What it is

Backs up and restores wallpaper and metadata related to it.

This agent has its own package because it does full backup as opposed to SystemBackupAgent which does key/value backup.

This class stages wallpaper files for backup by copying them into its own directory because of the following reasons:

Non-system users don't have permission to read the directory that the system stores the wallpaper files in

BackupAgent enforces that backed up files must live inside the package's getFilesDir()

There are 3 files to back up:

The "wallpaper info" file which contains metadata like the crop applied to the wallpaper or the live wallpaper component name.

The "system" wallpaper file.

An optional "lock" wallpaper, which is shown on the lockscreen instead of the system wallpaper if set.

On restore, the metadata file is parsed and WallpaperManager APIs are used to set the wallpaper.

Note that if there's a live wallpaper, the live wallpaper package name will be part of the metadata file and the wallpaper will be applied when the package it's installed.

Commands

adb shell pm uninstall --user 0 com.android.wallpaperbackup

To put it back:

adb shell cmd package install-existing com.android.wallpaperbackup

Every removal listed here is per-user only: the system image is untouched, and the restore command puts the app back from the copy already on the device. Nothing is downloaded.

This is not the directory. Here we say what a package is in general; what happens on your particular television is on your model's entry, and that one wins. The same package can be dead weight on one set and hold the home screen up on another.

What it is

Commands

References