Photos and screenshots

Pictures go through the phone’s media collection rather than through a folder grant, which is why they are a separate subject from files. A folder grant knows a directory; the media collection knows a collection — which is the only thing that can answer “the newest photo”, “everything in Screenshots” or “pictures taken last Tuesday”.

The nodes

Node	Kind	Needs
Picture Saved	Trigger	Photo access
Screenshot Taken	Trigger	Photo access
Latest picture / Latest screenshot	Value	Photo access
Find Pictures	Action	Photo access
Picture Details	Action	Photo access; location access to read where it was taken
Edit Picture	Action	Photo access — resize, rotate, mirror, crop, re-encode
Change Picture Details	Action	Photo access, permission to change your photos, overlay
Move or Copy Picture	Action	as above
Delete Picture	Action	as above
Take Photo	Action	Camera access
Take Screenshot	Action	Accessibility access

There is one “Picture” field, filled from a chooser or from an upstream port. Whether the value behind it is a path or a media reference is never a question you are asked — but it is why a picture can be handed straight to Describe a picture or to a file node.

The three mutating nodes need more

Change Picture Details, Move or Copy Picture and Delete Picture modify rows that belong to other apps, and Android insists the user approve each one.

That approval is a system dialog, which needs a screen — and Easymatic’s engine is a background service. So those three also declare permission to draw over other apps, which is what allows the dialog to be raised from the background at all.

Three outcomes are kept apart, and it matters:

• changed — it worked;
• refused — the user said no. Not worth retrying;
• could not ask — nobody was there to answer. Worth retrying when the phone is in hand.

Folding the last into a plain error would make a locked screen indistinguishable from a decision.

Edit Picture is free of all of this, because it writes a new file that Easymatic owns.

Taking a screenshot

Take Screenshot rides the accessibility service, not screen projection. That is what makes it usable from a background macro: screen projection raises a consent dialog every time and cannot be started headlessly.

Turn Easymatic’s accessibility service on in Settings — the node’s card has a button that takes you there.

The picture trigger and the first arm

Picture Saved does not replay your camera roll when you first arm it. A macro armed on a phone with four thousand photos must not run four thousand times, so the first arm records where the collection is and fires nothing.

That mark is deliberately not cleared when you disarm, because a disarm and a re-arm are indistinguishable from the trigger’s point of view.

One behaviour is worth knowing because it explains a delay: from Android 10 a camera app inserts its row first, invisible, then fills in the bytes and publishes. The trigger looks back a few seconds precisely so the picture everybody actually wanted is not skipped.

Large pictures

Editing a picture decodes it into memory. Very large images are downsampled rather than crashing the process, so a re-encode of a 108-megapixel photo produces a smaller result than you might expect — the alternative is no result at all.