Gtk::Adjustment Class Reference

A class representing an adjustable bounded value. More...

Inheritance diagram for Gtk::Adjustment:
[legend]

## Public Member Functions

virtual | ~Adjustment ()
GtkAdjustment* | gobj ()
| Provides access to the underlying C GObject. More...
const GtkAdjustment* | gobj () const
| Provides access to the underlying C GObject. More...
GtkAdjustment* | gobj_copy ()
| Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
void | changed ()
| Emits a "changed" signal from the Adjustment. More...
void | value_changed ()
| Emits a "value_changed" signal from the Adjustment. More...
void | clamp_page (double lower, double upper)
| Updates the Adjustment value to ensure that the range between the parameters lower and upper is in the current page (i.e. between value and value + page_size). More...
void | set_value (double value)
| Sets the current value of the Adjustment. More...
double | get_value () const
| Gets the current value of the adjustment. More...
void | set_lower (double lower)
| Sets the minimum value of the adjustment. More...
double | get_lower () const
| Retrieves the minimum value of the adjustment. More...
void | set_upper (double upper)
| Sets the maximum value of the adjustment. More...
double | get_upper () const
| Retrieves the maximum value of the adjustment. More...
void | set_step_increment (double step_increment)
| Sets the step increment of the adjustment. More...
double | get_step_increment () const
| Retrieves the step increment of the adjustment. More...
void | set_page_increment (double page_increment)
| Sets the page increment of the adjustment. More...
double | get_page_increment () const
| Retrieves the page increment of the adjustment. More...
void | set_page_size (double page_size)
| Sets the page size of the adjustment. More...
double | get_page_size () const
| Retrieves the page size of the adjustment. More...
void | configure (double value, double lower, double upper, double step_increment, double page_increment, double page_size)
| Sets all properties of the adjustment at once. More...
double | get_minimum_increment () const
| Gets the smaller of step increment and page increment. More...
Glib::SignalProxy0< void > | signal_changed ()
Glib::SignalProxy0< void > | signal_value_changed ()
Glib::PropertyProxy< double > | property_value ()
| The value of the adjustment. More...
Glib::PropertyProxy_ReadOnly < double > | property_value () const
| The value of the adjustment. More...
Glib::PropertyProxy< double > | property_lower ()
| The minimum value of the adjustment. More...
Glib::PropertyProxy_ReadOnly < double > | property_lower () const
| The minimum value of the adjustment. More...
Glib::PropertyProxy< double > | property_upper ()
| The maximum value of the adjustment. More...
Glib::PropertyProxy_ReadOnly < double > | property_upper () const
| The maximum value of the adjustment. More...
Glib::PropertyProxy< double > | property_step_increment ()
| The step increment of the adjustment. More...
Glib::PropertyProxy_ReadOnly < double > | property_step_increment () const
| The step increment of the adjustment. More...
Glib::PropertyProxy< double > | property_page_increment ()
| The page increment of the adjustment. More...
Glib::PropertyProxy_ReadOnly < double > | property_page_increment () const
| The page increment of the adjustment. More...
Glib::PropertyProxy< double > | property_page_size ()
| The page size of the adjustment. More...
Glib::PropertyProxy_ReadOnly < double > | property_page_size () const
| The page size of the adjustment. More...

## Static Public Member Functions

static GType | get_type ()
| Get the GType for this class, for use with the underlying GObject type system. More...
static Glib::RefPtr< Adjustment > | create (double value, double lower, double upper, double step_increment=1, double page_increment=10, double page_size=0)

## Protected Member Functions

| Adjustment (double value, double lower, double upper, double step_increment=1, double page_increment=10, double page_size=0)
| Constructor to create an Adjustment object. More...
virtual void | on_changed ()
| This is a default handler for the signal signal_changed(). More...
virtual void | on_value_changed ()
| This is a default handler for the signal signal_value_changed(). More...

## Related Functions

(Note that these are not member functions.)
Glib::RefPtr< Gtk::Adjustment > | wrap (GtkAdjustment* object, bool take_copy=false)
| A Glib::wrap() method for this object. More...

## Detailed Description

A class representing an adjustable bounded value.

The Gtk::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 gtkmm widgets, including Gtk::SpinButton, Gtk::Viewport, and Gtk::Range (which is a base class for Gtk::HScrollbar, Gtk::VScrollbar, Gtk::HScale, and Gtk::VScale).

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

The owner of the Gtk::Adjustment typically calls the value_changed() and changed() functions after changing the value and its bounds. This results in the emission of the "value_changed" or "changed" signal respectively.

## Constructor & Destructor Documentation

virtual Gtk::Adjustment::~Adjustment | ( |  | ) |

virtual

Gtk::Adjustment::Adjustment | ( | double | value,
|  | double | lower,
|  | double | upper,
|  | double | step_increment = `1`,
|  | double | page_increment = `10`,
|  | double | page_size = `0`
| ) |  |

protected

Constructor to create an Adjustment object.

Parameters

  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

## Member Function Documentation

void Gtk::Adjustment::changed | ( |  | ) |

Emits a "changed" signal from the Adjustment.

This is typically called by the owner of the Adjustment after it has changed any of the Adjustment fields other than the value.

void Gtk::Adjustment::clamp_page | ( | double | lower,
|  | double | upper
| ) |  |

Updates the Adjustment value to ensure that the range between the parameters lower and upper is in the current page (i.e. between value and value + page_size).

If this range is larger than the page size, then only the start of it will be in the current page. A "changed" signal will be emitted if the value is changed.

Parameters

  upper | The upper value.
  lower | The lower value.

void Gtk::Adjustment::configure | ( | double | value,
|  | double | lower,
|  | double | upper,
|  | double | step_increment,
|  | double | page_increment,
|  | double | page_size
| ) |  |

Sets all properties of the adjustment at once.

Use this function to avoid multiple emissions of the Gtk::Adjustment::signal_changed() signal. See set_lower() for an alternative way of compressing multiple emissions of Gtk::Adjustment::signal_changed() into one.

Since gtkmm 2.14:

Parameters

  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.

static Glib::RefPtr<Adjustment> Gtk::Adjustment::create | ( | double | value,
|  | double | lower,
|  | double | upper,
|  | double | step_increment = `1`,
|  | double | page_increment = `10`,
|  | double | page_size = `0`
| ) |  |

static

double Gtk::Adjustment::get_lower | ( |  | ) | const

Retrieves the minimum value of the adjustment.

Since gtkmm 2.14:

Returns
  The current minimum value of the adjustment.

double Gtk::Adjustment::get_minimum_increment | ( |  | ) | const

Gets the smaller of step increment and page increment.

Since gtkmm 3.2:

Returns
  The minimum increment of adjustment.

double Gtk::Adjustment::get_page_increment | ( |  | ) | const

Retrieves the page increment of the adjustment.

Since gtkmm 2.14:

Returns
  The current page increment of the adjustment.

double Gtk::Adjustment::get_page_size | ( |  | ) | const

Retrieves the page size of the adjustment.

Since gtkmm 2.14:

Returns
  The current page size of the adjustment.

double Gtk::Adjustment::get_step_increment | ( |  | ) | const

Retrieves the step increment of the adjustment.

Since gtkmm 2.14:

Returns
  The current step increment of the adjustment.

static GType Gtk::Adjustment::get_type | ( |  | ) |

static

Get the GType for this class, for use with the underlying GObject type system.

double Gtk::Adjustment::get_upper | ( |  | ) | const

Retrieves the maximum value of the adjustment.

Since gtkmm 2.14:

Returns
  The current maximum value of the adjustment.

double Gtk::Adjustment::get_value | ( |  | ) | const

Gets the current value of the adjustment.

See set_value().

Returns
  The current value of the adjustment.

GtkAdjustment* Gtk::Adjustment::gobj | ( |  | ) |

inline

Provides access to the underlying C GObject.

const GtkAdjustment* Gtk::Adjustment::gobj | ( |  | ) | const

inline

Provides access to the underlying C GObject.

GtkAdjustment* Gtk::Adjustment::gobj_copy | ( |  | ) |

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

virtual void Gtk::Adjustment::on_changed | ( |  | ) |

protectedvirtual

This is a default handler for the signal signal_changed().

virtual void Gtk::Adjustment::on_value_changed | ( |  | ) |

protectedvirtual

This is a default handler for the signal signal_value_changed().

Glib::PropertyProxy< double > Gtk::Adjustment::property_lower | ( |  | ) |

The minimum value of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly< double > Gtk::Adjustment::property_lower | ( |  | ) | const

The minimum value of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy< double > Gtk::Adjustment::property_page_increment | ( |  | ) |

The page increment of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly< double > Gtk::Adjustment::property_page_increment | ( |  | ) | const

The page increment of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy< double > Gtk::Adjustment::property_page_size | ( |  | ) |

The page size of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly< double > Gtk::Adjustment::property_page_size | ( |  | ) | const

The page size of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy< double > Gtk::Adjustment::property_step_increment | ( |  | ) |

The step increment of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly< double > Gtk::Adjustment::property_step_increment | ( |  | ) | const

The step increment of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy< double > Gtk::Adjustment::property_upper | ( |  | ) |

The maximum value of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly< double > Gtk::Adjustment::property_upper | ( |  | ) | const

The maximum value of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy< double > Gtk::Adjustment::property_value | ( |  | ) |

The value of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly< double > Gtk::Adjustment::property_value | ( |  | ) | const

The value of the adjustment.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns
  A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

void Gtk::Adjustment::set_lower | ( | double | lower | ) |

Sets the minimum value of the adjustment.

When setting multiple adjustment properties via their individual setters, multiple Gtk::Adjustment::signal_changed() signals will be emitted. However, since the emission of the Gtk::Adjustment::signal_changed() signal is tied to the emission of the Object::signal_notify() signals of the changed properties, it's possible to compress the Gtk::Adjustment::signal_changed() signals into one by calling Glib::object_freeze_notify() and Glib::object_thaw_notify() around the calls to the individual setters.

Alternatively, using a single Glib::object_set() for all the properties to change, or using configure() has the same effect of compressing Gtk::Adjustment::signal_changed() emissions.

Since gtkmm 2.14:

Parameters

  lower | The new minimum value.

void Gtk::Adjustment::set_page_increment | ( | double | page_increment | ) |

Sets the page increment of the adjustment.

See set_lower() about how to compress multiple emissions of the Gtk::Adjustment::signal_changed() signal when setting multiple adjustment properties.

Since gtkmm 2.14:

Parameters

  page_increment | The new page increment.

void Gtk::Adjustment::set_page_size | ( | double | 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.

Since gtkmm 2.14:

Parameters

  page_size | The new page size.

void Gtk::Adjustment::set_step_increment | ( | double | step_increment | ) |

Sets the step increment of the adjustment.

See set_lower() about how to compress multiple emissions of the Gtk::Adjustment::signal_changed() signal when setting multiple adjustment properties.

Since gtkmm 2.14:

Parameters

  step_increment | The new step increment.

void Gtk::Adjustment::set_upper | ( | double | 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 Gtk::Adjustment::signal_changed() signal when setting multiple adjustment properties.

Since gtkmm 2.14:

Parameters

  upper | The new maximum value.

void Gtk::Adjustment::set_value | ( | double | value | ) |

Sets the current value of the Adjustment.

Parameters

  value | The new value of the Adjustment.

Glib::SignalProxy0< void > Gtk::Adjustment::signal_changed | ( |  | ) |

Slot Prototype:
  `void on_my_changed()`

Emitted when one or more of the Gtk::Adjustment properties have been changed, other than the Gtk::Adjustment::property_value() property.

Glib::SignalProxy0< void > Gtk::Adjustment::signal_value_changed | ( |  | ) |

Slot Prototype:
  `void on_my_value_changed()`

Emitted when the Gtk::Adjustment::property_value() property has been changed.

void Gtk::Adjustment::value_changed | ( |  | ) |

Emits a "value_changed" signal from the Adjustment.

This is typically called by the owner of the Adjustment after it has changed the Adjustment value field.

## Friends And Related Function Documentation

Glib::RefPtr< Gtk::Adjustment > wrap | ( | GtkAdjustment * | object,
|  | bool | take_copy = `false`
| ) |  |

related

A Glib::wrap() method for this object.

Parameters

  object | The C instance.
  take_copy | False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns
  A C++ instance that wraps this C instance.

The documentation for this class was generated from the following file:

- gtkmm/adjustment.h