private static readonly int ControlHash = "ControlName".GetHashCode();

void OnGUI(Rect area)
{
    var control = new GUIControl(area, ControlHash);
    
    switch (control.EventType)
    {
        case EventType.MouseDown:
            if (control.TryUseMouseDown())
            {
            }
            break;
    
        case EventType.MouseUp:
            if (control.TryUseMouseUp())
            {
            }
            break;
    
        case EventType.MouseDrag:
            if (control.TryUseHotControl())
            {
            }
            break;
    }
}