It may be convenient to clear the tag text field on enter for entering a new tag, but this way the user isn't able to rename a tag. Inconvenient.
Furthermore this time (on clearing the tag field) you don't ask if the user wishes to save the changes! To make it clear:
enter tag
enter substitution
click tag field
substitution and tag are lost
ultimately annoying
But this is the purpose of the dialog. Consider to introduce a new button labeled 'New'. The user usually has plenty of space on the screen. We are not Apple users. We can handle big dialogs with lots of buttons.
It may be convenient to clear the tag text field on enter for entering a new tag, but this way the user isn't able to rename a tag. Inconvenient.
Furthermore this time (on clearing the tag field) you don't ask if the user wishes to save the changes! To make it clear:
But this is the purpose of the dialog. Consider to introduce a new button labeled 'New'. The user usually has plenty of space on the screen. We are not Apple users. We can handle big dialogs with lots of buttons.