Merge "Create VelocityTracker#getAxisVelocity API" (81defaa0) · Commits · e / os / android_frameworks_base

core/api/current.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -49939,10 +49939,13 @@ package android.view {
		method public void clear();
		method public void computeCurrentVelocity(int);
		method public void computeCurrentVelocity(int, float);
		method public float getAxisVelocity(int, int);
		method public float getAxisVelocity(int);
		method public float getXVelocity();
		method public float getXVelocity(int);
		method public float getYVelocity();
		method public float getYVelocity(int);
		method public boolean isAxisSupported(int);
		method public static android.view.VelocityTracker obtain();
		method public void recycle();
		}

core/java/android/view/VelocityTracker.java

+61 −3

Original line number	Diff line number	Diff line
		@@ -183,6 +183,7 @@ public final class VelocityTracker {
		private static native float nativeGetVelocity(long ptr, int axis, int id);
		private static native boolean nativeGetEstimator(
		long ptr, int axis, int id, Estimator outEstimator);
		private static native boolean nativeIsAxisSupported(int axis);

		static {
		// Strategy string and IDs mapping lookup.
		@@ -304,6 +305,22 @@ public final class VelocityTracker {
		}
		}

		/**
		* Checks whether a given motion axis is supported for velocity tracking.
		*
		* <p>The axis values that would make sense to use for this method are the ones defined in the
		* {@link MotionEvent} class.
		*
		* @param axis The axis to check for velocity support.
		* @return {@code true} if {@code axis} is supported for velocity tracking, or {@code false}
		* otherwise.
		* @see #getAxisVelocity(int, int)
		* @see #getAxisVelocity(int)
		*/
		public boolean isAxisSupported(int axis) {
		return nativeIsAxisSupported(axis);
		}

		/**
		* Reset the velocity tracker back to its initial state.
		*/
		@@ -345,7 +362,9 @@ public final class VelocityTracker {
		* {@link #getYVelocity()}.
		*
		* @param units The units you would like the velocity in. A value of 1
		* provides pixels per millisecond, 1000 provides pixels per second, etc.
		* provides units per millisecond, 1000 provides units per second, etc.
		* Note that the units referred to here are the same units with which motion is reported. For
		* axes X and Y, the units are pixels.
		* @param maxVelocity The maximum velocity that can be computed by this method.
		* This value must be declared in the same unit as the units parameter. This value
		* must be positive.
		@@ -396,6 +415,45 @@ public final class VelocityTracker {
		return nativeGetVelocity(mPtr, MotionEvent.AXIS_Y, id);
		}

		/**
		* Retrieve the last computed velocity for a given motion axis. You must first call
		* {@link #computeCurrentVelocity(int)} or {@link #computeCurrentVelocity(int, float)} before
		* 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
		* method:
		* <ul>
		* <li> {@link MotionEvent#AXIS_SCROLL}: supported starting
		* {@link Build.VERSION_CODES#UPSIDE_DOWN_CAKE}
		* </ul>
		*
		* @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
		* {@code axis} is supported for velocity tracking, or 0 if velocity tracking is not supported
		* for the axis.
		* @see #isAxisSupported(int)
		*/
		public float getAxisVelocity(int axis, int id) {
		return nativeGetVelocity(mPtr, axis, id);
		}

		/**
		* Equivalent to calling {@link #getAxisVelocity(int, int)} for {@code axis} and the active
		* pointer.
		*
		* @param axis Which axis' velocity to return.
		* @return The previously computed velocity for {@code axis} for the active pointer if
		* {@code axis} is supported for velocity tracking, or 0 if velocity tracking is not supported
		* for the axis.
		* @see #isAxisSupported(int)
		* @see #getAxisVelocity(int, int)
		*/
		public float getAxisVelocity(int axis) {
		return nativeGetVelocity(mPtr, axis, ACTIVE_POINTER_ID);
		}

		/**
		* Get an estimator for the movements of a pointer using past movements of the
		* pointer to predict future movements.
		@@ -426,8 +484,8 @@ public final class VelocityTracker {
		* Past estimated positions are at negative times and future estimated positions
		* are at positive times.
		*
		* First coefficient is position (in pixels), second is velocity (in pixels per second),
		* third is acceleration (in pixels per second squared).
		* First coefficient is position (in units), second is velocity (in units per second),
		* third is acceleration (in units per second squared).
		*
		* @hide For internal use only. Not a final API.
		*/

core/jni/android_view_VelocityTracker.cpp

+7 −0

Original line number	Diff line number	Diff line
		@@ -153,6 +153,11 @@ static jboolean android_view_VelocityTracker_nativeGetEstimator(JNIEnv* env, jcl
		return result;
		}

		static jboolean android_view_VelocityTracker_nativeIsAxisSupported(JNIEnv* env, jclass clazz,
		jint axis) {
		return VelocityTracker::isAxisSupported(axis);
		}

		// --- JNI Registration ---

		static const JNINativeMethod gVelocityTrackerMethods[] = {
		@@ -167,6 +172,8 @@ static const JNINativeMethod gVelocityTrackerMethods[] = {
		{"nativeGetVelocity", "(JII)F", (void*)android_view_VelocityTracker_nativeGetVelocity},
		{"nativeGetEstimator", "(JIILandroid/view/VelocityTracker$Estimator;)Z",
		(void*)android_view_VelocityTracker_nativeGetEstimator},
		{"nativeIsAxisSupported", "(I)Z",
		(void*)android_view_VelocityTracker_nativeIsAxisSupported},
		};

		int register_android_view_VelocityTracker(JNIEnv* env) {