Layer.onKeyUp

The value of the virtual key code for the released key.

This is the state of shift keys and mouse buttons that were pressed at the same time when the keys were released.
It is a combination of the following values by bit OR.

• ssAlt : The ALT key was pressed
• ssShift : The SHIFT key was pressed
• ssCtrl : CTRL key was pressed
• ssLeft : The left mouse button was pressed
• ssMiddle : The middle mouse button was pressed
• ssRight : The right mouse button was pressed

If you pass false to this argument when calling onKeyUp of the parent class, the parent class will not do the default processing for that key (such as moving focus).