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 |
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 |
|
Surface(SurfaceTexture surfaceTexture)
Create Surface from a |
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
|
lockHardwareCanvas()
Gets a |
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 |
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
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
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
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
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
public static final int ROTATION_0
Rotation constant: 0 degree rotation (natural orientation)
Constant Value: 0 (0x00000000)
ROTATION_180
public static final int ROTATION_180
Rotation constant: 180 degree rotation.
Constant Value: 2 (0x00000002)
ROTATION_270
public static final int ROTATION_270
Rotation constant: 270 degree rotation.
Constant Value: 3 (0x00000003)
ROTATION_90
public static final int ROTATION_90
Rotation constant: 90 degree rotation.
Constant Value: 1 (0x00000001)
Fields
Public constructors
Surface
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
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
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.
See also:
describeContents
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
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
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
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
public void readFromParcel (Parcel source)
Parameters | |
---|---|
source |
Parcel |
release
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
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 , or FRAME_RATE_COMPATIBILITY_FIXED_SOURCE |
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
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 , or FRAME_RATE_COMPATIBILITY_FIXED_SOURCE |
See also:
toString
public String toString ()
Returns a string representation of the object.
Returns | |
---|---|
String |
a string representation of the object. |
unlockCanvas
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
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
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
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 |
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Last updated 2024-05-15 UTC.