# Print output for @column tags ?>
public
final
class
CameraManager
extends Object
java.lang.Object | |
↳ | android.hardware.camera2.CameraManager |
A system service manager for detecting, characterizing, and connecting to
CameraDevices
.
For more details about communicating with camera devices, read the Camera
developer guide or the camera2
package documentation.
Nested classes | |
---|---|
class |
CameraManager.AvailabilityCallback
A callback for camera devices becoming available or unavailable to open. |
class |
CameraManager.TorchCallback
A callback for camera flash torch modes becoming unavailable, disabled, or enabled. |
Public methods | |
---|---|
CameraCharacteristics
|
getCameraCharacteristics(String cameraId)
Query the capabilities of a camera device. |
CameraExtensionCharacteristics
|
getCameraExtensionCharacteristics(String cameraId)
Query the camera extension capabilities of a camera device. |
String[]
|
getCameraIdList()
Return the list of currently connected camera devices by identifier, including cameras that may be in use by other camera API clients. |
Set<Set<String>>
|
getConcurrentCameraIds()
Return the set of combinations of currently connected camera device identifiers, which support configuring camera device sessions concurrently. |
boolean
|
isConcurrentSessionConfigurationSupported(Map<String, SessionConfiguration> cameraIdAndSessionConfig)
Checks whether the provided set of camera devices and their corresponding
|
void
|
openCamera(String cameraId, CameraDevice.StateCallback callback, Handler handler)
Open a connection to a camera with the given ID. |
void
|
openCamera(String cameraId, Executor executor, CameraDevice.StateCallback callback)
Open a connection to a camera with the given ID. |
void
|
registerAvailabilityCallback(Executor executor, CameraManager.AvailabilityCallback callback)
Register a callback to be notified about camera device availability. |
void
|
registerAvailabilityCallback(CameraManager.AvailabilityCallback callback, Handler handler)
Register a callback to be notified about camera device availability. |
void
|
registerTorchCallback(Executor executor, CameraManager.TorchCallback callback)
Register a callback to be notified about torch mode status. |
void
|
registerTorchCallback(CameraManager.TorchCallback callback, Handler handler)
Register a callback to be notified about torch mode status. |
void
|
setTorchMode(String cameraId, boolean enabled)
Set the flash unit's torch mode of the camera of the given ID without opening the camera device. |
void
|
unregisterAvailabilityCallback(CameraManager.AvailabilityCallback callback)
Remove a previously-added callback; the callback will no longer receive connection and disconnection callbacks. |
void
|
unregisterTorchCallback(CameraManager.TorchCallback callback)
Remove a previously-added callback; the callback will no longer receive torch mode status callbacks. |
Inherited methods | |
---|---|
public CameraCharacteristics getCameraCharacteristics (String cameraId)
Query the capabilities of a camera device. These capabilities are immutable for a given camera.
From API level 29, this function can also be used to query the capabilities of physical
cameras that can only be used as part of logical multi-camera. These cameras cannot be
opened directly via openCamera(String, CameraDevice.StateCallback, Handler)
Also starting with API level 29, while most basic camera information is still available
even without the CAMERA permission, some values are not available to apps that do not hold
that permission. The keys not available are listed by
CameraCharacteristics#getKeysNeedingPermission
.
Parameters | |
---|---|
cameraId |
String : The id of the camera device to query. This could be either a standalone
camera ID which can be directly opened by openCamera(String, CameraDevice.StateCallback, Handler) , or a physical camera ID that
can only used as part of a logical multi-camera.
This value cannot be null . |
Returns | |
---|---|
CameraCharacteristics |
The properties of the given camera
This value cannot be null . |
Throws | |
---|---|
IllegalArgumentException |
if the cameraId does not match any known camera device. |
CameraAccessException |
if the camera device has been disconnected. |
public CameraExtensionCharacteristics getCameraExtensionCharacteristics (String cameraId)
Query the camera extension capabilities of a camera device.
Parameters | |
---|---|
cameraId |
String : The id of the camera device to query. This must be a standalone
camera ID which can be directly opened by openCamera(String, CameraDevice.StateCallback, Handler) .
This value cannot be null . |
Returns | |
---|---|
CameraExtensionCharacteristics |
The properties of the given camera
This value cannot be null . |
Throws | |
---|---|
IllegalArgumentException |
if the cameraId does not match any known camera device. |
CameraAccessException |
if the camera device has been disconnected. |
public String[] getCameraIdList ()
Return the list of currently connected camera devices by identifier, including cameras that may be in use by other camera API clients.
Non-removable cameras use integers starting at 0 for their identifiers, while removable cameras have a unique identifier for each individual device, even if they are the same model.
This list doesn't contain physical cameras that can only be used as part of a logical multi-camera device.
Returns | |
---|---|
String[] |
The list of currently connected camera devices.
This value cannot be null . |
Throws | |
---|---|
CameraAccessException |
public Set<Set<String>> getConcurrentCameraIds ()
Return the set of combinations of currently connected camera device identifiers, which support configuring camera device sessions concurrently.
The devices in these combinations can be concurrently configured by the same client camera application. Using these camera devices concurrently by two different applications is not guaranteed to be supported, however.
For concurrent operation, in chronological order :
- Applications must first close any open cameras that have sessions configured, using
CameraDevice#close
.
- All camera devices intended to be operated concurrently, must be opened using
openCamera(String, CameraDevice.StateCallback, Handler)
, before configuring sessions on any of the camera devices.
Each device in a combination, is guaranteed to support stream combinations which may be
obtained by querying getCameraCharacteristics(String)
for the key
CameraCharacteristics.SCALER_MANDATORY_CONCURRENT_STREAM_COMBINATIONS
.
For concurrent operation, if a camera device has a non null zoom ratio range as specified
by
CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE
,
its complete zoom ratio range may not apply. Applications can use
CaptureRequest.CONTROL_ZOOM_RATIO
>=1 and <=
CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM
during concurrent operation.
The set of combinations may include camera devices that may be in use by other camera API clients.
Concurrent camera extension sessions CameraExtensionSession
are not currently
supported.
The set of combinations doesn't contain physical cameras that can only be used as part of a logical multi-camera device.
If a new camera id becomes available through
AvailabilityCallback#onCameraUnavailable(String)
, clients can call
this method to check if new combinations of camera ids which can stream concurrently are
available.
Returns | |
---|---|
Set<Set<String>> |
The set of combinations of currently connected camera devices, that may have sessions configured concurrently. The set of combinations will be empty if no such combinations are supported by the camera subsystem. |
Throws | |
---|---|
CameraAccessException |
if the camera device has been disconnected. |
public boolean isConcurrentSessionConfigurationSupported (Map<String, SessionConfiguration> cameraIdAndSessionConfig)
Checks whether the provided set of camera devices and their corresponding
SessionConfiguration
can be configured concurrently.
This method performs a runtime check of the given SessionConfiguration
and camera
id combinations. The result confirms whether or not the passed session configurations can be
successfully used to create camera capture sessions concurrently, on the given camera
devices using CameraDevice#createCaptureSession(SessionConfiguration)
.
The method can be called at any point before, during and after active capture sessions. It will not impact normal camera behavior in any way and must complete significantly faster than creating a regular or constrained capture session.
Although this method is faster than creating a new capture session, it is not intended
to be used for exploring the entire space of supported concurrent stream combinations. The
available mandatory concurrent stream combinations may be obtained by querying
getCameraCharacteristics(String)
for the key
CameraCharacteristics.SCALER_MANDATORY_CONCURRENT_STREAM_COMBINATIONS
.
Note that session parameters will be ignored and calls to
SessionConfiguration#setSessionParameters
are not required.
Manifest.permission.CAMERA
Parameters | |
---|---|
cameraIdAndSessionConfig |
Map : This value cannot be null . |
Returns | |
---|---|
boolean |
true if the given combination of session configurations and corresponding
camera ids are concurrently supported by the camera sub-system,
false otherwise OR if the set of camera devices provided is not a subset of
those returned by getConcurrentCameraIds() . |
Throws | |
---|---|
CameraAccessException |
if one of the camera devices queried is no longer connected. |
public void openCamera (String cameraId, CameraDevice.StateCallback callback, Handler handler)
Open a connection to a camera with the given ID.
Use getCameraIdList()
to get the list of available camera
devices. Note that even if an id is listed, open may fail if the device
is disconnected between the calls to getCameraIdList()
and
openCamera(String, CameraDevice.StateCallback, Handler)
, or if a higher-priority camera API client begins using the
camera device.
As of API level 23, devices for which the
AvailabilityCallback#onCameraUnavailable(String)
callback has been called due to the
device being in use by a lower-priority, background camera API client can still potentially
be opened by calling this method when the calling camera API client has a higher priority
than the current camera API client using this device. In general, if the top, foreground
activity is running within your application process, your process will be given the highest
priority when accessing the camera, and this method will succeed even if the camera device is
in use by another camera API client. Any lower-priority application that loses control of the
camera in this way will receive an
CameraDevice.StateCallback.onDisconnected(CameraDevice)
callback.
Opening the same camera ID twice in the same application will similarly cause the
CameraDevice.StateCallback.onDisconnected(CameraDevice)
callback
being fired for the CameraDevice
from the first open call and all ongoing tasks
being droppped.
Once the camera is successfully opened, CameraDevice.StateCallback#onOpened
will
be invoked with the newly opened CameraDevice
. The camera device can then be set up
for operation by calling CameraDevice#createCaptureSession
and
CameraDevice#createCaptureRequest
Before API level 30, when the application tries to open multiple CameraDevice
of
different IDs and the device does not support opening such combination, either the
openCamera(String, CameraDevice.StateCallback, Handler)
will fail and throw a CameraAccessException
or one or more of
already opened CameraDevice
will be disconnected and receive
CameraDevice.StateCallback.onDisconnected(CameraDevice)
callback. Which
behavior will happen depends on the device implementation and can vary on different devices.
Starting in API level 30, if the device does not support the combination of cameras being
opened, it is guaranteed the openCamera(String, CameraDevice.StateCallback, Handler)
call will fail and none of existing
CameraDevice
will be disconnected.
If the camera becomes disconnected during initialization
after this function call returns,
CameraDevice.StateCallback#onDisconnected
with a
CameraDevice
in the disconnected state (and
CameraDevice.StateCallback#onOpened
will be skipped).
If opening the camera device fails, then the device callback's
onError
method will be called, and subsequent
calls on the camera device will throw a CameraAccessException
.
Manifest.permission.CAMERA
Parameters | |
---|---|
cameraId |
String : The unique identifier of the camera device to open
This value cannot be null . |
callback |
CameraDevice.StateCallback : The callback which is invoked once the camera is opened
This value cannot be null . |
handler |
Handler : The handler on which the callback should be invoked, or
null to use the current thread's looper .
This value may be null . |
Throws | |
---|---|
CameraAccessException |
if the camera is disabled by device policy, has been disconnected, is being used by a higher-priority camera API client, or the device has reached its maximal resource and cannot open this camera device. |
IllegalArgumentException |
if cameraId or the callback was null,
or the cameraId does not match any currently or previously available
camera device returned by getCameraIdList() . |
SecurityException |
if the application does not have permission to access the camera |
public void openCamera (String cameraId, Executor executor, CameraDevice.StateCallback callback)
Open a connection to a camera with the given ID.
The behavior of this method matches that of
openCamera(java.lang.String, StateCallback, android.os.Handler)
, except that it uses
Executor
as an argument instead of
Handler
.
Manifest.permission.CAMERA
Parameters | |
---|---|
cameraId |
String : The unique identifier of the camera device to open
This value cannot be null . |
executor |
Executor : The executor which will be used when invoking the callback.
This value cannot be null .
Callback and listener events are dispatched through this
Executor , providing an easy way to control which thread is
used. To dispatch events through the main thread of your
application, you can use
Context.getMainExecutor() .
To dispatch events through a shared thread pool, you can use
AsyncTask#THREAD_POOL_EXECUTOR . |
callback |
CameraDevice.StateCallback : The callback which is invoked once the camera is opened
This value cannot be null . |
Throws | |
---|---|
CameraAccessException |
if the camera is disabled by device policy, has been disconnected, or is being used by a higher-priority camera API client. |
IllegalArgumentException |
if cameraId, the callback or the executor was null, or the cameraId does not match any currently or previously available camera device. |
SecurityException |
if the application does not have permission to access the camera |
public void registerAvailabilityCallback (Executor executor, CameraManager.AvailabilityCallback callback)
Register a callback to be notified about camera device availability.
The behavior of this method matches that of
registerAvailabilityCallback(android.hardware.camera2.CameraManager.AvailabilityCallback, android.os.Handler)
,
except that it uses Executor
as an argument
instead of Handler
.
Parameters | |
---|---|
executor |
Executor : The executor which will be used to invoke the callback.
This value cannot be null .
Callback and listener events are dispatched through this
Executor , providing an easy way to control which thread is
used. To dispatch events through the main thread of your
application, you can use
Context.getMainExecutor() .
To dispatch events through a shared thread pool, you can use
AsyncTask#THREAD_POOL_EXECUTOR . |
callback |
CameraManager.AvailabilityCallback : the new callback to send camera availability notices to
This value cannot be null . |
Throws | |
---|---|
IllegalArgumentException |
if the executor is null . |
public void registerAvailabilityCallback (CameraManager.AvailabilityCallback callback, Handler handler)
Register a callback to be notified about camera device availability.
Registering the same callback again will replace the handler with the new one provided.
The first time a callback is registered, it is immediately called with the availability status of all currently known camera devices.
AvailabilityCallback#onCameraUnavailable(String)
will be called whenever a camera
device is opened by any camera API client. As of API level 23, other camera API clients may
still be able to open such a camera device, evicting the existing client if they have higher
priority than the existing client of a camera device. See open() for more details.
Since this callback will be registered with the camera service, remember to unregister it once it is no longer needed; otherwise the callback will continue to receive events indefinitely and it may prevent other resources from being released. Specifically, the callbacks will be invoked independently of the general activity lifecycle and independently of the state of individual CameraManager instances.
Parameters | |
---|---|
callback |
CameraManager.AvailabilityCallback : the new callback to send camera availability notices to
This value cannot be null . |
handler |
Handler : The handler on which the callback should be invoked, or null to use
the current thread's looper .
This value may be null . |
Throws | |
---|---|
IllegalArgumentException |
if the handler is null but the current thread has
no looper. |
public void registerTorchCallback (Executor executor, CameraManager.TorchCallback callback)
Register a callback to be notified about torch mode status.
The behavior of this method matches that of
registerTorchCallback(android.hardware.camera2.CameraManager.TorchCallback, android.os.Handler)
,
except that it uses Executor
as an argument
instead of Handler
.
Parameters | |
---|---|
executor |
Executor : The executor which will be used to invoke the callback
This value cannot be null .
Callback and listener events are dispatched through this
Executor , providing an easy way to control which thread is
used. To dispatch events through the main thread of your
application, you can use
Context.getMainExecutor() .
To dispatch events through a shared thread pool, you can use
AsyncTask#THREAD_POOL_EXECUTOR . |
callback |
CameraManager.TorchCallback : The new callback to send torch mode status to
This value cannot be null . |
Throws | |
---|---|
IllegalArgumentException |
if the executor is null . |
public void registerTorchCallback (CameraManager.TorchCallback callback, Handler handler)
Register a callback to be notified about torch mode status.
Registering the same callback again will replace the handler with the new one provided.
The first time a callback is registered, it is immediately called with the torch mode status of all currently known camera devices with a flash unit.
Since this callback will be registered with the camera service, remember to unregister it once it is no longer needed; otherwise the callback will continue to receive events indefinitely and it may prevent other resources from being released. Specifically, the callbacks will be invoked independently of the general activity lifecycle and independently of the state of individual CameraManager instances.
Parameters | |
---|---|
callback |
CameraManager.TorchCallback : The new callback to send torch mode status to
This value cannot be null . |
handler |
Handler : The handler on which the callback should be invoked, or null to use
the current thread's looper .
This value may be null . |
Throws | |
---|---|
IllegalArgumentException |
if the handler is null but the current thread has
no looper. |
public void setTorchMode (String cameraId, boolean enabled)
Set the flash unit's torch mode of the camera of the given ID without opening the camera device.
Use getCameraIdList()
to get the list of available camera devices and use
getCameraCharacteristics(String)
to check whether the camera device has a flash unit.
Note that even if a camera device has a flash unit, turning on the torch mode may fail
if the camera device or other camera resources needed to turn on the torch mode are in use.
If setTorchMode(String, boolean)
is called to turn on or off the torch mode successfully,
CameraManager.TorchCallback#onTorchModeChanged
will be invoked.
However, even if turning on the torch mode is successful, the application does not have the
exclusive ownership of the flash unit or the camera device. The torch mode will be turned
off and becomes unavailable when the camera device that the flash unit belongs to becomes
unavailable or when other camera resources to keep the torch on become unavailable (
CameraManager.TorchCallback#onTorchModeUnavailable
will be invoked). Also,
other applications are free to call setTorchMode(String, boolean)
to turn off the torch mode (
CameraManager.TorchCallback#onTorchModeChanged
will be invoked). If the latest
application that turned on the torch mode exits, the torch mode will be turned off.
Parameters | |
---|---|
cameraId |
String : The unique identifier of the camera device that the flash unit belongs to.
This value cannot be null . |
enabled |
boolean : The desired state of the torch mode for the target camera device. Set to
true to turn on the torch mode. Set to false to turn off the
torch mode. |
Throws | |
---|---|
CameraAccessException |
if it failed to access the flash unit.
CameraAccessException#CAMERA_IN_USE will be thrown if the camera device
is in use. CameraAccessException#MAX_CAMERAS_IN_USE will be thrown if
other camera resources needed to turn on the torch mode are in use.
CameraAccessException#CAMERA_DISCONNECTED will be thrown if camera
service is not available. |
IllegalArgumentException |
if cameraId was null, cameraId doesn't match any currently or previously available camera device, or the camera device doesn't have a flash unit. |
public void unregisterAvailabilityCallback (CameraManager.AvailabilityCallback callback)
Remove a previously-added callback; the callback will no longer receive connection and disconnection callbacks.
Removing a callback that isn't registered has no effect.
Parameters | |
---|---|
callback |
CameraManager.AvailabilityCallback : The callback to remove from the notification list
This value cannot be null . |
public void unregisterTorchCallback (CameraManager.TorchCallback callback)
Remove a previously-added callback; the callback will no longer receive torch mode status callbacks.
Removing a callback that isn't registered has no effect.
Parameters | |
---|---|
callback |
CameraManager.TorchCallback : The callback to remove from the notification list
This value cannot be null . |