I need to write a lot of class courses presentations to my programming class, and I constantly need to show source code (mainly C
Some people says that copying code from Eclipse editor works well (UPDATE: Proven FALSE). Another alternative is exporting to RTF (can also export line numbers), or to clipboard, from Highlight and then opening/pasting it in OpenOffice.org. (UPDATE: Proven TRUE)
Here is a Highlight GUI screen shot:
You can also switch from OpenOffice.org to LibreOffice, and get COOoder from here.
This answer is perfect for the job:
I have exactly the same problem, but with PHP code rather than C. My almost-solution is to copy the code as HTML in Kate and paste it into a temporary Open Office Writer document. That converts it to Open Office's own styled text format, and from there you can copy and paste it into Impress. Aside from the slightly annoying double-step copy-and-paste, this mostly works fine except that lines that were entirely in bold lose their emboldening and I have to manually fix them. A few other strange bugs can occur too - Impress's import of styled text from OOWriter appears to be a bit buggy.
If you are familiar with LaTeX, you should consider using beamer to create your presentation. The wikipedia page has pointers to many tutorials and documents. The user guide is probably the best one I've found.
This can give you all the power of LaTeX for source code snippets (listings package or any other you prefer) along with the rest of the usual features of LaTeX that you're used to. It comes bundled with a score of really nice themes.
You can do this easily
I have tested this with LibreOffice 4.2.8 under Ubuntu.
I do this all the time with open office with source code under Windows. View the code in your favorite editor (emacs, notepad, ...), and select/copy the text of interest. Make a text box in open office, and paste. This works because all of Windows tools share a global cut buffer. I don't use Linux enough to know if it has such a shared cut-buffer, if it doesn't, I kind of understand your problem.( If it does, I really don't understand your problem). My solution of course doesn't get nicely formatted/highlighted code by itself.
Specific steps: In Open Office Impress ("Presentation") with a slide open, click the box labelled "T" on the lower tool bar (or push F2). Then click on the slide roughly where you want the the text, and drag to make the box about the right size. Click in box and you can enter text. For code, I cut from some editor window, and paste after selecting the text box. If you click on the outline of the text box, you can change the font (courier new is good for code) and print size.
After you get the text sized right, you can revisit specific substrings, and select/bold or select/color if you want fancy text.
You might consider cutting and pasting from JavaDoc or Doxygen output; you are likely to get the formatting data along with the text.