Edit: Actually, it IS possible!
TabbedPanelItem:
text: '2'
canvas.before:
PushMatrix
Rotate:
angle: -90
axis: 0,0,1
origin: self.center
canvas.after:
PopMatrix
With current api impossible. And it'll be really ugly if you manage to do it, because it'll stretch the tab-header and make it a square or even another, 90° rotated rectangle, which will screw your Layout
as much as possible - the original tab will look like a casual Button
and whole TabbedPanel
as a beginner's try to make html page if you don't want to limit yourself to 3-4 characters with current font size. Just saying.
You may try to edit the source and one of the ways how to do it directly is making a custom ToggleButton
from which TabbedPanelHeader
inherits and rotate it with Push/PopMatrix()
.
The other (and more reasonable) way would be to make tabs look like this:
t|
a| content
b|
_|
i.e. text going up -> down, though I don't know how to do it except rotating the whole thing and work with characters like this: t\na\nb