apprt/gtk: working on some reorg

src/apprt/gtk/Paned.zig

@@ -56,7 +56,8 @@ pub fn init(self: *Paned, sibling: *Surface, direction: input.SplitDirection) !v
     const gtk_paned: *c.GtkPaned = @ptrCast(paned);
     self.paned = gtk_paned;
 
-    const surface = try sibling.tab.newSurface(&sibling.core_surface);
+    const tab = sibling.container.tab().?; // TODO
+    const surface = try tab.newSurface(&sibling.core_surface);
     surface.setParent(.{ .paned = .{ self, .end } });
 
     self.addChild1(.{ .surface = sibling });

src/apprt/gtk/Surface.zig

@@ -55,6 +55,38 @@ pub const Options = struct {
     parentSurface: bool = false,
 };
 
+/// The container that this surface is directly attached to.
+pub const Container = union(enum) {
+    /// The surface is not currently attached to anything. This means
+    /// that the GLArea has been created and potentially initialized
+    /// but the widget is currently floating and not part of any parent.
+    none: void,
+
+    /// Directly attached to a tab. (i.e. no splits)
+    tab_: *Tab,
+
+    /// A split within a split hierarchy.
+    paned: *Paned,
+
+    /// Returns the window that this surface is attached to.
+    pub fn window(self: Container) ?*Window {
+        return switch (self) {
+            .none => null,
+            .tab_ => |v| v.window,
+            else => @panic("TODO"),
+        };
+    }
+
+    /// Returns the tab container if it exists.
+    pub fn tab(self: Container) ?*Tab {
+        return switch (self) {
+            .none => null,
+            .tab_ => |v| v,
+            else => @panic("TODO"),
+        };
+    }
+};
+
 /// Where the title of this surface will go.
 const Title = union(enum) {
     none: void,
@@ -69,15 +101,16 @@ realized: bool = false,
 /// See Options.parentSurface
 parentSurface: bool = false,
 
+/// The GUI container that this surface has been attached to. This
+/// dictates some behaviors such as new splits, etc.
+container: Container = .{ .none = {} },
+
 /// The app we're part of
 app: *App,
 
 /// The window we're part of
 window: *Window,
 
-/// The tab we're part of
-tab: *Tab,
-
 /// The parent we belong to
 parent: Parent,
 
@@ -177,7 +210,7 @@ pub fn init(self: *Surface, app: *App, opts: Options) !void {
     self.* = .{
         .app = app,
         .window = opts.window,
-        .tab = opts.tab,
+        .container = .{ .tab_ = opts.tab },
         .parent = opts.parent,
         .gl_area = opts.gl_area,
         .title = if (opts.title_label) |label| .{
@@ -456,8 +489,9 @@ pub fn setSizeLimits(self: *Surface, min: apprt.SurfaceSize, max_: ?apprt.Surfac
 }
 
 pub fn grabFocus(self: *Surface) void {
+    if (self.container.tab()) |tab| tab.focus_child = self;
+
     self.updateTitleLabels();
-    self.tab.focus_child = self;
     const widget = @as(*c.GtkWidget, @ptrCast(self.gl_area));
     _ = c.gtk_widget_grab_focus(widget);
 }
@@ -859,7 +893,7 @@ fn gtkMouseDown(
     // If we don't have focus, grab it.
     const gl_widget = @as(*c.GtkWidget, @ptrCast(self.gl_area));
     if (c.gtk_widget_has_focus(gl_widget) == 0) {
-        self.tab.focus_child = self;
+        if (self.container.tab()) |tab| tab.focus_child = self;
         _ = c.gtk_widget_grab_focus(gl_widget);
 
         // If we have siblings, we also update the title, since it means

src/apprt/gtk/Tab.zig

@@ -1,3 +1,6 @@
+/// The state associated with a single tab in the window.
+///
+/// A tab can contain one or more terminals due to splits.
 const Tab = @This();
 
 const std = @import("std");
@@ -20,7 +23,6 @@ pub const GHOSTTY_TAB = "ghostty_tab";
 
 window: *Window,
 label_text: *c.GtkLabel,
-close_button: *c.GtkButton,
 // We'll put our children into this box instead of packing them directly, so
 // that we can send the box into `c.g_signal_connect_data` for the close button
 box: *c.GtkBox,
@@ -38,11 +40,12 @@ pub fn create(alloc: Allocator, window: *Window, parent_: ?*CoreSurface) !*Tab {
     return tab;
 }
 
+/// Initialize the tab, create a surface, and add it to the window. "self"
+/// needs to be a stable pointer, since it is used for GTK events.
 pub fn init(self: *Tab, window: *Window, parent_: ?*CoreSurface) !void {
     self.* = .{
         .window = window,
         .label_text = undefined,
-        .close_button = undefined,
         .box = undefined,
         .child = undefined,
         .focus_child = undefined,
@@ -56,13 +59,11 @@ pub fn init(self: *Tab, window: *Window, parent_: ?*CoreSurface) !void {
     c.gtk_box_append(label_box, label_text_widget);
     self.label_text = label_text;
 
+    // Build the close button for the tab
     const label_close_widget = c.gtk_button_new_from_icon_name("window-close");
     const label_close: *c.GtkButton = @ptrCast(label_close_widget);
     c.gtk_button_set_has_frame(label_close, 0);
     c.gtk_box_append(label_box, label_close_widget);
-    self.close_button = label_close;
-
-    _ = c.g_signal_connect_data(label_close, "clicked", c.G_CALLBACK(&gtkTabCloseClick), self, null, c.G_CONNECT_DEFAULT);
 
     // Wide style GTK tabs
     if (window.app.config.@"gtk-wide-tabs") {
@@ -88,11 +89,10 @@ pub fn init(self: *Tab, window: *Window, parent_: ?*CoreSurface) !void {
     c.gtk_widget_set_vexpand(box_widget, 1);
     self.box = @ptrCast(box_widget);
 
-    // Create the Surface
+    // Create the initial surface since all tabs start as a single non-split
     const surface = try self.newSurface(parent_);
     errdefer surface.deinit();
-
-    self.child = Child{ .surface = surface };
+    self.child = .{ .surface = surface };
 
     // Add Surface to the Tab
     const gl_area_widget = @as(*c.GtkWidget, @ptrCast(surface.gl_area));
@@ -123,6 +123,9 @@ pub fn init(self: *Tab, window: *Window, parent_: ?*CoreSurface) !void {
     // Set the userdata of the box to point to this tab.
     c.g_object_set_data(@ptrCast(box_widget), GHOSTTY_TAB, self);
 
+    // Attach all events
+    _ = c.g_signal_connect_data(label_close, "clicked", c.G_CALLBACK(&gtkTabCloseClick), self, null, c.G_CONNECT_DEFAULT);
+
     // Switch to the new tab
     c.gtk_notebook_set_current_page(window.notebook, page_idx);
 
@@ -131,6 +134,17 @@ pub fn init(self: *Tab, window: *Window, parent_: ?*CoreSurface) !void {
     surface.grabFocus();
 }
 
+/// Deinits tab by deiniting child if child is Paned.
+pub fn deinit(self: *Tab) void {
+    switch (self.child) {
+        .none, .surface => return,
+        .paned => |paned| {
+            paned.deinit(self.window.app.core_app.alloc);
+            self.window.app.core_app.alloc.destroy(paned);
+        },
+    }
+}
+
 /// Allocates and initializes a new Surface, but doesn't add it to the Tab yet.
 /// Can also be added to a Paned.
 pub fn newSurface(self: *Tab, parent_: ?*CoreSurface) !*Surface {
@@ -206,17 +220,6 @@ pub fn setChild(self: *Tab, child: Child) void {
     self.child = child;
 }
 
-/// Deinits tab by deiniting child if child is Paned.
-pub fn deinit(self: *Tab) void {
-    switch (self.child) {
-        .none, .surface => return,
-        .paned => |paned| {
-            paned.deinit(self.window.app.core_app.alloc);
-            self.window.app.core_app.alloc.destroy(paned);
-        },
-    }
-}
-
 fn gtkTabCloseClick(_: *c.GtkButton, ud: ?*anyopaque) callconv(.C) void {
     const tab: *Tab = @ptrCast(@alignCast(ud));
     const window = tab.window;

src/apprt/gtk/Window.zig

@@ -1,4 +1,8 @@
-/// A Window is a single, real GTK window.
+/// A Window is a single, real GTK window that holds terminal surfaces.
+///
+/// A Window always contains a notebook (what GTK calls a tabbed container)
+/// even while no tabs are in use, because a notebook without a tab bar has
+/// no visible UI chrome.
 const Window = @This();
 
 const std = @import("std");
@@ -327,7 +331,12 @@ pub fn hasTabs(self: *const Window) bool {
 
 /// Go to the previous tab for a surface.
 pub fn gotoPreviousTab(self: *Window, surface: *Surface) void {
-    const page = c.gtk_notebook_get_page(self.notebook, @ptrCast(surface.tab.box)) orelse return;
+    const tab = surface.container.tab() orelse {
+        log.info("surface is not attached to a tab bar, cannot navigate", .{});
+        return;
+    };
+
+    const page = c.gtk_notebook_get_page(self.notebook, @ptrCast(tab.box)) orelse return;
     const page_idx = getNotebookPageIndex(page);
 
     // The next index is the previous or we wrap around.
@@ -345,7 +354,12 @@ pub fn gotoPreviousTab(self: *Window, surface: *Surface) void {
 
 /// Go to the next tab for a surface.
 pub fn gotoNextTab(self: *Window, surface: *Surface) void {
-    const page = c.gtk_notebook_get_page(self.notebook, @ptrCast(surface.tab.box)) orelse return;
+    const tab = surface.container.tab() orelse {
+        log.info("surface is not attached to a tab bar, cannot navigate", .{});
+        return;
+    };
+
+    const page = c.gtk_notebook_get_page(self.notebook, @ptrCast(tab.box)) orelse return;
     const page_idx = getNotebookPageIndex(page);
     const max = c.gtk_notebook_get_n_pages(self.notebook) -| 1;
     const next_idx = if (page_idx < max) page_idx + 1 else 0;