c63087a563
To build a better world sometimes means having to tear the old one down.
-- Alexander Pierce, "Captain America: The Winter Soldier"
ATK served us well for nearly 20 years, but the world has changed, and
GTK has changed with it. Now ATK is mostly a hindrance towards improving
the accessibility stack:
- it maps to a very specific implementation, AT-SPI, which is Linux and
Unix specific
- it requires implementing the same functionality in three different
layers of the stack: AT-SPI, ATK, and GTK
- only GTK uses it; every other Linux and Unix toolkit and application
talks to AT-SPI directly, including assistive technologies
Sadly, we cannot incrementally port GTK to a new accessibility stack;
since ATK insulates us entirely from the underlying implementation, we
cannot replace it piecemeal. Instead, we're going to remove everything
and then incrementally build on a clean slate:
- add an "accessible" interface, implemented by GTK objects directly,
which describe the accessible role and state changes for every UI
element
- add an "assistive technology context" to proxy a native accessibility
API, and assign it to every widget
- implement the AT context depending on the platform
For more information, see: https://gitlab.gnome.org/GNOME/gtk/-/issues/2833
2.7 KiB
Compiling GTK Applications on UNIX
To compile a GTK application, you need to tell the compiler where to
find the GTK header files and libraries. This is done with the
pkg-config utility.
The following interactive shell session demonstrates how pkg-config
is used (the actual output on your system may be different):
$ pkg-config --cflags gtk4
-pthread -I/usr/include/gtk-4.0 -I/usr/lib64/gtk-4.0/include -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng12
$ pkg-config --libs gtk4
-pthread -lgtk-4 -lgdk-4 -lgio-2.0 -lpangoft2-1.0 -lgdk_pixbuf-2.0 -lpangocairo-1.0 -lcairo -lpango-1.0 -lfreetype -lfontconfig -lgobject-2.0 -lgmodule-2.0 -lgthread-2.0 -lrt -lglib-2.0
The simplest way to compile a program is to use the "backticks" feature of the shell. If you enclose a command in backticks (not single quotes), then its output will be substituted into the command line before execution. So to compile a GTK Hello, World, you would type the following:
$ cc `pkg-config --cflags gtk4` hello.c -o hello `pkg-config --libs gtk4`
Deprecated GTK functions are annotated to make the compiler
emit warnings when they are used (e.g. with gcc, you need to use
the -Wdeprecated-declarations option). If these warnings are
problematic, they can be turned off by defining the preprocessor
symbol %GDK_DISABLE_DEPRECATION_WARNINGS by using the commandline
option -DGDK_DISABLE_DEPRECATION_WARNINGS.
GTK deprecation annotations are versioned; by defining the macros %GDK_VERSION_MIN_REQUIRED and %GDK_VERSION_MAX_ALLOWED, you can specify the range of GTK versions whose API you want to use. APIs that were deprecated before or introduced after this range will trigger compiler warnings.
Here is how you would compile hello.c if you want to allow it to use symbols that were not deprecated in 4.2:
$ cc `pkg-config --cflags gtk4` -DGDK_VERSION_MIN_REQUIRED=GDK_VERSION_4_2 hello.c -o hello `pkg-config --libs gtk4`
And here is how you would compile hello.c if you don't want it to use any symbols that were introduced after 4.2:
$ cc `pkg-config --cflags gtk4` -DGDK_VERSION_MAX_ALLOWED=GDK_VERSION_4_2 hello.c -o hello `pkg-config --libs gtk4`
The older deprecation mechanism of hiding deprecated interfaces
entirely from the compiler by using the preprocessor symbol
GTK_DISABLE_DEPRECATED is still used for deprecated macros,
enumeration values, etc. To detect uses of these in your code,
use the commandline option -DGTK_DISABLE_DEPRECATED.
There are similar symbols GDK_DISABLE_DEPRECATED,
GDK_PIXBUF_DISABLE_DEPRECATED and G_DISABLE_DEPRECATED for GDK,
GdkPixbuf and GLib.