Regarding the focusGained and iteratorBindingChange events

Question

Dear Jdev/JClient team,
I'm trying to build up a self-style API based upon the
JClient classes to emulate more or less the mechanisms
of the Developer tool. My first efforts were to match
next concepts:
JUApplication <---> Application (Frame)
JPanelBinding <---> Form
JUIteratorBinding <---> Block
Moreover, I'm using my own toolbar that I want it to
act at application level. This toolbar uses the
JUActionBinding dynamically because it's able to target
the current panel binding "in focus". I'm also intercepting
the focusGained events to perform the typical navigation
triggers in Developer: WHEN-NEW-ITEM-INSTANCE,
WHEN-NEW-RECORD-INSTANCE, WHEN-NEW-BLOCK-INSTANCE and
WHEN-NEW-FORM-INSTANCE.
In this context, I have some major concerns:
1) I've reading about the next 9.0.3 version, and I'm very
interested, and quite worried, about possible changes
in the way the focusGained and iteratorBindingChange
events will be delivered. I mean, these events will be
delivered in the same situations in the next version??
Knowledge about this is vital due to the fact that my
API relies in the JClient current behavior.
2) Regarding the structure of bindings, I've read and
I've seen that the JPanelBinding really don't act
at "Form" level. That is, you can associate all your
panels to only one JPanelBinding. However, I prefer
to use one JPanelBinding for each "Form". In this
context, I have the next particular problem. I have
two or more JUPanelBinding and I have a class that
implements the JUNavigationBarInterface to track
the current JUIteratorBinding by registering itself to
all these JUPanelBinding, and one of these JUPanelBinding
has only one JUIteratorBinding. In this case, when
I navigate to this last JUPanelBinding from another one
I don't receive the iteratorBindingChange event.
Browsing the source code this is "normal" because a
JUPanelBinding with only one JUIteratorBinding is
expected to delivered this event once. However, this
mechanism seems very restrictive (or maybe a bug). The
problem seems to be that the standard toolbar are
expected to receive these events and track the iterator
binding, and this standard toolbar only acts at
JUIteratorBinding or JUPanelBinding level. Nevertheless,
I want a toolbar that can share all the panel bindings!!
Is this something you plan to change in 9.0.3? is this
a bug? a non-supported functionality? What can I do?
I'm thinking in ignoring the iteratorBindingChange
events and generating them by myself upon receiving
the focusGained events which act at JUApplication level.
Is this a good idea? Will this be compatible with 9.0.3?
The next piece of code is part of the current implementation
of the JUPanelBinding. You can see that the mNavBarInit
variable make the class to only deliver the iteratorBindingChange
event once if we have only one JUIteratorBinding. This is
issue I'm referring to.
public void focusGained(...)
if (mNavigationBarList != null)
JUIteratorBinding currentIter = null;
ArrayList al = getIterBindingList();
if (al.size() > 1)
//this could be optimized by keeping track of current iterator.
currentIter = iterBinding;
else if (!mNavBarInit)
mNavBarInit = true;
currentIter = (JUIteratorBinding)al.get(0);
if (currentIter != null)
al = mNavigationBarList;
for (int i = 0; i < al.size(); i++)
((JUNavigationBarInterface)al.get(i)).iteratorBindingChanged(currentIter);
I would appreciate any comments, advice or information you
can address to me.
Thanks in advance.
Jaume Espriu
Software engineer
[email protected]
SAME S.I. S.A.

Answer 1

1) I've reading about the next 9.0.3 version, and I'm very
interested, and quite worried, about possible changes
in the way the focusGained and iteratorBindingChange
events will be delivered. I mean, these events will be
delivered in the same situations in the next version??
Knowledge about this is vital due to the fact that my
API relies in the JClient current behavior. I'm not sure where you get the "impression" that raising of focusGained and iteratorBindingChanged events will be changed?
- focusGained is generated by Swing and should stay the same. JClient does not raise/block raising of this event.
- iteratorBindingChanged event is generated by JClient when the RowSetIterator for an iteratorBinding is changed
No bugs were fixed/resolved for this area of the code.
2) Regarding the structure of bindings, I've read and
I've seen that the JPanelBinding really don't act
at "Form" level. That is, you can associate all your
panels to only one JPanelBinding. However, I prefer
to use one JPanelBinding for each "Form". In this
context, I have the next particular problem. I have
two or more JUPanelBinding and I have a class that
implements the JUNavigationBarInterface to track
the current JUIteratorBinding by registering itself to
all these JUPanelBinding, and one of these JUPanelBinding
has only one JUIteratorBinding. In this case, when
I navigate to this last JUPanelBinding from another one
I don't receive the iteratorBindingChange event.
Browsing the source code this is "normal" because a
JUPanelBinding with only one JUIteratorBinding is
expected to delivered this event once. However, this
mechanism seems very restrictive (or maybe a bug). The
problem seems to be that the standard toolbar are
expected to receive these events and track the iterator
binding, and this standard toolbar only acts at
JUIteratorBinding or JUPanelBinding level. Nevertheless,
I want a toolbar that can share all the panel bindings!!
Is this something you plan to change in 9.0.3?No.
is this
a bug? a non-supported functionality? What can I do?You may want to implement some kind of focus changed mechanism where you "common" toolbar is notified of the current panel in focus so that it can then update it's iterator binding to current panel's iterator binding.
Default raising of the event iteratorBindingChanged(), is only within the context of one JUPanelBinding instance.
I'm thinking in ignoring the iteratorBindingChange
events and generating them by myself upon receiving
the focusGained events which act at JUApplication level.
Is this a good idea? Will this be compatible with 9.0.3?I believe so.
The next piece of code is part of the current implementation
of the JUPanelBinding. You can see that the mNavBarInit
variable make the class to only deliver the iteratorBindingChange
event once if we have only one JUIteratorBinding. This is
issue I'm referring to.
public void focusGained(...)
if (mNavigationBarList != null)
JUIteratorBinding currentIter = null;
ArrayList al = getIterBindingList();
if (al.size() > 1)
//this could be optimized by keeping track of current iterator.
currentIter = iterBinding;
else if (!mNavBarInit)
mNavBarInit = true;
currentIter = (JUIteratorBinding)al.get(0);
if (currentIter != null)
al = mNavigationBarList;
for (int i = 0; i < al.size(); i++)
((JUNavigationBarInterface)al.get(i)).iteratorBindingChanged(currentIter);
I would appreciate any comments, advice or information you
can address to me.
Thanks in advance.
Jaume Espriu
Software engineer
[email protected]
SAME S.I. S.A.