refactor into separate files for app structure

src/ui/app/widgets.rs

@@ -0,0 +1,39 @@
+use relm4::{
+    adw::{
+        self,
+        prelude::{BoxExt, GtkWindowExt, OrientableExt, WidgetExt},
+        traits::AdwApplicationWindowExt,
+    },
+    gtk::{self, SelectionMode},
+    WidgetPlus, Widgets,
+};
+
+use super::model::AppModel;
+
+#[relm4::widget(pub)]
+impl Widgets<AppModel, ()> for AppWidgets {
+    view! {
+        main_window = adw::ApplicationWindow {
+            set_default_width: 800,
+            set_default_height: 600,
+
+            set_content: main_box = Some(&gtk::Box) {
+                set_orientation: gtk::Orientation::Vertical,
+
+                append = &adw::HeaderBar {
+                    set_title_widget = Some(&gtk::Label) {
+                        set_label: "Toolbox Tuner",
+                    }
+                },
+
+                append = &gtk::ListBox {
+                    set_selection_mode: SelectionMode::None,
+                    set_margin_all: 30,
+                    set_css_classes: &["boxed-list"],
+                    factory!(model.toolboxes)
+                }
+
+            },
+        }
+    }
+}