On 11/16/2012 4:10 PM, Jaroslav Tulach wrote:
Hello Alexander,
thanks for your reply. The source code for NetBeans TreeView component is
available here:
http://hg.netbeans.org/main-
golden/file/ccea2dfe47eb/openide.explorer/src/org/openide/explorer/view/TreeView.java
I'll be glad for any review, however I am also positively pleased by your
answer:
Is it possible to know from the filled NB issues which NB
module/component has been used when the NPE occures?
Or could you point any NB panel where the TreeView is used.
The ui.getPathBounds(tree, newPath) method definitely can return
null so it needs to have this check.
Should I start working on a webrev, so (in case you don't find any violation of
good Swing practices in TreeView) we can eliminate this NPE once and forever?
Yes, please.
What should be part of such webrev? Just the NPE check? Or do you want some
test, change in documentation, etc.?
The fix should check the NPE and may be do some possible default
actions in this case.
It is a good idea to add an automated test but it can be possible
if there are known steps which reproduce the issue.
At least you can run the test/javax/swing/JTree automated test to
check possible regressions.
Thanks,
Alexandr.
Thanks again for your comments.
-jt
Dne Pá 16. listopadu 2012 15:30:00, Alexander Scherbatiy napsal(a):
On 11/15/2012 7:58 PM, Jaroslav Tulach wrote:
Dear Swing maintainers,
my name is Jaroslav Tulach and I am maintaining NetBeans explorer - a
component that is using JTree heavily.
From time to time I receive a user report with a NPE from Swing where
little>
or even no NetBeans code involved. Just today I got
http://netbeans.org/bugzilla/show_bug.cgi?id=222081
We have about 35 other ones (which is not that much given the fact we have
million of users), but still...
According to
http://statistics.netbeans.org/exceptions/exception.do?id=628832
the report comes from jdk7u9-b05. The source code is here
http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/jdk7u9-
b05/src/share/classes/javax/swing/plaf/basic/BasicTreeUI.java
and thus it looks like the call on line 4468 to
ui.getPathBounds(tree, newPath);
can return null (under some rare and unknown circumstances).
I can close the bug #222081 as "worksforme", but it is clear that such
error happens from time to time and we don't want our users to face
errors. A simple:
4469 if (newRect == null) return;
would do the trick. One question remains: if I try to donate such patch,
will you accept it?
The ui.getPathBounds(tree, newPath) method definitely can return
null so it needs to have this check.
However, such fix can mask the real issue, for example, in the
treeState.getBounds() method where the treeState can be instance of
FixedHeightLayoutCache or VariableHeightLayoutCache class.
If it is possible, could you send a code snippet that shows how
NetBeans uses JTree? May be it can give a hint what can be wrong in this
case.
Thanks,
Alexandr.
-jt
