My colleague was meaning that you should modify the pdf file itself during the generation or the manual annotation, so that you could highlight email with a different colour.
Hyperlinks, theoretically, could contains everything you would like to write into: http://, https://, mailto: but also your own reserved url structure like my://.
That's the reason hyperlinks are simply hyperlinks and aren't aware of their own type.
About reserved url: i.e. we're adopting such kind of encoding to make our native applications interact with pdf files.
The rendering is done within the native library and not modifiable by the java/objective-c code.
After a brainstorming, the workaround we thought about is:
- open the page and render it (simple)
- scan page's annotations (pro and premium) (simple)
- take uri type annotation list (simple)
- extract uri strings (simple)
- evaluate mailto: strings annotations (simple)
- take annotations coordinates (simple)
- transform that page coordinates into screen coordinates and put an overlay on the rendered page
(look at demo code, where search function highlight word on the page)