Interfacing Raku to Gnome GTK+

Gnome::Gtk3::CssProvider

CSS-like styling for widgets

Description

Gnome::Gtk3::CssProvider is an object implementing the Gnome::Gtk3::StyleProvider interface. It is able to parse CSS-like input in order to style widgets.

An application can make GTK+ parse a specific CSS style sheet by calling load_from_file() or load_from_resource() and adding the provider with Gnome::Gtk3::StyleContext.add_provider() or Gnome::Gtk3::StyleContext.add_provider_for_screen().

In addition, certain files will be read when GTK+ is initialized. First, the file $XDG_CONFIG_HOME/gtk-3.0/gtk.css is loaded if it exists. Then, GTK+ loads the first existing file among $XDG_DATA_HOME/themes/theme-name/gtk-VERSION/gtk.css, $HOME/.themes/theme-name/gtk-VERSION/gtk.css, $XDG_DATA_DIRS/themes/theme-name/gtk-VERSION/gtk.css and DATADIR/share/themes/THEME/gtk-VERSION/gtk.css, where THEME is the name of the current theme (see the prop gtk-theme-name setting), DATADIR is the prefix configured when GTK+ was compiled (unless overridden by the GTK_DATA_PREFIX environment variable), and VERSION is the GTK+ version number. If no file is found for the current version, GTK+ tries older versions all the way back to 3.0.

In the same way, GTK+ tries to load a gtk-keys.css file for the current key theme, as defined by prop gtk-key-theme-name setting.

See Also

Gnome::Gtk3::StyleContext, Gnome::Gtk3::StyleProvider

Synopsis

Declaration

unit class Gnome::Gtk3::CssProvider;
also is Gnome::GObject::Object;
also does Gnome::Gtk3::StyleProvider;

Uml Diagram

Types

enum GtkCssProviderError

Error codes for GTK_CSS_PROVIDER_ERROR.

  • GTK_CSS_PROVIDER_ERROR_FAILED: Failed.

  • GTK_CSS_PROVIDER_ERROR_SYNTAX: Syntax error.

  • GTK_CSS_PROVIDER_ERROR_IMPORT: Import error.

  • GTK_CSS_PROVIDER_ERROR_NAME: Name error.

  • GTK_CSS_PROVIDER_ERROR_DEPRECATED: Deprecation error.

  • GTK_CSS_PROVIDER_ERROR_UNKNOWN_VALUE: Unknown value.

Methods

new

default, no options

Create a new CssProvider object.

multi method new ( )

:named

Loads a theme from the usual theme paths

Creates a CssProvider> with the theme loaded. This memory is owned by GTK+, and you must not free it.

method new( Str :$name!, Str :$variant? )

  • $name; A theme name like ‘Breeze’ or ‘Oxygen’.

  • $variant; variant to load, for example, ‘dark’.

:native-object

Create a CssProvider object using a native object from elsewhere. See also Gnome::N::TopLevelClassSupport.

multi method new ( N-GObject :$native-object! )

:build-id

Create a CssProvider object using a native object returned from a builder. See also Gnome::GObject::Object.

multi method new ( Str :$build-id! )

error-quark

Return the domain code of the builder error domain.

method error-quark ( --> UInt )

load-from-data

Loads data into css-provider, and by doing so clears any previously loaded information.

Returns: Gnome::Glib::Error. Test .is-valid() of that object to see if there was an error.

A way to track errors while loading CSS is to connect to the sig parsing-error signal.

method load-from-data ( Str $data --> Gnome::Glib::Error )
  • $data; CSS data loaded in memory

load-from-file

Loads the data contained in file into css-provider, making it clear any previously loaded information.

Returns: Gnome::Glib::Error. Test .is-valid() of that object to see if there was an error.

method load-from-file ( N-GObject() $file --> Gnome::Glib::Error )
  • $file; a Gnome::Gio::File pointing to a file to load

load-from-path

Loads the data contained in path into css-provider, making it clear any previously loaded information.

Returns: Gnome::Glib::Error. Test .is-valid() of that object to see if there was an error.

method load-from-path ( Str $path --> Gnome::Glib::Error )
  • $path; the path of a filename to load, in the GLib filename encoding

load-from-resource

Loads the data contained in the resource at resource-path into the Gnome::Gtk3::CssProvider, clearing any previously loaded information.

To track errors while loading CSS, connect to the parsing-error signal.

method load-from-resource ( Str $resource_path )
  • $resource_path; a Gnome::Gtk3::Resource resource path

to-string

Converts the provider into a string representation in CSS format.

Using load-from-data() with the return value from this function on a new provider created with new() will basically create a duplicate of this provider.

Returns: a new string representing the provider.

method to-string ( --> Str )

Signals

parsing-error

Signals that a parsing error occurred. the path, line and position describe the actual location of the error as accurately as possible.

Parsing errors are never fatal, so the parsing will resume after the error. Errors may however cause parts of the given data or even all of it to not be parsed at all. So it is a useful idea to check that the parsing succeeds by connecting to this signal.

Note that this signal may be emitted at any time as the css provider may opt to defer parsing parts or all of the input to a later time than when a loading function was called.

method handler (
  N-GObject $section,
  N-GError $error,
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($provider),
  *%user-options
);

  • $section; section the error happened in, a native Gnome::Gtk3::Section.

  • $error; the parsing error.

  • $provider; the provider that had a parsing error.

  • $_handle_id; the registered event handler id.

  • $_native-object; The native object provided by the caller wrapped in the Raku object.

  • %user-options; A list of named arguments provided at the register-signal() method