refactor to separated entities, init abstractions

src/Entity/Window.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yggverse\Yoda\Entity;
+
+use \Yggverse\Yoda\Entity\Window\Header;
+use \Yggverse\Yoda\Entity\Window\Tab;
+
+class Window
+{
+    public \GtkWindow $gtk;
+
+    public \Yggverse\Yoda\Model\Database $database;
+
+    public \Yggverse\Yoda\Entity\Window\Header $header;
+    public \Yggverse\Yoda\Entity\Window\Tab $tab;
+
+    // Defaults
+    private int $_width  = 640;
+    private int $_height = 480;
+
+    public function __construct(
+        \Yggverse\Yoda\Model\Database $database
+    ) {
+        $this->database = $database;
+
+        $this->gtk = new \GtkWindow;
+
+        $this->gtk->set_size_request(
+            $this->_width,
+            $this->_height
+        );
+
+        $this->header = new Header(
+            $this
+        );
+
+        $this->gtk->set_titlebar(
+            $this->header->gtk
+        );
+
+        $this->tab = new Tab(
+            $this
+        );
+
+        $this->gtk->add(
+            $this->tab->gtk
+        );
+
+        $this->gtk->show_all();
+    }
+}