In Chromium extensions, the viewer's URL looks like this:
chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/http://example.com/file.pdf
Furthermore, the PDF Viewer itself can also add something to the reference fragment:
chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/http://example.com/file.pdf#page=2
Consequently, it is difficult to copy a clean URL (e.g. for sharing over mail)
without having to tidy-up the URL manually.
This commit solves this issue by adding a button to the omnibox,
which shows the clean PDF URL on click.
Before commit:
chrome-extension://EXTENSIONID/content/web/viewer.html?file=http%3A%2F%2Fexample.com%2Ffile.pdf
After commit:
chrome-extension://EXTENSIONID/http://example/file.pdf
Technical details:
- The extension's background page uses the webRequest API to intercept
requests for <extension host>/<real path to pdf>, and redirect it to
the viewer's URL.
- viewer.js uses history.replaceState to rewrite the URL, so that it's
easier for users to recognize and copy-paste URLs.
- The fake paths /http:, /https:, /file:, etc. have been added to the
web_accessible_resources section of the manifest file, in order to
avoid seeing chrome-extension://invalid/ instead of the actual URL
when using history back/forward to navigate from/to the PDF viewer.
- Since the relative path resolving doesn't work because relative URLs
are inaccurate, a <base> tag has been added. This method has already
been proven to work in the Firefox add-on.
Notes:
- This commit has been cherry-picked from crx-using-streams-api.
- Need to merge https://github.com/mozilla/pdf.js/pull/3582 to deal with
a bug in Chrome <=30
- In Chrome, getting the contents of a FTP file is not possible, so
there's no support for FTP files, even though the extension router
recognizes the ftp: scheme.
