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# Gtk::Scale Class Reference
[Widgets]

Inheritance diagram for Gtk::Scale:

[legend]

List of all members.

## Detailed Description

Abstract base clase for Gtk::HScale and Gtk::VScale.

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().

The Gtk::Scale widget is an abstract class, used only for deriving the subclasses Gtk::HScale and Gtk::VScale, so you should instantiate them instead.

## Public Member Functions

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().
int | get_digits () const
| Get the number of decimal digits.
bool | get_draw_value () const
| Get whether the current value is displayed as a string next to the slider.
Glib::RefPtr<const Pango::Layout> | get_layout () const
| Gets the Pango::Layout used to display the scale.
Glib::RefPtr<Pango::Layout> | get_layout ()
| 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.
PositionType | get_value_pos () const
| Get the position in which the value is displayed.
const GtkScale* | gobj () const
| Provides access to the underlying C GtkObject.
GtkScale* | gobj ()
| Provides access to the underlying C GtkObject.
Glib::PropertyProxy_ReadOnly<int> | property_digits () const
| The number of decimal places that are displayed in the value.
Glib::PropertyProxy<int> | property_digits ()
| Number of displayed decimal digits.
Glib::PropertyProxy_ReadOnly <bool> | property_draw_value () const
| Whether the current value is displayed as a string next to the slider.
Glib::PropertyProxy<bool> | property_draw_value ()
| Whether to draw the value as a string next to slider.
Glib::PropertyProxy_ReadOnly <PositionType> | property_value_pos () const
| The position in which the current value is displayed.
Glib::PropertyProxy<PositionType> | property_value_pos ()
| The position in which the value is displayed.
void | set_digits (int digits)
| Set 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.
void | set_value_pos (PositionType pos)
| Set the position in which the value is displayed.
Glib::SignalProxy1 <Glib::ustring, double> | signal_format_value ()
| Determines how the value is formatted.
virtual | ~Scale ()

## Protected Member Functions

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

## Related Functions

(Note that these are not member functions.)
Gtk::Scale* | wrap (GtkScale* object, bool take_copy=false)
| A Glib::wrap() method for this object.

## Constructor & Destructor Documentation

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

Gtk::Scale::Scale | ( |  | ) | `[protected]`

## 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 is drawn above the scale, anything else below. For a vertical scale, Gtk::POS_LEFT is drawn to the left of the scale, anything else to the right.
  | markup | Text to be shown at the mark, using <link linkend="PangoMarkupFormat">Pango markup</link>, 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.

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

Returns:
  The number of decimal places that are displayed.

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

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

Returns: whether the current value is displayed as a string

Returns:
  Whether the current value is displayed as a string.

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.

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

Since gtkmm 2.4:

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.

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

Since gtkmm 2.4:

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.

Gets the position in which the current value is displayed.

Returns:
  The position in which the current value is displayed.

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.

GtkScale* Gtk::Scale::gobj | ( |  | ) | `[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_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<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<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.

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.

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. Sets the number of decimal places that are displayed in the value. Also causes the value of the adjustment to be rounded off to this number of digits, so the retrieved value matches the value the user saw.

Parameters:

  | digits | The number of decimal places to display, e.g. use 1 to display 1.0, 2 to display 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.

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

Parameters:

  | draw_value | `true` to draw the value.

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

Set the position in which the value is displayed.

Sets the position in which the current value is displayed.

Parameters:

  | pos | The position in which the current 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

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:

- scale.h