Re: Field name from "this"

Brandon McCombs <>
Wed, 18 Oct 2006 22:33:07 GMT
G. Ralph Kuntz, MD wrote:

I am trying to find a way to get a field's name (variable name) given a
pointer to "this".

I am trying to log all user actions in an application. In every case
where a JButton appears in my app, I use a subclass:

JButton aButton = new MyButton();

I can modify the constructor for MyButton to automatically log when the
button is clicked by adding an ActionListener. I would like to print
the class of the containing window (JDialog or JFrame) and the variable
name of the button. This way I can recreate what the user clicked.

I realize that I could use getClass().getFields() and loop thought the
Field[] until I find "this" then use Field.getName(), but I was hoping
for a faster way (less impact on performance).

Any ideas?

I did this when using textfields to know which textfield currently had
focus which would dictate which attribute from an object class to
modify. I made a custom textfield class that implemented FocusListener.
Each time focusGained() was called it set the value of a global variable
which contained the name of the field that I set during the field's
instantiating using setName(). This has worked for me for dialogs where
the # of textfields was unknown and could vary from 1 to 50 or more.

I also had a document listener for the textfields so that when a change
was detected in the fields' text I'd grab the value of my global
variable to determine which field was modified and the text in the field
was the new value for the attribute that corresponded to that field. I
found the attribute in a vector by searching for its name(from the
global variable) and assigned it the new value. Later I saved all the
attribute data back to the LDAP server.

There are probably better ways but that's just an idea that may work for
you in a bind.

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