How to check, from the tabs root, if current tab can go back - ionic2

Question

TLDR:
I have the ref of my tabs
#ViewChild('tabsPage') tabRef: Tabs;
I need to get the nav stack of the current tab, check if it can go back and do go back if needed.
Full story:
I have a tabs page which I arrive from another page with a custom animation.
The behavior of my tabs when the user presses the hardware back button must be as follow:
If the user is in the tab 0, go back with custom animation;
If the user isn't in the tab 0, go to tab 0;
If the user has navigated in the current tab, go back in the nav stack of that tab.
Trying to achieve that behavior, I used this code in my tab root page, inside of ionViewDidEnter():
if (this.tabRef.getSelected().index == 0) {
this.navCtrl.pop({
animation: 'nav-shrink'
, direction: 'back'
})
} else {
this.tabRef.select(0);
}
The problem is: when I have navigated in another tab, the back button won't go back in the tab (from the detail to the list, for instance), it will go back to the tab 0 at once.
ionViewWillLeave() isn't called when I navigate further in any tab, so i can't deregister the backButtonAction.
The solution would be to check if the current tab can go back, so, instead of going to tab 0 or going back from the tabs page with a custom animation, I would just nav.pop() the current tab.

Answer 1

https://ionicframework.com/docs/v2/api/navigation/NavController/
canGoBack()
Returns true if there’s a valid previous page that we can pop back to. Otherwise returns false.

Answer 2

Apparently, the Tab itself is the NavController. So I solved my problem this way:
if (this.tabRef.getSelected().canGoBack()) {
this.tabRef.getSelected().pop();
} else if (this.tabRef.getSelected().index == 0) {
this.navCtrl.pop({
animation: 'nav-shrink'
, direction: 'back'
})
} else {
this.tabRef.select(0);
}