The X1 button.
The X1 button. This is typically the mouse Back button, but is often reconfigured. On Linux (GTK) this is unsupported. On Windows if advanced pointer software (such as IntelliPoint) is installed this doesn't register.
The Eraser pen button on PointerEvent supported devices only.
The X2 button.
The X2 button. This is typically the mouse Forward button, but is often reconfigured. On Linux (GTK) this is unsupported. On Windows if advanced pointer software (such as IntelliPoint) is installed this doesn't register.
The Middle Mouse button.
No buttons at all.
The Right Mouse button, or in PointerEvent devices a Pen contact with a barrel button.
Pointer Singleton