Subclass of GtkTextBuffer.

A GtkSourceBuffer object is the model for GtkSourceView widgets. It extends the GtkTextBuffer class by adding features useful to display and edit source code such as syntax highlighting and bracket matching.

To create a GtkSourceBuffer use gtk_source_buffer_new() or gtk_source_buffer_new_with_language(). The second form is just a convenience function which allows you to initially set a GtkSourceLanguage. You can also directly create a GtkSourceView and get its GtkSourceBuffer with gtk_text_view_get_buffer().

The highlighting is enabled by default, but you can disable it with gtk_source_buffer_set_highlight_syntax().

Context Classes:

It is possible to retrieve some information from the syntax highlighting engine. The default context classes that are applied to regions of a GtkSourceBuffer:

• comment: the region delimits a comment;
• no-spell-check: the region should not be spell checked;
• path: the region delimits a path to a file;
• string: the region delimits a string.

Custom language definition files can create their own context classes, since the functions like gtk_source_buffer_iter_has_context_class() take a string parameter as the context class.

GtkSourceBuffer provides an API to access the context classes: gtk_source_buffer_iter_has_context_class(), gtk_source_buffer_get_context_classes_at_iter(), gtk_source_buffer_iter_forward_to_context_class_toggle() and gtk_source_buffer_iter_backward_to_context_class_toggle().

And the GtkSourceBuffer::highlight-updated signal permits to be notified when a context class region changes.

Each context class has also an associated GtkTextTag with the name gtksourceview:context-classes:<name>. For example to retrieve the GtkTextTag for the string context class, one can write:

GtkTextTagTable *tag_table;
GtkTextTag *tag;

tag_table = gtk_text_buffer_get_tag_table (buffer);
tag = gtk_text_tag_table_lookup (tag_table, "gtksourceview:context-classes:string");

The tag must be used for read-only purposes.

Accessing a context class via the associated GtkTextTag is less convenient than the GtkSourceBuffer API, because:

• The tag doesn’t always exist, you need to listen to the GtkTextTagTable::tag-added and GtkTextTagTable::tag-removed signals.
• Instead of the GtkSourceBuffer::highlight-updated signal, you can listen to the GtkTextBuffer::apply-tag and GtkTextBuffer::remove-tag signals.

A possible use-case for accessing a context class via the associated GtkTextTag is to read the region but without adding a hard dependency on the GtkSourceView library (for example for a spell-checking library that wants to read the no-spell-check region).