isPrimary property
The isPrimary read-only property of the
PointerEvent interface indicates whether or not the pointer device that
created the event is the primary pointer. It returns true if the
pointer that caused the event to be fired is the primary one and returns
false otherwise.
In a multi-pointer scenario (such as a touch screen that supports more than one touch point), this property is used to identify a master pointer among the set of active pointers for each pointer type. Only a primary pointer will produce compatibility mouse events. Authors who desire only single-pointer interaction can achieve that by ignoring non-primary pointers.
A pointer is considered primary if the pointer represents a mouse device.
A pointer
representing pen input is considered the primary pen input if its
Element.pointerdown_event event was dispatched when no other active
pointers representing
pen input existed. A pointer representing touch input is considered the
primary touch
input if its Element.pointerdown_event event was dispatched when no
other active pointers
representing touch input existed.
When two or more pointer device types are being used concurrently,
multiple pointers
(one for each PointerEvent.pointerType) are considered
primary. For example, a touch contact and a mouse cursor moved
simultaneously will
produce pointers that are both considered primary. If there are multiple
primary
pointers, these pointers will all produce compatibility mouse events
(see
Pointer_events for more information about pointer, mouse and touch
interaction).
Implementation
external bool get isPrimary;