# Qt application screen orientation **URL:** \ **Category:** Linux\ **Created:** [December 27, 2009, 1:58am UTC](https://forums.digi.com/t/qt-application-screen-orientation/6266 "2009-12-27T01:58:25Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![philgp](https://avatars.discourse-cdn.com/v4/letter/p/d26b3c/32.png) [@philgp](https://forums.digi.com/u/philgp)\ **Post date:** [December 27, 2009, 1:58am UTC](https://forums.digi.com/t/qt-application-screen-orientation/6266/1 "2009-12-27T01:58:25Z")
I have DigiESP build 20090423-RevA DEL-5.0 and I’m developing an application using Qt, but need the display to use a portrait orientation. I’ve never developed using Qt before, but after bit of googling I discovered that adding ‘-display transformed:Rot90’ to the application’s command line should have the desired result, but this doesn’t work - I get a ‘transformed: driver not found’ error. I’m guessing that this is because the Qt libraries supplied with DigiESP are not built with the ‘-qt-gfx-transformed’ option enabled. Is this correct? If so, then is there some other way to rotate the display orientation or will I need to rebuild the Qt libraries? If I need to rebuild the libraries, will it be possible to integrate them into DigiESP so that they get put into the rootfs automatically? Can I use the latest version of Qt (which is 4.6) or should I get version 4.4.3 (the version provided with DigiESP)? ---
**Author:** ![philgp](https://avatars.discourse-cdn.com/v4/letter/p/d26b3c/32.png) [@philgp](https://forums.digi.com/u/philgp)\ **Post date:** [January 6, 2010, 3:47am UTC](https://forums.digi.com/t/qt-application-screen-orientation/6266/2 "2010-01-06T03:47:15Z")
I’ve worked out the solution to this myself, and am posting instructions for updating Qt libraries here in case anyone else needs to use a rotated screen (or any other Qt feature no included in the supplied version). I had no luck getting Qt version 4.6 to work - I managed to cross-compile the libraries, but when I installed them in the rootfs, I just got a segmentation fault when running applications, so I got the Qt 4.4.3 source from Nokia’s FTP site (ftp://ftp.qt.nokia.com/qt/source/qt-embedded-linux-opensource-src-4.4.3.tar.bz2), and tried that. I started by trying to duplicate the exact libraries supplied with DigiEL-5.0: Start a shell, extract the sources and ‘cd’ to the qt-embedded-linux-opensource-src-4.4.3 directory, then: [b]mv mkspecs mkspecs-orig cp -a /usr/local/DigiEL-5.0/usr/bin/mkspecs . cp -a mkspecs-orig/qws/linux-x86-g++ mkspecs/qws (if using x86 host platform), or cp -a mkspecs-orig/qws/linux-x86\_64-g++ mkspecs/qws (if using x86 64-bit host platform) export PATH=/usr/local/DigiEL-5.0/usr/bin:$PATH ./configure -confirm-license -embedded arm -xplatform qws/linux-arm-g++ -prefix /usr/local/QtEmbedded-4.4.3 -hostprefix /usr/local/DigiEL-5.0/usr -nomake examples -nomake demos -nomake docs -nomake translations -no-rpath -no-pch -no-largefile -no-accessibility -no-stl -no-qt3support -no-webkit -qt-sql-sqlite -depths 15,16 -qt-kbd-usb -qt-mouse-tslib -no-gif -no-libtiff -no-libmng -no-libjpeg -no-freetype make [/b] The above process builds the exact Qt libraries supplied with DigiEL-5.0. To change the functionality built into Qt, modify the above ./configure command line. ./configure -embedded arm -help | less will list the options available. In my case, I added -qt-gfx-transformed (to allow screen rotation) and removed -no-accessibility (the accessibility feature was needed by an on-screen keyboard widget I was trying to test out). To install: make install\_subtargets install\_qmake Finally, move the installed plugins into the rootfs: mv /usr/local/DigiEL-5.0/usr/plugins /usr/local/DigiEL-5.0/rootfs/rootfs\_extras/qt-embedded/rootfs/usr/local/QtEmbedded-4.4.3 After this, rebuild your root filesystem with DigiEL to include the new libraries.