Gnome::Gtk3::Adjustment

A representation of an adjustable bounded value

Description

The Gnome::Gtk3::Adjustment object represents a value which has an associated lower and upper bound, together with step and page increments, and a page size. It is used within several GTK+ widgets, including Gnome::Gtk3::SpinButton, Gnome::Gtk3::Viewport, and Gnome::Gtk3::Range (which is a base class for Gnome::Gtk3::Scrollbar and Gnome::Gtk3::Scale).

The Gnome::Gtk3::Adjustment object does not update the value itself. Instead it is left up to the owner of the Gnome::Gtk3::Adjustment to control the value.

Synopsis

Declaration

unit class Gnome::Gtk3::Adjustment;
also is Gnome::GObject::InitiallyUnowned;

Uml Diagram

Methods

new

:value, :lower, :upper, :step-increment, :page-increment, :page-size

Create a new Adjustment object.

multi method new (
  Num() :$value!, Num() :$lower!, Num() :$upper!,
  Num() :$step-increment!, Num() :$page-increment!,
  Num() :$page-size!
)

• $value; the initial value.

• $lower; the minimum value.

• $upper; the maximum value

• $step_increment; the step increment

• $page_increment; the page increment

• $page_size; the page size

:native-object

Create an object using a native object from elsewhere. See also Gnome::N::TopLevelSupportClass.

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

clamp-page

Updates the value property to ensure that the range between lower and upper is in the current page (i.e. between value and value + page-size). If the range is larger than the page size, then only the start of it will be in the current page.

A value-changed signal will be emitted if the value is changed.

method clamp-page ( Num() $lower, Num() $upper )

• $lower; the lower value

• $upper; the upper value

configure

Sets all properties of the adjustment at once.

Use this function to avoid multiple emissions of the changed signal. See set-lower() for an alternative way of compressing multiple emissions of changed into one.

method configure ( Num() $value, Num() $lower, Num() $upper, Num() $step_increment, Num() $page_increment, Num() $page_size )

• $value; the new value

• $lower; the new minimum value

• $upper; the new maximum value

• $step_increment; the new step increment

• $page_increment; the new page increment

• $page_size; the new page size

get-lower

Retrieves the minimum value of the adjustment.

Returns: The current minimum value of the adjustment

method get-lower ( --> Num() )

get-minimum-increment

Gets the smaller of step increment and page increment.

Returns: the minimum increment of adjustment

method get-minimum-increment ( --> Num() )

get-page-increment

Retrieves the page increment of the adjustment.

Returns: The current page increment of the adjustment

method get-page-increment ( --> Num() )

get-page-size

Retrieves the page size of the adjustment.

Returns: The current page size of the adjustment

method get-page-size ( --> Num() )

get-step-increment

Retrieves the step increment of the adjustment.

Returns: The current step increment of the adjustment.

method get-step-increment ( --> Num() )

get-upper

Retrieves the maximum value of the adjustment.

Returns: The current maximum value of the adjustment

method get-upper ( --> Num() )

get-value

Gets the current value of the adjustment. See set-value().

Returns: The current value of the adjustment

method get-value ( --> Num() )

set-lower

Sets the minimum value of the adjustment.

When setting multiple adjustment properties via their individual setters, multiple changed signals will be emitted. However, since the emission of the changed signal is tied to the emission of the notify signals of the changed properties, it’s possible to compress the changed signals into one by calling g-object-freeze-notify() and g-object-thaw-notify() around the calls to the individual setters.

Alternatively, using a single g-object-set() for all the properties to change, or using configure() has the same effect of compressing changed emissions.

method set-lower ( Num() $lower )

• $lower; the new minimum value

set-page-increment

Sets the page increment of the adjustment.

See set-lower() about how to compress multiple emissions of the changed signal when setting multiple adjustment properties.

method set-page-increment ( Num() $page_increment )

• $page_increment; the new page increment

set-page-size

Sets the page size of the adjustment.

See set-lower() about how to compress multiple emissions of the GtkAdjustment::changed signal when setting multiple adjustment properties.

method set-page-size ( Num() $page_size )

• $page_size; the new page size

set-step-increment

Sets the step increment of the adjustment.

See set-lower() about how to compress multiple emissions of the changed signal when setting multiple adjustment properties.

method set-step-increment ( Num() $step_increment )

• $step_increment; the new step increment

set-upper

Sets the maximum value of the adjustment.

Note that values will be restricted by upper - page-size if the page-size property is nonzero.

See set-lower() about how to compress multiple emissions of the changed signal when setting multiple adjustment properties.

method set-upper ( Num() $upper )

• $upper; the new maximum value

set-value

Sets the Gnome::Gtk3::Adjustment value. The value is clamped to lie between lower and upper.

Note that for adjustments which are used in a Gnome::Gtk3::Scrollbar, the effective range of allowed values goes from lower to upper - page-size.

method set-value ( Num() $value )

• $value; the new value

Signals

changed

Emitted when one or more of the Gnome::Gtk3::Adjustment properties have been changed, other than the value property.

method handler (
  Gnome::Gtk3::Adjustment :_widget($adjustment),
  Int :$_handler-id,
  N-GObject :$_native-object,
  *%user-options
)

• $adjustment; The instance which registered the signal

• $_handler-id; The handler id which is returned from the registration

• $_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

value-changed

Emitted when the value property has been changed.

method handler (
  Gnome::Gtk3::Adjustment :_widget($adjustment),
  Int :$_handler-id,
  N-GObject :$_native-object,
  *%user-options
)

• $adjustment; The instance which registered the signal

• $_handler-id; The handler id which is returned from the registration

• $_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

Properties

lower

The minimum value of the adjustment

The Gnome::GObject::Value type of property lower is G_TYPE_DOUBLE.

• Parameter is readable and writable.

• Minimum value is -G_MAXDOUBLE.

• Maximum value is G_MAXDOUBLE.

• Default value is 0.0.

page-increment

The page increment of the adjustment

The Gnome::GObject::Value type of property page-increment is G_TYPE_DOUBLE.

• Parameter is readable and writable.

• Minimum value is -G_MAXDOUBLE.

• Maximum value is G_MAXDOUBLE.

• Default value is 0.0.

page-size

The page size of the adjustment

The Gnome::GObject::Value type of property page-size is G_TYPE_DOUBLE.

• Parameter is readable and writable.

• Minimum value is -G_MAXDOUBLE.

• Maximum value is G_MAXDOUBLE.

• Default value is 0.0.

step-increment

The step increment of the adjustment

The Gnome::GObject::Value type of property step-increment is G_TYPE_DOUBLE.

• Parameter is readable and writable.

• Minimum value is -G_MAXDOUBLE.

• Maximum value is G_MAXDOUBLE.

• Default value is 0.0.

upper

The maximum value of the adjustment

The Gnome::GObject::Value type of property upper is G_TYPE_DOUBLE.

• Parameter is readable and writable.

• Minimum value is -G_MAXDOUBLE.

• Maximum value is G_MAXDOUBLE.

• Default value is 0.0.

value

The value of the adjustment

The Gnome::GObject::Value type of property value is G_TYPE_DOUBLE.

• Parameter is readable and writable.

• Minimum value is -G_MAXDOUBLE.

• Maximum value is G_MAXDOUBLE.

• Default value is 0.0.