<p>Applications can install add-ons so they can be invoked easily on a selection of files from Tracker. Only the add-ons that can handle a specific filetype are presented under <spanclass="menu">Add-Ons</span> from the context menu or the <spanclass="menu">File</span> menu of a Tracker window. Some add-ons don't necessarily need a file to work on and are thus always present.</p>
<p>New Tracker add-ons that don't come as part of a regular .hpkg package, can be installed by copying them into their respective non-packaged folder (see topic <ahref="filesystem-layout.html">Filesystem layout</a>):</p>
<p>The file name of an add-on can be suffixed with a dash and capital letter, and is then available via keyboard shortcut. For example, <spanclass="app">Open Target Folder-O</span> opens with <spanclass="key">ALT</span><spanclass="key">OPT</span><spanclass="key">O</span>.<br/>
Of course, you have to take care of possible shortcut collisions when deciding on a shortcut. You can't have the same for different add-ons.</p>
<tdvalign="top">Opens the <ahref="preferences/backgrounds.html">Background</a> preferences to change the color or image of the Desktop or any folder. Invoked on an image file the Background panel is launched with that image already loaded as a potential background.</td></tr>
<tdvalign="top">Invoked on a file, opens its specific <ahref="filetypes.html">FileType</a> panel, otherwise the general FileTypes preferences are launched.</td></tr>
<tdvalign="top">Starts the <ahref="applications/textsearch.html">TextSearch</a> application to look for a string in the selected folder (and its subfolders).</td></tr>
<tdvalign="top">A selection of files will be added to a zip archive, invoked without a selection opens a panel to create an archive via drag & drop.</td></tr>
