feat: add theme-aware expandable Draw panel

build.rs

@@ -4,6 +4,7 @@
 use std::path::Path;
 
 fn main() {
+    generate_draw_panel_tools();
     let version = std::env::var("CARGO_PKG_VERSION").expect("Cargo package version");
     let parts: Vec<&str> = version.split('.').collect();
     let app_version = if parts.len() == 3 && parts[0].len() == 4
@@ -81,3 +82,27 @@ fn main() {
         }
     }
 }
+
+/// Each drawing button can contribute its own expression without editing a registry.
+fn generate_draw_panel_tools() {
+    let manifest = std::path::PathBuf::from(std::env::var_os("CARGO_MANIFEST_DIR").expect("Cargo manifest directory"));
+    let directory = manifest.join("src/ui/ribbon/draw_tools");
+    println!("cargo:rerun-if-changed={}", directory.display());
+    let mut files = match std::fs::read_dir(&directory) {
+        Ok(entries) => entries.map(|entry| entry.expect("Draw tool directory entry").path())
+            .filter(|path| path.is_file() && path.extension().is_some_and(|extension| extension == "rs"))
+            .collect::<Vec<_>>(),
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => Vec::new(),
+        Err(error) => panic!("Cannot read Draw tool contributions: {error}"),
+    };
+    files.sort_by(|left, right| left.file_name().cmp(&right.file_name()));
+    let mut source = String::from("const TOOLS: &[Tool] = &[\n");
+    for path in files {
+        println!("cargo:rerun-if-changed={}", path.display());
+        // Debug string formatting produces a quoted Rust literal, including Windows escapes.
+        source.push_str(&format!("    include!({:?}),\n", path.to_str().expect("UTF-8 Draw tool path")));
+    }
+    source.push_str("];\n");
+    let output = std::path::PathBuf::from(std::env::var_os("OUT_DIR").expect("Cargo output directory"));
+    std::fs::write(output.join("draw_panel_tools.rs"), source).expect("Write Draw tool registry");
+}

src/ui/ribbon/draw_panel.rs

@@ -0,0 +1,87 @@
+//! Additional drawing tools, reached from the Draw panel's title.
+
+use std::time::Duration;
+
+use iced::widget::{button, column, container, row, scrollable, text, tooltip};
+use iced::{Element, Fill, Length, Theme};
+
+use super::widgets::{make_icon, make_tip, muted_text_style, popup_panel_style, popup_row_style, tip_style, tool_btn_style};
+use super::{dropdown_backdrop, position_ribbon_dropdown, Ribbon};
+use crate::app::Message;
+use crate::modules::IconKind;
+use crate::t;
+use crate::ui::{icons, wrap_bar::PosReport};
+
+const PANEL_ID: &str = "draw_extension";
+const CELL: f32 = 36.0;
+const GAP: f32 = 3.0;
+
+struct Tool {
+    command: &'static str,
+    label: &'static str,
+    icon: &'static [u8],
+    options: &'static [(&'static str, &'static str)],
+}
+
+include!(concat!(env!("OUT_DIR"), "/draw_panel_tools.rs"));
+
+pub(super) fn owns_dropdown(id: &str) -> bool {
+    id == PANEL_ID || TOOLS.iter().any(|tool| tool.command == id && !tool.options.is_empty())
+}
+
+pub(super) fn group_title<'a>(title: &'static str, open: &Option<String>) -> Element<'a, Message> {
+    if title != "Draw" || TOOLS.is_empty() {
+        return container(text(t!(title)).size(9).style(muted_text_style)).padding([1, 4]).into();
+    }
+    let expanded = open.as_deref().is_some_and(owns_dropdown);
+    let arrow = if expanded { icons::themed_arrow_up(7.0) } else { icons::themed_arrow_down(7.0) };
+    PosReport::new(PANEL_ID, button(row![text(t!(title)).size(9), arrow].spacing(4).align_y(iced::Center))
+        .on_press(Message::ToggleRibbonDropdown(PANEL_ID.to_string()))
+        .style(move |theme: &Theme, status| tool_btn_style(theme, expanded, status))
+        .padding([1, 4])).into()
+}
+
+fn tool_button(tool: &Tool, active: bool) -> Element<'static, Message> {
+    let face = button(make_icon(IconKind::Svg(tool.icon), 23.0))
+        .on_press(Message::DropdownSelectItem { dropdown_id: PANEL_ID, cmd: tool.command })
+        .style(move |theme: &Theme, status| tool_btn_style(theme, active, status))
+        .width(if tool.options.is_empty() { CELL } else { CELL - 11.0 })
+        .height(CELL)
+        .padding(3);
+    let tip = format!("{}\n{} {}", t!(tool.label), t!("Command:"), tool.command);
+    let face: Element<'static, Message> = tooltip(face, make_tip(tip), tooltip::Position::Bottom)
+        .delay(Duration::from_millis(400)).style(tip_style).into();
+    if !tool.options.is_empty() {
+        row![face, button(icons::themed_arrow_down(6.0))
+            .on_press(Message::ToggleRibbonDropdown(tool.command.to_string()))
+            .style(move |theme: &Theme, status| tool_btn_style(theme, false, status))
+            .width(11).height(CELL).padding(2)].into()
+    } else {
+        face
+    }
+}
+
+pub(super) fn overlay<'a>(ribbon: &Ribbon, id: &str, win: (f32, f32)) -> Element<'a, Message> {
+    let width = (7.0 * (CELL + GAP) - GAP + 12.0).min((win.0 - 8.0).max(CELL + 12.0));
+    let (_, x, anchor_top) = ribbon.dd_anchor(PANEL_ID, width, win.0);
+    let anchor = crate::ui::wrap_bar::dropdown_bounds(PANEL_ID);
+    let left = anchor.map_or(x, |b| b.x).clamp(0.0, (win.0 - width).max(0.0));
+    let top = anchor_top.min((win.1 - 80.0).max(0.0));
+    let available_height = (win.1 - top - 4.0).max(1.0);
+    let contents: Element<'static, Message> = if let Some(tool) = TOOLS.iter().find(|tool| tool.command == id && !tool.options.is_empty()) {
+        column(tool.options.iter().map(|&(cmd, label)| {
+            button(text(t!(label)).size(11))
+                .on_press(Message::DropdownSelectItem { dropdown_id: tool.command, cmd })
+                .style(popup_row_style).width(Fill).padding([6, 10]).into()
+        }).collect::<Vec<Element<'static, Message>>>()).into()
+    } else {
+        let cols = (((width - 12.0 + GAP) / (CELL + GAP)).floor() as usize).clamp(1, 7);
+        column(TOOLS.chunks(cols).map(|tools| {
+            row(tools.iter().map(|tool| tool_button(tool, ribbon.active_tool.as_deref() == Some(tool.command)))
+                .collect::<Vec<_>>()).spacing(GAP).into()
+        }).collect::<Vec<Element<'static, Message>>>()).spacing(GAP).padding(6).into()
+    };
+    let panel = container(scrollable(contents).height(Length::Shrink))
+        .max_height(available_height).width(width).style(popup_panel_style);
+    dropdown_backdrop(position_ribbon_dropdown(panel.into(), false, left, top))
+}

src/ui/ribbon/mod.rs

@@ -21,6 +21,7 @@ use crate::plugin::all_ribbon_modules;
 use crate::ui::properties::{linetype_display_name, lw_options, LinetypeItem};
 
 mod widgets;
+mod draw_panel;
 use widgets::{StyleContext, *};
 mod collapse;
 use collapse::{CollapsePanels, Panel};
@@ -391,7 +392,7 @@ impl Ribbon {
 
     pub fn select_dropdown_item(&mut self, dropdown_id: &'static str, cmd: &'static str) {
         self.last_cmd.insert(dropdown_id, cmd);
-        self.open_dropdown = None;
+        self.close_dropdown();
     }
 
     // ── View ──────────────────────────────────────────────────────────────
@@ -725,6 +726,10 @@ impl Ribbon {
         }
         let open_id = self.open_dropdown.as_deref()?;
 
+        if draw_panel::owns_dropdown(open_id) {
+            return Some(draw_panel::overlay(self, open_id, win));
+        }
+
         if open_id == UNDO_HISTORY_ID || open_id == REDO_HISTORY_ID {
             let is_undo = open_id == UNDO_HISTORY_ID;
             let labels = if is_undo { undo_labels } else { redo_labels };
@@ -1364,7 +1369,7 @@ fn render_group<'a>(
 
     column![
         tools_el,
-        container(text(t!(group.title)).size(9).style(muted_text_style)).padding([1, 4]),
+        draw_panel::group_title(group.title, open_dd),
     ]
     .align_x(iced::Center)
     .spacing(0)