add nova

nova/src/Fields/Collapsable.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace Laravel\Nova\Fields;
+
+trait Collapsable
+{
+    /**
+     * The menu's collapsable state.
+     *
+     * @var bool
+     */
+    public $collapsable = false;
+
+    /**
+     * Determines whether the menu section should be collapsed by default.
+     *
+     * @var bool
+     */
+    public $collapsedByDefault = false;
+
+    /**
+     * Set the menu group as collapsable.
+     *
+     * @return $this
+     */
+    public function collapsable()
+    {
+        $this->collapsable = true;
+
+        return $this;
+    }
+
+    /**
+     * Set the menu group as collapsable.
+     *
+     * @return $this
+     */
+    public function collapsible()
+    {
+        return $this->collapsable();
+    }
+
+    /**
+     * Set the menu section as collapsed by default.
+     *
+     * @return $this
+     */
+    public function collapsedByDefault()
+    {
+        $this->collapsable();
+        $this->collapsedByDefault = true;
+
+        return $this;
+    }
+}