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This is an automatically generated e-mail. To reply, visit:
<a href="https://git.reviewboard.kde.org/r/125208/">https://git.reviewboard.kde.org/r/125208/</a>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Can you comment on a proposed Qt fix for this issue, which would remove the need for the delayed show workaround?</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">https://codereview.qt-project.org/144710</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">(please comment there, not here).</p></pre>
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<p>- David Faure</p>
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<p>On September 30th, 2015, 6:04 p.m. UTC, Xuetian Weng wrote:</p>
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<div>Review request for KDE Frameworks, David Faure and Jean-Baptiste Mardelle.</div>
<div>By Xuetian Weng.</div>
<p style="color: grey;"><i>Updated Sept. 30, 2015, 6:04 p.m.</i></p>
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<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://bugs.kde.org/show_bug.cgi?id=350758">350758</a>
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<b style="color: #575012; font-size: 10pt;">Repository: </b>
frameworkintegration
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><ol style="padding: 0;text-rendering: inherit;margin: 0 0 0 2em;line-height: inherit;white-space: normal;">
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<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">The directly reason of 350758 is https://bugreports.qt.io/browse/QTBUG-48248, which seems to be a Qt problem. See the code example. One possible to avoid this is to remove the m_dialog->hide().</p>
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<li style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: normal;">
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Why hide() is needed in the first place?
If one runs dialog.show() and dialog.exec(), it should works. So there is something happened in between the calls to KDEPlatformFileDialogHelper::show() and KDEPlatformFileDialogHelper::exec().</p>
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<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">The real reason is the platform dialog helper doesn't expect that user may use "Qt" dialog to implement it.
https://github.com/qtproject/qtbase/blob/5bfac9d653357c906946563b9494d7ae69cdad92/src/widgets/dialogs/qfiledialog.cpp#L845
here it sets Qt::WA_DontShowOnScreen on the actual dialog.</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">https://github.com/qtproject/qtbase/blob/5bfac9d653357c906946563b9494d7ae69cdad92/src/widgets/dialogs/qfiledialog.cpp#L868</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">and call QDialog::setVisible() here</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">https://github.com/qtproject/qtbase/blob/17d6b2d1f02e5f679008d97036befd713025a0f2/src/widgets/dialogs/qdialog.cpp#L713</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Thus it will by pass the check, and QDialog will actually show an invisible qdialog. I assume https://git.reviewboard.kde.org/r/123335/ tries to solve this issue by "steal" the focus from that invisible dialog by hide our dialog and show it again.</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">It makes some sense for Qt with "real" native dialog which is not controlled by Qt, because this invisble dialog helps Qt to aware that there's a modal dialog, but doesn't work for our case since our dialog is also a QDialog.</p>
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<li style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: normal;">To avoid calling hide() in exec()
I'd rather to see that KDEPlatformFileDialogHelper::show() is not called in QDialog::exec(), but that's not gonna happen anytime soon. So here I used a trick with QTimer to delegate the call to show() to next event.</li>
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<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">I uses QTimer instead of QMetaObject::invoke here, because we can discard the "m_dialog->show()" if hide() or exec() is called immediately. (Actually we don't need to discard the one in exec(), but we can save a call to m_dialog->show() if we discard it.)</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Before this change, the calling sequence is </p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">m_dialog->show();
The dummy dialog setVisible(true);
m_dialog->hide();
m_dialog->exec();</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">After this change, it becomes
The dummy dialog setVisible(true);
m_dialog->exec();</p>
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<li style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: normal;">Required changes to autotest
QTest::qWaitForWindowExposed(fw->window()) is added to some necessary places.</li>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">not able to reproduce the bug.</p></pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>autotests/kfiledialog_unittest.cpp <span style="color: grey">(0d4c816)</span></li>
<li>autotests/kfiledialogqml_unittest.cpp <span style="color: grey">(f805ef2)</span></li>
<li>src/platformtheme/kdeplatformfiledialogbase.cpp <span style="color: grey">(8e696bd)</span></li>
<li>src/platformtheme/kdeplatformfiledialogbase_p.h <span style="color: grey">(5936dfb)</span></li>
<li>src/platformtheme/kdeplatformfiledialoghelper.h <span style="color: grey">(dfbbed1)</span></li>
<li>src/platformtheme/kdeplatformfiledialoghelper.cpp <span style="color: grey">(94f2059)</span></li>
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<p><a href="https://git.reviewboard.kde.org/r/125208/diff/" style="margin-left: 3em;">View Diff</a></p>
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