const val EDGE_TYPE_INSIDE = 0: Int

Edge type that specifies an activation area starting at the view bounds and extending inward. Moving outside the view bounds will stop scrolling.

const val EDGE_TYPE_INSIDE_EXTEND = 1: Int

Edge type that specifies an activation area starting at the view bounds and extending inward. After activation begins, moving outside the view bounds will continue scrolling.

const val EDGE_TYPE_OUTSIDE = 2: Int

Edge type that specifies an activation area starting at the view bounds and extending outward. Moving inside the view bounds will stop scrolling.

const val NO_MAX = 3.4028235E38f: Float

Constant passed to setMaximumEdges, setMaximumVelocity, or setMinimumVelocity. Using this value ensures that the computed relative value is always used without constraining to a particular minimum or maximum value.

const val NO_MIN = 0.0f: Float

Constant passed to setMaximumEdges, or setMaximumVelocity, or setMinimumVelocity. Using this value ensures that the computed relative value is always used without constraining to a particular minimum or maximum value.

const val RELATIVE_UNSPECIFIED = 0.0f: Float

Constant passed to setRelativeEdges or setRelativeVelocity. Using this value ensures that the computed relative value is ignored and the absolute maximum value is always used.

AutoScrollHelper(target: View)

Creates a new helper for scrolling the specified target view.

The resulting helper may be configured by chaining setter calls and should be set as a touch listener on the target view.

By default, the helper is disabled and will not respond to touch events until it is enabled using setEnabled.

abstract fun canTargetScrollHorizontally(direction: Int): Boolean

Override this method to return whether the target view can be scrolled horizontally in a certain direction.

abstract fun canTargetScrollVertically(direction: Int): Boolean

Override this method to return whether the target view can be scrolled vertically in a certain direction.

fun isExclusive(): Boolean

Indicates whether the scroll helper handles touch events exclusively during scrolling.

fun onTouch(v: View!, event: MotionEvent!): Boolean

Handles touch events by activating automatic scrolling, adjusting scroll velocity, or stopping.

If isExclusive is false, always returns false so that the host view may handle touch events. Otherwise, returns true when automatic scrolling is active and false otherwise.

abstract fun scrollTargetBy(deltaX: Int, deltaY: Int): Unit

Override this method to scroll the target view by the specified number of pixels.

fun setActivationDelay(delayMillis: Int): AutoScrollHelper

Sets the delay after entering an activation edge before activation of auto-scrolling. By default, the activation delay is set to getTapTimeout.

Specifying a delay of zero will start auto-scrolling immediately after the touch position enters an activation edge.

fun setEdgeType(type: Int): AutoScrollHelper

Sets the activation edge type, one of:

• EDGE_TYPE_INSIDE for edges that respond to touches inside the bounds of the host view. If touch moves outside the bounds, scrolling will stop.
• EDGE_TYPE_INSIDE_EXTEND for inside edges that continued to scroll when touch moves outside the bounds of the host view.
• EDGE_TYPE_OUTSIDE for edges that only respond to touches that move outside the bounds of the host view.

fun setEnabled(enabled: Boolean): AutoScrollHelper!

Sets whether the scroll helper is enabled and should respond to touch events.

fun setExclusive(exclusive: Boolean): AutoScrollHelper!

Enables or disables exclusive handling of touch events during scrolling. By default, exclusive handling is disabled and the target view receives all touch events.

When enabled, onTouch will return true if the helper is currently scrolling and false otherwise.

fun setMaximumEdges(horizontalMax: Float, verticalMax: Float): AutoScrollHelper

Sets the absolute maximum edge size.

If relative edge size is not specified, activation edges will always be the maximum edge size. If both relative and maximum edges are specified, the maximum edge will be used to constrain the calculated relative edge size.

fun setMaximumVelocity(horizontalMax: Float, verticalMax: Float): AutoScrollHelper

Sets the absolute maximum scrolling velocity.

If relative velocity is not specified, scrolling will always reach the same maximum velocity. If both relative and maximum velocities are specified, the maximum velocity will be used to clamp the calculated relative velocity.

fun setMinimumVelocity(horizontalMin: Float, verticalMin: Float): AutoScrollHelper

Sets the absolute minimum scrolling velocity.

If both relative and minimum velocities are specified, the minimum velocity will be used to clamp the calculated relative velocity.

fun setRampDownDuration(durationMillis: Int): AutoScrollHelper

Sets the amount of time after de-activation of auto-scrolling that is takes to slow to a stop.

Specifying a duration greater than zero prevents sudden jumps in velocity.

fun setRampUpDuration(durationMillis: Int): AutoScrollHelper

Sets the amount of time after activation of auto-scrolling that is takes to reach target velocity for the current touch position.

Specifying a duration greater than zero prevents sudden jumps in velocity.

fun setRelativeEdges(horizontal: Float, vertical: Float): AutoScrollHelper

Sets the activation edge size relative to the host view's dimensions.

If both relative and maximum edges are specified, the maximum edge will be used to constrain the calculated relative edge size.

fun setRelativeVelocity(horizontal: Float, vertical: Float): AutoScrollHelper

Sets the target scrolling velocity relative to the host view's dimensions.

If both relative and maximum velocities are specified, the maximum velocity will be used to clamp the calculated relative velocity.