DataKey
Index values for storing item details in QGraphicsItem using setData/data.
@ DATA_KEY_POSITION_HAS_CHANGED
Item type (i.e. image versus point)
@ DATA_KEY_GRAPHICS_ITEM_TYPE
Unique identifier for QGraphicsItem object
@ DATA_KEY_GHOST
True if item has changed since last mousePressEvent
QString dataKeyToString(DataKey dataKey)
const int INNER_RADIUS_MIN