Built a this control this control can double-click the cell to edit the contents of this cell, but I think at the time of user to edit the content of cells, I gave him the default add some contents, such as user double-click or edit TAB to switch to the cell when I read this cell x y and then give him 111 this set a default text, double-click the good implementation, have a cellDoubleClicked signal can be judged double-click the grid, but what if the user is to use TAB, why I don't work, the signal itemActivated