Plugin for TinyMCE 4.x that set a tabindex= on the iframe for tabbing to/from TinyMCE
Copy the tabindex
folder in src to the plugins directory of your TinyMCE installation.
Include the tabindex plugin in your TinyMCE configuration by adding it to the end of the list of plugins.
plugins: '... tabindex'
The tabindex plugin uses a single configration setting called "tabindex" that should be passed with other settings to the tinymce.init() function.
tabindex: number or 'element'
where
number is a value for the tabindex (e.g. 4) or -1 for no tabindex
'element' copies the tabindex= attribute of the element replaced by TinyMCE
'element' is the default value.
See the TinyMCE Documentation for more info about plugins.