Optionally disable header bars with NVIM_GTK_NO_HEADERBAR=1

src/ui.rs

@@ -1,5 +1,5 @@
 use std::cell::{RefCell, Ref, RefMut};
-use std::thread;
+use std::{env, thread};
 use std::rc::Rc;
 use std::sync::Arc;
 
@@ -25,7 +25,6 @@ pub struct Ui {
 
 pub struct Components {
     window: Option<ApplicationWindow>,
-    header_bar: HeaderBar,
     open_btn: ToolButton,
 }
 
@@ -37,7 +36,6 @@ impl Components {
         Components {
             open_btn: ToolButton::new(Some(&save_image), "Open"),
             window: None,
-            header_bar: HeaderBar::new(),
         }
     }
 
@@ -74,18 +72,35 @@ impl Ui {
         }
         self.initialized = true;
 
+        // Only add an application menu if requested by the desktop environment as to avoid an
+        // additional menu bar just for the "About" item
+        if app.prefers_app_menu() {
             self.create_main_menu(app);
+        }
 
         let mut settings = self.settings.borrow_mut();
         settings.init();
 
         let mut comps = self.comps.borrow_mut();
 
-        comps.header_bar.set_show_close_button(true);
+        self.shell.borrow_mut().init();
 
+        comps.window = Some(ApplicationWindow::new(app));
+        let window = comps.window.as_ref().unwrap();
+
+        // Client side decorations including the toolbar are disabled via NVIM_GTK_NO_HEADERBAR=1
+        let mut use_header_bar = true;
+        if let Ok(opt) = env::var("NVIM_GTK_NO_HEADERBAR") {
+            if opt.trim() == "1" {
+                use_header_bar = false;
+            }
+        }
+
+        if use_header_bar {
+            let header_bar = HeaderBar::new();
 
             let projects = self.projects.clone();
-        comps.header_bar.pack_start(&comps.open_btn);
+            header_bar.pack_start(&comps.open_btn);
             comps
                 .open_btn
                 .connect_clicked(move |_| projects.borrow_mut().show());
@@ -96,21 +111,19 @@ impl Ui {
 
             let shell = self.shell.clone();
             save_btn.connect_clicked(move |_| shell.borrow_mut().edit_save_all());
-        comps.header_bar.pack_start(&save_btn);
+            header_bar.pack_start(&save_btn);
 
             let paste_image = Image::new_from_icon_name("edit-paste",
                                                         gtk_sys::GTK_ICON_SIZE_SMALL_TOOLBAR as i32);
             let paste_btn = ToolButton::new(Some(&paste_image), "Paste");
             let shell = self.shell.clone();
             paste_btn.connect_clicked(move |_| shell.borrow_mut().edit_paste());
-        comps.header_bar.pack_start(&paste_btn);
+            header_bar.pack_start(&paste_btn);
+            header_bar.set_show_close_button(true);
 
-        self.shell.borrow_mut().init();
+            window.set_titlebar(Some(&header_bar));
+        }
 
-        comps.window = Some(ApplicationWindow::new(app));
-        let window = comps.window.as_ref().unwrap();
-
-        window.set_titlebar(Some(&comps.header_bar));
         window.set_default_size(800, 600);
 
         let shell = self.shell.borrow();
@@ -144,7 +157,6 @@ impl Ui {
 
         app.set_app_menu(Some(&menu));
 
-
         let about_action = SimpleAction::new("HelpAbout", None);
         let comps = self.comps.clone();
         about_action.connect_activate(move |_, _| on_help_about(&*comps.borrow()));