Function handling "down" events. If the function returns true then a drag
sequence is started.
handleDragEvent
function
<optional>
Function handling "drag" events. This function is called on "move" events
during a drag sequence.
handleEvent
function
<optional>
Method called by the map to notify the interaction that a browser event was
dispatched to the map. The function may return false to prevent the
propagation of the event to other interactions in the map's interactions
chain.
handleMoveEvent
function
<optional>
Function handling "move" events. This function is called on "move" events,
also during a drag sequence (so during a drag sequence both the
handleDragEvent function and this function are called).
handleUpEvent
function
<optional>
Function handling "up" events. If the function returns false then the
current drag sequence is stopped.
stopDown
function
<optional>
Should the down event be propagated to other interactions, or should be
stopped?