We wanted to have own Views for Tab Buttons so we built a custom Tabbed Page.
Now we want to make it swipable.
I started making a custom renderer for StackLayouts, because in every Tab is a stacklayout with all its content.
But this didnt work because if you tried to swipe on anything except a stacklayout it wouldnt swipe.
This is clear to us.
So next step was trying to Render every Visual Element but this resulted in just seeing their containers in the corresponding BackgroundColor.
Buttons, TextViews etc. were all just not visible...
But their containers were swipable jippie! ... 
So is there any other approach on this whole Gesture-thing?
Even if it would be global, well we tried it too... In the android activity. But the Gestures weren't detected.