Thursday, July 16, 2009

Source-highlight-qt: A library for highlighting Qt documents using GNU Source-highlight

A few days ago I released a new software that uses the new library provided by GNU Source-highlight: Source-highlight-qt, "a library for performing syntax highlighting in Qt documents by relying on GNU Source-Highlight library".

This library provides an implementation of the qt abstract class QSyntaxHighlighter class, and it deals both with Qt3 and Qt4 (you will need to build a separate version of the library for the two different qt frameworks). Please note, the Qt3 version has less features and it is there only for old qt applications; furthermore, QSyntaxHighlighter class in Qt3 has some design problems which make it quite inefficient to use.

The library can be downloaded from the sourceforge site using this link:

For standard usage, it's just a matter of executing this code (you can pass the language syntax, i.e., the source-highlight language definition file, to the init method):

QTextEdit *editor = new QTextEdit;
srchiliteqt::Qt4SyntaxHighlighter *highlighter =
new srchiliteqt::Qt4SyntaxHighlighter(editor->document());
We also suggest to take a look at the example program qeditexample, for some use cases of the library. Please notice that this qeditexample program is not intended to be used as an editor for production, it's just to show how to use source-highlight-qt library (and it uses the qt4 version).

This is a screenshot of the program qeditexample, editing a C file; basically most of the code is taken directly from the library. For instance, it provides the combo boxes for selecting the highlighting language and the output style (and they be connected to the editor, so that all the changes are automatically applied):

This is another screenshot, where we're editing a C++ file, with a different style

The library also provides a dialog to customize the output style:

Happy Qt Highlighting! :-)