Before utilizing this method to get a minimum fling velocity for a motion generated by the + * input device, scale the velocity of the motion events generated by the input device to pixels + * per second. + * + *
For instance, if you tracked {@link MotionEvent#AXIS_SCROLL} vertical velocities generated + * from a {@link InputDevice#SOURCE_ROTARY_ENCODER}, the velocity returned from + * {@link VelocityTracker} will be in the units with which the axis values were reported in the + * motion event. Before comparing that velocity against the minimum fling velocity specified + * here, make sure that the {@link MotionEvent#AXIS_SCROLL} velocity from the tracker is + * calculated in "units per second" (see {@link VelocityTracker#computeCurrentVelocity(int)}, + * {@link VelocityTracker#computeCurrentVelocity(int, float)} to adjust your velocity + * computations to "per second"), and use {@link #getScaledVerticalScrollFactor} to change this + * velocity value to "pixels/second". + * + *
If the provided {@code inputDeviceId} is not valid, or if the input device whose ID is + * provided does not support the given motion event source and/or axis, this method will return + * {@code Integer.MAX_VALUE}. + * + *
inputDeviceId: if calling this method in response to a {@link MotionEvent}, use + * the device ID that is reported by the event, which can be obtained using + * {@link MotionEvent#getDeviceId()}. Otherwise, use a valid ID that is obtained from + * {@link InputDevice#getId()}, or from an {@link InputManager} instance + * ({@link InputManager#getInputDeviceIds()} gives all the valid input device IDs). + * + *
axis: a {@link MotionEvent} may report data for multiple axes, and each axis may + * have multiple data points for different pointers. Use the axis for which you obtained the + * velocity for ({@link VelocityTracker} lets you calculate velocities for a specific axis. Use + * the axis for which you calculated velocity). You can use + * {@link InputDevice#getMotionRanges()} to get all the {@link InputDevice.MotionRange}s for the + * {@link InputDevice}, from which you can derive all the valid axes for the device. + * + *
source: use {@link MotionEvent#getSource()} if calling this method in response to a + * {@link MotionEvent}. Otherwise, use a valid source for the {@link InputDevice}. You can use + * {@link InputDevice#getMotionRanges()} to get all the {@link InputDevice.MotionRange}s for the + * {@link InputDevice}, from which you can derive all the valid sources for the device. + * + * + *
This method optimizes calls over multiple input device IDs, so caching the return value of + * the method is not necessary if you are handling multiple input devices. + * + * @param inputDeviceId the ID of the {@link InputDevice} that generated the motion triggering + * fling. + * @param axis the axis on which the motion triggering the fling happened. This axis should be + * a valid axis that can be reported by the provided input device from the provided + * input device source. + * @param source the input source of the motion causing fling. This source should be a valid + * source for the {@link InputDevice} whose ID is {@code inputDeviceId}. + * + * @return the minimum velocity, in pixels/second, to trigger fling. + * + * @see InputDevice#getMotionRange(int, int) + * @see InputDevice#getMotionRanges() + * @see VelocityTracker#getAxisVelocity(int, int) + * @see VelocityTracker#getAxisVelocity(int) + */ + public int getScaledMinimumFlingVelocity(int inputDeviceId, int axis, int source) { + if (!isInputDeviceInfoValid(inputDeviceId, axis, source)) return NO_FLING_MIN_VELOCITY; + + if (source == InputDevice.SOURCE_ROTARY_ENCODER) return mMinimumRotaryEncoderFlingVelocity; + + return mMinimumFlingVelocity; + } + + /** + * Maximum absolute value of velocity to initiate a fling for a motion generated by an + * {@link InputDevice} with an id of {@code inputDeviceId}, from an input {@code source} and on + * a given motion event {@code axis}. + * + *
Similar to {@link #getScaledMinimumFlingVelocity(int, int, int)}, but for maximum fling
+ * velocity, instead of minimum. Also, unlike that method which returns
+ * {@code Integer.MAX_VALUE} for bad input device ID, source and/or motion event axis inputs,
+ * this method returns {@code Integer.MIN_VALUE} for such bad inputs.
+ */
+ public int getScaledMaximumFlingVelocity(int inputDeviceId, int axis, int source) {
+ if (!isInputDeviceInfoValid(inputDeviceId, axis, source)) return NO_FLING_MAX_VELOCITY;
+
+ if (source == InputDevice.SOURCE_ROTARY_ENCODER) return mMaximumRotaryEncoderFlingVelocity;
+
+ return mMaximumFlingVelocity;
+ }
+
+ private static boolean isInputDeviceInfoValid(int id, int axis, int source) {
+ InputDevice device = InputManager.getInstance().getInputDevice(id);
+ return device != null && device.getMotionRange(axis, source) != null;
+ }
+
/**
* Check if shortcuts should be displayed in menus.
*
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 37d5b84d242bf..1e3074c505e45 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -2674,6 +2674,14 @@