Packaging a Qt application

Contents

Packaging a Qt application for Maemo

Finding your package in debian

If you want to port a Qt package to Maemo, you should check and see if it is already packaged for debian and use that package if you can - this will save you time and effort. You can search in debian's Package Tracking System (PTS) to see if it is there. There is a search system on the PTS page, under the "distribution" drop-down, select 'any', this will search throughout debian's repositories to find the package. Debian has more than 20,000 packages just in its stable distribution so your application is likely already packaged.

If you find the package already exists in debian, you can get the source, including the packaging source, with apt-get. To do this, you'll have to edit your /etc/apt/sources.list, you can follow this recipe;

$ echo “deb http://ftp.it.debian.org/debian/ unstable main contrib non-free” >> /etc/apt/source.list
$ apt-get update
$ apt-cache search "application name"
$ apt-get source "application name"

To learn more about the /etc/apt/sources.list you can do a 'man sources.list' if you are running debian or a debian based GNU/Linux distro.

Porting the debian package to a Maemo package

If your application has been already packaged for debian, you can begin your maemo packaging with this section. Once you have the source of the debian package, you will need to make some modifications to that package for it to build under Maemo. For the complete Maemo Package Policy, use this link to a pdf.

In order to create a new package for maemo, you'll need to:

  • Rename the upstream source directory in Package-Version (eg: myapp-0.1)
  • Create “src” directory in Package-Version/
  • Copy all the files in the src/
  • Rename src/appname.pro in src/src.pro
$mv myapp myapp-0.1
$cd myapp-0.1
$mkdir src
$cp * src
$mv src/appname.pro src/src.pro

Append the following chunk to end of your src/src.pro . The chunk adds install section to your qmakefile

  unix {
    #VARIABLES
    isEmpty(PREFIX) {
        PREFIX = /usr/local
  }
BINDIR = $$PREFIX/bin
DATADIR =$$PREFIX/share

DEFINES += DATADIR=\"$$DATADIR\" PKGDATADIR=\"$$PKGDATADIR\"

#MAKE INSTALL

INSTALLS += target desktop iconxpm icon26 icon40 icon64

  target.path =$$BINDIR

  desktop.path = $$DATADIR/applications/hildon
  desktop.files += $${TARGET}.desktop

  iconxpm.path = $$DATADIR/pixmap
  iconxpm.files += ../data/maemo/$${TARGET}.xpm

  icon26.path = $$DATADIR/icons/hicolor/26x26/apps
  icon26.files += ../data/26x26/$${TARGET}.png

  icon40.path = $$DATADIR/icons/hicolor/40x40/apps
  icon40.files += ../data/40x40/$${TARGET}.png

  icon64.path = $$DATADIR/icons/hicolor/64x64/apps
  icon64.files += ../data/64x64/$${TARGET}.png
}


  • Create a myapp-0.1/myapp.pro file like this:
QMAKEVERSION = $$[QMAKE_VERSION]
ISQT4 = $$find(QMAKEVERSION, ^[2-9])
isEmpty( ISQT4 ) {
error("Use the qmake include with Qt4.4 or greater, on Debian that is qmake-qt4");
}

TEMPLATE = subdirs
SUBDIRS  = src
  • Run dh_make to debianize the source archive, it creates:
    • An archive with the unchanged upstream source (orig.tar.gz)
    • Some basic files in the debian directory
    • Some example files (*.EX *.ex)
export DEBFULLNAME="maintainer first name and last name"
dh_make --createorig --single -e maintainer@email.org -c gpl

Having a look inside the debian/ dir

At this point the directory my-app contains

  • the source directory ( src/ )
  • the debian directory (debian/)

Inside the debian dir we have the files needed for the creation of the debian package

  • Changelog - Application's change log
  • Compat - Debian helper compatibly version
  • Control - Describes the packages to be made
  • Copyright - Copyright text
  • Rules - A binary makefile containing the rules to build the package

Maemo Packaging Policy

Maemo packages follow the Debian Policy, but there are some items where Maemo:

  • Is more strict (it is an embedded distribution)
  • Is more relaxed
    • Only a target device (Nokia Internet Tablet)
    • Only a specified UI (Hildon)
    • Only one user.
  • Differs from Debian because Maemo has different:
    • Objectives
    • Maintainers
    • Infrastructure

Editing the Control file

Basically it specifies for each package (source or binary) a name, some dependencies, a description etc... For a Maemo package these fields are very important:

  • Section: Only the packages in the user segment are showed by App Installer.
  • Maintainer: This field MUST be changed if the upstream package is modified
  • XB-Maemo-Icon26: It contains the PNG icon encoded in base64 visible in the Application Installer

If you need to encode your icon as base64, there are instructions here.

Source: my-application
Section: user/valid_subsection
Priority: optional 
Maintainer: name surname <xxxxxxx.xxxxxx@maemo.org>
XSBC-Original-Maintainer: name surname <yyyyy.yyyyy@debian.org>
Build-Depends: debhelper (>= 5), libqt4-dev, OTHERS_BUILD DEPENDECIES 
Standards-Version: 3.7.3

Package: my-application 
Architecture: any
Depends: ${shlibs:Depends}, ${misc:Depends}
Description: A simple test application
 A very simple application with a short description.
 Which spans multiple lines actually. 
XB-Maemo-Icon-26:
 iVBORw0KGgoAAAANSUhEUgAAABoAAAAaCAYAAACpSkzOAAAABmJLR0QA/wD/AP+g
 vaeTAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH1gURDQoYya0JlwAAAU9J 
 REFUSMftlL1KA0EUhb/NZl/ggnHQxsJUxt5CUucVJCCkDfgyKdIGG5/A0s5HEBtJ
 EdDAQGBgmw0YJmMzgXXYza5CtNkDW9zZw5z7c+ZCgwb/Ai3i9sVl/Bq8RIs4LRK1 
 gJDsKvJyNXmJMuYTsMoY1zpgozaABdYArQNPZQ1kfyGU7SpqVwxzAMwABWhgpIwp
 4vWBB+AUWAI3ypjnfEXtPU4bLKx9vErTeCeiRSYF+fTn1j5dp2myE9EiU+DSi3wX 
 ymeqRQAmZ3EcA5E/fgO6BULT8zhOcrwXoJdrXRa2Lgps2y2odAUcBUIXQdz78YyC
 SldAp8b7+bXrIv91qjZBietqCc2DjbAt4b2WxJkyZljVujlwp0U0cPxuLcAIuC+4 
 dKxFlsDJarvdAGP/b6hFnDImYs+uG3hbO2AB3Jbsur63tQM+fFx3bzZocEB8AdV2
 gJBZgKTwAAAAAElFTkSuQmCC 

Package: my-application-dbg
Section: devel
Architecture: any
Depends: my-application (= ${binary:Version})
Description: Debug symbols for a simple test application
 Debug symbols for a very simple application, which allow
 tracing and debugging.

Valid subsections are:

  • accessories
  • communication
  • games
  • multimedia
  • office
  • other
  • programming
  • support
  • themes
  • tools

Editing the rules file

The rules file generated by dh_make will be modified in order to look like this one. We are using qmake, so we haven't a configure file to run. If you cut-and-paste following file, notify that empty space beginning of lines it TAB characters, it is not multiple space characters. If you cut-and-paste the following chunk, you most propably get spaces instead tabs and the file does not wok

#!/usr/bin/make -f
APPNAME := my_app_name
builddir:
        mkdir -p builddir

builddir/Makefile: builddir
        cd builddir && qmake-qt4 PREFIX=/usr ../$(APPNAME).pro

build: build-stamp

build-stamp: builddir/Makefile
        dh_testdir
        # Add here commands to compile the package.
        cd builddir && $(MAKE)
        touch $@

clean:
        dh_testdir
        dh_testroot
        rm -f build-stamp
        # Add here commands to clean up after the build process.
        rm -rf builddir
        dh_clean
install: build
        dh_testdir
        dh_testroot
        dh_clean -k
        dh_installdirs

        # Add here commands to install the package into debian/your_appname
        cd builddir && $(MAKE) INSTALL_ROOT=$(CURDIR)/debian/$(APPNAME) install
# Build architecture-independent files here.
binary-indep: build install
# We have nothing to do by default.

# Build architecture-dependent files here.
binary-arch: build install
        dh_testdir
        dh_testroot
        dh_installdocs
        dh_installexamples
        dh_installman
        dh_link
        dh_strip --dbg-package=my-application-dbg
        dh_compress
        dh_fixperms
        dh_installdeb
        dh_shlibdeps
        dh_gencontrol
        dh_md5sums
        dh_builddeb

binary: binary-indep binary-arch
.PHONY: build clean binary-indep binary-arch binary install configure

Editing the Changelog file

It is the log of the changes for a specified application version. It's important file because it sets the binary/binaries and the source packages version and revision. If an upstream package is re-packaged or modified for maemo, the Maemo revision string should be appended to the upstream revision. So if in Debian the package name was something like "Myapp-0.4-2" in maemo this package will be called "Myapp-0.4-2maemo0". The number after the "maemo" string is a progressive number.

Application menu icon & position

The Maemo application menu detects automatically an app that provides a .desktop file in /usr/share/application/hildon . If you don't have desktop file, create one in the src directory.

[Desktop Entry]
Encoding=UTF-8
Version=0.1
Type=Application
Name=myapp
Exec=/usr/bin/myapp
Icon=myapp
X-HildonDesk-ShowInToolbar=true
X-Osso-Type=application/x-executable


Maemo menu structure is completely different from Debian:

  • An unmodified Debian package installs the proper .desktop in /usr/share/applications
  • Applications that use the debian menu are displayed in the extra menu

In order to show our application in the correct Maemo menu:

  • debian/myapp.install moves the .desktop file and icons in the right directory
src/*.desktop usr/share/applications/hildon
src/*.png usr/share/icons/hicolor/26x26/apps
  • debian/postinst should call maemo-select-menu-location utility to permit the user to choose the menu location. This works only in Diablo, it doesn't work in Fremantle.
#!/bin/sh
maemo-select-menu-location myapp.desktop

Checking Maemo Packages

Lintian dissects Debian packages and reports bugs and policy violations. It contains automated checks for many aspects of Debian policy as well as some checks for common errors. Unfortunately it doesn't check conformance to the additional Maemo policy.

Currently Maemo is creating Maemian to check its policy.

Building the binary and the source package

To build only binary package/s

$dpkg-buildpackage -rfakeroot -b

we can install these binary package with dpkg:

$dpkg -i myapp.deb

To build the source package and to sign it with your gpg key (ABCDEF12)

dpkg-buildpackage -rfakeroot -sa -S -kABCDEF12

At this point, if you have tested your package and it works fine you can upload it in extras/extras-devel.

Example

You can download the source package of qt-maemo-example from the extras-devel repository just running if you have source packages enabled in your sources file;

apt-get source qt-maemo-example

This command will download the:

- unmodified source (.orig.tar.gz)

- debian dsc file (.dsc)

- diff file (.diff)

and after it will launch automatically dpkg -x file.dsc in order to uncompress the orig.tar.gz and apply the changes.

Useful Links

Qt4Maemo at garage

Desktop entry spec 0.9.4

Debhelper 7

Debhelper 7 is not available in fremantle. Debian packages that requires level 7 needs some changes: eg:

  • debian/compat: 7 -> 5
  • debian/control: Build-Depends: debhelper (>= 7) -> debhelper (>= 5)
  • And maybe comment out a few dh_* calls from debian/rules, which might not exist on level 5

Now things might get complex if the packaging already uses some new features of level 7, like those CDBS-like helper rules. In such cases, looking at versions prior to the compatibility level upgrade might help doing the downgrade (and most Debian packages are kept in public SCMs like svn.debian.org).