Fix user selectable text for public links for text files

[MorrisJobke]

Makes public link share text files selectable.

Was added in owncloud/core#15652

As discussed with @jancborchardt - cc @nextcloud/designers

Found while reviewing https://github.com/nextcloud/files_texteditor/pull/71/files

[codecov]

Codecov Report

Merging #9206 into master will increase coverage by <.01%.
The diff coverage is n/a.

@@ Coverage Diff @@## master #9206 +/- ##
===========================================
+ Coverage 51.9% 51.9% +<.01% 
Complexity 25354 25354 ===========================================
Files 1606 1606 Lines 95301 95301 Branches 1394 1394 ===========================================
+ Hits 49465 49466 +1 + Misses 45836 45835 -1

Impacted Files	Coverage Δ	Complexity Δ
apps/files_trashbin/lib/Trashbin.php	72.7% <0%> (+0.24%)	136% <0%> (ø)	⬇️

[oparoz]

I don't think it's the right solution since we only get the first few characters, but if it matches what's done elsewhere then it's probably OK.

[danxuliu]

Tested and works 👍

Note that this change affects too the Text editor app.

For reference, as mentioned in nextcloud/files_texteditor#71 (comment) the height of the text preview is cropped (down to 200px) to ensure that the Download button is visible. When the preview is cropped and the text is selected part of the hidden text could end being selected too, which could be surprising for the user. However, as since Nextcloud 13 the Download button is shown in the header too and thus it is always visible the cropping could be removed (from both the default preview and the Text editor app preview), which would make this issue go away ;-)

[danxuliu]

@oparoz

I don't think it's the right solution since we only get the first few characters, but if it matches what's done elsewhere then it's probably OK.

Making the text selectable was approved by @jancborchardt, so it should be OK ;-) (although he was referring to the Text editor app, which loads a lot more text than the default preview, but I suppose that it is OK in this case too).

[rullzer]

@oparoz well it is a preview sure. But still having real text there and not being selectable is a bti weird ;)