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 from the context menu or the menu of a Tracker window. Some add-ons don't necessarily need a file to work on and are thus always present.
Tracker Add-Ons, or links to applications that can act as add-ons, can be installed in three different locations (see topic Filesystem layout):
| /boot/system/system/add-ons/Tracker/ | for system provided add-ons. | |
| /boot/common/add-ons/Tracker/ | for add-ons available to every user. | |
| /boot/home/config/add-ons/Tracker/ | for add-ons only available to yourself. |
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, Open Target Folder-T opens with ALT AltGr T (at least with my keymap, you may have a different key combination).
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.
Haiku's Tracker Add-Ons
These Tracker Add-Ons come with every Haiku installation:
| Background-B | Opens the Background 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. |
| DiskUsage-I | Starts the DiskUsage application with the according folder as basis. |
| FileType-F | Invoked on a file, opens its specific FileType panel, otherwise the general FileTypes preferences are launched. |
| Open Target Folder-T | It can only be used on a linked file and opens the folder that file lives in. |
| TextSearch-G | Starts the TextSearch application to look for a string in the selected folder (and its subfolders). |
| ZipOMatic-Z | 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. |