PDF reader: Support word lookup on macOS

[dstillman]

Word lookup on macOS (I use Cmd-Ctrl-D, but I guess it's force click or three-finger tap on a trackpad) works in our textboxes, in the new note editor, in the annotation sidebar, and even in tab titles, but it doesn't work for the PDF content itself. This is true even in Fx89 with our demo online, though the official pdf.js demo works fine.

Any idea what's causing this?

https://forums.zotero.org/discussion/comment/382772/#Comment_382772

[mrtcode]

It's because we use our own text layer and those things aren't implemented yet. The same is with #2012.

[mrtcode]

Although even the newest Firefox + PDF.js doesn't work as nice as Safari + PDF.js and often takes word that is next to or after the target word. Most likely this is affected by PDF.js text layer absolute positioning and transformations not playing nice with macOS. At some point I will try to optimize that text layer to work better with macOS.