Surface

public class Surface
extends Object implements Parcelable

java.lang.Object
   ↳ android.view.Surface


Handle onto a raw buffer that is being managed by the screen compositor.

A Surface is generally created by or from a consumer of image buffers (such as a SurfaceTexture, MediaRecorder, or Allocation), and is handed to some kind of producer (such as OpenGL, MediaPlayer, or CameraDevice) to draw into.

Note: A Surface acts like a weak reference to the consumer it is associated with. By itself it will not keep its parent consumer from being reclaimed.

Summary

Nested classes

class Surface.OutOfResourcesException

Exception thrown when a Canvas couldn't be locked with Surface#lockCanvas, or when a SurfaceTexture could not successfully be allocated. 

Constants

int CHANGE_FRAME_RATE_ALWAYS

Change the frame rate even if the transition is going to be non-seamless, i.e.

int CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS

Change the frame rate only if the transition is going to be seamless.

int FRAME_RATE_COMPATIBILITY_DEFAULT

There are no inherent restrictions on the frame rate of this surface.

int FRAME_RATE_COMPATIBILITY_FIXED_SOURCE

This surface is being used to display content with an inherently fixed frame rate, e.g. a video that has a specific frame rate.

int ROTATION_0

Rotation constant: 0 degree rotation (natural orientation)

int ROTATION_180

Rotation constant: 180 degree rotation.

int ROTATION_270

Rotation constant: 270 degree rotation.

int ROTATION_90

Rotation constant: 90 degree rotation.

Inherited constants

Fields

public static final Creator<Surface> CREATOR

Public constructors

Surface(SurfaceControl from)

Create a Surface associated with a given SurfaceControl.

Surface(SurfaceTexture surfaceTexture)

Create Surface from a SurfaceTexture.

Public methods

void clearFrameRate()

Clears the frame rate which was set for this surface.

int describeContents()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.

boolean isValid()

Returns true if this object holds a valid surface.

Canvas lockCanvas(Rect inOutDirty)

Gets a Canvas for drawing into this surface.

Canvas lockHardwareCanvas()

Gets a Canvas for drawing into this surface.

void readFromParcel(Parcel source)
void release()

Release the local reference to the server-side surface.

void setFrameRate(float frameRate, int compatibility, int changeFrameRateStrategy)

Sets the intended frame rate for this surface.

void setFrameRate(float frameRate, int compatibility)

Sets the intended frame rate for this surface.

String toString()

Returns a string representation of the object.

void unlockCanvas(Canvas canvas)

This method was deprecated in API level 17. This API has been removed and is not supported. Do not use.

void unlockCanvasAndPost(Canvas canvas)

Posts the new contents of the Canvas to the surface and releases the Canvas.

void writeToParcel(Parcel dest, int flags)

Flatten this object in to a Parcel.

Protected methods

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

Inherited methods

Constants

CHANGE_FRAME_RATE_ALWAYS

Added in API level 31
public static final int CHANGE_FRAME_RATE_ALWAYS

Change the frame rate even if the transition is going to be non-seamless, i.e. with visual interruptions for the user. Non-seamless switches might be used when the benefit of matching the content's frame rate outweighs the cost of the transition, for example when displaying long-running video content.

Constant Value: 1 (0x00000001)

CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS

Added in API level 31
public static final int CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS

Change the frame rate only if the transition is going to be seamless.

Constant Value: 0 (0x00000000)

FRAME_RATE_COMPATIBILITY_DEFAULT

Added in API level 30
public static final int FRAME_RATE_COMPATIBILITY_DEFAULT

There are no inherent restrictions on the frame rate of this surface. When the system selects a frame rate other than what the app requested, the app will be able to run at the system frame rate without requiring pull down. This value should be used when displaying game content, UIs, and anything that isn't video.

Constant Value: 0 (0x00000000)

FRAME_RATE_COMPATIBILITY_FIXED_SOURCE

Added in API level 30
public static final int FRAME_RATE_COMPATIBILITY_FIXED_SOURCE

This surface is being used to display content with an inherently fixed frame rate, e.g. a video that has a specific frame rate. When the system selects a frame rate other than what the app requested, the app will need to do pull down or use some other technique to adapt to the system's frame rate. The user experience is likely to be worse (e.g. more frame stuttering) than it would be if the system had chosen the app's requested frame rate. This value should be used for video content.

Constant Value: 1 (0x00000001)

ROTATION_0

Added in API level 1
public static final int ROTATION_0

Rotation constant: 0 degree rotation (natural orientation)

Constant Value: 0 (0x00000000)

ROTATION_180

Added in API level 1
public static final int ROTATION_180

Rotation constant: 180 degree rotation.

Constant Value: 2 (0x00000002)

ROTATION_270

Added in API level 1
public static final int ROTATION_270

Rotation constant: 270 degree rotation.

Constant Value: 3 (0x00000003)

ROTATION_90

Added in API level 1
public static final int ROTATION_90

Rotation constant: 90 degree rotation.

Constant Value: 1 (0x00000001)

Fields

CREATOR

Added in API level 1
public static final Creator<Surface> CREATOR

Public constructors

Surface

Added in API level 1
public Surface (SurfaceControl from)

Create a Surface associated with a given SurfaceControl. Buffers submitted to this surface will be displayed by the system compositor according to the parameters specified by the control. Multiple surfaces may be constructed from one SurfaceControl, but only one can be connected (e.g. have an active EGL context) at a time.

Parameters
from SurfaceControl: The SurfaceControl to associate this Surface with This value cannot be null.

Surface

Added in API level 1
public Surface (SurfaceTexture surfaceTexture)

Create Surface from a SurfaceTexture. Images drawn to the Surface will be made available to the SurfaceTexture, which can attach them to an OpenGL ES texture via SurfaceTexture.updateTexImage(). Please note that holding onto the Surface created here is not enough to keep the provided SurfaceTexture from being reclaimed. In that sense, the Surface will act like a weak reference to the SurfaceTexture.

Parameters
surfaceTexture SurfaceTexture: The SurfaceTexture that is updated by this Surface.

Throws
Surface.OutOfResourcesException if the surface could not be created.

Public methods

clearFrameRate

Added in API level 34
public void clearFrameRate ()

Clears the frame rate which was set for this surface.

This is equivalent to calling setFrameRate(float, int, int) using 0 for frameRate.

Note that this only has an effect for surfaces presented on the display. If this surface is consumed by something other than the system compositor, e.g. a media codec, this call has no effect.

describeContents

Added in API level 1
public int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(android.os.Parcel, int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

Returns
int a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or CONTENTS_FILE_DESCRIPTOR

isValid

Added in API level 1
public boolean isValid ()

Returns true if this object holds a valid surface.

Returns
boolean True if it holds a physical surface, so lockCanvas() will succeed. Otherwise returns false.

lockCanvas

Added in API level 1
public Canvas lockCanvas (Rect inOutDirty)

Gets a Canvas for drawing into this surface. After drawing into the provided Canvas, the caller must invoke unlockCanvasAndPost(Canvas) to post the new contents to the surface.

Parameters
inOutDirty Rect: A rectangle that represents the dirty region that the caller wants to redraw. This function may choose to expand the dirty rectangle if for example the surface has been resized or if the previous contents of the surface were not available. The caller must redraw the entire dirty region as represented by the contents of the inOutDirty rectangle upon return from this function. The caller may also pass null instead, in the case where the entire surface should be redrawn.

Returns
Canvas A canvas for drawing into the surface.

Throws
IllegalArgumentException If the inOutDirty rectangle is not valid.
Surface.OutOfResourcesException If the canvas cannot be locked.

lockHardwareCanvas

Added in API level 23
public Canvas lockHardwareCanvas ()

Gets a Canvas for drawing into this surface. After drawing into the provided Canvas, the caller must invoke unlockCanvasAndPost(Canvas) to post the new contents to the surface. Unlike lockCanvas(android.graphics.Rect) this will return a hardware-accelerated canvas. See the unsupported drawing operations for a list of what is and isn't supported in a hardware-accelerated canvas. It is also required to fully cover the surface every time lockHardwareCanvas() is called as the buffer is not preserved between frames. Partial updates are not supported.

Returns
Canvas A canvas for drawing into the surface.

Throws
IllegalStateException If the canvas cannot be locked.

readFromParcel

Added in API level 1
public void readFromParcel (Parcel source)

Parameters
source Parcel

release

Added in API level 14
public void release ()

Release the local reference to the server-side surface. Always call release() when you're done with a Surface. This will make the surface invalid.

setFrameRate

Added in API level 31
public void setFrameRate (float frameRate, 
                int compatibility, 
                int changeFrameRateStrategy)

Sets the intended frame rate for this surface.

On devices that are capable of running the display at different refresh rates, the system may choose a display refresh rate to better match this surface's frame rate. Usage of this API won't introduce frame rate throttling, or affect other aspects of the application's frame production pipeline. However, because the system may change the display refresh rate, calls to this function may result in changes to Choreographer callback timings, and changes to the time interval at which the system releases buffers back to the application.

Note that this only has an effect for surfaces presented on the display. If this surface is consumed by something other than the system compositor, e.g. a media codec, this call has no effect.

Parameters
frameRate float: The intended frame rate of this surface, in frames per second. 0 is a special value that indicates the app will accept the system's choice for the display frame rate, which is the default behavior if this function isn't called. The frameRate parameter does not need to be a valid refresh rate for this device's display - e.g., it's fine to pass 30fps to a device that can only run the display at 60fps. Value is 0.0 or greater

compatibility int: The frame rate compatibility of this surface. The compatibility value may influence the system's choice of display frame rate. This parameter is ignored when frameRate is 0. Value is FRAME_RATE_COMPATIBILITY_DEFAULT, FRAME_RATE_COMPATIBILITY_FIXED_SOURCE, android.view.Surface.FRAME_RATE_COMPATIBILITY_EXACT, android.view.Surface.FRAME_RATE_COMPATIBILITY_NO_VOTE, android.view.Surface.FRAME_RATE_COMPATIBILITY_MIN, or android.view.Surface.FRAME_RATE_COMPATIBILITY_GTE

changeFrameRateStrategy int: Whether display refresh rate transitions caused by this surface should be seamless. A seamless transition is one that doesn't have any visual interruptions, such as a black screen for a second or two. This parameter is ignored when frameRate is 0. Value is CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS, or CHANGE_FRAME_RATE_ALWAYS

Throws
IllegalArgumentException If frameRate, compatibility or changeFrameRateStrategy are invalid.

See also:

setFrameRate

Added in API level 30
public void setFrameRate (float frameRate, 
                int compatibility)

Sets the intended frame rate for this surface. Any switching of refresh rates is most probably going to be seamless.

Parameters
frameRate float: Value is 0.0 or greater

compatibility int: Value is FRAME_RATE_COMPATIBILITY_DEFAULT, FRAME_RATE_COMPATIBILITY_FIXED_SOURCE, android.view.Surface.FRAME_RATE_COMPATIBILITY_EXACT, android.view.Surface.FRAME_RATE_COMPATIBILITY_NO_VOTE, android.view.Surface.FRAME_RATE_COMPATIBILITY_MIN, or android.view.Surface.FRAME_RATE_COMPATIBILITY_GTE

toString

Added in API level 1
public String toString ()

Returns a string representation of the object.

Returns
String a string representation of the object.

unlockCanvas

Added in API level 1
Deprecated in API level 17
public void unlockCanvas (Canvas canvas)

This method was deprecated in API level 17.
This API has been removed and is not supported. Do not use.

Parameters
canvas Canvas

unlockCanvasAndPost

Added in API level 1
public void unlockCanvasAndPost (Canvas canvas)

Posts the new contents of the Canvas to the surface and releases the Canvas.

Parameters
canvas Canvas: The canvas previously obtained from lockCanvas(Rect).

writeToParcel

Added in API level 1
public void writeToParcel (Parcel dest, 
                int flags)

Flatten this object in to a Parcel.

Parameters
dest Parcel: 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.PARCELABLE_WRITE_RETURN_VALUE. Value is either 0 or a combination of Parcelable.PARCELABLE_WRITE_RETURN_VALUE, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES

Protected methods

finalize

Added in API level 1
protected void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.

Throws
Throwable