Hello! This is something that's come up more than once: how to use themes (styles) in Qt5 like it used to be possibe with Qt4. After seeing how Qt5 applications would use the selected theme when running under Linux inside a KDE5 plasma session I set out to figure out how, and how to port/adapt that to OS X.
It turns out that only minor changes to Qt are required: 1) the QCocoa integration glue must (evidently) include the theme in question to the list of available theme names; this is not the name of the style selected through KDE, but simply "kde". 2) the qgenericunixservices and qgenericunixtheme components should be built -- and I'm actually not even certain that this is indeed the case. On Linux, a specific KF5 framework is required to enable automatic loading of the KDE theme, and that framework requires a few a little more intricate changes which are discussed in the message (and KDE review request) below. I hope this is of interest to others who have been looking to do the same (see my remarks about fonts below). I intend to make the required patches available for use with MacPorts. Once more fully tested in that context I may submit the Qt patches on gerrit ... if there's any hope at all they would be considered for incorporation. René ---------- Forwarded Message ---------- Subject: Review Request 126198: [OS X] adaptations for the KdePlatformTheme (and autotests) Date: Sunday November 29 2015, 17:19:37 ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://git.reviewboard.kde.org/r/126198/ ----------------------------------------------------------- Review request for KDE Software on Mac OS X and KDE Frameworks. Repository: frameworkintegration Description ------- The KdePlatformTheme plugin can be enabled on OS X with a minimal patch to Qt5; all that is required is to include the `qgenericunixservices` and `qgenericunixthemes` components in the build, and to append `"kde"` to the list returned by `QCocoaIntegration::themeNames()` for instance under the condition that `KDE_SESSION_VERSION` is set to a suitable value in the environment. This will allow KF5 and Qt5 applications to use the theme selected through KDE if FrameworkIntegration is installed and KDE_SESSION_VERSION is set, which seems like a sufficiently specific set of conditions that is easy to avoid by users who prefer to use the Mac native theme. While requestion the KDE theme is also possible through `-style kde` or `env QT_STYLE_OVERRIDE=kde` the use of the KdePlatformTheme plugin appears to be the only way to get the full theme, including the font and colour selection. In my opinion it is above all the font customisation which is a very welcome feature for Qt/Mac; by default Qt applications use the default system font (Lucida Grande 13pt or even 14pt) throughout. This is a good UI font, but not at that size (and most "native" OS X applications indeed use a range of smaller sizes, depending on role. It does have introduce a number of regressions, which the current patch aims to address. The most visible and problematic of these regressions is the loss of the Mac-style menu bar and thus of all menu items (actions). The fix is straightforward : on OS X (and similarly affected platforms?), an instance of the native Cocoa platform theme is created through the private API, and used as a fallback rather than immediately falling back to the default implementations from `QPlatformTheme`. In addition, methods missing from (not overridden by) `KdePlatformTheme` are provided on OS X and call the corresponding methods from the native theme. It is this change which restores the menubar and even the Dock menu functionality. One minor regression remains but should be easy to fix (elsewhere?): the Preferences menu loses its keyboard shortcut (Command-,). Given the fallback nature of the native platform instance I have preferred to print a warning rather than using something like `qFatal`, above all because the message printed by qFatal tends to get lost on OS X. I can replace my use of `qWarning` with a dialog giving the choice between continuing or exiting the application - code that would be called in the menu methods because only there is it certain that the application actually needs a menubar. In line with experience and feedback from the KDE(4)-Mac community I have decided to force the use of native dialogs rather than the ones from the KdePlatformPlugin. In addition I set the fallback value for `ShowIconsOnPushButtons` to false in line with platform guidelines, and ensure that the autotests are not built as app bundles. Diffs ----- src/platformtheme/khintssettings.cpp 8adf6c5 src/platformtheme/kdeplatformtheme.cpp 80dbcb7 src/kstyle/kstyle.cpp 6ba5d51 src/platformtheme/kdeplatformtheme.h 97d09df autotests/CMakeLists.txt 7c2129c Diff: https://git.reviewboard.kde.org/r/126198/diff/ Testing ------- On Mac OS X with Qt 5.5.1, KF5 frameworks 5.16.0 and QtCurve git/head. I have not verified to what extent my use of a private `QGuiApplication` API links builds to a specific Qt version (I consider that nothing shocking and a minor price to pay). >>> Do I need to add some glue to the CMake file so that it will warn if the >>> private headerfiles are not available? Apparently no changes were required >>> to find them. Thanks, René J.V. Bertin ----------------------------------------- _______________________________________________ Interest mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/interest
