[Feature] Support opening images via Android’s Intent system (ACTION_VIEW) to allow Immich to appear as an image viewer

[PassionateBytes]

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

Status Quo:
Currently, Immich does not appear as an option (on my Pixel 8) when attempting to open image files from other apps on Android.
Example: I want to preview a .png file attachment in the Thunderbird app. I select the attachment and Android shows a pop-up to select which app I want to use to open the image, but the list only includes Google Photos, Snapseed, etc. - But no Immich.

Feature Request:
Enable Immich to handle Android’s ACTION_VIEW intents for supported image and video file types (e.g., image/jpeg, image/png, image/webp, video/mp4, etc.), so it can appear in the system's "Open with..." dialog when a user attempts to open image or video files from other apps.

Expected behavior:

• When the user selects an image or video to preview from another app (e.g., Thunderbird, Gmail, file managers, or messaging app), Immich should be listed among the available apps to open/view the media.
• Selecting Immich should open the file in Immich's media viewer UI, the same way as when previewing non-synced media via the On this device library.
• There should be an option to backup the file to the immich timeline.

Implementation notes & references:

• Register an activity in the Android manifest that handles Intent.ACTION_VIEW with the appropriate MIME types (image/, video/).
• Include <category android:name="android.intent.category.DEFAULT" /> and set up intent-filter entries that define the supported MIME types.
• Ensure the viewer activity can handle URIs (content/file schemes) and has permission to read external URIs passed from other apps.
• Android Intents and Intent Filters - Official Docs

Platform

• Server
• Web
• Mobile

[bo0tzz]

#1605