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Packaging a Qt application

Revision as of 10:20, 1 February 2010

Packaging a Qt application for Maemo

Packaging a Qt application for Maemo is very similar to packaging any other application, so this document only contains information on Qt-specific packaging issues.

Porting a 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 icon48 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

  icon48.path = $$DATADIR/icons/hicolor/48x48/apps
  icon48.files += ../data/48x48/$${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

• Maintainer:

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

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

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

• Qt for Maemo
• Packaging guide for Maemo
• Desktop entry specification

Debhelper 7

A backport of Debhelper 7 for fremantle is available in extras-devel. It works transparently and can coexist with debhelper 5 in the SDK. It even works on autobuilder, if you specify the correct build-dependency debhelper7. Read the mails about debhelper7 and cdbs-dh7.

Alternatively, you can try to use debhelper 5 in some cases:

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).