Hi AWT and Swing teams,
Could you please review the updated fix:
http://cr.openjdk.java.net/~dmarkov/8039383/jdk9/webrev.02/
What has changed since version .01?
The issue was still reproducible with the .01 version of the fix,
however it was harder to reproduce.
So in version .02 I added checks for null where possible. If theme
becomes unavailable, a dummy value will be used; this way applications
will be more stable. As soon as the theme change events are handled, the
entire UI will update properly.
Thank you,
Alexey.
On 24.04.2014 16:23, Alexey Ivanov wrote:
Hi Anthony, AWT and Swing teams,
Here's the updated fix:
http://cr.openjdk.java.net/~dmarkov/8039383/jdk9/webrev.01/
Description:
In the new version of the fix, I use a new xpstyleEnabled field of
AtomicBoolean in WToolkit to track the current value of
"win.xpstyle.themeActive" desktop property. Its value is updated in
windowsSettingChange() and in updateProperties().
XPStyle.getXP() checks its cached value in themeActive and the current
value in WToolkit; if the value changes, it schedules updateAllUIs and
invalidates the current style right away, so that components would not
access data from the theme that became unavailable.
Two functions in ThemeReader also check this special field from
WToolkit which prevents throwing InternalError when paint is called
before theme change is fully handled.
Before updateAllUIs is invoked, it's possible that application will
paint with some values cached from the previous theme. Usually it
happens before "Theme change" dialog disappears from the screen, at
least I noticed no UI glitches during normal theme change.
Regression test:
No regression test is provided due to its complexity. Additionally,
whether NullPointerException or InternalError are thrown depends on
the order of event handling, sometimes exceptions do not occur when
changing theme of visual styles enabled theme to a classic theme.
Thank you,
Alexey.
On 18.04.2014 18:52, Anthony Petrov wrote:
Hi Alexey,
No, unfortunately I don't have any suggestions right now.
As for allowing executing user code on the toolkit thread, we can't
accept such a fix. Sorry about that.
--
best regards,
Anthony
On 4/18/2014 6:48 PM, Alexey Ivanov wrote:
Hi Anthony,
Thank you for your review.
Yes, user code can install a property change listener... It was my
concern too, that's why I explicitly noted about this.
Do you have any suggestion how this situation can be handled?
Is it a general rule that all desktop property change listeners must be
called on EDT?
Thanks,
Alexey.
On 18.04.2014 16:02, Anthony Petrov wrote:
Hi Alexey,
With this change, property "win.xpstyle.themeActive" change is fired
on the toolkit thread
Is it possible to install a change listener for this property from
user code, and hence eventually allow executing some user code on the
toolkit thread with your fix?
--
best regards,
Anthony
On 4/18/2014 12:09 PM, Alexey Ivanov wrote:
Hello Swing and AWT teams,
Could you please review the fix for jdk9:
bug: https://bugs.openjdk.java.net/browse/JDK-8039383
webrev:
http://cr.openjdk.java.net/~dmarkov/8039383/jdk9/webrev.00/
Problem description:
When changing Windows themes from a theme with visual styles (Windows
Aero or Windows Basic) to a classic one, NullPointerException
could be
thrown from Swing code during component tree validation, or
InternalError could be thrown during component painting.
Root cause:
Windows theme data are "cached" in XPStyle object. When the theme is
switched to a classic one, HTHEME handle becomes unavailable and data
cannot be accessed from the theme any more. The change in theme in
posted to EDT via invokeLater. At the same time, the UI needs to
repaint
itself as soon as Windows changed the theme, and paint code is often
called before the theme change is handled in Java. This leads to
NPE and
InternalError as the code tries to access the data that has become
unavailable.
The fix:
Update "win.xpstyle.themeActive" desktop property and invalidate the
cached XPStyle as soon as windowsSettingChange() is called from
native
code. Thus when Swing code needs to access theme data, it will see no
theme is available and will fallback to classic painting.
Note: Before the fix, PropertyChangeEvents for desktop properties in
Windows were fired on the Event Dispatch Thread. With this change,
property "win.xpstyle.themeActive" change is fired on the toolkit
thread; all other properties are changed on the EDT as before.
Regards,
Alexey.
