Fwd: extragear/graphics/digikam/lib
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Fwd: extragear/graphics/digikam/lib
 
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Since we don't delete the pointer in the DCursorTracker, the error must have
been an invalid access due to a nullpointer. But QPointer should help us here, too. If not, we might need to check in every method of DCursorTracker if the parent pointer is still valid. Right? Andi SVN commit 1030535 by aclemens: I experienced a crash in DCursorTracker, I guess due to the fact that the parent widget was deleted before the DCursorTracker was destroyed. I was not able to reproduce it anymore, but as the Qt docs describe, it is always better to use a QPointer when saving pointers of other widgets inside a class. These pointers will keep track of all references and destroy themselves (set themselves to NULL) when all references are gone. This should avoid the crash I experienced in here. M +6 -5 dcursortracker.cpp --- trunk/extragear/graphics/digikam/libs/widgets/common/dcursortracker.cpp #1030534:1030535 @@ -32,6 +32,7 @@ #include <QFrame> #include <QLabel> #include <QMouseEvent> +#include <QPointer> #include <QTimer> #include <QToolTip> @@ -55,11 +56,11 @@ parent = 0; } - Qt::Alignment alignment; - bool enable; - bool keepOpen; - QTimer* autoHideTimer; - QWidget* parent; + Qt::Alignment alignment; + bool enable; + bool keepOpen; + QTimer* autoHideTimer; + QPointer<QWidget> parent; }; DCursorTracker::DCursorTracker(const QString& txt, QWidget *parent, Qt::Alignment align) _______________________________________________ Digikam-devel mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-devel |
Re: Fwd: extragear/graphics/digikam/lib
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With GDB, the backtrace must said parent=0x0. It's clear... else
pointer is a dumy valid. Yes QPointer must reset parent addess to zero when parent widget is deleted... Gilles 2009/10/2 Andi Clemens <[hidden email]>: > Since we don't delete the pointer in the DCursorTracker, the error must have > been an invalid access due to a nullpointer. > But QPointer should help us here, too. > If not, we might need to check in every method of DCursorTracker if the parent > pointer is still valid. > Right? > > Andi > > > ---------- Message transféré ---------- > From: Andi Clemens <[hidden email]> > To: [hidden email] > Date: Fri, 02 Oct 2009 13:28:30 +0000 > Subject: extragear/graphics/digikam/libs/widgets/common > SVN commit 1030535 by aclemens: > > I experienced a crash in DCursorTracker, I guess due to the fact that the > parent widget was deleted before the DCursorTracker was destroyed. > I was not able to reproduce it anymore, but as the Qt docs describe, it is > always better to use a QPointer when saving pointers of other widgets inside a > class. These pointers will keep track of all references and destroy themselves > (set themselves to NULL) when all references are gone. > This should avoid the crash I experienced in here. > > M +6 -5 dcursortracker.cpp > > > --- trunk/extragear/graphics/digikam/libs/widgets/common/dcursortracker.cpp #1030534:1030535 > @@ -32,6 +32,7 @@ > #include <QFrame> > #include <QLabel> > #include <QMouseEvent> > +#include <QPointer> > #include <QTimer> > #include <QToolTip> > > @@ -55,11 +56,11 @@ > parent = 0; > } > > - Qt::Alignment alignment; > - bool enable; > - bool keepOpen; > - QTimer* autoHideTimer; > - QWidget* parent; > + Qt::Alignment alignment; > + bool enable; > + bool keepOpen; > + QTimer* autoHideTimer; > + QPointer<QWidget> parent; > }; > > DCursorTracker::DCursorTracker(const QString& txt, QWidget *parent, Qt::Alignment align) > > _______________________________________________ > Digikam-devel mailing list > [hidden email] > https://mail.kde.org/mailman/listinfo/digikam-devel > > Digikam-devel mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-devel |
Re: Fwd: extragear/graphics/digikam/lib
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Unfortuantely I had no backtrace, I was using a release build for performance
tests. Well anyway using QPointer AND checking for valid pointer in moveToParent() should avoid any possible crash now. Andi On Friday 02 October 2009 15:39:46 Gilles Caulier wrote: > With GDB, the backtrace must said parent=0x0. It's clear... else > pointer is a dumy valid. > > Yes QPointer must reset parent addess to zero when parent widget is > deleted... > > Gilles > > 2009/10/2 Andi Clemens <[hidden email]>: > > Since we don't delete the pointer in the DCursorTracker, the error must > > have been an invalid access due to a nullpointer. > > But QPointer should help us here, too. > > If not, we might need to check in every method of DCursorTracker if the > > parent pointer is still valid. > > Right? > > > > Andi > > > > > > ---------- Message transféré ---------- > > From: Andi Clemens <[hidden email]> > > To: [hidden email] > > Date: Fri, 02 Oct 2009 13:28:30 +0000 > > Subject: extragear/graphics/digikam/libs/widgets/common > > SVN commit 1030535 by aclemens: > > > > I experienced a crash in DCursorTracker, I guess due to the fact that the > > parent widget was deleted before the DCursorTracker was destroyed. > > I was not able to reproduce it anymore, but as the Qt docs describe, it > > is always better to use a QPointer when saving pointers of other widgets > > inside a class. These pointers will keep track of all references and > > destroy themselves (set themselves to NULL) when all references are gone. > > This should avoid the crash I experienced in here. > > > > M +6 -5 dcursortracker.cpp > > > > > > --- > > trunk/extragear/graphics/digikam/libs/widgets/common/dcursortracker.cpp > > #1030534:1030535 @@ -32,6 +32,7 @@ > > #include <QFrame> > > #include <QLabel> > > #include <QMouseEvent> > > +#include <QPointer> > > #include <QTimer> > > #include <QToolTip> > > > > @@ -55,11 +56,11 @@ > > parent = 0; > > } > > > > - Qt::Alignment alignment; > > - bool enable; > > - bool keepOpen; > > - QTimer* autoHideTimer; > > - QWidget* parent; > > + Qt::Alignment alignment; > > + bool enable; > > + bool keepOpen; > > + QTimer* autoHideTimer; > > + QPointer<QWidget> parent; > > }; > > > > DCursorTracker::DCursorTracker(const QString& txt, QWidget *parent, > > Qt::Alignment align) > > > > _______________________________________________ > > Digikam-devel mailing list > > [hidden email] > > https://mail.kde.org/mailman/listinfo/digikam-devel > > _______________________________________________ > Digikam-devel mailing list > [hidden email] > https://mail.kde.org/mailman/listinfo/digikam-devel > Digikam-devel mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-devel |
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