Re: Could you comment on my little program? Thank you!
"Shawn" <shaw@nospam.com> wrote in message
news:eepln9$f2m$1@news.nems.noaa.gov...
I have finished my little gui program. Code is pasted below. Two things
I feel proud about my code:
(1)I wrote one class JMenuPower, subclass of JMenu. I can put objects of
JMenuItem, which will 1)automatically register ActionListener to "this"
object 2)setActionCommand to the String parameter passed in 3)put both
the actionCommand string and the Mapper reference into a HashMap for
later retrieval.
In conclusion, my JMenuPower class is in higher level than JMenu class.
JMenu class is like primitive class for me now.
So my brain can have less burden.
(2)When user clicks the different Menu Item, the corresponding operation
is evoked dynamically. I achieved this goal by using an interface
Mapper. So if I need to add one Menu Item, I only need to do two things:
a)
MenuItem m = new JMenuItem("new one");
memoMenu.addMenuItemAndListener(m, "newone", newoneMapper,
this); //throw it into my JMenuPower object, which takes care of the rest
b) //write the Maper do what I want to do
Mapper newoneMapper = new Mapper()
{
public void menuItemAction()
{
//put code here
}
};
Do you think I am twisting too much or I am doing correct thing?
[code snipped]
I don't think you should have the client code pass a string in, because
if the client unwittingly passes in the same string twice, that could screw
things up. Instad, your JMenuPower class should take care of generating a
unique identifier (not nescessarly a String) for every Mapper passed in.
I'd also probably use more anonymous classes. That is, instead of:
<oldCode>
Mapper newoneMapper = new Mapper() {
public void menuItemAction() {
//put code here
}
};
MenuItem m = new JMenuItem("new one");
memoMenu.addMenuItemAndListener(m, newoneMapper, this);
</oldCode>
I'd write:
<newCode>
MenuItem m = new JMenuItem("new one");
memoMenu.addMenuItemAndListener(m,
new Mapper() {
public void menuItemAction() {
//put code here
}
}, this);
</newCode>
Finally, what you've implemented is very similar to the "Command" design
pattern: http://en.wikipedia.org/wiki/Command_pattern
Sun's class library already has some facilities for exploiting the
command design pattern, using the Action interface and AbstractAction class.
To use it, you'd write code like:
<code>
AbstractAction someAction = new AbstractAction("Save to memo 1", iconSave) {
public void actionPerformed(ActionEvent ae) {
//put code here
}
}
MenuItem m = new JMenuItem(someAction);
</code>
- Oliver