active_modal.is_some() {
             if matches!(msg, Message::CommandEscape)
                 || matches!(&msg, Message::ShortcutPressed(key) if key.rsplit('+').next() == Some("ESCAPE"))
@@ -3806,7 +3837,7 @@ impl OpenCADStudio {
             Message::PaneClicked(pane) => self.on_pane_clicked(pane),
             Message::PaneDragged(ev) => self.on_pane_dragged(ev),
             Message::PaneMove(idx, local) => {
-                if self.color_pick_target.is_some() {
+                if self.color_picker.is_some() {
                     return Task::none();
                 }
                 let p = self.pane_canvas_point(idx, local);
@@ -11005,10 +11036,10 @@ impl OpenCADStudio {
                 Task::none()
             }
             Message::OpenColorWindow(target, color) => {
-                self.color_pick_target = Some((target, color));
-
-                // Always open the shared CAD colour picker on the indexed ACI page.
-                self.color_picker_tab = crate::app::ColorPickerTab::Index;
+                let (current, varies) = self.color_picker_current(&target, color);
+                self.color_picker = Some(crate::ui::color_select::ColorPicker::new(
+                    target, current, varies,
+                ));
                 self.modal_offset = iced::Vector::ZERO;
                 self.ds_color_open = None;
                 self.mls_color_open = None;
@@ -11023,18 +11054,23 @@ impl OpenCADStudio {
                 Task::none()
             }
 
-            Message::ColorPickerTabChanged(tab) => {
-                self.color_picker_tab = tab;
-                Task::none()
-            }
-            Message::ColorPickerColorChanged(color) => {
-                if let Some((_, current)) = self.color_pick_target.as_mut() {
-                    *current = color;
+            Message::ColorPicker(msg) => {
+                let Some(picker) = self.color_picker.as_mut() else {
+                    return Task::none();
+                };
+                match picker.update(msg) {
+                    Some(crate::ui::color_select::Outcome::Commit(color)) => {
+                        self.update(Message::ColorWindowPick(color))
+                    }
+                    Some(crate::ui::color_select::Outcome::Cancel) => {
+                        self.color_picker = None;
+                        Task::none()
+                    }
+                    None => Task::none(),
                 }
-                Task::none()
             }
             Message::CloseColorPicker => {
-                self.color_pick_target = None;
+                self.color_picker = None;
                 Task::none()
             }
 
@@ -11046,6 +11082,39 @@ impl OpenCADStudio {
         }
     }
 
+    /// The colour the Select Color panel shows as "Current", and whether the
+    /// selection it edits has mixed colours. A mixed selection starts from the
+    /// colour of its most recently drawn object (the highest handle).
+    fn color_picker_current(
+        &self,
+        target: &crate::app::ColorPickTarget,
+        color: codec::types::Color,
+    ) -> (codec::types::Color, bool) {
+        if !matches!(target, crate::app::ColorPickTarget::Properties) {
+            return (color, false);
+        }
+        let i = self.active_tab;
+        let document = &self.tabs[i].scene.document;
+        let mut colors = self
+            .property_target_handles(i)
+            .into_iter()
+            .filter_map(|handle| {
+                document
+                    .get_entity(handle)
+                    .map(|entity| (handle, entity.common().color))
+            })
+            .collect::<Vec<_>>();
+        let Some(&(_, first)) = colors.first() else {
+            return (color, false);
+        };
+        if colors.iter().all(|&(_, c)| c == first) {
+            return (first, false);
+        }
+        colors.sort_by_key(|&(handle, _)| handle);
+        let newest = colors.last().map_or(color, |&(_, c)| c);
+        (newest, true)
+    }
+
     pub(crate) fn note_recent_color(&mut self, color: codec::types::Color) {
         // Keep only real colours in the recent list. ByLayer / ByBlock / None
         // are logical CAD states rather than reusable colours.

src/app/update/style.rs

@@ -1137,10 +1137,10 @@ impl OpenCADStudio {
 
     pub(super) fn on_color_window_pick(&mut self, color: codec::types::Color) -> Task<Message> {
         if matches!(
-            self.color_pick_target.as_ref().map(|(target, _)| target),
+            self.color_picker.as_ref().map(|picker| &picker.target),
             Some(crate::app::ColorPickTarget::PlotStyle)
         ) {
-            self.color_pick_target = None;
+            self.color_picker = None;
 
             let rgb = match color {
                 codec::types::Color::Rgb { r, g, b } => Some((r, g, b)),
@@ -1155,7 +1155,7 @@ impl OpenCADStudio {
             return self.on_plot_style_panel_apply();
         }
         let s = crate::ui::color_select::color_to_aci_string(color);
-        let edit = match self.color_pick_target.take().map(|(target, _)| target) {
+        let edit = match self.color_picker.take().map(|picker| picker.target) {
             Some(crate::app::ColorPickTarget::DimStyle(f)) => Some(Message::DsEdit(f, s)),
             Some(crate::app::ColorPickTarget::MLeader(f)) => {
                 Some(Message::MLeaderStyleEdit { field: f, value: s })

src/app/update/viewport.rs

@@ -1119,7 +1119,7 @@ impl OpenCADStudio {
         p: Point,
         expected_viewport: Option<codec::Handle>,
     ) -> Task<Message> {
-        if self.color_pick_target.is_some() {
+        if self.color_picker.is_some() {
             return Task::none();
         }
 
@@ -1207,7 +1207,7 @@ impl OpenCADStudio {
         // leaks through the stack to the pane mouse_area beneath and
         // would track the crosshair over the dropdown's empty areas.
         // Drop the move here instead. (#227)
-        if self.ribbon.open_dropdown.is_some() || self.color_pick_target.is_some() {
+        if self.ribbon.open_dropdown.is_some() || self.color_picker.is_some() {
             return Task::none();
         }
         let i = self.active_tab;