gtk: refactor code and add comments to Paned

src/apprt/gtk/Paned.zig

@@ -75,7 +75,7 @@ pub fn init(self: *Paned, window: *Window, sibling: *Surface, direction: input.S
     self.addChild2(.{ .surface = surface });
 }
 
-pub fn newSurface(self: *Paned, tab: *Tab, parent_: ?*CoreSurface) !*Surface {
+fn newSurface(self: *Paned, tab: *Tab, parent_: ?*CoreSurface) !*Surface {
     // Grab a surface allocation we'll need it later.
     var surface = try self.window.app.core_app.alloc.create(Surface);
     errdefer self.window.app.core_app.alloc.destroy(surface);
@@ -110,16 +110,19 @@ pub fn newSurface(self: *Paned, tab: *Tab, parent_: ?*CoreSurface) !*Surface {
     return surface;
 }
 
+/// Set the parent of Paned.
 pub fn setParent(self: *Paned, parent: Parent) void {
     self.parent = parent;
 }
 
+/// Focus on the Surface's gl_area in the given position.
 pub fn focusSurfaceInPosition(self: *Paned, position: Position) void {
     const surface: *Surface = self.surfaceInPosition(position) orelse return;
     const widget = @as(*c.GtkWidget, @ptrCast(surface.gl_area));
     _ = c.gtk_widget_grab_focus(widget);
 }
 
+/// Split the Surface in the given position into a Paned with two surfaces.
 pub fn splitSurfaceInPosition(self: *Paned, position: Position, direction: input.SplitDirection) !void {
     const surface: *Surface = self.surfaceInPosition(position) orelse return;
 
@@ -148,6 +151,7 @@ pub fn splitSurfaceInPosition(self: *Paned, position: Position, direction: input
     paned.focusSurfaceInPosition(.end);
 }
 
+/// Replace the existing .start or .end Child with the given new Child.
 pub fn replaceChildInPosition(self: *Paned, child: Child, position: Position) void {
     // Keep position of divider
     const parent_paned_position_before = c.gtk_paned_get_position(self.paned);
@@ -167,11 +171,25 @@ pub fn replaceChildInPosition(self: *Paned, child: Child, position: Position) vo
     c.gtk_paned_set_position(self.paned, parent_paned_position_before);
 }
 
+/// Remove both children, setting *c.GtkPaned start/end children to null.
 pub fn removeChildren(self: *Paned) void {
     self.removeChildInPosition(.start);
     self.removeChildInPosition(.end);
 }
 
+/// Deinit the Paned by deiniting its child Paneds, if they exist.
+pub fn deinit(self: *Paned, alloc: Allocator) void {
+    for ([_]Child{ self.child1, self.child2 }) |child| {
+        switch (child) {
+            .none, .surface => continue,
+            .paned => |paned| {
+                paned.deinit(alloc);
+                alloc.destroy(paned);
+            },
+        }
+    }
+}
+
 fn removeChildInPosition(self: *Paned, position: Position) void {
     switch (position) {
         .start => {
@@ -218,15 +236,3 @@ fn surfaceInPosition(self: *Paned, position: Position) ?*Surface {
         else => null,
     };
 }
-
-pub fn deinit(self: *Paned, alloc: Allocator) void {
-    for ([_]Child{ self.child1, self.child2 }) |child| {
-        switch (child) {
-            .none, .surface => continue,
-            .paned => |paned| {
-                paned.deinit(alloc);
-                alloc.destroy(paned);
-            },
-        }
-    }
-}

src/apprt/gtk/Tab.zig

@@ -158,12 +158,6 @@ pub fn setChild(self: *Tab, child: Child) void {
     self.child = child;
 }
 
-fn gtkTabCloseClick(_: *c.GtkButton, ud: ?*anyopaque) callconv(.C) void {
-    const tab: *Tab = @ptrCast(@alignCast(ud));
-    const window = tab.window;
-    window.closeTab(tab);
-}
-
 pub fn deinit(self: *Tab) void {
     switch (self.child) {
         .none, .surface => return,
@@ -173,3 +167,9 @@ pub fn deinit(self: *Tab) void {
         },
     }
 }
+
+fn gtkTabCloseClick(_: *c.GtkButton, ud: ?*anyopaque) callconv(.C) void {
+    const tab: *Tab = @ptrCast(@alignCast(ud));
+    const window = tab.window;
+    window.closeTab(tab);
+}

src/apprt/gtk/Window.zig

@@ -15,6 +15,7 @@ const App = @import("App.zig");
 const Paned = @import("Paned.zig");
 const Surface = @import("Surface.zig");
 const Tab = @import("Tab.zig");
+const Position = @import("relation.zig").Position;
 const icon = @import("icon.zig");
 const c = @import("c.zig");
 
@@ -213,7 +214,6 @@ pub fn removeTab(self: *Window, tab: *Tab) !void {
         if (t == tab) break i;
     } else null;
 
-    // TODO: Shrink capacity?
     if (tab_idx) |idx| _ = self.tabs.orderedRemove(idx) else return error.TabNotFound;
 
     // Deallocate the tab
@@ -256,8 +256,6 @@ pub fn closeTab(self: *Window, tab: *Tab) void {
 pub fn closeSurface(self: *Window, surface: *Surface) void {
     assert(surface.window == self);
 
-    const alloc = self.app.core_app.alloc;
-
     switch (surface.parent) {
         .none => unreachable,
         .tab => |tab| self.closeTab(tab),
@@ -265,56 +263,60 @@ pub fn closeSurface(self: *Window, surface: *Surface) void {
             const paned = paned_tuple[0];
             const position = paned_tuple[1];
 
-            const sibling = switch (position) {
+            self.closeSurfaceInPaned(surface, paned, position);
-                .start => .{
-                    paned.child2,
-                    c.gtk_paned_get_end_child(paned.paned),
-                },
-                .end => .{
-                    paned.child1,
-                    c.gtk_paned_get_start_child(paned.paned),
-                },
-            };
-            // TODO: Use destructuring syntax once it doesn't break ZLS
-            const sibling_child = sibling[0];
-            const sibling_widget = sibling[1];
-
-            // Keep explicit reference to sibling's gl_area, so it's not
-            // destroyed when we remove it from GtkPaned.
-            const sibling_object: *c.GObject = @ptrCast(sibling_widget);
-            _ = c.g_object_ref(sibling_object);
-            defer c.g_object_unref(sibling_object);
-
-            // Remove reference on the surface we're closing
-            surface.setParent(.none);
-
-            // Remove children.
-            paned.removeChildren();
-            // Don't need to call paned.deinit, because we already removed children.
-            defer alloc.destroy(paned);
-
-            switch (paned.parent) {
-                .none => unreachable,
-                .tab => |tab| {
-                    // If parent of Paned we belong to is a tab, we can
-                    // replace the child with the other surface
-                    tab.removeChild();
-                    tab.setChild(sibling_child);
-                },
-                .paned => |parent_paned_tuple| {
-                    const parent_paned = parent_paned_tuple[0];
-                    const parent_paned_position = parent_paned_tuple[1];
-
-                    parent_paned.replaceChildInPosition(sibling_child, parent_paned_position);
-                },
-            }
-
-            const widget = @as(*c.GtkWidget, @ptrCast(sibling_widget));
-            _ = c.gtk_widget_grab_focus(widget);
         },
     }
 }
 
+fn closeSurfaceInPaned(self: *Window, surface: *Surface, paned: *Paned, position: Position) void {
+    const sibling = switch (position) {
+        .start => .{
+            paned.child2,
+            c.gtk_paned_get_end_child(paned.paned),
+        },
+        .end => .{
+            paned.child1,
+            c.gtk_paned_get_start_child(paned.paned),
+        },
+    };
+    // TODO: Use destructuring syntax once it doesn't break ZLS
+    const sibling_child = sibling[0];
+    const sibling_widget = sibling[1];
+
+    // Keep explicit reference to sibling's gl_area, so it's not
+    // destroyed when we remove it from GtkPaned.
+    const sibling_object: *c.GObject = @ptrCast(sibling_widget);
+    _ = c.g_object_ref(sibling_object);
+    defer c.g_object_unref(sibling_object);
+
+    // Remove reference on the surface we're closing
+    surface.setParent(.none);
+
+    // Remove children.
+    paned.removeChildren();
+    // Don't need to call paned.deinit, because we already removed children.
+    defer self.app.core_app.alloc.destroy(paned);
+
+    switch (paned.parent) {
+        .none => unreachable,
+        .tab => |tab| {
+            // If parent of Paned we belong to is a tab, we can
+            // replace the child with the other surface
+            tab.removeChild();
+            tab.setChild(sibling_child);
+        },
+        .paned => |parent_paned_tuple| {
+            const parent_paned = parent_paned_tuple[0];
+            const parent_paned_position = parent_paned_tuple[1];
+
+            parent_paned.replaceChildInPosition(sibling_child, parent_paned_position);
+        },
+    }
+
+    const widget = @as(*c.GtkWidget, @ptrCast(sibling_widget));
+    _ = c.gtk_widget_grab_focus(widget);
+}
+
 /// Returns true if this window has any tabs.
 pub fn hasTabs(self: *const Window) bool {
     return c.gtk_notebook_get_n_pages(self.notebook) > 1;