覆盖Android中文本选择（在WebView中）的默认上下文操作栏

I want to override the existing default Contextual Action Bar(CAB) for text selection. I mean, I want to display my own CAB, with my own buttons, when some text is selected on the webview. I tried implementing a CAB using Android Documentation. OnLongClickListener doesn't capture the text selection event in the web view. What is the event that captures text selection? Is it possible to hide the default CAB and display my CAB on Text selection? I want to override the existing default Context