diff --git a/docs/gtk/overview.md b/docs/gtk/overview.md new file mode 100644 index 0000000000..0ae6a19157 --- /dev/null +++ b/docs/gtk/overview.md @@ -0,0 +1,134 @@ +# wxWidgets on the GNOME Desktop + +wxWidgets is a C++ cross-platform GUI library, whose distintive feature is the +use of native calls and native widgets on the respective platform, i.e. an +application compiled for the Linux platform will use the [GTK+][] library for +displaying the various widgets. There is also a version ("port") of wxWidgets +which uses the Motif toolkit for displaying its widgets (this port is commonly +referred to as wxMotif) and another one, which only uses X11 calls and which +draws its widgets entirely itself, without using any outside library. This port +is called wxX11 or sometimes more generally wxUniv (short for wxUniversal), +since this widget set (implemented entirely within wxWidgets) is available +wherever wxWidgets is available. Since this short overview is mainly about how +to write wxWidgets applications for the [GNOME][] desktop, I will focus on the +GTK+ port, which is generally referred to as wxGTK. + +wxGTK still supports the old version GTK+ 1.2, but it now defaults to the +uptodate version GTK+ 2.X, which is the basis for the current GNOME desktop. By +way of using GTK+ 2.X and its underlying text rendering library [Pango][], wxGTK +fully supports the Unicode character set and it can render text in any language +and script, that is supported by Pango. + +[GTK+]: http://www.gtk.org/ +[GNOME]: https://www.gnome.org/ +[Pango]: http://www.pango.org/ + +## Design Principles + +The three main design goals of the wxWidgets library are portability across the +supported platforms, complete integration with the supported platforms and a +broad range of functionality covering most aspects of GUI and non-GUI +application programming. Sometimes, various aspects of these design goals +contradict each other and this holds true especially for the Linux platform +which – from the point of view of the desktop environment integration – is +lagging behind the other two major desktops (Windows and OS X) mostly because of +the schism between the GTK+ based GNOME desktop and the [Qt][] based [KDE][] +desktop. So far, the typical wxWidgets user targeted Windows, maybe OS X and +Linux _in general_, so the aim was to make wxGTK applications run as well as +possible on as many versions of Linux as possible, including those using the KDE +environment. Luckily, most of these distributions included the GTK+ library (for +running applications like the GIMP, GAIM, Evolution or Mozilla) whereas the +GNOME libraries were not always installed by default. Also, the GNOME libraries +didn't really offer substantial value so that the hassle of installing them was +hardly justified. Therefore, much effort was spent on making wxGTK fully +functional without relying on the GNOME libraries, mostly by reimplementing as +much as sensible of the missing functionality. This included a usable file +selection dialog, a printing system for PostScript output, code for querying +MIME-types and file-icon associations, classes for storing application +preferences and configurations, the possibility to display mini-apps in the +taskbar, a full-featured HTML based help system etc. With all that in place you +can write a pretty fully featured wxWidgets application on an old Linux system +with little more installed than X11 and GTK+. + +[Qt]: http://www.qt.io/ +[KDE]: https://www.kde.org/ + +## Recent Developments + +Recently, several key issues have been addressed by the GNOME project. Sometimes +integrated into the newest GTK+ releases (such as the file selecter), sometimes +as part of the GNOME libraries (such as the new printing system with Pango +integration or the mime-types handling in gnome-vfs), sometimes as outside +projects (such as the media/video backend based on the [Gstreamer][] project). +Also, care has been taken to unify the look and feel of GNOME applications by +writing down a number of rules (modestly called +["Human Interface Guidelines"][GNOME-HIG]) and more and more decisions are taken +in a desktop neutral way (for both GNOME and KDE), mostly as part of the +[FreeDesktop][] initiative. This development together with the rising number of +OpenSource projects using wxWidgets mainly for the Linux and more specifically +GNOME desktop has led to a change of direction within the wxWidgets project, now +working on making more use of GNOME features when present. The general idea is +to call the various GNOME libraries if they are present and to offer a +reasonable fallback if not. I'll detail on the various methods chosen below: + +[Gstreamer]: http://gstreamer.freedesktop.org/ +[GNOME-HIG]: http://developer.gnome.org/projects/gup/hig +[FreeDesktop]: http://www.freedesktop.org/ + +## Printing System + +The old printing system .... + +## MIME-type Handling + +The old mime-type system used to simply query some files stored in "typical" +locations for the respective desktop environment. Since both the format and the +location of these files changed rather frequently, this system was never fully +working as desired for reading the MIME-types and it never worked at all for +writing MIME-types or icon/file associations. ... + +## File Dialogs + +Previously, wxGTK application made use of a file dialog written in wxWidgets +itself, since the default GTK+ file dialog was simplistic to say the least. This +has changed with version GTK+ 2.4, where a nice and powerful dialog has been +added. wxGTK is using it now. + +## File Configuration and Preferences + +The usual Unix way of saving file configuration and preferences is to write and +read a so called "dot-file", basically a text file in a user's home directory +starting with a dot. This was deemed insufficient by the GNOME desktop project +and therefore they introduced the so called GConf system, for storing and +retrieving application and sessions information.... + +## Results and Discussion + +One of wxWidgets' greatest merits is the ability to write an application that +not only runs on different operating systems but especially under Linux even on +rather old systems with only a minimal set of libraries installed – using a +single application binary. This was possible since most of the relevant +functionality was either located in the only required library (GTK+) or was +implemented within wxWidgets. Recent development outside the actual GTK+ project +has made it necessary to rethink this design and make use of other projects' +features in order to stay uptodate with current techological trends. Therefore, +a system was implemented within wxWidgets that queries the system at runtime +about various libraries and makes use of their features whenever possible, but +falls back to a reasonable solution if not. The result is that you can create +and distribute application binaries that run on old Linux systems and integrate +fully with modern desktops, if they are available. This is not currently +possible with any other software. + +Copyright 2004 © Robert Roebling, MD. No reprint permitted without written prior +authorisation. Last modified 14/11/04. + +## About the Author + +Robert Roebling works as a medical doctor in the Department of Neurology at the +University clinic of Ulm in Germany. He has studied Computer Sciences for a few +semesters and is involved in the wxWidgets projects since about 1996. He has +started and written most of wxGTK port (beginning with GTK+ around 0.9) and has +contributed to quite a number projects within wxWidgets, ranging from the image +classes to Unicode support to making both the Windows and the GTK+ ports work on +embedded platform (mostly PDAs). He is happily married, has two children and +never has time. diff --git a/docs/gtk/wxGNOME/wxGNOME.html b/docs/gtk/wxGNOME/wxGNOME.html deleted file mode 100644 index 2b9df2577a..0000000000 --- a/docs/gtk/wxGNOME/wxGNOME.html +++ /dev/null @@ -1,161 +0,0 @@ - - - - - - - - - - -

Whitepaper: wxWidgets on the GNOME desktop

-

Introduction

-

wxWidgets[1] -(formely known as wxWindows) is a C++ cross-platform GUI library, -whose distintive feature is the use of native calls and native -widgets on the respective platform, i.e. an application compiled for -the Linux platform will use the GTK+[2] -library for displaying the various widgets. There is also a version -(„port“) of wxWidgets which uses the Motif toolkit for -displaying its widgets (this port is commonly referred to as wxMotif) -and another one, which only uses X11 calls and which draws its -widgets entirely itself, without using any outside library. This port -is called wxX11 or sometimes more generally wxUniv (short for -wxUniversal), since this widget set (implemented entirely within -wxWidgets) is available wherever wxWidgets is available. Since this -short overview is mainly about how to write wxWidgets applications -for the GNOME[3] -desktop, I will focus on the GTK+ port, which is generally referred -to as wxGTK. -

-

wxGTK still supports the old version GTK+ 1.2, but it now defaults -to the uptodate version GTK+ 2.X, which is the basis for the current -GNOME desktop. By way of using GTK+ 2.X and its underlying text -rendering library Pango[4], -wxGTK fully supports the Unicode character set and it can render text -in any language and script, that is supported by Pango.

-

wxWidgets' -design principles sofar

-

The three main design goals of the wxWidgets library are -portability across the supported platforms, complete integration with -the supported platforms and a broad range of functionality covering -most aspects of GUI and non-GUI application programming. Sometimes, -various aspects of these design goals contradict each other and this -holds true especially for the Linux platform which – from the -point of view of the desktop environment integration – is -lagging behind the other two major desktops (Windows and OS X) -mostly because of the schism between the GTK+ based GNOME desktop and -the Qt[5] based -KDE[6] desktop. So far, -the typical wxWidgets user targeted Windows, maybe OS X and Linux -in general, so the aim was to make wxGTK applications run as -well as possible on as many versions of Linux as possible, including -those using the KDE environment. Luckily, most of these distributions -included the GTK+ library (for running applications like the GIMP, -GAIM, Evolution or Mozilla) whereas the GNOME libraries were not -always installed by default. Also, the GNOME libraries didn't really -offer substantial value so that the hassle of installing them was -hardly justified. Therefore, much effort was spent on making wxGTK -fully functional without relying on the GNOME libraries, mostly by -reimplementing as much as sensible of the missing functionality. This -included a usable file selection dialog, a printing system for -PostScript output, code for querying MIME-types and file-icon -associations, classes for storing application preferences and -configurations, the possibility to display mini-apps in the taskbar, -a full-featured HTML based help system etc. With all that in place -you can write a pretty fully featured wxWidgets application on an -old Linux system with little more installed than X11 and GTK+.

-

Recent -developments

-

Recently, several key issues have been addressed by the GNOME -project. Sometimes integrated into the newest GTK+ releases (such as -the file selecter), sometimes as part of the GNOME libraries (such as -the new printing system with Pango integration or the mime-types -handling in gnome-vfs), sometimes as outside projects (such as the -media/video backend based on the Gstreamer[7] -project). Also, care has been taken to unify the look and feel of -GNOME applications by writing down a number of rules (modestly called -„Human Interface Guidelines“[8]) -and more and more decisions are taken in a desktop neutral way (for -both GNOME and KDE), mostly as part of the FreeDesktop[9] -initiative. This development together with the rising number of -OpenSource projects using wxWidgets mainly for the Linux and more -specifically GNOME desktop has led to a change of direction within -the wxWidgets project, now working on making more use of GNOME -features when present. The general idea is to call the various GNOME -libraries if they are present and to offer a reasonable fallback if -not. I'll detail on the various methods chosen below:

-

Printing -system

-

The old printing system ....

-

MIME-type -handling

-

The old mime-type system used to simply query some files stored in -„typical“ locations for the respective desktop -environment. Since both the format and the location of these files -changed rather frequently, this system was never fully working as -desired for reading the MIME-types and it never worked at all for -writing MIME-types or icon/file associations. ...

-

The -new file dialog

-

Previously, wxGTK application made use of a file dialog written in -wxWidgets itself, since the default GTK+ file dialog was simplistic -to say the least. This has changed with version GTK+ 2.4, where a -nice and powerful dialog has been added. wxGTK is using it now.

-

File -configuration and preferences

-

The usual Unix way of saving file configuration and preferences is -to write and read a so called „dot-file“, basically a -text file in a user's home directory starting with a dot. This was -deemed insufficient by the GNOME desktop project and therefore they -introduced the so called GConf system, for storing and retrieving -application and sessions information....

-

Results -and discussion

-

One of wxWidgets' greatest merits is the ability to write an -application that not only runs on different operating systems but -especially under Linux even on rather old systems with only a minimal -set of libraries installed – using a single application binary. -This was possible since most of the relevant functionality was either -located in the only required library (GTK+) or was implemented within -wxWidgets. Recent development outside the actual GTK+ project has -made it necessary to rethink this design and make use of other -projects' features in order to stay uptodate with current -techological trends. Therefore, a system was implemented within -wxWidgets that queries the system at runtime about various libraries -and makes use of their features whenever possible, but falls back to -a reasonable solution if not. The result is that you can create and -distribute application binaries that run on old Linux systems and -integrate fully with modern desktops, if they are available. This is -not currently possible with any other software.

-

Copyright 2004 © Robert Roebling, MD. No reprint permitted -without written prior authorisation.
Last modified 14/11/04

-

About -the author

-

Robert Roebling works as a medical doctor in the Department of -Neurology at the University clinic of Ulm in Germany. He has studied -Computer Sciences for a few semesters and is involved in the -wxWidgets projects since about 1996. He has started and written most -of wxGTK port (beginning with GTK+ around 0.9) and has contributed to -quite a number projects within wxWidgets, ranging from the image -classes to Unicode support to making both the Windows and the GTK+ -ports work on embedded platform (mostly PDAs). He is happily married, -has two children and never has time.

-

Links -and citations

-

[1] See the wxWidgets homepage at www.wxwidgets.org.
[2] -See the GTK+ homepage at www.gtk.org.
[3] -See more about GNOME at www.gnome.org, -www.gnomedesktop.org, -www.gnomejournal.org, -www.gnomefiles.org.
[4] -See the Pango homepage at www.pango.org.
[5] -See the Qt homepage at www.trolltech.com.
[6] -See the KDE homepage at www.kde.org.
[7] -See Gstreamer homepage at gstreamer.freedesktop.org.
[8] -See GNOME's Human Interface Guidelines at -developer.gnome.org/projects/gup/hig.
[9] -See FreeDesktop's homepage at www.freedesktop.org.


-

- -