GI.Gtk.Objects.Expander

A Expander allows the user to hide or show its child by clicking on an expander triangle similar to the triangles used in a TreeView.

Normally you use an expander as you would use any other descendant of Bin; you create the child widget and use containerAdd to add it to the expander. When the expander is toggled, it will take care of showing and hiding the child automatically.

Special Usage

There are situations in which you may prefer to show and hide the expanded widget yourself, such as when you want to actually create the widget at expansion time. In this case, create a Expander but do not add a child to it. The expander widget has an Expander:expanded property which can be used to monitor its expansion state. You should watch this property with a signal connection as follows:

C code

static void
expander_callback (GObject    *object,
                   GParamSpec *param_spec,
                   gpointer    user_data)
{
  GtkExpander *expander;

  expander = GTK_EXPANDER (object);

  if (gtk_expander_get_expanded (expander))
    {
      // Show or create widgets
    }
  else
    {
      // Hide or destroy widgets
    }
}

static void
create_expander (void)
{
  GtkWidget *expander = gtk_expander_new_with_mnemonic ("_More Options");
  g_signal_connect (expander, "notify::expanded",
                    G_CALLBACK (expander_callback), NULL);

  // ...
}

GtkExpander as GtkBuildable

The GtkExpander implementation of the GtkBuildable interface supports placing a child in the label position by specifying “label” as the “type” attribute of a <child> element. A normal content child can be specified without specifying a <child> type attribute.

An example of a UI definition fragment with GtkExpander: > >class="GtkExpander" > type="label" > class="GtkLabel" id="expander-label"/ > /child > child > class="GtkEntry" id="expander-content"/ > /child >/object

CSS nodes

plain code

expander
├── title
│   ├── arrow
│   ╰── <label widget>
╰── <child>

GtkExpander has three CSS nodes, the main node with the name expander, a subnode with name title and node below it with name arrow. The arrow of an expander that is showing its child gets the :checked pseudoclass added to it.

Exported types

newtype Expander

Memory-managed wrapper type.

Constructors

Expander (ManagedPtr Expander)

Instances

GObject Expander

Defined in GI.Gtk.Objects.Expander

Methods

gobjectType :: IO GType

HasParentTypes Expander

Defined in GI.Gtk.Objects.Expander

type ParentTypes Expander

Defined in GI.Gtk.Objects.Expander

type ParentTypes Expander = Bin ': (Container ': (Widget ': (Object ': (ImplementorIface ': (Buildable ': ([] :: [Type]))))))

class (GObject o, IsDescendantOf Expander o) => IsExpander o

Type class for types which can be safely cast to Expander, for instance with toExpander.

Instances

(GObject o, IsDescendantOf Expander o) => IsExpander o

Defined in GI.Gtk.Objects.Expander

toExpander :: (MonadIO m, IsExpander o) => o -> m Expander

Cast to Expander, for types for which this is known to be safe. For general casts, use castTo.

noExpander :: Maybe Expander

A convenience alias for Nothing :: Maybe Expander.

Methods

getExpanded

expanderGetExpanded

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m Bool

Returns: the current state of the expander

Queries a Expander and returns its current state. Returns True if the child widget is revealed.

See expanderSetExpanded.

Since: 2.4

getLabel

expanderGetLabel

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m (Maybe Text)

Returns: The text of the label widget. This string is owned by the widget and must not be modified or freed.

Fetches the text from a label widget including any embedded underlines indicating mnemonics and Pango markup, as set by expanderSetLabel. If the label text has not been set the return value will be Nothing. This will be the case if you create an empty button with buttonNew to use as a container.

Note that this function behaved differently in versions prior to 2.14 and used to return the label text stripped of embedded underlines indicating mnemonics and Pango markup. This problem can be avoided by fetching the label text directly from the label widget.

Since: 2.4

getLabelFill

expanderGetLabelFill

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m Bool

Returns: True if the label widget will fill all available horizontal space

Returns whether the label widget will fill all available horizontal space allocated to expander.

Since: 2.22

getLabelWidget

expanderGetLabelWidget

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m (Maybe Widget)

Returns: the label widget, or Nothing if there is none

Retrieves the label widget for the frame. See expanderSetLabelWidget.

Since: 2.4

getResizeToplevel

expanderGetResizeToplevel

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m Bool

Returns: the “resize toplevel” setting.

Returns whether the expander will resize the toplevel widget containing the expander upon resizing and collpasing.

Since: 3.2

getSpacing

expanderGetSpacing

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m Int32

Returns: spacing between the expander and child

Deprecated: (Since version 3.20)Use margins on the child instead.

Gets the value set by expanderSetSpacing.

Since: 2.4

getUseMarkup

expanderGetUseMarkup

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m Bool

Returns: True if the label’s text will be parsed for markup

Returns whether the label’s text is interpreted as marked up with the [Pango text markup language][PangoMarkupFormat]. See expanderSetUseMarkup.

Since: 2.4

getUseUnderline

expanderGetUseUnderline

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> m Bool

Returns: True if an embedded underline in the expander label indicates the mnemonic accelerator keys

Returns whether an embedded underline in the expander label indicates a mnemonic. See expanderSetUseUnderline.

Since: 2.4

new

expanderNew

Arguments

:: (HasCallStack, MonadIO m)

=> Maybe Text

label: the text of the label

-> m Expander

Returns: a new Expander widget.

Creates a new expander using label as the text of the label.

Since: 2.4

newWithMnemonic

expanderNewWithMnemonic

Arguments

:: (HasCallStack, MonadIO m)

=> Maybe Text

label: the text of the label with an underscore in front of the mnemonic character

-> m Expander

Returns: a new Expander widget.

Creates a new expander using label as the text of the label. If characters in label are preceded by an underscore, they are underlined. If you need a literal underscore character in a label, use “__” (two underscores). The first underlined character represents a keyboard accelerator called a mnemonic. Pressing Alt and that key activates the button.

Since: 2.4

setExpanded

expanderSetExpanded

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Bool

expanded: whether the child widget is revealed

-> m ()

Sets the state of the expander. Set to True, if you want the child widget to be revealed, and False if you want the child widget to be hidden.

Since: 2.4

setLabel

expanderSetLabel

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Maybe Text

label: a string

-> m ()

Sets the text of the label of the expander to label.

This will also clear any previously set labels.

Since: 2.4

setLabelFill

expanderSetLabelFill

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Bool

labelFill: True if the label should should fill all available horizontal space

-> m ()

Sets whether the label widget should fill all available horizontal space allocated to expander.

Since: 2.22

setLabelWidget

expanderSetLabelWidget

Arguments

:: (HasCallStack, MonadIO m, IsExpander a, IsWidget b)

=> a

expander: a Expander

-> Maybe b

labelWidget: the new label widget

-> m ()

Set the label widget for the expander. This is the widget that will appear embedded alongside the expander arrow.

Since: 2.4

setResizeToplevel

expanderSetResizeToplevel

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Bool

resizeToplevel: whether to resize the toplevel

-> m ()

Sets whether the expander will resize the toplevel widget containing the expander upon resizing and collpasing.

Since: 3.2

setSpacing

expanderSetSpacing

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Int32

spacing: distance between the expander and child in pixels

-> m ()

Deprecated: (Since version 3.20)Use margins on the child instead.

Sets the spacing field of expander, which is the number of pixels to place between expander and the child.

Since: 2.4

setUseMarkup

expanderSetUseMarkup

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Bool

useMarkup: True if the label’s text should be parsed for markup

-> m ()

Sets whether the text of the label contains markup in [Pango’s text markup language][PangoMarkupFormat]. See labelSetMarkup.

Since: 2.4

setUseUnderline

expanderSetUseUnderline

Arguments

:: (HasCallStack, MonadIO m, IsExpander a)

=> a

expander: a Expander

-> Bool

useUnderline: True if underlines in the text indicate mnemonics

-> m ()

If true, an underline in the text of the expander label indicates the next character should be used for the mnemonic accelerator key.

Since: 2.4

Properties

expanded

No description available in the introspection data.

constructExpanderExpanded :: IsExpander o => Bool -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “expanded” property. This is rarely needed directly, but it is used by new.

getExpanderExpanded :: (MonadIO m, IsExpander o) => o -> m Bool

Get the value of the “expanded” property. When overloading is enabled, this is equivalent to

get expander #expanded

setExpanderExpanded :: (MonadIO m, IsExpander o) => o -> Bool -> m ()

Set the value of the “expanded” property. When overloading is enabled, this is equivalent to

set expander [ #expanded := value ]

label

No description available in the introspection data.

clearExpanderLabel :: (MonadIO m, IsExpander o) => o -> m ()

Set the value of the “label” property to Nothing. When overloading is enabled, this is equivalent to

clear #label

constructExpanderLabel :: IsExpander o => Text -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “label” property. This is rarely needed directly, but it is used by new.

getExpanderLabel :: (MonadIO m, IsExpander o) => o -> m (Maybe Text)

Get the value of the “label” property. When overloading is enabled, this is equivalent to

get expander #label

setExpanderLabel :: (MonadIO m, IsExpander o) => o -> Text -> m ()

Set the value of the “label” property. When overloading is enabled, this is equivalent to

set expander [ #label := value ]

labelFill

No description available in the introspection data.

constructExpanderLabelFill :: IsExpander o => Bool -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “label-fill” property. This is rarely needed directly, but it is used by new.

getExpanderLabelFill :: (MonadIO m, IsExpander o) => o -> m Bool

Get the value of the “label-fill” property. When overloading is enabled, this is equivalent to

get expander #labelFill

setExpanderLabelFill :: (MonadIO m, IsExpander o) => o -> Bool -> m ()

Set the value of the “label-fill” property. When overloading is enabled, this is equivalent to

set expander [ #labelFill := value ]

labelWidget

No description available in the introspection data.

clearExpanderLabelWidget :: (MonadIO m, IsExpander o) => o -> m ()

Set the value of the “label-widget” property to Nothing. When overloading is enabled, this is equivalent to

clear #labelWidget

constructExpanderLabelWidget :: (IsExpander o, IsWidget a) => a -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “label-widget” property. This is rarely needed directly, but it is used by new.

getExpanderLabelWidget :: (MonadIO m, IsExpander o) => o -> m (Maybe Widget)

Get the value of the “label-widget” property. When overloading is enabled, this is equivalent to

get expander #labelWidget

setExpanderLabelWidget :: (MonadIO m, IsExpander o, IsWidget a) => o -> a -> m ()

Set the value of the “label-widget” property. When overloading is enabled, this is equivalent to

set expander [ #labelWidget := value ]

resizeToplevel

When this property is True, the expander will resize the toplevel widget containing the expander upon expanding and collapsing.

Since: 3.2

constructExpanderResizeToplevel :: IsExpander o => Bool -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “resize-toplevel” property. This is rarely needed directly, but it is used by new.

getExpanderResizeToplevel :: (MonadIO m, IsExpander o) => o -> m Bool

Get the value of the “resize-toplevel” property. When overloading is enabled, this is equivalent to

get expander #resizeToplevel

setExpanderResizeToplevel :: (MonadIO m, IsExpander o) => o -> Bool -> m ()

Set the value of the “resize-toplevel” property. When overloading is enabled, this is equivalent to

set expander [ #resizeToplevel := value ]

spacing

Space to put between the label and the child when the expander is expanded.

constructExpanderSpacing :: IsExpander o => Int32 -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “spacing” property. This is rarely needed directly, but it is used by new.

getExpanderSpacing :: (MonadIO m, IsExpander o) => o -> m Int32

Get the value of the “spacing” property. When overloading is enabled, this is equivalent to

get expander #spacing

setExpanderSpacing :: (MonadIO m, IsExpander o) => o -> Int32 -> m ()

Set the value of the “spacing” property. When overloading is enabled, this is equivalent to

set expander [ #spacing := value ]

useMarkup

No description available in the introspection data.

constructExpanderUseMarkup :: IsExpander o => Bool -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “use-markup” property. This is rarely needed directly, but it is used by new.

getExpanderUseMarkup :: (MonadIO m, IsExpander o) => o -> m Bool

Get the value of the “use-markup” property. When overloading is enabled, this is equivalent to

get expander #useMarkup

setExpanderUseMarkup :: (MonadIO m, IsExpander o) => o -> Bool -> m ()

Set the value of the “use-markup” property. When overloading is enabled, this is equivalent to

set expander [ #useMarkup := value ]

useUnderline

No description available in the introspection data.

constructExpanderUseUnderline :: IsExpander o => Bool -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “use-underline” property. This is rarely needed directly, but it is used by new.

getExpanderUseUnderline :: (MonadIO m, IsExpander o) => o -> m Bool

Get the value of the “use-underline” property. When overloading is enabled, this is equivalent to

get expander #useUnderline

setExpanderUseUnderline :: (MonadIO m, IsExpander o) => o -> Bool -> m ()

Set the value of the “use-underline” property. When overloading is enabled, this is equivalent to

set expander [ #useUnderline := value ]

Signals

activate

type C_ExpanderActivateCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type ExpanderActivateCallback = IO ()

No description available in the introspection data.

afterExpanderActivate :: (IsExpander a, MonadIO m) => a -> ExpanderActivateCallback -> m SignalHandlerId

Connect a signal handler for the “activate” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after expander #activate callback

genClosure_ExpanderActivate :: MonadIO m => ExpanderActivateCallback -> m (GClosure C_ExpanderActivateCallback)

Wrap the callback into a GClosure.

mk_ExpanderActivateCallback :: C_ExpanderActivateCallback -> IO (FunPtr C_ExpanderActivateCallback)

Generate a function pointer callable from C code, from a C_ExpanderActivateCallback.

noExpanderActivateCallback :: Maybe ExpanderActivateCallback

A convenience synonym for Nothing :: Maybe ExpanderActivateCallback.

onExpanderActivate :: (IsExpander a, MonadIO m) => a -> ExpanderActivateCallback -> m SignalHandlerId

Connect a signal handler for the “activate” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on expander #activate callback

wrap_ExpanderActivateCallback :: ExpanderActivateCallback -> C_ExpanderActivateCallback

Wrap a ExpanderActivateCallback into a C_ExpanderActivateCallback.