[Interest] “Qt Embedded” fonts in Qt Creator
Hi! When selecting a font for a widget in Qt Creator 4.6.2, some of the fonts have a postfix [Qt embedded] in their name. E.g. "DejaVu Sans Mono [Qt Embedded]". What does [Qt Embedded] mean exactly? -- Best Rergards, Bernhard ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] promoting a QGuiApplication to a QApplication?
On Wednesday July 11 2018 14:27:25 Furkan Üzümcü wrote: >dynamic_cast returns nullptr when the class you are casting is cannot be >cast down to Type. Casting does not create a new instance for you. Yeah, I think I was misinformed or I misunderstood something at some point when someone first introduced the concept of dynamic_cast to me. R. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] promoting a QGuiApplication to a QApplication?
> That's > what dynamic_cast also does when it doesn't simply return the original > pointer, no? dynamic_cast returns nullptr when the class you are casting is cannot be cast down to Type. Casting does not create a new instance for you. Regards, Furkan Üzümcü On Jul 11, 2018, 13:33 -0400, René J.V. Bertin , wrote: > On Wed, 11 Jul 2018 08:01:25 -0700, Thiago Macieira wrote: > > > There's no such C++ concept as "promote a class". What you're asking is > > not possible. > > I think I got confused myself with dynamic_cast, but of course what I had > in mind was not modifying the instance itself, but create a new > QApplication instance from the original QGuiApplication instance. That's > what dynamic_cast also does when it doesn't simply return the original > pointer, no? > > > I have now seen from the code that this would probably be possible but not > without refactoring. > > As I wrote in a private reply, maybe that one day it will be concluded > that QGuiApplication could be rolled into QApplication (because what's a > GUI application without widgets of some kind?). From an admittedly cursory > glance at qapplication.cpp it seems that a QApplication initialised with a > "noWidgets" flag would be largely identical to a QGuiApplication instance. > It also seems that the widget-related initialisations could be deferred > until they're actually needed in which case every QApplication would start > out as a QGuiApplication. > > Maybe in Qt 7? :) > > R. > > ___ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Detecting subdirectories in QDir
On Wednesday, 11 July 2018 07:59:28 PDT Thiago Macieira wrote: > On Wednesday, 11 July 2018 07:44:46 PDT Oleg Yadrov wrote: > > qDebug() << a.absolutePath().startsWith(b.absolutePath()); > > > > qDebug() << a.absolutePath().startsWith(c.absolutePath()); > > Except that this has a bug (which we had in Qt too): these two directories > are considered to be parent-child, when they're not > > C:\One\TwoAndTwenty > C:\One\Two > > And since we're talking about Windows, you also need to use case-insensitive > comparison. Because of these gotchas, it's probably worth having a QDir::isParentOf() function. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] promoting a QGuiApplication to a QApplication?
On Wed, 11 Jul 2018 08:01:25 -0700, Thiago Macieira wrote: > There's no such C++ concept as "promote a class". What you're asking is > not possible. I think I got confused myself with dynamic_cast, but of course what I had in mind was not modifying the instance itself, but create a new QApplication instance from the original QGuiApplication instance. That's what dynamic_cast also does when it doesn't simply return the original pointer, no? I have now seen from the code that this would probably be possible but not without refactoring. As I wrote in a private reply, maybe that one day it will be concluded that QGuiApplication could be rolled into QApplication (because what's a GUI application without widgets of some kind?). From an admittedly cursory glance at qapplication.cpp it seems that a QApplication initialised with a "noWidgets" flag would be largely identical to a QGuiApplication instance. It also seems that the widget-related initialisations could be deferred until they're actually needed in which case every QApplication would start out as a QGuiApplication. Maybe in Qt 7? :) R. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Detecting subdirectories in QDir
Ha. I hope I didn't screw up this time.
#include
#include
#include
// returns true if 'a' is a subdirectory of 'b'
bool isSubdirectory(QDir a, QDir b)
{
while (!a.isRoot()) {
if (a.absolutePath() == b.absolutePath())
return true;
a.cdUp();
}
return false;
}
int main(int argc, char *argv[])
{
QCoreApplication app(argc, argv);
QDir a("/Users/olegyadrov/one/two/three");
QDir b("/Users/olegyadrov/one/two");
QDir c("/Users/olegyadrov/one/four");
qDebug() << isSubdirectory(a, b);
qDebug() << isSubdirectory(a, c);
return app.exec();
}
On Jul 11, 2018, at 10:59 AM, Thiago Macieira
mailto:thiago.macie...@intel.com>> wrote:
On Wednesday, 11 July 2018 07:44:46 PDT Oleg Yadrov wrote:
qDebug() << a.absolutePath().startsWith(b.absolutePath());
qDebug() << a.absolutePath().startsWith(c.absolutePath());
Except that this has a bug (which we had in Qt too): these two directories are
considered to be parent-child, when they're not
C:\One\TwoAndTwenty
C:\One\Two
And since we're talking about Windows, you also need to use case-insensitive
comparison.
--
Thiago Macieira - thiago.macieira (AT) intel.com
Software Architect - Intel Open Source Technology Center
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Re: [Interest] promoting a QGuiApplication to a QApplication?
On Wednesday, 11 July 2018 07:48:31 PDT René J.V. Bertin wrote: > The only guarantee I can think of is would be promoting a QGuiApplication > instance to QApplication at runtime, in the plugin. There's no such C++ concept as "promote a class". What you're asking is not possible. If the QCoreApplication instance is an object of class QGuiApplication, it's an object of class QGuiApplication and no other. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Detecting subdirectories in QDir
On Wednesday, 11 July 2018 07:44:46 PDT Oleg Yadrov wrote: > qDebug() << a.absolutePath().startsWith(b.absolutePath()); > > qDebug() << a.absolutePath().startsWith(c.absolutePath()); Except that this has a bug (which we had in Qt too): these two directories are considered to be parent-child, when they're not C:\One\TwoAndTwenty C:\One\Two And since we're talking about Windows, you also need to use case-insensitive comparison. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] promoting a QGuiApplication to a QApplication?
On Wednesday July 11 2018 17:20:51 Konstantin Tokarev wrote: Hi > If application object is created as QGuiApplication, you obviously cannot > cast it to QApplication. Maybe for casting, but > If you want to do something only when application object is created as > QApplication (or its subclass), use qApp pointer Well, that's not enough. qApp exists and isn't NULL in other Q*Applications because qApp is just a cast of QCoreApplication::instance(). A bit of context may help. The plugin I'm tinkering with is KDE's qqc2-desktop-style, which aims to implement a QtQuickControls2 style that follows the user's current desktop (= widget) style. In its current implementation it does this by querying `qApp->style()` every time the style must be called upon. When you select that style in a basic QQC2 application (say, the gallery demo) it will crash horribly. My tinkering is under review here: https://phabricator.kde.org/D14000 . Instead of using qApp->style() directly I use QStyleFactory to create a style instance when qApp->style() returns NULL, and cache it because qApp->setStyle(newStyle) would also crash. This works fine, as long as the style doesn't do anything that requires a QApplication and will crash (or abort) otherwise. The only guarantee I can think of is would be promoting a QGuiApplication instance to QApplication at runtime, in the plugin. R. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Detecting subdirectories in QDir
Hi there,
You can compare their absolute paths.
#include
#include
#include
int main(int argc, char *argv[])
{
QCoreApplication app(argc, argv);
QDir a("/Users/olegyadrov/one/two/three");
QDir b("/Users/olegyadrov/one/two");
QDir c("/Users/olegyadrov/one/four");
qDebug() << a.absolutePath().startsWith(b.absolutePath());
qDebug() << a.absolutePath().startsWith(c.absolutePath());
return app.exec();
}
outputs
true
false
Best regards,
Oleg Yadrov - oleg.yad...@qt.io
On Jul 11, 2018, at 5:04 AM, Tom Isaacson via Interest
mailto:interest@qt-project.org>> wrote:
Is there any way of finding if one QDir is a subdirectory of another? So for
instance:
C:\One\Two\Three
is a subdirectory of:
C:\One\Two
but not of:
C:\One\Four
Thanks.
Tom Isaacson
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Re: [Interest] promoting a QGuiApplication to a QApplication?
11.07.2018, 12:29, "René J.V. Bertin" : > Hi, > > I'm tinkering with using a Qt plugin that expects a QApplication in a > QGuiApplication (specifically, a QML application using QGuiApplication). > I'm not doing anything that causes a straight crash (or haven't run into that > one fatal instruction yet), but I do wonder: > > is it in any way possible to promote a QGuiApplication instance to a > QApplication? Somewhat unexpectedly, `dynamic_cast(qApp)` > behaves as `static_cast` or `const_cast` in this case (= it returns qApp). Or > it returns a nullptr in > > QGuiApplication app(argc, argv); > QApplication *gapp = dynamic_cast(); > > which is probably what you'd expect. > > Still, with QApplication inheriting QGuiApplication one could think that the > former does some initialisation the latter lacks and that it should be > possible to perform those steps at a later stade. Is it? If application object is created as QGuiApplication, you obviously cannot cast it to QApplication. If you want to do something only when application object is created as QApplication (or its subclass), use qApp pointer -- Regards, Konstantin ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] promoting a QGuiApplication to a QApplication?
Hi, I'm tinkering with using a Qt plugin that expects a QApplication in a QGuiApplication (specifically, a QML application using QGuiApplication). I'm not doing anything that causes a straight crash (or haven't run into that one fatal instruction yet), but I do wonder: is it in any way possible to promote a QGuiApplication instance to a QApplication? Somewhat unexpectedly, `dynamic_cast(qApp)` behaves as `static_cast` or `const_cast` in this case (= it returns qApp). Or it returns a nullptr in QGuiApplication app(argc, argv); QApplication *gapp = dynamic_cast(); which is probably what you'd expect. Still, with QApplication inheriting QGuiApplication one could think that the former does some initialisation the latter lacks and that it should be possible to perform those steps at a later stade. Is it? Thanks, R. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] Detecting subdirectories in QDir
Is there any way of finding if one QDir is a subdirectory of another? So for instance: C:\One\Two\Three is a subdirectory of: C:\One\Two but not of: C:\One\Four Thanks. Tom Isaacson ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
