Class: Gtk::IconTheme

Inherits:
Object
  • Object
show all
Extended by:
GLib::Deprecatable
Defined in:
lib/gtk4/deprecated.rb,
lib/gtk4/icon-theme.rb

Overview

GtkIconTheme provides a facility for loading themed icons.

The main reason for using a name rather than simply providing a filename is to allow different icons to be used depending on what “icon theme” is selected by the user. The operation of icon themes on Linux and Unix follows the Icon Theme Specification There is a fallback icon theme, named hicolor, where applications should install their icons, but additional icon themes can be installed as operating system vendors and users choose.

In many cases, named themes are used indirectly, via [classGtk.Image] rather than directly, but looking up icons directly is also simple. The GtkIconTheme object acts as a database of all the icons in the current theme. You can create new GtkIconTheme objects, but it’s much more efficient to use the standard icon theme of the GtkWidget so that the icon information is shared with other people looking up icons.

GtkIconTheme *icon_theme;
GtkIconPaintable *icon;
GdkPaintable *paintable;

icon_theme = gtk_icon_theme_get_for_display (gtk_widget_get_display (my_widget));
icon = gtk_icon_theme_lookup_icon (icon_theme,
                                   "my-icon-name", // icon name
                                   48, // icon size
                                   1,  // scale
                                   0,  // flags);
paintable = GDK_PAINTABLE (icon);
// Use the paintable
g_object_unref (icon);

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Gtk::IconTheme

Creates a new icon theme object.

Icon theme objects are used to lookup up an icon by name in a particular icon theme. Usually, you’ll want to use [funcGtk.IconTheme.get_for_display] rather than creating a new icon theme object for scratch.

Class Method Details

.get_for_display(display) ⇒ Gtk::IconTheme

Gets the icon theme object associated with display.

If this function has not previously been called for the given display, a new icon theme object will be created and associated with the display. Icon theme objects are fairly expensive to create, so using this function is usually a better choice than calling [ctorGtk.IconTheme.new] and setting the display yourself; by using this function a single icon theme object will be shared between users.

Parameters:

Returns:

  • (Gtk::IconTheme) —

    A unique GtkIconTheme associated with the given display. This icon theme is associated with the display and can be used as long as the display is open. Do not ref or unref it.

Instance Method Details

#add_resource_path(path) ⇒ nil

Adds a resource path that will be looked at when looking for icons, similar to search paths.

See [methodGtk.IconTheme.set_resource_path].

This function should be used to make application-specific icons available as part of the icon theme.

Parameters:

  • path (String) —

    a resource path

Returns:

  • (nil)

#add_search_path(path) ⇒ nil

Appends a directory to the search path.

See [methodGtk.IconTheme.set_search_path].

Parameters:

  • path (Gtk::filename) —

    directory name to append to the icon path

Returns:

  • (nil)

#display ⇒ Gdk::Display

The display that this icon theme object is attached to.

Returns:

#display=(display) ⇒ Gdk::Display

The display that this icon theme object is attached to.

Parameters:

Returns:

#get_icon_sizes(icon_name) ⇒ Array<Integer>

Returns an array of integers describing the sizes at which the icon is available without scaling.

A size of -1 means that the icon is available in a scalable format. The array is zero-terminated.

Parameters:

  • icon_name (String) —

    the name of an icon

Returns:

  • (Array<Integer>) —

    A newly allocated array describing the sizes at which the icon is available. The array should be freed with g_free() when it is no longer needed.

#has_gicon(gicon) ⇒ Boolean

Checks whether an icon theme includes an icon for a particular GIcon.

Parameters:

  • gicon (Gio::Icon) —

    a GIcon

Returns:

  • (Boolean) —

    true if self includes an icon for gicon

#has_icon(icon_name) ⇒ Boolean

Checks whether an icon theme includes an icon for a particular name.

Parameters:

  • icon_name (String) —

    the name of an icon

Returns:

  • (Boolean) —

    true if self includes an icon for icon_name.

#icon_names ⇒ Gtk::

The icon names that are supported by the icon theme.

Returns:

#icon_names=(icon_names) ⇒ Gtk::

The icon names that are supported by the icon theme.

Parameters:

Returns:

#lookup_by_gicon(icon, size, scale, direction, flags) ⇒ Gtk::IconPaintable

Looks up a icon for a desired size and window scale.

The icon can then be rendered by using it as a GdkPaintable, or you can get information such as the filename and size.

Parameters:

  • icon (Gio::Icon) —

    the GIcon to look up

  • size (Integer) —

    desired icon size

  • scale (Integer) —

    the desired scale

  • direction (Gtk::TextDirection) —

    text direction the icon will be displayed in

  • flags (Gtk::IconLookupFlags) —

    flags modifying the behavior of the icon lookup

Returns:

  • (Gtk::IconPaintable) —

    a GtkIconPaintable containing information about the icon. Unref with g_object_unref()

#lookup_icon(icon, size, scale: 1, direction: :none, flags: nil) ⇒ Gtk::IconPaintable

Looks up a named icon for a desired size and window scale, returning a GtkIconPaintable.

The icon can then be rendered by using it as a GdkPaintable, or you can get information such as the filename and size.

If the available icon_name is not available and fallbacks are provided, they will be tried in order.

If no matching icon is found, then a paintable that renders the "missing icon" icon is returned. If you need to do something else for missing icons you need to use [methodGtk.IconTheme.has_icon].

Note that you probably want to listen for icon theme changes and update the icon. This is usually done by overriding the GtkWidgetClass.css-changed() function.

Parameters:

  • icon_name (String) —

    the name of the icon to lookup

  • fallbacks (Array<String>)
  • size (Integer) —

    desired icon size.

  • scale (Integer) (defaults to: 1) —

    the window scale this will be displayed on

  • direction (Gtk::TextDirection) (defaults to: :none) —

    text direction the icon will be displayed in

  • flags (Gtk::IconLookupFlags) (defaults to: nil) —

    flags modifying the behavior of the icon lookup

Returns:



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# File 'lib/gtk4/icon-theme.rb', line 20

def lookup_icon(icon, size, scale: 1, direction: :none, flags: nil)
  case icon
  when String, Symbol
    flags ||= 0
    lookup_icon_raw(icon.to_s, nil, size, scale, direction, flags)
  when Array
    icon, *fallbacks = *icon
    flags ||= 0
    lookup_icon_raw(icon.to_s, fallbacks, size, scale, direction, flags)
  else
    flags ||= 0
    lookup_by_gicon(icon, size, scale, direction, flags)
  end
end

#lookup_icon_raw ⇒ Gtk::IconPaintable

Looks up a named icon for a desired size and window scale, returning a GtkIconPaintable.

The icon can then be rendered by using it as a GdkPaintable, or you can get information such as the filename and size.

If the available icon_name is not available and fallbacks are provided, they will be tried in order.

If no matching icon is found, then a paintable that renders the "missing icon" icon is returned. If you need to do something else for missing icons you need to use [methodGtk.IconTheme.has_icon].

Note that you probably want to listen for icon theme changes and update the icon. This is usually done by overriding the GtkWidgetClass.css-changed() function.

Parameters:

  • icon_name (String) —

    the name of the icon to lookup

  • fallbacks (Array<String>)
  • size (Integer) —

    desired icon size.

  • scale (Integer) —

    the window scale this will be displayed on

  • direction (Gtk::TextDirection) —

    text direction the icon will be displayed in

  • flags (Gtk::IconLookupFlags) —

    flags modifying the behavior of the icon lookup

Returns:




# File 'lib/gtk4/icon-theme.rb', line 19

#resource_path ⇒ Gtk::

Resource paths that will be looked at when looking for icons, similar to search paths.

The resources are considered as part of the hicolor icon theme and must be located in subdirectories that are defined in the hicolor icon theme, such as <b>path</b>/16x16/actions/run.png. Icons that are directly placed in the resource path instead of a subdirectory are also considered as ultimate fallback.

Returns:

  • (Gtk::) —

    resource-path

#resource_path=(resource_path) ⇒ Gtk::

Resource paths that will be looked at when looking for icons, similar to search paths.

The resources are considered as part of the hicolor icon theme and must be located in subdirectories that are defined in the hicolor icon theme, such as <b>path</b>/16x16/actions/run.png. Icons that are directly placed in the resource path instead of a subdirectory are also considered as ultimate fallback.

Parameters:

Returns:

  • (Gtk::) —

    resource-path

  • (Gtk::) —

    resource-path

#search_path ⇒ Gtk::

The search path for this icon theme.

When looking for icons, GTK will search for a subdirectory of one or more of the directories in the search path with the same name as the icon theme containing an index.theme file. (Themes from multiple of the path elements are combined to allow themes to be extended by adding icons in the user’s home directory.)

Returns:

  • (Gtk::) —

    search-path

#search_path=(search_path) ⇒ Gtk::

The search path for this icon theme.

When looking for icons, GTK will search for a subdirectory of one or more of the directories in the search path with the same name as the icon theme containing an index.theme file. (Themes from multiple of the path elements are combined to allow themes to be extended by adding icons in the user’s home directory.)

Parameters:

Returns:

#theme_name ⇒ String

The name of the icon theme that is being used.

Unless set to a different value, this will be the value of the GtkSettings:gtk-icon-theme-name property of the GtkSettings object associated to the display of the icontheme object.

Returns:

  • (String) —

    theme-name

#theme_name=(theme_name) ⇒ String

The name of the icon theme that is being used.

Unless set to a different value, this will be the value of the GtkSettings:gtk-icon-theme-name property of the GtkSettings object associated to the display of the icontheme object.

Parameters:

  • theme_name (String)

Returns:

  • (String) —

    theme-name

  • (String) —

    theme-name