LibreOffice (LO) is a familiar sight on most Linux desktops. The free office suite is capable of handling spreadsheets, presentations, word processing documents, drawings, and more. A powerful collection of capabilities is already built into the default configuration, but if you're looking for more power – and more convenience – LO also supports an ecosystem of extensions. The LO project maintains an extensions page [1] with extensions available for easy download. The most popular extensions appear in the main window, and dozens of other extensions are available by browsing or searching.

To integrate an extension with your own LO installation, download the extension, then click Tools in the LO main window, and select Extension Manager. Click on the Add button and specify the path to the extension (file suffix OXT or ZIP). Confirm this setting with OK and restart LO to include the add-on. You then typically access the extension via Tools | Add-Ons, unless the specific tool adds a main menu entry or icon for itself.

This article highlights some of my favorite LO extensions.

More Convenience

The PDF, Export and Send [2] plugin converts a document opened in an LO application into a PDF and automatically attaches it to an email message.

According to the description at the LO Extensions page, this helpful extension "combines two regular functions in one." PDF, Export and Send is intended for users who regularly tweak ODT templates with customized information to email quotes, invoices, or other documents to customers or other business contacts.

In LO Writer, the appearance of the PDF successfully matches the original in most cases. With LO Calc, you might need to change the page settings to avoid truncating tables. If you run out of table space, you might just need to change the page layout from portrait to landscape format by selecting Format | Page and clicking on the Page tab in the dialog. In the Table tab of the same window, you can bundle several pages into one sheet, if necessary, by selecting scaling mode Fit print range(s) on number of pages and limiting the number of pages (Figure 1). This setting tells LO to print several pages on one sheet, which also applies to the PDF document. You can check the results in the preview by selecting File | Print Preview.

Figure 1: The Scale setting shown in the figure causes LO Calc to print several pages on one sheet.

You'll find the most important settings for PDF, Export and Send in the General tab. For example, you can define the resolution and the compression factor for images. In addition to PDFs, the tool also exports HTML, XML, and FDF files. If you need the LO document in other formats, you can save a huge amount of time with MultiSave [3]. After clicking on its icon, MultiSave saves the opened document as ODF, PDF, MS Office, and RTF all at once.

More Styles and Colors

The CADLO extension [4] turns LO Draw into a CAD program. CADLO determines coordinates, dimensions lines, locates arcs, draws polygons, and performs other tasks that make Draw behave more like a conventional drafting program (Figure 2). If you have shapes that intersect, the remainder can be removed. A polygon tool can create arbitrary shapes with multiple corners and edges. When you connect lines, CADLO highlights the line you want to connect in color and snaps the connecting line into place.

Figure 2: With the CADLO extension, you can create arcs of different sizes in LO Draw.

The Parabolic Colour Palette [5] extension offers more varied gradations for both light colors and gray tones (Figure 3). You can integrate this extension manually by copying the files with the .soc suffix into the LO user folder and then restarting the application (Listing 1). Then call up the color palette by selecting one of the entries beginning with parabolic in the color settings.

Figure 3: The Parabolic Colour Palette offers numerous light and pastel shades to prevent dark printouts.

One of the most efficient LO extensions is Change Picture [6]. The Change Picture extension lets you replace one image with another in LO while maintaining the scaling as well as the position and size of the previous image.

Language Fluency

The LanguageTool extension [7] not only detects spelling mistakes but also simple grammar errors – even for multiple languages. The add-on requires an existing Java Runtime Environment (JRE) [8], which you have to activate additionally in LO. Click Tools | Options | LibreOffice | Advanced and elect to let LO use Java. You also need to select a specific JRE in the same window (Figure 4). You can call the plugin itself via Tools | LanguageTool.

Figure 4: Java-based plugins need access to the JRE.

Another tool that is all about languages goes by the name of Code Highlighter [9]. The add-on color highlights the code in several programming languages with just a few clicks. To do so, it needs Python 3 and the python3-pygments package, which you can install using your distribution's package manager.

Insert a text field into the document by clicking on the corresponding icon or via Insert | Text Box. Place your code snippet there, and you can then spice it up with color by selecting Tools | Highlight Code and subsequently choosing a programming language (Figure 5).

Figure 5: The Code Highlighter displays keywords of a programming language in color.