Problems in activating and hiding editor cursors

[cl_fragen]

I have created a custom control. In the control I have problems with cursor. When moving focus to the control I do not get cursor visible. And if the cursor is visible when launching menu, the it does not disappear.

[OSXDev]

Generally this kind of problems happen because of missing or incorrect implementation of FocusChanged function. FocusChanged should take the focus out from control (and hide cursor) before moving focus to another control (including menu). When gaining focus cursor should be activated.