targetingnotifications
Notification channels are required
Every notification must belong to a channel, and channel importance controls user-visible behaviour.
What to doCreate channels at startup and assign each notification to one.
API 26 · O
Android 8.0 Oreo
Picture-in-picture
The story
Android 8.0 was the release where Google finally restructured the platform to make updates possible.
The problem
Vendor code and platform code were intertwined, so updating the platform meant rebuilding the device.
Project Treble split the vendor implementation behind HIDL and a versioned interface. Android 8.0 also added notification channels, background execution limits, picture-in-picture and adaptive icons.
The release that made Android updatable in principle.
What shipped
- Picture-in-picture
- Notification channels
- Adaptive icons
- Autofill
- Project Treble
Platform internals
What changed underneath the APIs. These are the changes this site's architecture modules explain in depth.
- Project Treble: the vendor interface separates vendor and system code
- Background execution limits
- Broadcast and service restrictions
- HIDL for HALs
What developers had to deal with
- Notification channels are mandatory when targeting 26
- Background service limits
- Adaptive icons
- Autofill framework
- Implicit broadcast restrictions
Behaviour changes
The full archive has every recorded change with its migration advice.
targetingbackground
Background execution limits
Background services are stopped shortly after the app leaves the foreground, and most implicit broadcasts are banned.
What to doUse foreground services or JobScheduler for work that must continue.
targetingbackground
Background location limits
Apps receive location updates less frequently in the background.
What to doUse a foreground service with the location type for continuous tracking.
targetingui
Adaptive icons
Launchers can mask app icons into different shapes.
What to doProvide adaptive icons with a foreground and background layer.
targetingsecurity
Unknown sources are per-app
The system-wide unknown-sources setting is replaced by per-app install permission.
What to doUse the package installer intent and handle the permission flow.
targetingsecurity
StrictMode cleartext detection
File URI exposure is detected and throws FileUriExposedException.
What to doUse FileProvider to share files.
all appsnotifications
Notification importance
Notifications have importance levels that control sound and visibility.
What to doSet importance correctly per channel.
all appsruntime
Runtime restrictions on background services
Even apps not targeting 8.0 see some service restrictions.
What to doMove background work to scheduled jobs.
Permissions introduced here
ANSWER_PHONE_CALLSdangerousBIND_AUTOFILL_SERVICEsignatureBIND_VISUAL_VOICEMAIL_SERVICEsignature|privilegedINSTANT_APP_FOREGROUND_SERVICEsignature|development|instant|appopMANAGE_OWN_CALLSnormalREAD_PHONE_NUMBERSdangerousREQUEST_COMPANION_RUN_IN_BACKGROUNDnormalREQUEST_COMPANION_USE_DATA_IN_BACKGROUNDnormalREQUEST_DELETE_PACKAGESnormal
Where this sits
Release 26 of 37 API levels, by date
- Headline features
- 5
- Architecture changes
- 4
- Developer changes
- 5
- Sources cited
- 5
Kernel
This release shipped on Linux kernel versions 4.4. Kernel versions vary by device.