Add helper function to find the index of the given page. Closes #15125. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73734 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add helper function to find the index of the given page. Closes #15125. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73734 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775