Is it possible to get the ACTION_VIEW activity to run within my process and user context (of activity A)?
No, nor would you want it to, for security reasons.
How do I share files between activities?
This question is the same as your next one, as far as I can tell.
Is there a way to pass the file content (not file pointer) from my activity to the Gallery activity or other activities?
The best solution is to use a ContentProvider
. The simplest solution is to use FileProvider
, which you can just add to your manifest and configure to serve up your files, without any need to create a subclass. See also: http://developer.android.com/training/secure-file-sharing/index.html