This tutorial will demonstrate how to:
create a small "Hello, World" application using GTK+
make the
how to set up the build system
class MyApplication : Gtk.Application {
protected override void activate () {
var window = new Gtk.ApplicationWindow (this);
window.set_title ("Welcome to GNOME");
window.set_default_size (200, 100);
window.show_all ();
}
}
Gtk.Application initializes GTK+. It also connects the
We can start building our first window. We do this by creating a variable called window and assigning it a new Gtk.ApplicationWindow.
We give the window a title using set_title
. The title can be any string you want it to be. To be on the safe side, it's best to stick to UTF-8 encoding.
Now we have a window which has a title and a working "close" button. Let's add the actual "Hello World" text.
var label = new Gtk.Label ("Hello GNOME!");
window.add (label);
Finally, we create and run the application:
int main (string[] args) {
return new MyApplication ().run (args);
}
Gtk.ApplicationWindow can only hold one widget at a time. To construct more elaborate programs you need to create a holder widget like Gtk.Grid inside the window, and then add all the other widgets to it.
Die vollständige Datei:
public class MyApplication : Gtk.Application {
protected override void activate () {
var window = new Gtk.ApplicationWindow (this);
var label = new Gtk.Label ("Hello GNOME!");
window.add (label);
window.set_title ("Welcome to GNOME");
window.set_default_size (200, 100);
window.show_all ();
}
}
public int main (string[] args) {
return new MyApplication ().run (args);
}
To run this application, first save it as hello-world.vala. Then open Terminal, go to the folder where your application is stored.
Compile the program:
Run the program:
Running applications from the Terminal is useful at the beginning of the application making process. To have fully working application integration in GNOME 3 requires a desktop launcher. For this you need to create a
The example shows you the minimum requirements for a .desktop.in
file.
[Desktop Entry]
Version=1.0
Encoding=UTF-8
Name=Hello World
Comment=Say Hello
Exec=@prefix@/bin/hello-world
Icon=application-default-icon
Terminal=false
Type=Application
StartupNotify=true
Categories=GNOME;GTK;Utility;
Now let's go through some parts of the .desktop.in
file.
Der Anwendungsname.
Eine kurze Beschreibung der Anwendung.
Specifies a command to execute when you choose the application from the menu. In this example exec just tells where to find the
Specifies whether the command in the Exec key runs in a terminal window.
To put your application into the appropriate category, you need to add the necessary categories to the Categories line. More information on the different categories can be found in the menu specification.
In this example we use an existing icon. For a custom icon you need to have a .svg file of your icon, stored in
To make your application truly a part of the GNOME 3 system you need to install it with the help of autotools. The autotools build will install all the necessary files to all the right places.
For this you need to have the following files:
#!/bin/sh
set -e
test -n "$srcdir" || srcdir=`dirname "$0"`
test -n "$srcdir" || srcdir=.
olddir=`pwd`
cd "$srcdir"
# This will run autoconf, automake, etc. for us
autoreconf --force --install
cd "$olddir"
if test -z "$NOCONFIGURE"; then
"$srcdir"/configure "$@"
fi
After the
# The actual runnable program is set to the SCRIPTS primitive.
# # Prefix bin_ tells where to copy this
bin_PROGRAMS = hello-world
hello_world_CFLAGS = $(gtk_CFLAGS)
hello_world_LDADD = $(gtk_LIBS)
hello_world_VALAFLAGS = --pkg gtk+-3.0
hello_world_SOURCES = hello-world.vala
desktopdir = $(datadir)/applications
desktop_DATA = \
hello-world.desktop
# This file is processed by autoconf to create a configure script
AC_INIT([Hello World], 1.0)
AM_INIT_AUTOMAKE([1.10 no-define foreign dist-xz no-dist-gzip])
AC_PROG_CC
AM_PROG_VALAC([0.16])
PKG_CHECK_MODULES(gtk, gtk+-3.0)
AC_CONFIG_FILES([Makefile hello-world.desktop])
AC_OUTPUT
Information users should read first. This file can be blank.
When you have the
To build and install this program:
./autogen.sh --prefix=/home/your_username/.local
make
make install
-------------
Running the first line above creates the following files:
aclocal.m4
autom4te.cache
config.log
config.status
configure
depcomp
hello-world
hello-world.c
hello-world.desktop
hello_world-hello-world.o
hello_world_vala.stamp
install-sh
missing
Makefile.in
Makefile
Running "make" links all the appropriate libraries.
Running "make install", installs the application in /home/your_username/.local/bin
and installs the hello-world.desktop file in /home/your_username/.local/share/applications
You can now run the application by typing "Hello World" in the Overview.
----------------
To uninstall, type:
make uninstall
----------------
To create a tarball type:
make distcheck
This will create hello-world-1.0.tar.xz