9.3 Installing Themes
A theme is a group of coordinated settings that specifies the
visual appearance of a part of the GNOME Desktop. Users can select
themes to change the appearance of the GNOME Desktop.
A theme contains settings that affect different parts of the
GNOME Desktop, as follows:
- Controls
-
Determines the visual appearance of windows, panels, and
applets. It also determines the visual appearance of the
GNOME-compliant interface items that appear on windows, panels,
and applets (such as menus, icons, and buttons). Some of the
controls setting options that are available are designed for
special accessibility needs. Users can select an option for the
controls setting from the Controls tabbed section in the Theme
preference tool.
- Window frame
-
Determines the appearance of the frames around windows only.
Users can select an option for the window frame setting from the
Window Border tabbed section in the Theme preference tool.
- Icon
-
Determines the appearance of the icons on panels and the
desktop background. Users can select an option for the icon
setting from the Icons tabbed section in the Theme preference
tool.
9.3.1 Theme Index File
Each theme has an index file which defines the characteristics
of the theme. The name of the index file is
/opt/gnome/share/themes/theme-name/index.theme.
The following is a sample theme index file:
[Desktop Entry]
Type=X-GNOME-Metatheme
Name=High Contrast Large
Name[es]=Alto contraste grande
Comment=Large black-on-white text and icons
Comment[es]=Textos e iconos grandes en negro sobre blanco
Encoding=UTF-8
[X-GNOME-Metatheme]
GtkTheme=HighContrastLargePrint
IconTheme=HighContrast
MetacityTheme=Atlanta
ApplicationFont=sans 18
The following table describes the keys in theme index files:
Table 9-10 Theme Index File Keys
|
Type |
Specifies that this theme determines the appearance of
several theme options, such as controls, window frames, and
icons. |
|
Name |
The name of the theme, which is displayed in the Theme
preference tool. |
|
Comment |
A brief description of the theme, which is displayed under
the name of the theme in the Theme preference tool. |
|
GtkTheme |
Corresponds to the controls setting in the Theme
preference tool. Specifies which controls setting option to
apply to windows, panels, and applets. |
|
IconTheme |
Corresponds to the icons setting in the Theme preference
tool. Specifies which icons setting option to apply to panels
and the desktop background. |
|
MetacityTheme |
Corresponds to the window frame setting in the Theme
preference tool. Specifies which window frame setting option to
apply to windows. |
|
ApplicationFont |
Corresponds to the application font setting in the Font
preference tool. |
9.3.2 Installing a New Controls Option
You can add a new option for the controls setting in the Theme
preference tool. Controls options reside in the
/opt/gnome/share/themes
directory. The typical structure of a controls option in the file
system is as follows.
Option file
/opt/gnome/share/themes/option-name/gtk-2.0/gtkrc
Image files
/opt/gnome/share/themes/option-name/pixmaps/*.*
Typically, a new option for the controls setting is supplied as
a .tar.gz file. To install the new controls
option, unzip the .tar.gz file and then untar
the .tar file into the
/opt/gnome/share/themes
directory.
Users can install their own options for the controls setting.
If a user installs an option for the controls setting, the option is
stored in the $HOME/.themes
directory.
9.3.3 Installing a New Window Frame Option
You can add a new option for the window frame setting in the
Theme preference tool. Window frame options reside in the
/opt/gnome/share/themes/option-name/metacity-1
directory. The typical structure of a window frame option in the
file system is as follows.
Option file
/opt/gnome/share/themes/option-name/metacity-1/metacity-theme-1.xml
Image files
/opt/gnome/share/themes/option-name/metacity-1/*.*
Typically, a new option for the window frame setting is
supplied as a .tar.gz file. To install the new
window frame option, unzip the .tar.gz file and
then untar the .tar file into the
/opt/gnome/share/themes
directory.
Users can install their own options for the window frame
setting. If a user installs an option for the window frame setting,
the option is stored in the
$HOME/.themes directory.
9.3.4 Installing a New Icons Option
You can add a new option for the icons setting in the Theme
preference tool. Icons options reside in the
/opt/gnome/share/icons/option-name
directory. The typical structure of an icons option in the file
system is as follows.
Option file
/opt/gnome/share/icons/option-name
Image files
/opt/gnome/share/icons/option-name/icons/*.*
Typically, a new option for the icons setting is supplied as a
.tar.gz file. To install the new icons option,
unzip the .tar.gz file and then untar the
.tar file into the
/opt/gnome/share/icons
directory.
Users can install their own options for the icons setting. If a
user installs an option for the icons setting, the option is stored
in the
$HOME/.icons/option-name
directory.
9.3.5 Installing Icons for Themes
The GNOME Desktop provides several themes that are designed for
users with special visual needs. For example, some of the themes are
designed for users with low vision. Several versions of icons might
be required so that the icon can be displayed properly in each
theme.
You might need to install a new icon for an application. When
you install a new icon, you must create several versions of the icon
so that the icon displays correctly in the themes. You must create
several versions of the following types of icon:
You can create the icons in several formats (for example,
Portable Network Graphic (PNG) format). The suggested size of icons
for the desktop environment is 48 x 48 pixels; at this size, most
themes can rescale the icons.
When you install a new icon, create the following 48 x 48 pixel
versions of the icon:
If possible, also create 16 x 16 pixel versions of the each of
the icons above, for themes that do not require large print.
Install the icons to the image files location that is specified
for the theme in
Installing a New Controls Option or
Installing a New Window Frame Option. For example, to add icons to the HighContrastLargePrint
theme, add the icons to the
/opt/gnome/share/themes/HighContrastLargePrint/pixmaps
directory. Add references to the icons to the relevant theme files.
For example, to add icons to the HighContrastLargePrint theme, add
references to the icons to the
/opt/gnome/share/themes/HighContrastLargePrint/
gtk-2.0/gtkrc file. Modify the gtkrc file for
the theme to associate the icon with a GTK stock icon identifier.
For more information on how to create icons for application
launchers and panels, see the Icon
Themes.
9.3.6 Creating a Custom Controls Option
If the options for the controls setting are not suitable for
the needs of your users, you can create a custom controls option.
-
Create a directory structure for the option in the
/opt/gnome/share/themes
directory.
Use the same directory structure that other options use. For
example, to create an option that is called SmallPrint, create the
following directories:
-
Locate the gtkrc file that is closest to meeting the needs of
your users, then copy the file to the gtk-2.0
directory of your new option.
-
Open the gtkrc file in a text editor and
modify the attributes of the interface elements as needed.
-
(Conditional) If the new option includes images, install the
images for the new option in the pixmaps directory of your new
option.
If the new option uses images from another option, you do not
need to create copies of the images for the new option. Instead,
make sure that the reference to the images in the
pixmap_path entry in the
gtkrc file is correct.
Users can now select the new option for the controls setting.
For more information on gtkrc files, see the
GTK+ Reference Manual
.
