I'm trying to develop a GUI for a web application and I wanted to set a TabPane with tabs placed at left keeping the tab headers horizontal. I already found how to place the tabs at left, but after many searches I didn't succeed to set the headers in the right alignment. They still vertical and difficult to read.
How could I fixed that?
There is an open feature request for this: RT-19547 New API to rotate text on tabpane tabs
The feature request is currently open, but not scheduled for implementation. You can vote for or comment on the feature request and link back to this StackOverflow post to register your interest in the feature.
To implement this yourself, you will need to create a new TabPane skin or patch the existing TabPane skin, which is likely not trivial.