Re: [access to instance of parent]Ridiculous question ?
Daniel Moyne wrote:
I thought there should have been an automatic record in the child
instance of the instance of the parent ; apparentltly java do not
care and it is up to the user to handle this as explained above.
The need for this may appear in the following case and I think this
is quite typical : - you have a parent instance with its own methods
; everything works fine but you think that part of the code can be
profitably used by others objects ; then you decide to create
Some_Class to handle this. - unfortunately by doing so you loose the
direct connection with the methods of the parent instance which in my
case are (for some of them) still needed - this especially may appear
in handling events that will then be transferred to the child
instance where the process may still need to call some methods of the
parent.
Is all this ridiculous like me where I think that I can formulate a
question on this list that make sense ? Regards.
Here's my ??0.02 worth ...
-----------------------------8<------------------------------
class Foo {
Foo() {
// blah
}
private void doThis() { ... }
private void doThat() { ... }
private Coffee makeCoffee() { ... }
private void saveWorld(Coffee cup) { ... }
private void getAway() { ... }
private void tryEverything() { ... }
private void init() {
saveWorld(makeCoffee());
}
}
-----------------------------8<------------------------------
You decide there's too much in Foo and that some methods may be useful
in other apps.
-----------------------------8<------------------------------
class Foo {
Foo() {
// blah
}
private void init() {
Bar bar = new Bar();
bar.saveWorld(bar.makeCoffee());
}
}
class Bar() {
private void doThis() { ... }
private void doThat() { ... }
private Coffee makeCoffee() { ... }
private void saveWorld() { ... }
private void getAway() { ... }
private void tryEverything() { ... }
}
-----------------------------8<------------------------------
Bar shouldn't need to know about Foo - else Bar would be unhelpfully
entangled with and dependent on Foo. We usually want as clean a
separation as is possible.
If Bar or it's methods need something, pass something of the
*appropriate* type to a constructor or method of Bar. Only very rarely
would/should that be an instance of Foo IMO. More likely a field of Foo
or (less likely) something it implements or something it extends.
--
RGB