[Tab] TabIndicator z position is the same as the tab label and icon

[cvanem]

Summary

I find it to useful to have a tab selector that has a full height TabIndicator that does not block the tab's icon and label. This can be accomplished in userspace by overriding the classes below, but is there any reason that the TabIndicator position should not be behind the icon and label by default? Possibly even go as far as having a tabIndicatorFullHeight option on the Tab component?

tabIndicator: {		
	height: '100%',
	zIndex: 0,
},
labelContainer: {
	zIndex: 1,
},
rootLabelIcon: {
	zIndex: 1,
},

Expected Behavior

I would expect the TabIndicator to not block the text and icon and show up behind them when the TabIndicator height causes it to overlap the text and icon.

Current Behavior

Currently when the TabIndicator height is set to a value that will overlap the text and icon, the TabIndicator blocks the text and icon.

[oliviertassinari]

@cvanem We don't rely at all on the z-index for the Tab component.

I would expect the TabIndicator to not block the text and icon and show up behind them when the TabIndicator height causes it to overlap the text and icon.

I don't expect this behavior. It's counter-intuitive to me. What if people want to change the background color? The indicator will no longer be visible.

[cvanem]

@oliviertassinari The indicator would be in front of the background color, but behind the text and icon. Am I looking at this wrong? Here is how I have it setup with the indicator animating full height when the tab changes.

Anyway, not a big deal as it can be implemented via class overrides.