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Merge "VelocityTracker API Documentation Improvements"

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This commit is contained in:
Yeabkal Wubshit
2022-11-15 04:27:21 +00:00
committed by Android (Google) Code Review
parent 7ff51b5e06 d968d45bd4
commit 16c0e8925b
1 changed files with 22 additions and 8 deletions
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30
core/java/android/view/VelocityTracker.java
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@@ -28,7 +28,7 @@ import java.lang.annotation.RetentionPolicy;
import java.util.Map;
/**
* Helper for tracking the velocity of touch events, for implementing
* Helper for tracking the velocity of motion events, for implementing
* flinging and other such gestures.
*
* Use {@link #obtain} to retrieve a new instance of the class when you are going
@@ -43,6 +43,15 @@ public final class VelocityTracker {
private static final int ACTIVE_POINTER_ID = -1;
/** @hide */
@IntDef(value = {
MotionEvent.AXIS_X,
MotionEvent.AXIS_Y,
MotionEvent.AXIS_SCROLL
})
@Retention(RetentionPolicy.SOURCE)
public @interface VelocityTrackableMotionEventAxis {}
/**
* Velocity Tracker Strategy: Invalid.
*
@@ -306,10 +315,12 @@ public final class VelocityTracker {
}
/**
* Checks whether a given motion axis is supported for velocity tracking.
* Checks whether a given velocity-trackable {@link MotionEvent} axis is supported for velocity
* tracking by this {@link VelocityTracker} instance (refer to
* {@link #getAxisVelocity(int, int)} for a list of potentially velocity-trackable axes).
*
* <p>The axis values that would make sense to use for this method are the ones defined in the
* {@link MotionEvent} class.
* <p>Note that the value returned from this method will stay the same for a given instance, so
* a single check for axis support is enough per a {@link VelocityTracker} instance.
*
* @param axis The axis to check for velocity support.
* @return {@code true} if {@code axis} is supported for velocity tracking, or {@code false}
@@ -317,7 +328,7 @@ public final class VelocityTracker {
* @see #getAxisVelocity(int, int)
* @see #getAxisVelocity(int)
*/
public boolean isAxisSupported(int axis) {
public boolean isAxisSupported(@VelocityTrackableMotionEventAxis int axis) {
return nativeIsAxisSupported(axis);
}
@@ -421,13 +432,16 @@ public final class VelocityTracker {
* calling this function.
*
* <p>In addition to {@link MotionEvent#AXIS_X} and {@link MotionEvent#AXIS_Y} which have been
* supported since the introduction of this class, the following axes are supported for this
* supported since the introduction of this class, the following axes can be candidates for this
* method:
* <ul>
* <li> {@link MotionEvent#AXIS_SCROLL}: supported starting
* {@link Build.VERSION_CODES#UPSIDE_DOWN_CAKE}
* </ul>
*
* <p>Before accessing velocities of an axis using this method, check that your
* {@link VelocityTracker} instance supports the axis by using {@link #isAxisSupported(int)}.
*
* @param axis Which axis' velocity to return.
* @param id Which pointer's velocity to return.
* @return The previously computed velocity for {@code axis} for pointer ID of {@code id} if
@@ -435,7 +449,7 @@ public final class VelocityTracker {
* for the axis.
* @see #isAxisSupported(int)
*/
public float getAxisVelocity(int axis, int id) {
public float getAxisVelocity(@VelocityTrackableMotionEventAxis int axis, int id) {
return nativeGetVelocity(mPtr, axis, id);
}
@@ -450,7 +464,7 @@ public final class VelocityTracker {
* @see #isAxisSupported(int)
* @see #getAxisVelocity(int, int)
*/
public float getAxisVelocity(int axis) {
public float getAxisVelocity(@VelocityTrackableMotionEventAxis int axis) {
return nativeGetVelocity(mPtr, axis, ACTIVE_POINTER_ID);
}