WindowContentFrameStats

Kotlin |Java

class WindowContentFrameStats : FrameStats, Parcelable

kotlin.Any
↳	android.view.FrameStats
	↳	android.view.WindowContentFrameStats

This class contains window content frame statistics. For example, a window content is rendred in frames when a view is scrolled. The frame statistics are a snapshot for the time interval from getStartTimeNano() to getEndTimeNano().

The key idea is that in order to provide a smooth user experience an application has to draw a frame at a specific time interval obtained by calling getRefreshPeriodNano(). If the application does not render a frame every refresh period the user will see irregular UI transitions.

An application posts a frame for presentation by synchronously rendering its contents in a buffer which is then posted or posting a buffer to which the application is asychronously rendering the content via GL. After the frame is posted and rendered (potentially asynchronosly) it is presented to the user. The time a frame was posted can be obtained via getFramePostedTimeNano(int), the time a frame content was rendered and ready for dsiplay (GL case) via getFrameReadyTimeNano(int), and the time a frame was presented on the screen via getFramePresentedTimeNano(int).

Summary

Inherited constants

From class Parcelable

Int

CONTENTS_FILE_DESCRIPTOR

Descriptor bit used with describeContents(): indicates that the Parcelable object's flattened representation includes a file descriptor.

Int

PARCELABLE_WRITE_RETURN_VALUE

Flag for use with writeToParcel: the object being written is a return value, that is the result of a function such as "Parcelable someFunction()", "void someFunction(out Parcelable)", or "void someFunction(inout Parcelable)". Some implementations may want to release resources at this point.

From class FrameStats

Long

UNDEFINED_TIME_NANO

Undefined time.

Public methods
Int	`describeContents()`
Long	`getFramePostedTimeNano(index: Int)` Get the time a frame at a given index was posted by the producer (e.g. the application).
Long	`getFrameReadyTimeNano(index: Int)` Get the time a frame at a given index was ready for presentation.
String	`toString()`
Unit	`writeToParcel(parcel: Parcel, flags: Int)`

Inherited functions

From class FrameStats

`Long`	`getEndTimeNano()` Gets the end time of the interval for which these statistics apply. The end interval is the time when the last frame was presented.
`Int`	`getFrameCount()` Gets the number of frames for which there is data.
`Long`	`getFramePresentedTimeNano(index: Int)` Get the time a frame at a given index was presented.
`Long`	`getRefreshPeriodNano()` Gets the refresh period of the display hosting the window(s) for which these statistics apply.
`Long`	`getStartTimeNano()` Gets the start time of the interval for which these statistics apply. The start interval is the time when the first frame was presented.

Properties
static Parcelable.Creator<WindowContentFrameStats!>	`CREATOR`

Public methods

describeContents

Added in API level 21

fun describeContents(): Int

Return
`Int`	a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either `0` or `android.os.Parcelable#CONTENTS_FILE_DESCRIPTOR`

getFramePostedTimeNano

Added in API level 21

fun getFramePostedTimeNano(index: Int): Long

Get the time a frame at a given index was posted by the producer (e.g. the application). It is either explicitly set or defaulted to the time when the render buffer was posted.

Note: A frame can be posted and still it contents being rendered asynchronously in GL. To get the time the frame content was completely rendered and ready to display call getFrameReadyTimeNano(int).

Parameters
`index`	Int: The frame index.

Return
`Long`	The posted time in nanoseconds.

getFrameReadyTimeNano

Added in API level 21

fun getFrameReadyTimeNano(index: Int): Long

Get the time a frame at a given index was ready for presentation.

Note: A frame can be posted and still it contents being rendered asynchronously in GL. In such a case this is the time when the frame contents were completely rendered.

Parameters
`index`	Int: The frame index.

Return
`Long`	The ready time in nanoseconds or `UNDEFINED_TIME_NANO` if the frame is not ready yet.

toString

Added in API level 21

fun toString(): String

Return
`String`	a string representation of the object.

writeToParcel

Added in API level 21

fun writeToParcel(
    parcel: Parcel, 
    flags: Int
): Unit

Parameters
`dest`	The Parcel in which the object should be written. This value cannot be `null`.
`flags`	Int: Additional flags about how the object should be written. May be 0 or `PARCELABLE_WRITE_RETURN_VALUE`. Value is either `0` or a combination of `android.os.Parcelable#PARCELABLE_WRITE_RETURN_VALUE`, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES

Properties

CREATOR

Added in API level 21

static val CREATOR: Parcelable.Creator<WindowContentFrameStats!>