gtk: add option to always display the tab bar

Also fixes crashes in both vanilla GTK and Adwaita implementations of
`closeTab`, which erroneously close windows twice when there are no
more tabs left (we probably already handle it somewhere else).

Author: pluiedev

src/apprt/gtk/Window.zig

@@ -295,6 +295,7 @@ pub fn init(self: *Window, app: *App) !void {
             c.adw_tab_bar_set_view(tab_bar, self.notebook.adw.tab_view);
 
             if (!app.config.@"gtk-wide-tabs") c.adw_tab_bar_set_expand_tabs(tab_bar, 0);
+            c.adw_tab_bar_set_autohide(tab_bar, @intFromBool(!app.config.@"window-always-show-tabs"));
 
             const tab_bar_widget: *c.GtkWidget = @ptrCast(@alignCast(tab_bar));
             switch (self.app.config.@"gtk-tabs-location") {
@@ -346,6 +347,7 @@ pub fn init(self: *Window, app: *App) !void {
                 c.adw_tab_bar_set_view(tab_bar, adw.tab_view);
 
                 if (!app.config.@"gtk-wide-tabs") c.adw_tab_bar_set_expand_tabs(tab_bar, 0);
+                c.adw_tab_bar_set_autohide(tab_bar, @intFromBool(!app.config.@"window-always-show-tabs"));
             },
 
             .gtk => {},

src/apprt/gtk/notebook_adw.zig

@@ -134,26 +134,6 @@ pub const NotebookAdw = struct {
 
         const page = c.adw_tab_view_get_page(self.tab_view, @ptrCast(tab.box)) orelse return;
         c.adw_tab_view_close_page(self.tab_view, page);
-
-        // If we have no more tabs we close the window
-        if (self.nPages() == 0) {
-            const window = tab.window.window;
-
-            // libadw versions <= 1.3.x leak the final page view
-            // which causes our surface to not properly cleanup. We
-            // unref to force the cleanup. This will trigger a critical
-            // warning from GTK, but I don't know any other workaround.
-            // Note: I'm not actually sure if 1.4.0 contains the fix,
-            // I just know that 1.3.x is broken and 1.5.1 is fixed.
-            // If we know that 1.4.0 is fixed, we can change this.
-            if (!adwaita.versionAtLeast(1, 4, 0)) {
-                c.g_object_unref(tab.box);
-            }
-
-            // `self` will become invalid after this call because it will have
-            // been freed up as part of the process of closing the window.
-            c.gtk_window_destroy(window);
-        }
     }
 };
 

src/apprt/gtk/notebook_gtk.zig

@@ -31,7 +31,6 @@ pub const NotebookGtk = struct {
         };
         c.gtk_notebook_set_tab_pos(gtk_notebook, notebook_tab_pos);
         c.gtk_notebook_set_scrollable(gtk_notebook, 1);
-        c.gtk_notebook_set_show_tabs(gtk_notebook, 0);
         c.gtk_notebook_set_show_border(gtk_notebook, 0);
 
         // This enables all Ghostty terminal tabs to be exchanged across windows.
@@ -81,6 +80,7 @@ pub const NotebookGtk = struct {
         log.warn("currentTab", .{});
         const page = self.currentPage() orelse return null;
         const child = c.gtk_notebook_get_nth_page(self.notebook, page);
+
         return @ptrCast(@alignCast(
             c.g_object_get_data(@ptrCast(child), Tab.GHOSTTY_TAB) orelse return null,
         ));
@@ -164,9 +164,7 @@ pub const NotebookGtk = struct {
         c.gtk_notebook_set_tab_reorderable(self.notebook, box_widget, 1);
         c.gtk_notebook_set_tab_detachable(self.notebook, box_widget, 1);
 
-        if (self.nPages() > 1) {
-            c.gtk_notebook_set_show_tabs(self.notebook, 1);
-        }
+        self.updateShowTabs(window);
 
         // Switch to the new tab
         c.gtk_notebook_set_current_page(self.notebook, page_idx);
@@ -183,20 +181,21 @@ pub const NotebookGtk = struct {
         c.gtk_notebook_remove_page(self.notebook, page_idx);
 
         const remaining = self.nPages();
-        switch (remaining) {
-            // If we have no more tabs we close the window
-            0 => c.gtk_window_destroy(tab.window.window),
-
-            // If we have one more tab we hide the tab bar
-            1 => c.gtk_notebook_set_show_tabs(self.notebook, 0),
-
-            else => {},
-        }
 
         // If we have remaining tabs, we need to make sure we grab focus.
         if (remaining > 0)
             (self.currentTab() orelse return).window.focusCurrentTab();
     }
+
+    fn updateShowTabs(self: *NotebookGtk, window: *Window) void {
+        const show_tabs = switch (self.nPages()) {
+            0 => false,
+            1 => window.app.config.@"window-always-show-tabs",
+            else => true,
+        };
+
+        c.gtk_notebook_set_show_tabs(self.notebook, @intFromBool(show_tabs));
+    }
 };
 
 fn getNotebookPageIndex(page: *c.GtkNotebookPage) c_int {
@@ -245,12 +244,7 @@ fn gtkPageRemoved(
     log.warn("gtkPageRemoved", .{});
     const window: *Window = @ptrCast(@alignCast(ud.?));
 
-    // Hide the tab bar if we only have one tab after removal
-    const remaining = c.gtk_notebook_get_n_pages(window.notebook.gtk.notebook);
-
-    if (remaining == 1) {
-        c.gtk_notebook_set_show_tabs(window.notebook.gtk.notebook, 0);
-    }
+    window.notebook.gtk.updateShowTabs(window);
 }
 
 fn gtkSwitchPage(_: *c.GtkNotebook, page: *c.GtkWidget, _: usize, ud: ?*anyopaque) callconv(.C) void {

src/config/Config.zig

@@ -1336,6 +1336,11 @@ keybind: Keybinds = .{},
 ///   * `end` - Insert the new tab at the end of the tab list.
 @"window-new-tab-position": WindowNewTabPosition = .current,
 
+/// Whether tabs should always be displayed, regardless of how many tabs
+/// are open. If false (default), the tab bar is only displayed when there
+/// are two or more tabs.
+@"window-always-show-tabs": bool = false,
+
 /// Background color for the window titlebar. This only takes effect if
 /// window-theme is set to ghostty. Currently only supported in the GTK app
 /// runtime.