Remove IE<11 support

[oparoz]

From @manishbisht on July 20, 2016 1:28

Description

As OC9+ doesn's support IE<11 anymore. So now we can also remove support for IE<11 from the gallery.
owncloud/core#25240

Are you a developer willing to implement this feature?: yes

Copied from original issue: owncloud/gallery#693

[oparoz]

You can go ahead and remove all the PNGs, thank you :)

[oparoz]

From @manishbisht on July 21, 2016 13:49

@oparoz The test function public function getPreviewOfPng() in getPreviewCest.php is of no use after removing PNG files.
Also the if condition should be removed from the _getMimeIcon() function in thumbnail.js

I think these are the only 2 changes we have to do apart from removing the PNG images.

[oparoz]

The test function public function getPreviewOfPng() in getPreviewCest.php is of no use after removing PNG files

That's incorrect. Gallery still displays previews of PNG files even though it doesn't use PNG icons.

Also the if condition should be removed from the _getMimeIcon() function in thumbnail.js

That's correct

I think these are the only 2 changes we have to do apart from removing the PNG images.

There is more, per example:
https://github.com/owncloud/gallery/blob/5a33e86e568d267239d1982f38e7d113717f595f/js/slideshow.js#L56

Have another look to see if there aren't any other exceptions.

[oparoz]

From @manishbisht on July 21, 2016 14:30

Then there are three things which I able to find.

1. if condition should be removed from the _getMimeIcon() function in thumbnail.js to remove png option in gallery view
2. https://github.com/owncloud/gallery/blob/5a33e86e568d267239d1982f38e7d113717f595f/js/slideshow.js#L56 if condition should be removed to remove png support from slideshow.
3. Remove getPreviewOfPng() in getPreviewCest.php to remove the PNG test case.

[oparoz]

I don't understand the difference between 1) and 3)

[oparoz]

From @manishbisht on July 21, 2016 14:37

Sorry updated the third point.
The test that I have mentioned in third point is used for icons or it is used for png images. I have no experience in testing.

[oparoz]

OK, but I've just said that getPreviewOfPng() should not be removed ;)

[oparoz]

From @manishbisht on July 21, 2016 14:41

Ok I will be implementing 1) and 2) and submitted the PR in next half an hour.

[oparoz]

Thank you :)

[oparoz]

PR is in #178