# `TabBarControlDelegate tabBar:willCloseTabItem:`

*Instance Method*

## Declaration

```swift
optional func tabBar(_ aTabBar: GSTabBarControl, willCloseTabItem tabItem: NSViewController)
```

```objc
- (void) tabBar:(GSTabBarControl *) aTabBar willCloseTabItem:(NSViewController *) tabItem;
```

```python
tabBar_willCloseTabItem_(aTabBar: GSTabBarControl, tabItem: NSViewController)
```