Hi William,<br><br><div class="gmail_quote">On Thu, May 10, 2012 at 11:28 AM, William Kyngesburye <span dir="ltr"><<a href="mailto:woklist@kyngchaos.com" target="_blank">woklist@kyngchaos.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
On May 10, 2012, at 11:43 AM, Larry Shaffer wrote:<br>
<br>
> Hi William,<br>
><br>
> On Thu, May 10, 2012 at 8:26 AM, William Kyngesburye <<a href="mailto:woklist@kyngchaos.com">woklist@kyngchaos.com</a>> wrote:<br>
> On May 9, 2012, at 12:08 PM, Larry Shaffer wrote:<br>
><br>
> > During a recent audit of almost every PyQGIS plugin (casually studying repetitive design patterns) and helping some users on <a href="http://gis.stackexhange.com" target="_blank">gis.stackexhange.com</a> [0] I have come across an issue that may affect over 30 plugins (for now, only on Mac).<br>
> ><br>
> > From what I can gather, William Kyngesburye's Mac builds (and Unix/Linux, too?) consistently use a current, stable version of Qt, now at 4.8, while the OSGEO4W package is at 4.4 [1]. This hasn't been an issue since, I believe (and assume), the bundled Qt in Mac builds included Qt3 support. The most recent 1.7.4 Mac version appears to have a bundled Qt with no Qt3 support (is this correct?).<br>
> ><br>
> I haven't included Qt3Support since QGIS 1.2, when the last of the Qt3 usage was removed (I think GRASS plugin was the last holdout).<br>
><br>
> I'm referring to Qt4 being compiled with the legacy '-qt3support' option (supposedly on by default [0]), not direct Qt3 support (frameworks, etc). Recently, when there was an issue with QWebKit on 10.6, you posted a configure line for compiling Qt4 to fix the problem [1]. I noted that you chose the '-no-qt3support' option. Is that the same Qt you used for bundling the recent QGIS 1.7.4-x? Had you nixed -qt3support in past builds, or used Nokia's pre-compiled Qt4 builds with '-qt3support'?<br>
><br>
> [0] <a href="http://qt-project.org/doc/qt-4.8/configure-options.html" target="_blank">http://qt-project.org/doc/qt-4.8/configure-options.html</a><br>
> [1] <a href="http://osgeo-org.1560.n6.nabble.com/OS-X-QtWebKit-problem-fixed-PyQwt-still-broken-td4513113.html#a4519323" target="_blank">http://osgeo-org.1560.n6.nabble.com/OS-X-QtWebKit-problem-fixed-PyQwt-still-broken-td4513113.html#a4519323</a><br>
><br>
"Qt3Support" is the library/framework you get with the qt3support compile option. I don't think there is anything extra in the other frameworks/libraries when you compile with this option.<br></blockquote>
<div><br>Thank you for the clarification on the Qt3Support framework.<br><br>OK, I think I've figured it out. When compiling Qt, and setting the -qt3support option, the variable QT3_SUPPORT is set [0]. While this is expected to produce the Qt3Support framework, it also affects the build of Qt4 frameworks in ~580 places (results of search for '#ifdef QT3_SUPPORT' in src directory [1]). This includes QAction, which is reverted to emitting the activated() signal again [2][3].<br>
<br>The upshot of this is PyQt4, when compiled against a Qt4 build with the -qt3support option, will have that support, regardless (I think) of whether the Qt3Support framework is included in the Mac app bundle or not.<br>
<br>So, I'm guessing that when you compiled Qt to fix the QWebKit issue (with no -qt3support option) you truly nixed the Qt3 support, as expected. BTW, I think this is good: it will ferret-out the current plugins still relying upon legacy Qt3 code (unfortunately only on Mac, causing some confusion for users).<br>
<br>[0] <a href="http://qt.gitorious.org/qt/qt/blobs/4.8/src/qbase.pri#line163">http://qt.gitorious.org/qt/qt/blobs/4.8/src/qbase.pri#line163</a><br>[1] <a href="http://dl.dropbox.com/u/4058089/qgis/ifdef_QT3_SUPPORT.txt">http://dl.dropbox.com/u/4058089/qgis/ifdef_QT3_SUPPORT.txt</a><br>
[2] <a href="http://qt.gitorious.org/qt/qt/blobs/4.8/src/gui/kernel/qaction.h#line232">http://qt.gitorious.org/qt/qt/blobs/4.8/src/gui/kernel/qaction.h#line232</a><br>[3] <a href="http://qt.gitorious.org/qt/qt/blobs/4.8/src/gui/kernel/qaction.cpp#line1260">http://qt.gitorious.org/qt/qt/blobs/4.8/src/gui/kernel/qaction.cpp#line1260</a><br>
<br><br></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
> > This has caused many PyQGIS plugins to fail to launch on Mac, due to their use of a Qt3-only QAction signal of activated() in a plugin's initGui() method. Basically, the plugin does not launch (i.e. does nothing), with no error. However, for Windows users, the plugin launches fine, causing problems when trying to offer cross-platform support for plugin issues.<br>
> ><br>
> > Can someone else verify these findings?<br>
> ><br>
> > I am slightly surprised Qt3 is still supported, and think dropping its support sounds like a good idea, especially for QGIS version 1.8 or >, but certainly don't know all the details on versioning for QGIS distributions. I understand this may cause problems with the OSGEO4W package. (btw: Why is it still on Qt 4.4?)<br>
> ><br>
> I would assume that Qt3 usage in external plugins would require support in PyQt, but PyQt has never compiled a PyQt3 module for me, and I'm not sure if it can, or how.<br>
><br>
> Can you think of anything else that might have caused this issue, via differences between your 1.7.3 and 1.7.4 builds? It may be even between the latest 1.7.4-x builds. I can try to re-install each of the versions to find when the issue occurs.<br>
><br>
There is something going on with the Qt 4.8.1 that I upgraded to in QGIS 1.7.4 (1.7.3 used Qt 4.8.0, which had the QtWebKit problem) - there are mysterious crashes is various places. There may be other problems in the latest Qt that don't cause a crash, but break plugins.<br>
<br>
><br>
> > Here are the plugins I have found that use the deprecated activated() signal, including two core C++ [2]<br>
><br>
> This is odd because those plugins then should not even compile if Qt3 is missing. And spatialquery works for me without Qt3Support. (GRASS works, but has its own problems)<br>
><br>
> The 'Hello World' plugin is the simplest for testing/exhibiting the issue [2]. Odd that I get no launch of Spatial Query plugin, on all my 1.7.4-4 installs, but you're having success with it.<br>
><br>
> [2] <a href="http://plugins.qgis.org/plugins/HelloWorld/" target="_blank">http://plugins.qgis.org/plugins/HelloWorld/</a><br>
><br>
I tried on OSX 10.7, I'll try it this evening on OSX 10.6 when I get home.<br></blockquote><div><br>I tried with 1.7.4-4 on 10.7 and 10.6.8 with same results: no launching of plugins. It works with my nightly builds of QGIS (1.8 RC1), which are bundled with '-D QGIS_MACAPP_BUNDLE=2', i.e. app does not contain the Qt3Support framework, but PyQt4 still supports the Qt3 deprecated features (as noted above), allowing all of the affected plugins to launch [4].<br>
<br>[4] <a href="http://dl.dropbox.com/u/4058089/qgis/qt3support_with-no-framework.png">http://dl.dropbox.com/u/4058089/qgis/qt3support_with-no-framework.png</a><br><br><br><br></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
><br>
> > and a ZIP archive of the particular files that I found to contain that signal [3]. Without a complete examination of each plugin, I am not entirely certain all of the signals are of QAction. I tried to include only those that appear to be. (Note: there may be more uses of Qt3 deprecated methods, etc.)<br>
> ><br>
> > Please correct me if I am off on my assessment of this situation, or if I am late to the discussion.<br>
> ><br>
> > [0] <a href="http://gis.stackexchange.com/a/22953/6725" target="_blank">http://gis.stackexchange.com/a/22953/6725</a> , <a href="http://gis.stackexchange.com/a/24860/6725" target="_blank">http://gis.stackexchange.com/a/24860/6725</a><br>
> > [1] <a href="http://trac.osgeo.org/osgeo4w/wiki/pkg-qt4-libs" target="_blank">http://trac.osgeo.org/osgeo4w/wiki/pkg-qt4-libs</a><br>
> > [2] <a href="http://dl.dropbox.com/u/4058089/qgis/plugins_contain-qt3activated.txt" target="_blank">http://dl.dropbox.com/u/4058089/qgis/plugins_contain-qt3activated.txt</a><br>
> > [3] <a href="http://dl.dropbox.com/u/4058089/qgis/plugins_contain-qt3activated.zip" target="_blank">http://dl.dropbox.com/u/4058089/qgis/plugins_contain-qt3activated.zip</a><br>
> ><br>
> > Regards,<br>
> ><br>
> > Larry Shaffer<br>
> > Dakota Cartography<br>
> > Black Hills, South Dakota<br>
> > _______________________________________________<br>
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><br>
> -----<br>
> William Kyngesburye <kyngchaos*at*kyngchaos*dot*com><br>
> <a href="http://www.kyngchaos.com/" target="_blank">http://www.kyngchaos.com/</a><br>
><br>
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><br>
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-----<br>
William Kyngesburye <kyngchaos*at*kyngchaos*dot*com><br>
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</blockquote></div><br>Regards,<br><br>Larry Shaffer<br>Dakota Cartography<br>Black Hills, South Dakota<br>
<br>