# Gtk::Scale Class Reference
Widgets

A slider widget for selecting a value from a range. More...

Inheritance diagram for Gtk::Scale:
[legend]

List of all members.

## Public Member Functions

virtual | ~Scale ()
GtkScale* | gobj ()
| Provides access to the underlying C GtkObject.
const GtkScale* | gobj () const
| Provides access to the underlying C GtkObject.
| Scale ()
| Scale (Orientation orientation=ORIENTATION_HORIZONTAL)
| Scale (const Glib::RefPtr< Adjustment >& adjustment, Orientation orientation=ORIENTATION_HORIZONTAL)
void | set_digits (int digits)
| Set the number of decimal digits.
int | get_digits () const
| Get the number of decimal digits.
void | set_draw_value (bool draw_value=true)
| Set whether the current value is displayed as a string next to the slider.
bool | get_draw_value () const
| Get whether the current value is displayed as a string next to the slider.
void | set_value_pos (PositionType pos)
| Set the position in which the value is displayed.
PositionType | get_value_pos () const
| Get the position in which the value is displayed.
Glib::RefPtr< Pango::Layout > | get_layout ()
| Gets the Pango::Layout used to display the scale.
Glib::RefPtr< const Pango::Layout > | get_layout () const
| Gets the Pango::Layout used to display the scale.
void | get_layout_offsets (int& x, int& y) const
| Obtains the coordinates where the scale will draw the Pango::Layout representing the text in the scale.
void | add_mark (double value, PositionType position, const Glib::ustring& markup)
| Adds a mark at value.
void | clear_marks ()
| Removes any marks that have been added with add_mark().
Glib::SignalProxy1 < Glib::ustring, double > | signal_format_value ()
| Determines how the value is formatted.
Glib::PropertyProxy< int > | property_digits ()
| Number of displayed decimal digits.
Glib::PropertyProxy_ReadOnly< int > | property_digits () const
| The number of decimal places that are displayed in the value.
Glib::PropertyProxy< bool > | property_draw_value ()
| Whether to draw the value as a string next to slider.
Glib::PropertyProxy_ReadOnly < bool > | property_draw_value () const
| Whether the current value is displayed as a string next to the slider.
Glib::PropertyProxy< PositionType > | property_value_pos ()
| The position in which the value is displayed.
Glib::PropertyProxy_ReadOnly < PositionType > | property_value_pos () const
| The position in which the current value is displayed.

## Protected Member Functions

virtual Glib::ustring | on_format_value (double value)
virtual void | draw_value_vfunc ()
virtual int | calc_digits_ (double step) const

## Related Functions

(Note that these are not member functions.)
home murrayc checkouts gnome30 gtkmm gtk gtkmm scale h Gtk::Scale* | wrap (GtkScale* object, bool take_copy=false)
| A Glib::wrap() method for this object.

## Detailed Description

A slider widget for selecting a value from a range.

A Gtk::Scale is a slider control used to select a numeric value. To use it, you'll probably want to investigate the methods on its base class, Gtk::Range, in addition to the methods for Gtk::Scale itself. To set the value of a scale, you would normally use set_value(). To detect changes to the value, you would normally use signal_value_changed().

Note that using the same upper and lower bounds for the Scale (through the Range methods) will hide the slider itself. This is useful for applications that want to show an undeterminate value on the scale, without changing the layout of the application (such as movie or music players).

## Constructor & Destructor Documentation

virtual Gtk::Scale::~Scale | ( |  | ) | `[virtual]`

Gtk::Scale::Scale | ( |  | ) |

Gtk::Scale::Scale | ( | Orientation | orientation = `ORIENTATION_HORIZONTAL` | ) | `[explicit]`

Since gtkmm 3.2:

Gtk::Scale::Scale | ( | const Glib::RefPtr< Adjustment >& | adjustment,
|  | Orientation | orientation = `ORIENTATION_HORIZONTAL`
| ) |  | `[explicit]`

## Member Function Documentation

void Gtk::Scale::add_mark | ( | double | value,
|  | PositionType | position,
|  | const Glib::ustring & | markup
| ) |  |

Adds a mark at value.

A mark is indicated visually by drawing a tick mark next to the scale, and GTK+ makes it easy for the user to position the scale exactly at the marks value.

If markup is not `0`, text is shown next to the tick mark.

To remove marks from a scale, use clear_marks().

Since gtkmm 2.16:

Parameters:

  value | The value at which the mark is placed, must be between the lower and upper limits of the scales' adjustment.
  position | Where to draw the mark. For a horizontal scale, Gtk::POS_TOP and Gtk::POS_LEFT are drawn above the scale, anything else below. For a vertical scale, Gtk::POS_LEFT and Gtk::POS_TOP are drawn to the left of the scale, anything else to the right.
  markup | Text to be shown at the mark, using Pango markup, or `0`.

virtual int Gtk::Scale::calc_digits_ | ( | double | step | ) | const`[protected, virtual]`

void Gtk::Scale::clear_marks | ( |  | ) |

Removes any marks that have been added with add_mark().

Since gtkmm 2.16:

virtual void Gtk::Scale::draw_value_vfunc | ( |  | ) | `[protected, virtual]`

int Gtk::Scale::get_digits | ( |  | ) | const

Get the number of decimal digits.

bool Gtk::Scale::get_draw_value | ( |  | ) | const

Get whether the current value is displayed as a string next to the slider.

Glib::RefPtr<const Pango::Layout> Gtk::Scale::get_layout | ( |  | ) | const

Gets the Pango::Layout used to display the scale.

The returned object is owned by the scale so does not need to be freed by the caller.

Since gtkmm 2.4:

Returns:
  The Pango::Layout for this scale, or `0` if the Gtk::Scale:draw-value property is `false`.

Glib::RefPtr<Pango::Layout> Gtk::Scale::get_layout | ( |  | ) |

Gets the Pango::Layout used to display the scale.

The returned object is owned by the scale so does not need to be freed by the caller.

Since gtkmm 2.4:

Returns:
  The Pango::Layout for this scale, or `0` if the Gtk::Scale:draw-value property is `false`.

void Gtk::Scale::get_layout_offsets | ( | int & | x,
|  | int & | y
| ) |  | const

Obtains the coordinates where the scale will draw the Pango::Layout representing the text in the scale.

Remember when using the Pango::Layout function you need to convert to and from pixels using PANGO_PIXELS() or Pango::SCALE.

If the Gtk::Scale:draw-value property is `false`, the return values are undefined.

Since gtkmm 2.4:

Parameters:

  x | Location to store X offset of layout, or `0`.
  y | Location to store Y offset of layout, or `0`.

PositionType Gtk::Scale::get_value_pos | ( |  | ) | const

Get the position in which the value is displayed.

GtkScale* Gtk::Scale::gobj | ( |  | ) | `[inline]`

Provides access to the underlying C GtkObject.

Reimplemented from Gtk::Range.

Reimplemented in Gtk::VScale, and Gtk::HScale.

const GtkScale* Gtk::Scale::gobj | ( |  | ) | const`[inline]`

Provides access to the underlying C GtkObject.

Reimplemented from Gtk::Range.

Reimplemented in Gtk::VScale, and Gtk::HScale.

virtual Glib::ustring Gtk::Scale::on_format_value | ( | double | value | ) | `[protected, virtual]`

Glib::PropertyProxy_ReadOnly<int> Gtk::Scale::property_digits | ( |  | ) | const

The number of decimal places that are displayed in the value.

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 property of the value, or receive notification when the value of the property changes.

Glib::PropertyProxy<int> Gtk::Scale::property_digits | ( |  | ) |

Number of displayed decimal digits.

The number of decimal places that are displayed in the value.

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 property of the value, or receive notification when the value of the property changes.

Glib::PropertyProxy<bool> Gtk::Scale::property_draw_value | ( |  | ) |

Whether to draw the value as a string next to slider.

Whether the current value is displayed as a string next to the slider.

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 property of the value, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly<bool> Gtk::Scale::property_draw_value | ( |  | ) | const

Whether the current value is displayed as a string next to the slider.

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 property of the value, or receive notification when the value of the property changes.

Glib::PropertyProxy<PositionType> Gtk::Scale::property_value_pos | ( |  | ) |

The position in which the value is displayed.

The position in which the current value is displayed.

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 property of the value, or receive notification when the value of the property changes.

Glib::PropertyProxy_ReadOnly<PositionType> Gtk::Scale::property_value_pos | ( |  | ) | const

The position in which the current value is displayed.

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 property of the value, or receive notification when the value of the property changes.

void Gtk::Scale::set_digits | ( | int | digits | ) |

Set the number of decimal digits.

This also causes the adjustment to be rounded off so the retrieved value matches the value the user sees. Setting digits to 1 gives for example 1.0, 2 gives 1.00, etc.

void Gtk::Scale::set_draw_value | ( | bool | draw_value = `true` | ) |

Set whether the current value is displayed as a string next to the slider.

void Gtk::Scale::set_value_pos | ( | PositionType | pos | ) |

Set the position in which the value is displayed.

Glib::SignalProxy1< Glib::ustring,double > Gtk::Scale::signal_format_value | ( |  | ) |

Determines how the value is formatted.

This can be used to connect a custom function for determining how the value is formatted. The function (or function object) is given a the value as a double and should return the representation of it as a Glib::ustring.

Prototype:
  `Glib::ustring on_my_format_value(double value)`

## Friends And Related Function Documentation

home murrayc checkouts gnome30 gtkmm gtk gtkmm scale h Gtk::Scale* wrap | ( | GtkScale * | 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/scale.h