setInputMask prevent the use of spaces and avoid the sense that something's written

[hakermania]

Hello.
I have a lineedit and I have set its input mask to nnnnnn (numbers+letters) but I have two major problems:
1) I don't want when I click to the lineedit the cursor to go to the end(it goes to the X position where X is the number of the 'nnnn' I have set to the input mask), as there is something written to the lineedit, while it isn't.
2) I want also to prevent the user from inputting spaces, is this possible?