Icontheme

D library for dealing with icon themes in freedesktop environments.

Online documentation

The most of desktop environments on GNU/Linux and BSD flavors follow Icon Theme Specification when searching for icons. The goal of icontheme library is to provide implementation of this specification in D programming language. Please feel free to propose enchancements or report any related bugs to Issues page.

Platform support

The library is crossplatform for the most part, though there's little sense to use it on systems that don't follow freedesktop specifications. icontheme is developed and tested on FreeBSD and Debian GNU/Linux.

Features

Implemented features

icontheme provides all basic operations to deal with icon themes and icon lookup:

• Reading index.theme files.
• Icon lookup. Finding the icon file closest to given size.
• Lookup of fallback icons that don't belong to any theme.
• Reading and using icon-theme.cache files. Those are usually generated by gtk-update-icon-cache. This is not actually the part of specification, but icon caches are quite common nowadays.
• Automatic detection of icon theme currently used in the system. The specification does not indicate any unified way to detect a current icon theme, so the library implements a limited number of desktop-specific checks and assumptions.

Missing features

Features that currently should be handled by user, but may be implemented in the future versions of library.

• Installing icons to writable path.
• Some features regarding icon theme caches are missing, because I could not find specification on this topic.

Brief

import std.array;
import std.exception;
import std.stdio;

import icontheme;

try {
    string[] searchIconDirs = baseIconDirs(); // Base directories to search themes and icons

    // First read icon theme and all related information.

    string themeName = ...; // theme name, e.g. "gnome" for GNOME, "oxygen" for KDE4, etc.

    IconThemeFile[] iconThemes;
    IconThemeFile iconTheme = openIconTheme(themeName, searchIconDirs); // Read index.theme file contained description if icon theme.

    if (iconTheme) {
        writeln("Name: ", iconTheme.name); // Display name of icon theme.
        writeln("Comment: ", iconTheme.comment); // Extended comment on icon theme.
        writeln("Is hidden: ", iconTheme.hidden); // Whether to hide the theme in a theme selection user interface.
        writeln("Subdirectories: ", iconTheme.directories); // Sub directories of icon theme.
        writeln("Inherits: ", iconTheme.inherits()); // Names of themes the main theme inherits from.
        writeln("Example: ", iconTheme.example()); // The name of an icon that should be used as an example of how this theme looks.

        iconThemes ~= iconTheme;
        iconThemes ~= openBaseThemes(iconTheme, searchIconDirs); // find and load themes the main theme inherits from.
    } else {
        stderr.writeln("Could not find theme");
    }

    foreach(theme; iconThemes) {
        theme.tryLoadCache(); // Use cache on icon lookups.
    }

    // Now search for icon by name

    // Allowed extensions of image files, in order of preference. Put here extensions that your application supports.
    // Icon Theme Specification requires to support PNG and XPM. SVG support is optional.
    string[] extensions = [".png", ".xpm"];

    string iconName = ...; // Some icon name, e.g. "folder" or "edit-copy".


    // Find largest icon file with such name among given themes and directories.
    string iconPath = findLargestIcon(iconName, iconThemes, searchIconDirs, extensions);

    // Or find icon file with size nearest to desired.

    size_t size = ...; // Desired icon size.
    iconPath = findClosestIcon(iconName, size, iconThemes, searchIconDirs, extensions);

    // ... load icon from iconPath using preferable image library.
}
catch(IniLikeException e) { // Parsing error - found icon theme file is invalid or can't be read
    stderr.writeln(e.msg);
}

Examples

Describe icon theme

Prints the basic information about theme to stdout.

dub examples/describe.d gnome
dub examples/describe.d oxygen

You also can pass the absolute path to file:

dub examples/describe.d /usr/share/icons/gnome/index.theme

Or directory:

dub examples/describe.d /usr/share/icons/gnome

Icon theme test

Parses all found index.theme and icon-theme.cache files in base icon directories. Writes errors (if any) to stderr. Use this example to check if the icontheme library can parse all themes and theme caches on your system.

dub examples/test.d

Run to print names of all examined index.theme and icon-theme.cache files to stdout:

dub examples/test.d --verbose

Find icon

Utility that finds icon by its name. By default it tries to detect the current icon theme automatically.

dub examples/findicon.d edit-copy

You can specify another theme:

dub examples/findicon.d --theme=gnome folder
dub examples/findicon.d --theme=oxygen text-plain

And preferred size:

dub examples/findicon.d --theme=gnome --size=32 folder

Allow using cache:

dub examples/findicon.d --theme=gnome edit-copy --useCache

Print icons

Search icons in specified theme:

dub examples/print.d --theme=gnome > result.txt

Include hicolor theme, base themes and icons that don't belong to any theme:

dub examples/print.d --include-nonthemed --include-hicolor --include-base --theme=Faenza > result.txt