MotionPredictor
public
final
class
MotionPredictor
extends Object
Calculate motion predictions.
Feed motion events to this class in order to generate predicted future events. The prediction
functionality may not be available on all devices: check if a specific source is supported on a
given input device using isPredictionAvailable(int, int).
Send all of the events that were received from the system to record(MotionEvent) to generate
complete, accurate predictions from predict(long). When processing the returned predictions,
make sure to consider all of the historical samples.
Summary
Public methods |
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boolean
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isPredictionAvailable(int deviceId, int source)
Check whether a device supports motion predictions for a given source type.
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MotionEvent
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predict(long predictionTimeNanos)
Get a predicted event for the gesture that has been provided to record(MotionEvent).
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void
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record(MotionEvent event)
Record a movement so that in the future, a prediction for the current gesture can be
generated.
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Inherited methods |
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From class
java.lang.Object
Object
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clone()
Creates and returns a copy of this object.
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boolean
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equals(Object obj)
Indicates whether some other object is "equal to" this one.
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void
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finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
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final
Class<?>
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getClass()
Returns the runtime class of this Object.
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int
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hashCode()
Returns a hash code value for the object.
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final
void
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notify()
Wakes up a single thread that is waiting on this object's
monitor.
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final
void
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notifyAll()
Wakes up all threads that are waiting on this object's monitor.
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String
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toString()
Returns a string representation of the object.
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final
void
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wait(long timeoutMillis, int nanos)
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted, or until a
certain amount of real time has elapsed.
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final
void
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wait(long timeoutMillis)
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted, or until a
certain amount of real time has elapsed.
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final
void
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wait()
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted.
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Public constructors
MotionPredictor
public MotionPredictor (Context context)
Create a new MotionPredictor for the provided Context.
| Parameters |
|---|
context |
Context: The context for the predictions
This value cannot be null. |
Public methods
isPredictionAvailable
public boolean isPredictionAvailable (int deviceId,
int source)
Check whether a device supports motion predictions for a given source type.
| Parameters |
|---|
deviceId |
int: The input device id. |
source |
int: The source of input events. |
| Returns |
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boolean |
True if the current device supports predictions, false otherwise. |
predict
public MotionEvent predict (long predictionTimeNanos)
Get a predicted event for the gesture that has been provided to record(MotionEvent).
Predictions may not reach the requested timestamp if the confidence in the prediction results
is low.
| Parameters |
|---|
predictionTimeNanos |
long: The time that the prediction should target, in the
SystemClock.uptimeMillis() time base, but in nanoseconds. |
| Returns |
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MotionEvent |
The predicted motion event, or `null` if predictions are not supported, or not
possible for the current gesture. Be sure to check the historical data in addition to the
latest (getX(), getY()) coordinates for
smooth prediction curves. |
record
public void record (MotionEvent event)
Record a movement so that in the future, a prediction for the current gesture can be
generated. Only gestures from one input device at a time should be provided to an instance of
MotionPredictor.
| Parameters |
|---|
event |
MotionEvent: The received event
This value cannot be null. |
