[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-frameworks-devel
Subject:    Re: Review Request 125208: Workaround bug 350758
From:       "Luigi Toscano" <luigi.toscano () tiscali ! it>
Date:       2015-09-12 23:54:49
Message-ID: 20150912235449.24667.50927 () mimi ! kde ! org
[Download RAW message or body]

--===============8874131114689584953==
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/125208/#review85303
-----------------------------------------------------------


I can't help with the content of the bug, but I would suggest to change the review \
summary. The current one does not give many information on the issue and I bet many \
people simply skipped the email notification (and less useful for searches).

- Luigi Toscano


On Set. 12, 2015, 11:40 p.m., Xuetian Weng wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/125208/
> -----------------------------------------------------------
> 
> (Updated Set. 12, 2015, 11:40 p.m.)
> 
> 
> Review request for KDE Frameworks, David Faure and Jean-Baptiste Mardelle.
> 
> 
> Bugs: 350758
> https://bugs.kde.org/show_bug.cgi?id=350758
> 
> 
> Repository: frameworkintegration
> 
> 
> Description
> -------
> 
> 1. The reason of 350758: https://bugreports.qt.io/browse/QTBUG-48248 , I just tried \
> to reproduce it with pure Qt code. If a dialog called against show, hide, and exec \
> one immediately after another, the dialog may not show up. 
> 2. Why hide() is needed in the first place?
> If one runs dialog.show() and dialog.exec(), it usually works. So there is \
> something happened in between KDEPlatformFileDialogHelper::show() and \
> KDEPlatformFileDialogHelper::exec(). 
> 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.
> 
> https://github.com/qtproject/qtbase/blob/5bfac9d653357c906946563b9494d7ae69cdad92/src/widgets/dialogs/qfiledialog.cpp#L868
>  
> and call QDialog::setVisible() here
> 
> https://github.com/qtproject/qtbase/blob/17d6b2d1f02e5f679008d97036befd713025a0f2/src/widgets/dialogs/qdialog.cpp#L713
>  
> Thus it will by pass the first check, and QDialog will actually show an invisible \
> qdialog with it. I assume https://git.reviewboard.kde.org/r/123335/ tries to solve \
> this issue by "steal" the focus from that invisible dialog by hide it first. 
> It makes some sense for Qt with "real" native dialog, because this invisble dialog \
> helps Qt to aware that there's a modal dialog, but doesn't work for our case.  
> 3. 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. So here I used a trick with QTimer to \
> delegate the show to next event when calling to \
> KDEPlatformFileDialogHelper::show(). 
> 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.) 
> Before this change, the calling sequence on m_dialog is 
> 
> m_dialog->show();
> The dummy dialog setVisible(true);
> m_dialog->hide();
> m_dialog->exec();
> 
> After this change, it becomes
> The dummy dialog setVisible(true);
> m_dialog->exec();
> 
> 4. Required changes to autotest
> QTest::qWaitForWindowExposed(fw->window()) is added to some necessary places.
> 
> 
> Diffs
> -----
> 
> autotests/kfiledialog_unittest.cpp 0d4c816 
> autotests/kfiledialogqml_unittest.cpp f805ef2 
> src/platformtheme/kdeplatformfiledialogbase.cpp 8e696bd 
> src/platformtheme/kdeplatformfiledialogbase_p.h 5936dfb 
> src/platformtheme/kdeplatformfiledialoghelper.h dfbbed1 
> src/platformtheme/kdeplatformfiledialoghelper.cpp 94f2059 
> 
> Diff: https://git.reviewboard.kde.org/r/125208/diff/
> 
> 
> Testing
> -------
> 
> not able to reproduce the bug.
> 
> 
> Thanks,
> 
> Xuetian Weng
> 
> 


--===============8874131114689584953==
MIME-Version: 1.0
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: 7bit




<html>
 <body>
  <div style="font-family: Verdana, Arial, Helvetica, Sans-Serif;">
   <table bgcolor="#f9f3c9" width="100%" cellpadding="12" style="border: 1px #c9c399 \
solid; border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px;">  \
<tr>  <td>
      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>
  </td>
    </tr>
   </table>
   <br />





 <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;">I \
can't help with the content of the bug, but I would suggest to change the review \
summary. The current one does not give many information on the issue and I bet many \
people simply skipped the email notification (and less useful for \
searches).</p></pre>  <br />









<p>- Luigi Toscano</p>


<br />
<p>On settembre 12th, 2015, 11:40 p.m. CEST, Xuetian Weng wrote:</p>








<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="12" style="border: \
1px #888a85 solid; border-radius: 6px; -moz-border-radius: 6px; \
-webkit-border-radius: 6px;">  <tr>
  <td>

<div>Review request for KDE Frameworks, David Faure and Jean-Baptiste Mardelle.</div>
<div>By Xuetian Weng.</div>


<p style="color: grey;"><i>Updated Set. 12, 2015, 11:40 p.m.</i></p>







<div style="margin-top: 1.5em;">
 <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>


</div>



<div style="margin-top: 1.5em;">
 <b style="color: #575012; font-size: 10pt;">Repository: </b>
frameworkintegration
</div>


<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
 <table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0">  <tr>
  <td>
   <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;"> <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;">The \
reason of 350758: https://bugreports.qt.io/browse/QTBUG-48248 , I just tried to \
reproduce it with pure Qt code. If a dialog called against show, hide, and exec one \
immediately after another, the dialog may not show up.</p> </li>
<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 usually works. So there is \
something happened in between KDEPlatformFileDialogHelper::show() and \
KDEPlatformFileDialogHelper::exec().</p> </li>
</ol>
<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 first check, and QDialog will \
actually show an invisible qdialog with it. I assume \
https://git.reviewboard.kde.org/r/123335/ tries to solve this issue by "steal" the \
focus from that invisible dialog by hide it first.</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, because this invisble dialog helps \
Qt to aware that there's a modal dialog, but doesn't work for our case. </p> <ol \
style="padding: 0;text-rendering: inherit;margin: 0 0 0 2em;line-height: \
inherit;white-space: normal;"> <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. So here I used a trick with QTimer to \
delegate the show to next event when calling to \
KDEPlatformFileDialogHelper::show().</li> </ol>
<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-&gt;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-&gt;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 on m_dialog is </p> <p \
style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: \
inherit;">m_dialog-&gt;show(); The dummy dialog setVisible(true);
m_dialog-&gt;hide();
m_dialog-&gt;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-&gt;exec();</p>
<ol style="padding: 0;text-rendering: inherit;margin: 0 0 0 2em;line-height: \
inherit;white-space: normal;"> <li style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: normal;">Required changes to autotest \
QTest::qWaitForWindowExposed(fw-&gt;window()) is added to some necessary places.</li> \
</ol></pre>  </td>
 </tr>
</table>


<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0">  <tr>
  <td>
   <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>  </td>
 </tr>
</table>


<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">

 <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>

</ul>

<p><a href="https://git.reviewboard.kde.org/r/125208/diff/" style="margin-left: \
3em;">View Diff</a></p>






  </td>
 </tr>
</table>







  </div>
 </body>
</html>


--===============8874131114689584953==--


[Attachment #3 (text/plain)]

_______________________________________________
Kde-frameworks-devel mailing list
Kde-frameworks-devel@kde.org
https://mail.kde.org/mailman/listinfo/kde-frameworks-devel


[prev in list] [next in list] [prev in thread] [next in thread]

Configure | About | News | Add a list | Sponsored by KoreLogic