the option "Stretch type" doesn't matter, just leave it at "No stretch". Just checking the "stretch with overflow" option should make the textfield resize to show all the text. Maybe the textfield is resizing but you have another element (textfield, static text, whatever...) just below the textfield which is overlapping the textfield when it resizes? Checking the "stretch with overflow" option only tells the textfield to resize, but it doesn't make the elements below the textfield to "go down". If you want that behaviour for those elements you should set the option "Position type" to "Float" in all of them.