Gnome::Gtk3::ScrolledWindow

Adds scrollbars to its child widget

Description

Gnome::Gtk3::ScrolledWindow is a container that accepts a single child widget, makes that child scrollable using either internally added scrollbars or externally associated adjustments, and optionally draws a frame around the child.

Widgets with native scrolling support, i.e. those whose classes implement the Gnome::Gtk3::Scrollable interface, are added directly. For other types of widget, the class Gnome::Gtk3::Viewport acts as an adaptor, giving scrollability to other widgets. Gnome::Gtk3::ScrolledWindow’s implementation of gtk_container_add() intelligently accounts for whether or not the added child is a Gnome::Gtk3::Scrollable. If it isn’t, Gnome::Gtk3::ScrolledWindow wraps the child in a Gnome::Gtk3::Viewport and adds that for you. Therefore, you can just add any child widget and not worry about the details.

If gtk_container_add() has added a Gnome::Gtk3::Viewport for you, you can remove both your added child widget from the Gnome::Gtk3::Viewport, and the Gnome::Gtk3::Viewport from the Gnome::Gtk3::ScrolledWindow, like this:

Unless policy is GTK_POLICY_NEVER or GTK_POLICY_EXTERNAL, Gnome::Gtk3::ScrolledWindow adds internal Gnome::Gtk3::Scrollbar widgets around its child. The scroll position of the child, and if applicable the scrollbars, is controlled by the hadjustment and vadjustment that are associated with the Gnome::Gtk3::ScrolledWindow. See the docs on Gnome::Gtk3::Scrollbar for the details, but note that the “step_increment” and “page_increment” fields are only effective if the policy causes scrollbars to be present.

If a Gnome::Gtk3::ScrolledWindow doesn’t behave quite as you would like, or doesn’t have exactly the right layout, it’s very possible to set up your own scrolling with Gnome::Gtk3::Scrollbar and for example a Gnome::Gtk3::Grid.

Touch support

Gnome::Gtk3::ScrolledWindow has built-in support for touch devices. When a touchscreen is used, swiping will move the scrolled window, and will expose ‘kinetic’ behavior. This can be turned off with the kinetic-scrolling property if it is undesired.

Gnome::Gtk3::ScrolledWindow also displays visual ‘overshoot’ indication when the content is pulled beyond the end, and this situation can be captured with the edge-overshot signal.

If no mouse device is present, the scrollbars will overlayed as narrow, auto-hiding indicators over the content. If traditional scrollbars are desired although no mouse is present, this behaviour can be turned off with the overlay-scrolling property.

Css Nodes

Gnome::Gtk3::ScrolledWindow has a main CSS node with name scrolledwindow. It uses subnodes with names overshoot and undershoot to draw the overflow and underflow indications. These nodes get the .left, .right, .top or .bottom style class added depending on where the indication is drawn.

Gnome::Gtk3::ScrolledWindow also sets the positional style classes (.left, .right, .top, .bottom) and style classes related to overlay scrolling (.overlay-indicator, .dragging, .hovering) on its scrollbars.

If both scrollbars are visible, the area where they meet is drawn with a subnode named junction.

Synopsis

Declaration

unit class Gnome::Gtk3::ScrolledWindow;
also is Gnome::Gtk3::Bin;

Types

enum GtkCornerType

Specifies which corner a child widget should be placed in when packed into a Gnome::Gtk3::ScrolledWindow. This is effectively the opposite of where the scroll bars are placed.

GTK_CORNER_TOP_LEFT: Place the scrollbars on the right and bottom of the widget (default behaviour).
GTK_CORNER_BOTTOM_LEFT: Place the scrollbars on the top and right of the widget.
GTK_CORNER_TOP_RIGHT: Place the scrollbars on the left and bottom of the widget.
GTK_CORNER_BOTTOM_RIGHT: Place the scrollbars on the top and left of the widget.

enum GtkPolicyType

Determines how the size should be computed to achieve the one of the visibility mode for the scrollbars.

GTK_POLICY_ALWAYS: The scrollbar is always visible. The view size is independent of the content.
GTK_POLICY_AUTOMATIC: The scrollbar will appear and disappear as necessary. For example, when all of a Gnome::Gtk3::TreeView can not be seen.
GTK_POLICY_NEVER: The scrollbar should never appear. In this mode the content determines the size.
GTK_POLICY_EXTERNAL: Don’t show a scrollbar, but don’t force the size to follow the content. This can be used e.g. to make multiple scrolled windows share a scrollbar. Since: 3.16

Methods

new

Create a new ScrolledWindow object.

multi method new ( )

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

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

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

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

[gtk_scrolled_window_] set_hadjustment

Sets the Gnome::Gtk3::Adjustment for the horizontal scrollbar. You cannot cleanup the adjustment object afterwards because the scrolled window keeps a reference to it.

method gtk_scrolled_window_set_hadjustment ( N-GObject $hadjustment )

N-GObject $hadjustment; (nullable): the Gnome::Gtk3::Adjustment to use, or Any to create a new one

[gtk_scrolled_window_] set_vadjustment

Sets the Gnome::Gtk3::Adjustment for the vertical scrollbar. You cannot cleanup the adjustment object afterwards because the scrolled window keeps a reference to it.

method gtk_scrolled_window_set_vadjustment ( N-GObject $vadjustment )

N-GObject $vadjustment; (nullable): the Gnome::Gtk3::Adjustment to use, or Any to create a new one.

[gtk_scrolled_window_] get_hadjustment

Returns the horizontal scrollbar’s adjustment, used to connect the horizontal scrollbar to the child widget’s horizontal scroll functionality.

Returns: (transfer none): the horizontal Gnome::Gtk3::Adjustment

method gtk_scrolled_window_get_hadjustment ( --> N-GObject )

[gtk_scrolled_window_] get_vadjustment

Returns the vertical scrollbar’s adjustment, used to connect the vertical scrollbar to the child widget’s vertical scroll functionality.

Returns: (transfer none): the vertical Gnome::Gtk3::Adjustment

method gtk_scrolled_window_get_vadjustment ( --> N-GObject )

[gtk_scrolled_window_] get_hscrollbar

Returns the horizontal scrollbar of scrolled_window.

Returns: (transfer none): the horizontal scrollbar of the scrolled window.

method gtk_scrolled_window_get_hscrollbar ( --> N-GObject )

[gtk_scrolled_window_] get_vscrollbar

Returns the vertical scrollbar of scrolled_window.

Returns: (transfer none): the vertical scrollbar of the scrolled window.

method gtk_scrolled_window_get_vscrollbar ( --> N-GObject )

[gtk_scrolled_window_] set_policy

Sets the scrollbar policy for the horizontal and vertical scrollbars.

The policy determines when the scrollbar should appear; it is a value from the Gnome::Gtk3::PolicyType enumeration. If GTK_POLICY_ALWAYS, the scrollbar is always present; if GTK_POLICY_NEVER, the scrollbar is never present; if GTK_POLICY_AUTOMATIC, the scrollbar is present only if needed (that is, if the slider part of the bar would be smaller than the trough — the display is larger than the page size).

method gtk_scrolled_window_set_policy ( GtkPolicyType $hscrollbar_policy, GtkPolicyType $vscrollbar_policy )

GtkPolicyType $hscrollbar_policy; policy for horizontal bar
GtkPolicyType $vscrollbar_policy; policy for vertical bar

[gtk_scrolled_window_] get_policy

Retrieves the current policy values for the horizontal and vertical scrollbars. See gtk_scrolled_window_set_policy().

method gtk_scrolled_window_get_policy ( GtkPolicyType $hscrollbar_policy, GtkPolicyType $vscrollbar_policy )

GtkPolicyType $hscrollbar_policy; (out) (optional): location to store the policy for the horizontal scrollbar, or Any
GtkPolicyType $vscrollbar_policy; (out) (optional): location to store the policy for the vertical scrollbar, or Any

[gtk_scrolled_window_] set_placement

Sets the placement of the contents with respect to the scrollbars for the scrolled window.

The default is GTK_CORNER_TOP_LEFT, meaning the child is in the top left, with the scrollbars underneath and to the right. Other values in Gnome::Gtk3::CornerType are GTK_CORNER_TOP_RIGHT, GTK_CORNER_BOTTOM_LEFT, and GTK_CORNER_BOTTOM_RIGHT.

See also gtk_scrolled_window_get_placement() and gtk_scrolled_window_unset_placement().

method gtk_scrolled_window_set_placement ( GtkCornerType $window_placement )

GtkCornerType $window_placement; position of the child window

[gtk_scrolled_window_] unset_placement

Unsets the placement of the contents with respect to the scrollbars for the scrolled window. If no window placement is set for a scrolled window, it defaults to GTK_CORNER_TOP_LEFT.

See also gtk_scrolled_window_set_placement() and gtk_scrolled_window_get_placement().

method gtk_scrolled_window_unset_placement ( )

[gtk_scrolled_window_] get_placement

Gets the placement of the contents with respect to the scrollbars for the scrolled window. See gtk_scrolled_window_set_placement().

Returns: the current placement value.

See also gtk_scrolled_window_set_placement() and gtk_scrolled_window_unset_placement().

method gtk_scrolled_window_get_placement ( --> GtkCornerType )

[gtk_scrolled_window_] set_shadow_type

Changes the type of shadow drawn around the contents of scrolled_window.

method gtk_scrolled_window_set_shadow_type ( GtkShadowType $type )

GtkShadowType $type; kind of shadow to draw around scrolled window contents

[gtk_scrolled_window_] get_shadow_type

Gets the shadow type of the scrolled window. See gtk_scrolled_window_set_shadow_type().

Returns: the current shadow type

method gtk_scrolled_window_get_shadow_type ( --> GtkShadowType )

[gtk_scrolled_window_] get_min_content_width

Gets the minimum content width of scrolled_window, or -1 if not set.

Returns: the minimum content width

method gtk_scrolled_window_get_min_content_width ( --> Int )

[gtk_scrolled_window_] set_min_content_width

Sets the minimum width that scrolled_window should keep visible. Note that this can and (usually will) be smaller than the minimum size of the content.

It is a programming error to set the minimum content width to a value greater than max-content-width.

method gtk_scrolled_window_set_min_content_width ( Int $width )

Int $width; the minimal content width

[gtk_scrolled_window_] get_min_content_height

Gets the minimal content height of scrolled_window, or -1 if not set.

Returns: the minimal content height

method gtk_scrolled_window_get_min_content_height ( --> Int )

[gtk_scrolled_window_] set_min_content_height

Sets the minimum height that scrolled_window should keep visible. Note that this can and (usually will) be smaller than the minimum size of the content.

It is a programming error to set the minimum content height to a value greater than max-content-height.

method gtk_scrolled_window_set_min_content_height ( Int $height )

Int $height; the minimal content height

[gtk_scrolled_window_] set_kinetic_scrolling

Turns kinetic scrolling on or off. Kinetic scrolling only applies to devices with source GDK_SOURCE_TOUCHSCREEN.

method gtk_scrolled_window_set_kinetic_scrolling ( Int $kinetic_scrolling )

Int $kinetic_scrolling; 1 to enable kinetic scrolling

[gtk_scrolled_window_] get_kinetic_scrolling

Returns the specified kinetic scrolling behavior.

Returns: the scrolling behavior flags.

method gtk_scrolled_window_get_kinetic_scrolling ( --> Int )

[gtk_scrolled_window_] set_capture_button_press

Changes the behaviour of scrolled_window with regard to the initial event that possibly starts kinetic scrolling. When capture_button_press is set to 1, the event is captured by the scrolled window, and then later replayed if it is meant to go to the child widget.

This should be enabled if any child widgets perform non-reversible actions on button-press-event. If they don’t, and handle additionally handle grab-broken-event, it might be better to set capture_button_press to 0.

This setting only has an effect if kinetic scrolling is enabled.

method gtk_scrolled_window_set_capture_button_press ( Int $capture_button_press )

Int $capture_button_press; 1 to capture button presses

[gtk_scrolled_window_] get_capture_button_press

Return whether button presses are captured during kinetic scrolling. See gtk_scrolled_window_set_capture_button_press().

Returns: 1 if button presses are captured during kinetic scrolling

method gtk_scrolled_window_get_capture_button_press ( --> Int )

[gtk_scrolled_window_] set_overlay_scrolling

Enables or disables overlay scrolling for this scrolled window.

method gtk_scrolled_window_set_overlay_scrolling ( Int $overlay_scrolling )

Int $overlay_scrolling; whether to enable overlay scrolling

[gtk_scrolled_window_] get_overlay_scrolling

Returns whether overlay scrolling is enabled for this scrolled window.

Returns: 1 if overlay scrolling is enabled

method gtk_scrolled_window_get_overlay_scrolling ( --> Int )

[gtk_scrolled_window_] set_max_content_width

Sets the maximum width that scrolled_window should keep visible. The scrolled_window will grow up to this width before it starts scrolling the content.

It is a programming error to set the maximum content width to a value smaller than min-content-width.

method gtk_scrolled_window_set_max_content_width ( Int $width )

Int $width; the maximum content width

[gtk_scrolled_window_] get_max_content_width

Returns the maximum content width set.

Returns: the maximum content width, or -1

method gtk_scrolled_window_get_max_content_width ( --> Int )

[gtk_scrolled_window_] set_max_content_height

Sets the maximum height that scrolled_window should keep visible. The scrolled_window will grow up to this height before it starts scrolling the content.

It is a programming error to set the maximum content height to a value smaller than min-content-height.

method gtk_scrolled_window_set_max_content_height ( Int $height )

Int $height; the maximum content height

[gtk_scrolled_window_] get_max_content_height

Returns the maximum content height set.

Returns: the maximum content height, or -1

method gtk_scrolled_window_get_max_content_height ( --> Int )

[gtk_scrolled_window_] set_propagate_natural_width

Sets whether the natural width of the child should be calculated and propagated through the scrolled window’s requested natural width.

method gtk_scrolled_window_set_propagate_natural_width ( Int $propagate )

Int $propagate; whether to propagate natural width

[gtk_scrolled_window_] get_propagate_natural_width

Reports whether the natural width of the child will be calculated and propagated through the scrolled window’s requested natural width.

Returns: whether natural width propagation is enabled.

method gtk_scrolled_window_get_propagate_natural_width ( --> Int )

[gtk_scrolled_window_] set_propagate_natural_height

Sets whether the natural height of the child should be calculated and propagated through the scrolled window’s requested natural height.

method gtk_scrolled_window_set_propagate_natural_height ( Int $propagate )

Int $propagate; whether to propagate natural height

[gtk_scrolled_window_] get_propagate_natural_height

Reports whether the natural height of the child will be calculated and propagated through the scrolled window’s requested natural height.

Returns: whether natural height propagation is enabled.

method gtk_scrolled_window_get_propagate_natural_height ( --> Int )

Signals

There are two ways to connect to a signal. The first option you have is to use register-signal() from Gnome::GObject::Object. The second option is to use g_signal_connect_object() directly from Gnome::GObject::Signal.

First method

The positional arguments of the signal handler are all obligatory as well as their types. The named attributes :$widget and user data are optional.

# handler method
method mouse-event ( N-GdkEvent $event, :$widget ) { ... }

# connect a signal on window object
my Gnome::Gtk3::Window $w .= new( ... );
$w.register-signal( self, 'mouse-event', 'button-press-event');

Second method

my Gnome::Gtk3::Window $w .= new( ... );
my Callable $handler = sub (
  N-GObject $native, N-GdkEvent $event, OpaquePointer $data
) {
  ...
}

$w.connect-object( 'button-press-event', $handler);

Also here, the types of positional arguments in the signal handler are important. This is because both methods register-signal() and g_signal_connect_object() are using the signatures of the handler routines to setup the native call interface.

Supported signals

scroll-child

The scroll-child signal is a [keybinding signal][Gnome::Gtk3::BindingSignal] which gets emitted when a keybinding that scrolls is pressed. The horizontal or vertical adjustment is updated which triggers a signal that the scrolled window’s child may listen to and scroll itself.

method handler (
  Unknown type GTK_TYPE_SCROLL_TYPE $scroll,
  Int $horizontal,
  Int :$_handler_id,
  Gnome::GObject::Object :_widget($scrolled_window),
  *%user-options
  --> Int
);

$scrolled_window; a Gnome::Gtk3::ScrolledWindow
$scroll; a Gnome::Gtk3::ScrollType describing how much to scroll
$horizontal; whether the keybinding scrolls the child horizontally or not

move-focus-out

The move-focus-out signal is a [keybinding signal][Gnome::Gtk3::BindingSignal] which gets emitted when focus is moved away from the scrolled window by a keybinding. The move-focus signal is emitted with direction_type on this scrolled window’s toplevel parent in the container hierarchy. The default bindings for this signal are Ctrl + Tab to move forward and Ctrl + Shift + Tab to move backward.

method handler (
  Unknown type GTK_TYPE_DIRECTION_TYPE $direction_type,
  Int :$_handler_id,
  Gnome::GObject::Object :_widget($scrolled_window),
  *%user-options
);

$scrolled_window; a Gnome::Gtk3::ScrolledWindow
$direction_type; either GTK_DIR_TAB_FORWARD or GTK_DIR_TAB_BACKWARD

edge-overshot

The edge-overshot signal is emitted whenever user initiated scrolling makes the scrolled window firmly surpass (i.e. with some edge resistance) the lower or upper limits defined by the adjustment in that orientation.

A similar behavior without edge resistance is provided by the edge-reached signal.

Note: The pos argument is LTR/RTL aware, so callers should be aware too if intending to provide behavior on horizontal edges.

method handler (
  Unknown type GTK_TYPE_POSITION_TYPE $pos,
  Int :$_handler_id,
  Gnome::GObject::Object :_widget($scrolled_window),
  *%user-options
);

$scrolled_window; a Gnome::Gtk3::ScrolledWindow
$pos; edge side that was hit

edge-reached

The edge-reached signal is emitted whenever user-initiated scrolling makes the scrolled window exactly reach the lower or upper limits defined by the adjustment in that orientation.

A similar behavior with edge resistance is provided by the edge-overshot signal.