Developing your own applications

This guide is aimed at the complete beginner who would like to know how to develop their own applications for SHR. Using the familiar Hello World program as an example, it will use Vala as the programming language as this should be familiar and easy to understand for people with Java experience.

It is assumed that the reader has already successfully built SHR using the instructions at Building SHR.

1. Creating a source folder

$ cd /path/to/shr/build
$ mkdir myfirstapp
$ cd myfirstapp

2. Writing Hello World in Vala

Create and enter a sub folder for the source:

$ mkdir src
$ cd src

Create a file called myfirstapp.vala and insert the following text:

class Demo.HelloWorld : GLib.Object
{
    public static int main(string[] args)
    {
        stdout.printf("Hello, World\n");
        return 0;
    }
}

More information about Vala can be found here:  http://live.gnome.org/Vala/Tutorial

3. Set up autotools

Go back to the previous folder:

$ cd ..

Create a file called Makefile.am and insert the following text:

SUBDIRS = src

Now go to the source folder once again:

$ cd src

Create another file called Makefile.am and insert the following text:

bin_PROGRAMS = myfirstapp

AM_CFLAGS = $(DEPS_CFLAGS)
AM_LIBS = $(DEPS_LIBS) $(DEPS_LIBS)

AM_VALAFLAGS = --pkg "gio-2.0" --pkg "glib-2.0"

myfirstapp_SOURCES = myfirstapp.vala
myfirstapp_LDADD = $(INTI_LIBS)

myfirstapp_LDFLAGS = $(AM_LIBS)

clean:
rm -f *.c *.o *.stamp

Go back to the top level folder:

$ cd ..

Create a file called configure.ac and insert the following text:

AC_INIT([my_first_app],0.1)
AM_INIT_AUTOMAKE
AC_CONFIG_SRCDIR([src/myfirstapp.vala])

AC_PROG_CC
m4_pattern_allow
AM_PROG_VALAC

PKG_CHECK_MODULES([DEPS], [glib-2.0 gio-2.0])

AC_OUTPUT([Makefile src/Makefile])

Run the following commands:

$ aclocal
$ autoconf
$ touch AUTHORS NEWS README ChangeLog
$ automake --add-missing

4. Add a bitbake recipe

Create a file called myfirstapp.bb and insert the following text:

DESCRIPTION = "A hello world program written in Vala"
SRCREV_pn-${PN} = "${AUTOREV}"
PV = "0.1"
PR = "r0"

S = "${WORKDIR}/myfirstapp"

SRC_URI = "file:///path/to/shr/build/myfirstapp"

inherit autotools vala

5. Build a package

$ cd shr-unstable
$ . setup-env
$ bitbake -b /path/to/shr/build/myfirstapp/myfirstapp.bb

You should find that you now have an ipk package like this: /path/to/shr/build/shr-unstable/tmp/deploy/ipk/armv4t/myfirstapp_0.1-r0.6_armv4t.ipk

In order to test you program, simply install this package on your phone and run "/usr/bin/myfirstapp".