UnityEditor.AudioMixerDrawUtils.DrawRegionBg C# (CSharp) Method

        public static void DrawRegionBg(Rect rect, out Rect headerRect, out Rect contentRect)
        {
            headerRect = new Rect(rect.x + 2f, rect.y, rect.width - 2f, 22f);
            contentRect = new Rect(rect.x, headerRect.yMax, rect.width, rect.height - 22f);
            GUI.Label(new RectOffset(1, 1, 1, 1).Add(contentRect), GUIContent.none, EditorStyles.helpBox);
        }

        public void OnGUI(Rect rect)
        {
            int controlID = GUIUtility.GetControlID(FocusType.Keyboard);

            this.m_ScrollToItem = null;
            if (AudioMixerGroupTreeView.s_Styles == null)
            {
                AudioMixerGroupTreeView.s_Styles = new AudioMixerGroupTreeView.Styles();
            }
            this.m_AudioGroupTree.OnEvent();
            Rect r;
            Rect rect2;

            using (new EditorGUI.DisabledScope(this.m_Controller == null))
            {
                AudioMixerDrawUtils.DrawRegionBg(rect, out r, out rect2);
                AudioMixerDrawUtils.HeaderLabel(r, AudioMixerGroupTreeView.s_Styles.header, AudioMixerGroupTreeView.s_Styles.audioMixerGroupIcon);
            }
            if (this.m_Controller != null)
            {
                AudioMixerGroupController parent = (this.m_Controller.CachedSelection.Count != 1) ? this.m_Controller.masterGroup : this.m_Controller.CachedSelection[0];
                using (new EditorGUI.DisabledScope(EditorApplication.isPlaying))
                {
                    if (GUI.Button(new Rect(r.xMax - 15f, r.y + 3f, 15f, 15f), AudioMixerGroupTreeView.s_Styles.addText, EditorStyles.label))
                    {
                        this.AddAudioMixerGroup(parent);
                    }
                }
                this.m_AudioGroupTree.OnGUI(rect2, controlID);
                AudioMixerDrawUtils.DrawScrollDropShadow(rect2, this.m_AudioGroupTree.state.scrollPos.y, this.m_AudioGroupTree.gui.GetTotalSize().y);
                this.HandleKeyboardEvents(controlID);
                this.HandleCommandEvents(controlID);
            }
        }