refactor: make tab label their own widget

This helps with downcasting which greatly helps with type safety.

src/components/mod.rs

@@ -5,11 +5,13 @@
 pub mod app;
 pub mod editor;
 pub mod sidebar;
+pub mod tab_label;
 pub mod window;
 
 pub use app::EchidnaEditor;
 pub use editor::EchidnaCoreEditor;
 pub use sidebar::EchidnaSidebar;
+pub use tab_label::TabLabel;
 pub use window::EchidnaWindow;
 
 pub mod prelude {

src/components/tab_label/imp.rs

@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use gtk::prelude::*;
+use gtk::subclass::prelude::*;
+use gtk::CompositeTemplate;
+
+#[derive(Default, CompositeTemplate)]
+#[template(file = "./tab-label.ui")]
+pub struct TabLabel {
+    #[template_child]
+    pub button: TemplateChild<gtk::Button>,
+}
+
+#[glib::object_subclass]
+impl ObjectSubclass for TabLabel {
+    const NAME: &'static str = "TabLabel";
+    type Type = super::TabLabel;
+    type ParentType = gtk::Box;
+
+    fn class_init(klass: &mut Self::Class) {
+        Self::bind_template(klass);
+    }
+
+    fn instance_init(obj: &glib::subclass::InitializingObject<Self>) {
+        obj.init_template();
+    }
+}
+
+impl ObjectImpl for TabLabel {}
+impl WidgetImpl for TabLabel {}
+impl BoxImpl for TabLabel {}
+
+impl BuildableImpl for TabLabel {
+    fn add_child(
+        &self,
+        buildable: &Self::Type,
+        builder: &gtk::Builder,
+        child: &glib::Object,
+        type_: Option<&str>,
+    ) {
+        buildable.prepend(child.downcast_ref::<gtk::Widget>().unwrap());
+    }
+}

src/components/tab_label/mod.rs

@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+pub mod imp;
+use glib::IsA;
+use gtk::prelude::*;
+use gtk::subclass::prelude::*;
+
+glib::wrapper! {
+    pub struct TabLabel(ObjectSubclass<imp::TabLabel>)
+    @extends gtk::Box, gtk::Widget,
+    @implements gtk::Accessible, gtk::Buildable, gtk::ConstraintTarget, gtk::Orientable;
+}
+
+impl TabLabel {
+    pub fn new<U: IsA<gtk::Widget>>(tab_label: Option<&U>) -> Self {
+        let this: Self = glib::Object::new(&[]).expect("Failed to create 'TabLabel' component.");
+
+        if tab_label.is_some() {
+            this.prepend(tab_label.unwrap());
+        }
+        this
+    }
+
+    pub fn to_imp(&self) -> &imp::TabLabel {
+        imp::TabLabel::from_instance(self)
+    }
+}

src/components/tab_label/tab-label.ui

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk+" version="4.5.0" />
+  <!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at https://mozilla.org/MPL/2.0/.
+-->
+  <template class="TabLabel">
+    <property name="orientation">GTK_ORIENTATION_HORIZONTAL</property>
+    <child>
+        <object class="GtkButton" id="button">
+            <property name="has-frame">0</property>
+            <property name="icon-name">window-close-symbolic</property>
+        </object>
+    </child>
+  </template>
+</interface>

src/lib/closeable_tab.rs

@@ -2,6 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use crate::components::tab_label::TabLabel;
 use glib::IsA;
 use gtk::{prelude::*, Box, Button, Widget};
 
@@ -16,39 +17,24 @@ pub trait ClosableTabImplementedNotebook {
         child: &T,
         tab_label: Option<&U>,
     ) -> u32;
-
-    fn create_closable_tab<U: IsA<Widget>>(tab_label: Option<&U>) -> (Box, Button);
 }
 
 impl ClosableTabImplementedNotebook for gtk::Notebook {
-    fn create_closable_tab<U: IsA<Widget>>(tab_label: Option<&U>) -> (Box, Button) {
-        let tab = Box::new(gtk::Orientation::Horizontal, 5);
-        if tab_label.is_some() {
-            tab.append(tab_label.unwrap());
-        }
-
-        let button = gtk::Button::new();
-
-        button.set_icon_name("window-close-symbolic");
-        button.set_has_frame(false);
-
-        tab.append(&button);
-
-        (tab, button)
-    }
-
     fn prepend_closable_page<T: IsA<Widget>, U: IsA<Widget>>(
         &self,
         child: &T,
         tab_label: Option<&U>,
     ) -> u32 {
-        let (tab, button) = &Self::create_closable_tab(tab_label);
-        let page = self.prepend_page(child, Some(tab));
+        let tab_label_widget = TabLabel::new(tab_label);
+        let page = self.prepend_page(child, Some(&tab_label_widget));
 
-        button.connect_clicked(glib::clone!(@weak self as notebook =>
-            move |_| {
-            notebook.remove_page(Some(page));
-        }));
+        tab_label_widget
+            .to_imp()
+            .button
+            .connect_clicked(glib::clone!(@weak self as notebook =>
+                move |_| {
+                notebook.remove_page(Some(page));
+            }));
 
         page
     }
@@ -58,13 +44,16 @@ impl ClosableTabImplementedNotebook for gtk::Notebook {
         child: &T,
         tab_label: Option<&U>,
     ) -> u32 {
-        let (tab, button) = &Self::create_closable_tab(tab_label);
-        let page = self.append_page(child, Some(tab));
+        let tab_label_widget = TabLabel::new(tab_label);
+        let page = self.append_page(child, Some(&tab_label_widget));
 
-        button.connect_clicked(glib::clone!(@weak self as notebook =>
-            move |_| {
-            notebook.remove_page(Some(page));
-        }));
+        tab_label_widget
+            .to_imp()
+            .button
+            .connect_clicked(glib::clone!(@weak self as notebook =>
+                move |_| {
+                notebook.remove_page(Some(page));
+            }));
 
         page
     }