Qt application screen orientation

Embedded Devices Linux
1

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)?

2

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.