GNOME, Its State and Future

The GNOME team bring us up-to-date on the progress of this popular desktop environment.
Image Handling

GNOME 1.0 utilized the Imlib software library for image loading and manipulation. While Imlib fits the needs of some applications, its design does not mesh well with the typical GNOME use case. As a replacement, libart, an RGBA image-manipulation library, and GdkRGB, an API to allow high-performance display of RGB images, are integrated together in gdk-pixbuf, an image-loading library that solves the problems of Imlib and adds features such as anti-aliasing and high-quality rendering.

Canvas and Libart

GNOME 1.0 included libart and the anti-aliased canvas, but it was not used very much, and the anti-aliased canvas was marked as unstable. In the future, GNOME will use libart and the anti-aliased canvas much more. The new GNOME panel and GNOME pixmap widget already use libart and gdk-pixbuf to provide anti-aliased icons.

Glade and Libglade

Glade is a GUI designer which is currently being used in much of the new GNOME development. Normally, Glade will generate source code to build the interface you create. However, the truly revolutionary and useful way to use Glade is in combination with Libglade.

Libglade is a library that will load a saved Glade project and build the interface for you—on the fly. This means you could conceivably have different interface files for different languages, application modes or themes. It also gives the user the ultimate power of customization, since the interface of the application can be modified without any programming skill.

Various GNOME applications are now designed with Glade, and this substantially reduces their development time. It is easy to prototype, easy to customize and easy to extend. The joy has arrived.

Printing

UNIX printing is both a blessing and a curse, and while it may be flexible, it has always been hard to set up, and output quality was often low on non-PostScript printers. In addition, most applications didn't even include printing support, because no convenient, unified API was available for printing on UNIX. GNOME Print is a library which allows developers to easily add printing capabilities to their applications, and users to quickly and easily access all the output parameters through a consistent graphical interface.

Figure 6. GNOME Desktop, Using Anti-Aliasing

The GNOME Print imaging model is based on PostScript, with two extensions: anti-aliasing and transparency. Please note that I said “an imaging model based on PostScript”, not PostScript. You have the same imaging model, but the way you print is by using an API exported to your favorite language.

Currently, GNOME Print includes a PostScript driver, an on-screen driver (for doing previews), meta-file drivers (for storing printed information, transferring it, and rendering it on a scaled context) and a generic RGB driver (on which we will build the per-printer actual printer drivers).

As you might expect, we do reuse our technologies. The rasterization engine used in the canvas is the same rasterization engine used for the on-screen preview and for rasterizing the output for the native printer drivers. If you are interested in working on the native drivers, we most definitely welcome your help.

Work in Progress

The GNOME Project is not resting on its laurels. While the 1.0 release series addresses the basic need for a UNIX GUI, portions of the existing implementation need refinement, as well as additional features which are becoming essential on a modern desktop.

At the same time, the GNOME 1.0 API will still be supported through compatibility libraries, so that the migration of existing source code to the new libraries will be painless. This will allow developers to focus on the application development instead of having to worry about following GNOME API changes.

The New File Manager

The file manager is being completely redesigned. The new version will feature an asynchronous, network transparent virtual file system which is usable from all applications independent of the file manager. This will make it easy to have applications that are network aware, and it will make network administration a snap. This step forward from traditional virtual file system libraries, which are not asynchronous, allows better responsiveness from graphical applications.

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