Using the CEF wrapper CEFSharp for my .NET app, I can use the keyboard's Tab key to cycle through my app's controls and into the CEF browser. Once focus makes it to CEF, the Tab key will cycle through the elements of the currently loaded page, as expected. When focus reaches the end of the page, it loops back to the first page element. I have implemented the browser's focus handler to try to pull focus back to my app after focus reaches the bottom of the page, but it appears that the handler's methods are not properly called for offscreen browsers. I see OnSetFocus() get called once but no other focus handler methods ever get called after that.
How can I detect when focus has reached the end of my page?