### Class

# GtkSource Buffer

#### Description [src]

    class GtkSource.Buffer : Gtk.TextBuffer
    {
      /* No available fields */
    }

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");

    buffer = GtkSource.Buffer()

    tag_table = buffer.get_tag_table()
    tag = tag_table.lookup(name="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).

#### Ancestors

- GtkTextBuffer
- GObject

#### Constructors

###### gtk_source_buffer_new

Creates a new source buffer.

###### gtk_source_buffer_new_with_language

Creates a new source buffer using the highlighting patterns in `language`.

#### Instance methods

###### gtk_source_buffer_backward_iter_to_source_mark

Moves `iter` to the position of the previous `GtkSourceMark` of the given category.

###### gtk_source_buffer_change_case

Changes the case of the text between the specified iterators.

###### gtk_source_buffer_create_source_mark

Creates a source mark in the `buffer` of category `category`.

###### gtk_source_buffer_create_source_tag

In short, this is the same function as `gtk_text_buffer_create_tag()` but instead of creating a `GtkTextTag`, this function creates a `GtkSourceTag`.

###### gtk_source_buffer_ensure_highlight

Forces buffer to analyze and highlight the given area synchronously.

###### gtk_source_buffer_forward_iter_to_source_mark

Moves `iter` to the position of the next `GtkSourceMark` of the given `category`.

###### gtk_source_buffer_get_context_classes_at_iter

Get all defined context classes at `iter`.

###### gtk_source_buffer_get_highlight_matching_brackets

Determines whether bracket match highlighting is activated for the source buffer.

###### gtk_source_buffer_get_highlight_syntax

Determines whether syntax highlighting is activated in the source buffer.

###### gtk_source_buffer_get_implicit_trailing_newline

No description available.

###### gtk_source_buffer_get_language

Returns the `GtkSourceLanguage` associated with the buffer, see `gtk_source_buffer_set_language()`.

###### gtk_source_buffer_get_loading

No description available.

###### gtk_source_buffer_get_markup

Returns the text in the specified range converting any text formatting to equivalent Pango markup tags. This allows the styled text to be displayed in other widgets that support Pango markup, such as `GtkLabel`.

since: 5.18

###### gtk_source_buffer_get_source_marks_at_iter

Returns the list of marks of the given category at `iter`.

###### gtk_source_buffer_get_source_marks_at_line

Returns the list of marks of the given category at `line`.

###### gtk_source_buffer_get_style_scheme

Returns the `GtkSourceStyleScheme` associated with the buffer, see `gtk_source_buffer_set_style_scheme()`.

###### gtk_source_buffer_iter_backward_to_context_class_toggle

Moves backward to the next toggle (on or off) of the context class.

###### gtk_source_buffer_iter_forward_to_context_class_toggle

Moves forward to the next toggle (on or off) of the context class.

###### gtk_source_buffer_iter_has_context_class

Check if the class `context_class` is set on `iter`.

###### gtk_source_buffer_join_lines

Joins the lines of text between the specified iterators.

###### gtk_source_buffer_remove_source_marks

Remove all marks of `category` between `start` and `end` from the buffer.

###### gtk_source_buffer_set_highlight_matching_brackets

Controls the bracket match highlighting function in the buffer.

###### gtk_source_buffer_set_highlight_syntax

Controls whether syntax is highlighted in the buffer.

###### gtk_source_buffer_set_implicit_trailing_newline

Sets whether the `buffer` has an implicit trailing newline.

###### gtk_source_buffer_set_language

Associates a `GtkSourceLanguage` with the buffer.

###### gtk_source_buffer_set_style_scheme

Sets a `GtkSourceStyleScheme` to be used by the buffer and the view.

###### gtk_source_buffer_sort_lines

Sort the lines of text between the specified iterators.

##### Methods inherited from GtkTextBuffer (72)

Please see GtkTextBuffer for a full list of methods.

##### Methods inherited from GObject (43)

Please see GObject for a full list of methods.

#### Properties

###### GtkSource.Buffer:highlight-matching-brackets

Whether to highlight matching brackets in the buffer.

###### GtkSource.Buffer:highlight-syntax

Whether to highlight syntax in the buffer.

###### GtkSource.Buffer:implicit-trailing-newline

Whether the buffer has an implicit trailing newline. See `gtk_source_buffer_set_implicit_trailing_newline()`.

###### GtkSource.Buffer:language

No description available.

###### GtkSource.Buffer:loading

The “loading” property denotes that a `GtkSourceFileLoader` is currently loading the buffer.

since: 5.10

###### GtkSource.Buffer:style-scheme

Style scheme. It contains styles for syntax highlighting, optionally foreground, background, cursor color, current line color, and matching brackets style.

##### Properties inherited from GtkTextBuffer (7)

###### Gtk.TextBuffer:can-redo

Denotes that the buffer can reapply the last undone action.

###### Gtk.TextBuffer:can-undo

Denotes that the buffer can undo the last applied action.

###### Gtk.TextBuffer:cursor-position

The position of the insert mark.

###### Gtk.TextBuffer:enable-undo

Denotes if support for undoing and redoing changes to the buffer is allowed.

###### Gtk.TextBuffer:has-selection

Whether the buffer has some text currently selected.

###### Gtk.TextBuffer:tag-table

The GtkTextTagTable for the buffer.

###### Gtk.TextBuffer:text

The text content of the buffer.

#### Signals

###### GtkSource.Buffer::bracket-matched

`iter` is set to a valid iterator pointing to the matching bracket if `state` is `GTK_SOURCE_BRACKET_MATCH_FOUND`. Otherwise `iter` is meaningless.

###### GtkSource.Buffer::cursor-moved

The “cursor-moved” signal is emitted when then insertion mark has moved.

###### GtkSource.Buffer::highlight-updated

The ::highlight-updated signal is emitted when the syntax highlighting and context classes are updated in a certain region of the `buffer`.

###### GtkSource.Buffer::source-mark-updated

The ::source-mark-updated signal is emitted each time a mark is added to, moved or removed from the `buffer`.

##### Signals inherited from GtkTextBuffer (15)

###### GtkTextBuffer::apply-tag

Emitted to apply a tag to a range of text in a `GtkTextBuffer`.

###### GtkTextBuffer::begin-user-action

Emitted at the beginning of a single user-visible operation on a `GtkTextBuffer`.

###### GtkTextBuffer::changed

Emitted when the content of a `GtkTextBuffer` has changed.

###### GtkTextBuffer::delete-range

Emitted to delete a range from a `GtkTextBuffer`.

###### GtkTextBuffer::end-user-action

Emitted at the end of a single user-visible operation on the `GtkTextBuffer`.

###### GtkTextBuffer::insert-child-anchor

Emitted to insert a `GtkTextChildAnchor` in a `GtkTextBuffer`.

###### GtkTextBuffer::insert-paintable

Emitted to insert a `GdkPaintable` in a `GtkTextBuffer`.

###### GtkTextBuffer::insert-text

Emitted to insert text in a `GtkTextBuffer`.

###### GtkTextBuffer::mark-deleted

Emitted as notification after a `GtkTextMark` is deleted.

###### GtkTextBuffer::mark-set

Emitted as notification after a `GtkTextMark` is set.

###### GtkTextBuffer::modified-changed

Emitted when the modified bit of a `GtkTextBuffer` flips.

###### GtkTextBuffer::paste-done

Emitted after paste operation has been completed.

###### GtkTextBuffer::redo

Emitted when a request has been made to redo the previously undone operation.

###### GtkTextBuffer::remove-tag

Emitted to remove all occurrences of `tag` from a range of text in a `GtkTextBuffer`.

###### GtkTextBuffer::undo

Emitted when a request has been made to undo the previous operation or set of operations that have been grouped together.

##### Signals inherited from GObject (1)

###### GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

#### Class structure

    struct GtkSourceBufferClass {
      GtkTextBufferClass parent_class;
      void (* bracket_matched) (
        GtkSourceBuffer* buffer,
        GtkTextIter* iter,
        GtkSourceBracketMatchType state
      );

    }

No description available.

###### Class members

`parent_class: GtkTextBufferClass`

  No description available.

`bracket_matched: void (* bracket_matched) ( GtkSourceBuffer* buffer, GtkTextIter* iter, GtkSourceBracketMatchType state )`

  No description available.

#### Virtual methods

###### GtkSource.BufferClass.bracket_matched

No description available.