Html / Epub reader implementation

[michalrentka]

No description provided.

[jarbus]

I've literally been stalking this repo since last November because I've been so excited for epub support in Zotero haha, so great to see this PR

[mvasilak]

Some first comments. More will follow.

[chenggiant]

Looking forward to the epub and html support!

[haidar47x]

Glad to see it being implemented. :)

[mvasilak]

@michalrentka some comments from testing ePUB attachments.

general

• When I download an attachment to open, rarely, it opens empty and I have to close the reader and open it again, for the document to appear. Could there be a potential race issue when downloading, copying to temporary folder, and loading the document?
• For images in the document, e.g. a cover, I can hold-tap to get a context menu, which is nice, unless we think it may cause some confusion.

• I can even select text on an image, which may be confusing if a user tries to annotate it (like I tried 😅).

Annotations

• Creating an annotation may create 2 annotations with some text overlapping.

• Creating further annotations, may not be rendered, although text is selected, and you get an error like:

[ERROR] Zotero(+0000001): HtmlEpubDocumentViewController: navigating to 6NREE26N failed - Error Domain=WKErrorDomain Code=4 "A JavaScript exception occurred" UserInfo={WKJavaScriptExceptionLineNumber=31037, WKJavaScriptExceptionMessage=Error: Unsupported FragmentSelector.conformsTo: undefined, WKJavaScriptExceptionColumnNumber=103, WKJavaScriptExceptionSourceURL=file:///.../view.js, NSLocalizedDescription=A JavaScript exception occurred}. [(155) HtmlEpubDocumentViewController.selectInDocument(key:); com.apple.main-thread]

• Closing and re-opening the document after, in both iOS & macOS, will show a blank screen, as it seems corrupted. (No errors are logged in iOS log when re-opening)
• Trying to delete an annotation from the sidebar in this state, logs this error (although the annotation is deleted):

[ERROR] Zotero(+0000000): HtmlEpubDocumentViewController: updating document failed - Error Domain=WKErrorDomain Code=4 "A JavaScript exception occurred" UserInfo={WKJavaScriptExceptionLineNumber=31037, WKJavaScriptExceptionMessage=Error: Unsupported FragmentSelector.conformsTo: undefined, WKJavaScriptExceptionColumnNumber=103, WKJavaScriptExceptionSourceURL=file:///.../view.js, NSLocalizedDescription=A JavaScript exception occurred}. [(167) HtmlEpubDocumentViewController.updateView(modifications:insertions:deletions:); com.apple.main-thread]

• Deleting all the annotations (only possible in iOS), eliminates the corrupted state, and re-opening the document displays it as expected.

Rendering

• It’s not always the same in macOS and iOS, which makes sense, but I may see empty pages in iOS, that I don’t see in macOS.
• Decreasing reader height, e.g. by moving the toolbar to the top, may hide some of the bottom content.
• Changing reader size in any way, e.g. by rotating, will render annotation rects in the wrong place.

Navigation

• It would be nice to have a table of contents in the sidebar.
• It would be nice to have page controls in the toolbar.
• Tapping a link would be nice to create a back button.