Android P includes several new features such as WiFi round-trip-time positioning, display cutout support, the ImageDecoder class for image decoding, and a unified biometric authentication API. It also improves existing features like notifications with enhanced messaging styles, and includes privacy and power management changes such as placing restrictions on background access to sensors and limiting apps' resource usage based on usage patterns.

2. Somkiat Khitwongwattana
What’s new in
Android P

4. Preview 1 : Initial release, alpha
Preview 2 : Incremental update, beta
Preview 3 : Final APIs and official SDK, Play publishing, beta
Preview 4 : Release candidate for testing
Preview 5 : Release candidate for final testing
Final Release : To AOSP and ecosystem

6. Android P
Features & APIs

7. No more crash dialog

8. WiFi
Round-Trip-Time
Let you take advantage of indoor positioning
in your apps.
No need to connect to the AP

9. // Permission
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
// Feature
<uses-feature android:name="android.hardware.wifi.rtt" />
// WiFi RTT support?
var hasWifiRtt = getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI_RTT)

10. // Usage
val manager = getSystemService(Context.WIFI_RTT_RANGING_SERVICE) as WifiRttManager
...
manager.startRanging(rangingRequest, executor, object: RangingResultCallback() {
override fun onRangingResults(results: MutableList<RangingResult>?) {
// Do something
}
override fun onRangingFailure(code: Int) {
// Do something
}
})

11. Display Cutout

13. Corner Double Tall

14. Never Default Short Edges

15. // Style
<item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
<item name="android:windowLayoutInDisplayCutoutMode">default</item>
<item name="android:windowLayoutInDisplayCutoutMode">never</item>
// Code
val rootView: View = ...
rootView.setOnApplyWindowInsetsListener({ _, insets ->
val displayCutout = insets.displayCutout
// Do something
insets
})

16. ImageDecoder
Class for converting encoded images into Drawable or Bitmap objects.

17. // Oldschool with BitmapFactory
private fun doSomethingWithImageResourceThenReturnAsBitmap(FilePath): Bitmap {
val bitmap = decodeSampledBitmapFromFile(filePath, 200, 200)
...
return ...
}
private fun decodeSampledBitmapFromFile(filePath: String, reqWidth: Int, reqHeight: Int): Bitmap
{
val options = BitmapFactory.Options()
options.inJustDecodeBounds = true
BitmapFactory.decodeFile(filePath, options)
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight)
options.inJustDecodeBounds = false
return BitmapFactory.decodeFile(filePath, options)
}
private fun calculateInSampleSize(options: BitmapFactory.Options, reqWidth: Int, reqHeight:
Int): Int {
val height = options.outHeight
val width = options.outWidth

18. Concepts
• Source
• Post-processor
• Header listener

19. // ImageDecoder
val source = ImageDecoder.createSource(...)
val bitmap = ImageDecoder.decodeBitmap(source, { imageDecoder, _, _ ->
run {
imageDecoder.setResize(imageView.measuredWidth, imageView.measuredHeight)
imageDecoder.setPostProcessor({ canvas: Canvas ->
// Do something
PixelFormat.OPAQUE
})
}
})
imageView.setImageBitmap(bitmap)

20. // ImageDecoder
val source = ImageDecoder.createSource(...)
val bitmap = ImageDecoder.decodeBitmap(source, { imageDecoder, _, _ ->
run {
imageDecoder.setResize(imageView.measuredWidth, imageView.measuredHeight)
imageDecoder.setPostProcessor({ canvas: Canvas ->
// Do something
PixelFormat.OPAQUE
})
}
})
imageView.setImageBitmap(bitmap)
Source

21. // ImageDecoder
val source = ImageDecoder.createSource(...)
val bitmap = ImageDecoder.decodeBitmap(source, { imageDecoder, _, _ ->
run {
imageDecoder.setResize(imageView.measuredWidth, imageView.measuredHeight)
imageDecoder.setPostProcessor({ canvas: Canvas ->
// Do something
PixelFormat.OPAQUE
})
}
})
imageView.setImageBitmap(bitmap)
Decode + Header Listener

22. // ImageDecoder
val source = ImageDecoder.createSource(...)
val bitmap = ImageDecoder.decodeBitmap(source, { imageDecoder, _, _ ->
run {
imageDecoder.setResize(imageView.measuredWidth, imageView.measuredHeight)
imageDecoder.setPostProcessor({ canvas: Canvas ->
// Do something
PixelFormat.OPAQUE
})
}
})
imageView.setImageBitmap(bitmap) Post-processor

23. AnimatedImageDrawable
Drawing and displaying GIF and WebP animated images.

24. val drawable = ImageDecoder.decodeDrawable(...)
if (drawable is AnimatedImageDrawable) {
drawable.start()
...
}

25. Biometrics API
Unified biometric authentication

27. // Permission
<uses-permission android:name="android.permission.USE_BIOMETRIC" />
// Feature (XML)
<uses-feature android:name="android.hardware.fingerprint" />
<uses-feature android:name="android.hardware.iris" />
<uses-feature android:name="android.hardware.face" />
// Feature (Programmatically)
var hasFingerprint = getPackageManager().hasSystemFeature(PackageManager.FEATURE_FINGERPRINT)
var hasIris = getPackageManager().hasSystemFeature(PackageManager.FEATURE_IRIS)
var hasFaceScanner = getPackageManager().hasSystemFeature(PackageManager.FEATURE_FACE)

28. // Permission
<uses-permission android:name="android.permission.USE_BIOMETRIC" />
// Feature (XML)
<uses-feature android:name="android.hardware.fingerprint" />
<uses-feature android:name="android.hardware.iris" />
<uses-feature android:name="android.hardware.face" />
// Feature (Programmatically)
var hasFingerprint = getPackageManager().hasSystemFeature(PackageManager.FEATURE_FINGERPRINT)
var hasIris = getPackageManager().hasSystemFeature(PackageManager.FEATURE_IRIS)
var hasFaceScanner = getPackageManager().hasSystemFeature(PackageManager.FEATURE_FACE)
Not available at this time

29. // Create BiometricPrompt
val biometricPrompt = BiometricPrompt.Builder(context).apply {
setTitle("Verify purchase")
setSubtitle("This item is non-refundable")
setDescription("Seller : Akexorcist")
setNegativeButton("Cancel",
executor,
DialogInterface.OnClickListener { dialog, which ->
// Do something
})
}.build()

30. // Authenticate
biometricPrompt.authenticate(CancellationSignal(),
executor,
object : BiometricPrompt.AuthenticationCallback() {
override fun onAuthenticationError(errorCode: Int, errString: CharSequence?) {
// Do something
}
override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult?) {
// Do something
}
override fun onAuthenticationHelp(helpCode: Int, helpString: CharSequence?) {
// Do something
}
override fun onAuthenticationFailed() {
// Do something
}
})

32. Notification
• Enhanced messaging experience
• Channel settings, broadcasts, and Do Not Disturb

33. Enhanced messaging
experience
• Simplified support for conversation participants
• Support for images
• Save replies as drafts
• Identify if a conversation is a group conversation
• Set the semantic action for an intent
• SmartReply

34. val person = Person.Builder().apply {
setName(name)
setUri(uri)
setIcon(null)
}.build()
val message = Notification.MessagingStyle.Message("Picture", timestamp, person).apply {
setData("image", imageUri)
}
val style = Notification.MessagingStyle(person).apply {
addMessage("Check this out!", 0, person)
addMessage(message)
}

35. MessagingStyle with
photo attached

36. MessagingStyle
with replies and
conversation

37. Camera API v2
Multi-camera support, External USB cameras and more!

38. Text
• Baseline Distance
• Background Text Measurement
• Magnifier
• Smart Linkify

39. Baseline Distance
XML
.
<TextView .
... .
android:firstBaselineToTopHeight="28dp" .
android:lastBaselineToBottomHeight="20dp" .
/> .
.
Programmatically
.
textView.firstBaselineToTopHeight = 28.toDp() .
textView.lastBaselineToBottomHeight = 20.toDp() .
.

40. Background Text Measurement
.
val text = ...Very long text... .
val computeTextParam = textView.textMetricsParams .
val precomputedText = PrecomputedText.create(text, computeTextParam) .
textView.text = precomputedText .
.
Enabling you to compute and cache the required information ahead of time. It also
enables your app to perform text layout off the main thread.

41. Magnifier
Platform widget that provides a magnifier API
allowing consistent magnifier-feature experience
across all apps..
.
val magnifier = Magnifier(view) .
magnifier.show(x, y) .
magnifier.dismiss() .
.

42. Smart Linkify
.
val input = "0123456789" .
val manager = getSystemService(Context.TEXT_CLASSIFICATION_SERVICE) as TextClassificationManager .
val context = TextClassificationContext.Builder(packageName, TextClassifier.WIDGET_TYPE_EDITTEXT).build().
val session = manager.createTextClassificationSession(context) .
val classifier = session.classifyText(input, 0, input.length, LocaleList.getDefault()) .
... .
session.destroy() .
.
Leverages machine learning to identify some entities in selected text and suggest
actions.

43. Smart Linkify
.
var remoteActionList: List<RemoteAction> = classifier.actions .
var entityCount: Int = classifier.entityCount .
var id: String = classifier.id .
var text: String = classifier.text .
.
Leverages machine learning to identify some entities in selected text and suggest
actions

44. Background Input & Privacy
While apps are idle, they can no longer access camera, microphone, or
SensorManager sensors.

45. Build.SERIAL
Removal of direct access to Build.serial
Use
.
Build.getSerial() .
.
And
.
<uses-permission android:name="android.permission.READ_PHONE_STATE" /> .
.

46. Power Management
New battery management feature that along with features that were
already present before Android P, to ensure that system resources are
given to the apps that need them the most.

47. Power Management
• App Standby Buckets
• Background Restrictions
• Battery Saver
• Doze Mode

48. Power Management
• App Standby Buckets (New feature)
• Background Restrictions (New feature)
• Battery Saver (Improved)
• Doze Mode (Nothing change)

49. App Standby Bucket
The system limits apps' access to device resources (CPU or battery)
based on the user's usage patterns.

50. Active
Working
Set
Frequent Rare Never

51. Active
Working
Set
Frequent Rare Never
Usage
Condition
App

52. Active
Working
Set
Frequent Rare Never
App

53. Active
User is currently using the app.
• The app has launched an activity
• The app is running a foreground service
• The app has a sync adapter associated with a content provider used by a foreground app
• The user clicks on a notification from the app
System does not place any restrictions on the app's jobs, alarms, or FCM messages.

54. Working Set
Run often but it is not currently active.
System imposes mild restrictions on its ability to run jobs and trigger alarms.

55. Frequent
Used regularly, but not necessarily every day.
System imposes stronger restrictions on its ability to run jobs and trigger alarms, and also
imposes a cap on high-priority FCM messages.

56. Rare
Not often used.
System imposes strict restrictions on its ability to run jobs, trigger alarms, and receive
high-priority FCM messages. The system also limits the app's ability to connect to the
internet.

57. Never
Installed but have never been run
System imposes severe restrictions on these apps.
Brace yourself, dinosaur era is coming!

58. Recommendation
• Do not try to manipulate the system into putting your app into one bucket or
another.
• If an app does not have a launcher activity, it might never be promoted to
the active bucket.

59. • If the app's notifications aren't actionable, users won't be able to trigger the
app's promotion to the active bucket by interacting with the notifications.
• Only intended use for high-priority FCM messages is to push a notification
to the user.
• If apps are split across multiple packages, those packages might be in
different buckets and, thus, have different access levels.
• Do not spam the user with notifications just to try to keep your app in the
active bucket!

60. Background Restriction
Notices that an app is consuming excessive resources.
Excessive wake locks
- Wake lock held for an hour when screen is off
Excessive background services
- Targets API levels lower than 26 and has excessive background services

61. Battery Saver
• The system puts apps in app standby mode more aggressively, instead
of waiting for the app to be idle.
• Background execution limits apply to all apps, regardless of their target
API level.
• Location services may be disabled when the screen is off.
• Background apps do not have network access.

62. Doze
Still the same as it used to be.
https://developer.android.com/training/monitoring-device-state/doze-standby

63. Note
The precise restrictions imposed of App Standby Bucket, Background
Restriction and Battery Saver are determined by the device
manufacturer.

64. Best Solutions
Follow the best practice guideline or charging the device.

65. Testing

66. Testing
App Standby Buckets
Change an app's bucket
.
$ adb shell am set-standby-bucket packagename active|working_set|frequent|rare .
.
Multiple packages at once
.
$ adb shell am set-standby-bucket package1 bucket1 package2 bucket2... .
.

67. Testing
App Standby Buckets
What bucket an app is in
.
$ adb shell am get-standby-bucket [packagename] .
.
If you don't pass a packagename parameter, the command lists the
buckets for all apps.

68. Testing
Background Restrictions
Apply background restrictions
.
$ adb shell cmd appops set packagename RUN_ANY_IN_BACKGROUND ignore .
.
Remove background restrictions
.
$ adb shell cmd appops set packagename RUN_ANY_IN_BACKGROUND ignore .
.

69. Testing
Battery Saver
Simulate the device being unplugged
.
$ adb shell dumpsys battery unplug .
.
Device behaves under low power conditions
.
$ adb shell settings put global low_power 1 .
.
Reset manual device settings
.
$ adb shell dumpsys battery reset .
.

70. https://developer.android.com/preview/features/power-details

71. More, more and more!
Media
- HDR VP9
- HEIF file format
Neural Network API 1.1
Vulkan 1.1
...

72. Thank you
Somkiat Khitwongwattana
developers.android.com
Helpful resources
@Akexorcist