Packaging a Qt application

2008-10-29T10:54:26Z

87.158.23.94:

= Packaging a Qt Application =
== Looking for a debian package of your Application ==
If you want to port a popular Qt application probably it is already packaged for debian.
You can try to get the package source in a couple of different ways:
* Adding a debian src repository in your /etc/apt/source.list file
<pre>
$echo “deb http://ftp.it.debian.org/debian/ unstable main contrib non-free” >> /etc/apt/source.list
$apt-get update
$apt-cache search app_name
$apt-get source app_name
</pre>
* Checking http://packages.debian.org, downloading the following files and running ''dpkg-source -x app_name.dsc'' to decompress the upstream source and to apply the changes available in the diff.gz file.
** upstream source file (.tar.gz)
** package changes (.diff.gz)
** meta-data information file (.dsc)

== Creating a Debian package for a new Qt Application ==
If your application has been already packaged, you can jump this section.
If your application is quite younger and you need to package it by yourself,
in order to creating a new package, you 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
<pre>
$mv myapp myapp-0.1
$cd myapp-0.1
$mkdir src
$cp * src
$mv src/appname.pro src/src.pro
</pre>
*Create a myapp-0.1/myapp.pro file like this:
<pre>
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
</pre>
*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)
<pre>
dh_make --createorig --single -e maintainer@email.org -c gpl
</pre>

== 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 need 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 makefile containing the rules to build all kinds of packages

== 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 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.

<pre>
#!/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
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
</pre>

==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

<pre>
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: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</pre>

Valid subsections are:
* accessories
* communication
* games
* multimedia
* office
* other
* programming
* support
* themes
* tools

== 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
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
<pre>
src/*.desktop usr/share/applications/hildon
src/*.png usr/share/icons/hicolor/26x26/apps
</pre>

* debian/postinst should call maemo-select-menu-location utility to permit the user to choose the menu location.
<pre>
#!/bin/bash
maemo-select-menu-location myapp.desktop
</pre>

== 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 doesn't provide any tools to check its policy.

== Building the binary and the source package ==
To build only binary package/s
<pre>
$dpkg-buildpackage -rfakeroot -b
</pre>
we can install these binary package with dpkg:
<pre>
$dpkg -i myapp.deb
</pre>

To build the source package and to sign it with your gpg key (ABCDEF12)
<pre>
dpkg-buildpackage -rfakeroot -sa -S -kABCDEF12
</pre>
At this point, if you have tested your package and it works fine you can [http://wiki.maemo.org/Uploading_to_Extras upload it in extras/extras-devel].

= Example =
You can download the source package of qt-maemo-example from the extra-devel repository just running

''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 =
[http://qt4.garage.maemo.org Qt4Maemo at garage]

[http://doc.trolltech.com/4.4/index.html Official Qt 4.4 Documentation]

[http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-0.9.4.html Desktop entry spec 0.9.4]

[[Category:Development]]
[[Category:Qt]]

Maemo Wiki Mirror - User contributions [en]

Packaging a Qt application