diff --git a/source/tycho/editor.rs b/source/tycho/editor.rs
index a7185cd..25745c9 100644
--- a/source/tycho/editor.rs
+++ b/source/tycho/editor.rs
@@ -25,20 +25,20 @@ impl MapEditor
    }
 
    /// Draws the screen for this editor state.
-   pub fn draw<D, I>(&self, d: &D, im: &I)
+   pub fn draw<D, I>(&self, d: &mut D, im: &I)
       where D: DrawArea<NativeImage = I>,
             I: CacheImage
    {
+      let dw = d.w();
+      let dh = d.h();
+      let iw = im.w();
+      let ih = im.h();
+
       match self {
          MapEditor::Closed => {
             let tx_top = "Map Required To Proceed";
             let tx_bot = "CAS.qterm//CyberAcme Systems Inc.";
 
-            let dw = d.w();
-            let dh = d.h();
-            let iw = im.w();
-            let ih = im.h();
-
             d.clear(Color16::new(0, 0, 0));
 
             d.image((dw / 2 - iw / 2, dh / 2 - ih / 2), im);
@@ -49,8 +49,9 @@ impl MapEditor
             d.rect(Rect{x: 0, y: dh - 18, w: dw, h: 18}, CR_DARK_RED);
             d.text((4, dh - 4), tx_bot, CR_RED);
          }
-         MapEditor::Opened(_st) => {
+         MapEditor::Opened(st) => {
             d.clear(Color16::new(0, 0, 0));
+            d.text((dw/2, dh/2), &format!("tool: {:?}", st.tool), CR_RED);
          }
       }
    }
@@ -106,6 +107,7 @@ pub enum MapEditor
 }
 
 /// A tool in the map editor.
+#[derive(Debug)]
 pub enum Tool
 {
    Points,
diff --git a/source/tycho/main.rs b/source/tycho/main.rs
index a5ec599..0c00292 100644
--- a/source/tycho/main.rs
+++ b/source/tycho/main.rs
@@ -36,6 +36,7 @@ unsafe extern "C" fn app_activate(app: *mut GtkApplication, edit: gpointer)
 /// Sets up the map view window's drawing area.
 unsafe fn setup_draw_area(b: *mut GtkBuilder, edit: Rc<MapEditorRef>)
 {
+   /// All of the state necessary for the drawing area.
    struct RenderState
    {
       im_nomap: *mut GdkPixbuf,
@@ -84,11 +85,12 @@ unsafe fn setup_draw_area(b: *mut GtkBuilder, edit: Rc<MapEditorRef>)
 
    let wid: *mut GtkDrawingArea = get_obj(b, c_str!("draw-area"));
 
-   {
-      let mut edit = edit.borrow_mut();
-      edit.call.push(Box::new(move || gtk_widget_queue_draw(wid as _)));
-   }
+   // add a callback to draw the area when updated
+   edit.borrow_mut().call.push(Box::new(move || {
+      gtk_widget_queue_draw(wid as _);
+   }));
 
+   // get all of the necessary state and related objects
    let ax: *mut GtkAdjustment = get_obj(b, c_str!("adj-map-horz"));
    let ay: *mut GtkAdjustment = get_obj(b, c_str!("adj-map-vert"));
 
@@ -226,7 +228,7 @@ unsafe fn setup_win_main(b: *mut GtkBuilder,
       gtk_window_close(win as _);
    }
 
-   /// Callback to create a new editor state when the "New" button is pressed.
+   /// Callback to create a new map when the "New" button is pressed.
    unsafe extern "C" fn c_new_act(_: *mut GtkWidget, edit: gpointer)
    {
       let edit = edit as *const MapEditorRef;
@@ -386,7 +388,8 @@ fn main()
       let edit = MapEditor{edit: editor::MapEditor::new_closed(),
                            call: Vec::new(),
                            done: Vec::new()};
-      let edit = Rc::new(RefCell::new(edit));
+      let edit = RefCell::new(edit);
+      let edit = Rc::new(edit);
       let eptr = Rc::into_raw(edit.clone());
 
       // create and run the app
@@ -410,11 +413,13 @@ fn main()
 
 impl MapEditor
 {
+   /// Causes all update callbacks to be called.
    fn cause_update(&mut self) {for cb in &mut self.call {cb();}}
 }
 
 impl Drop for MapEditor
 {
+   /// Calls all finalization callbacks on drop.
    fn drop(&mut self) {for cb in &mut self.done {cb();}}
 }
 
@@ -430,6 +435,7 @@ impl std::ops::DerefMut for MapEditor
    fn deref_mut(&mut self) -> &mut editor::MapEditor {&mut self.edit}
 }
 
+/// Specialized map editor which has callbacks for frontend purposes.
 struct MapEditor
 {
    edit: editor::MapEditor,
@@ -437,6 +443,7 @@ struct MapEditor
    done: Vec<Box<dyn FnMut()>>,
 }
 
+/// A runtime reference to the map editor.
 type MapEditorRef = RefCell<MapEditor>;
 
 // EOF