GtkAdjustment {RGtk2} | R Documentation

## GtkAdjustment

### Description

A GtkObject representing an adjustable bounded value

### Methods and Functions

`gtkAdjustmentNew(value = NULL, lower = NULL, upper = NULL, step.incr = NULL, page.incr = NULL, page.size = NULL)`
`gtkAdjustmentGetValue(object)`
`gtkAdjustmentSetValue(object, value)`
`gtkAdjustmentClampPage(object, lower, upper)`
`gtkAdjustmentChanged(object)`
`gtkAdjustmentValueChanged(object)`
`gtkAdjustmentConfigure(object, value, lower, upper, step.increment, page.increment, page.size)`
`gtkAdjustmentGetLower(object)`
`gtkAdjustmentGetPageIncrement(object)`
`gtkAdjustmentGetPageSize(object)`
`gtkAdjustmentGetStepIncrement(object)`
`gtkAdjustmentGetUpper(object)`
`gtkAdjustmentSetLower(object, lower)`
`gtkAdjustmentSetPageIncrement(object, page.increment)`
`gtkAdjustmentSetPageSize(object, page.size)`
`gtkAdjustmentSetStepIncrement(object, step.increment)`
`gtkAdjustmentSetUpper(object, upper)`
`gtkAdjustment(value = NULL, lower = NULL, upper = NULL, step.incr = NULL, page.incr = NULL, page.size = NULL)`

### Hierarchy

    GObject
       +----GInitiallyUnowned
             +----GtkObject
                   +----GtkAdjustment

### Detailed Description

The `GtkAdjustment` 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 `GtkSpinButton`, `GtkViewport`, and `GtkRange` (which is a base class for `GtkHScrollbar`, `GtkVScrollbar`, `GtkHScale`, and `GtkVScale`).

The `GtkAdjustment` object does not update the value itself. Instead it is left up to the owner of the `GtkAdjustment` to control the value.

The owner of the `GtkAdjustment` typically calls the `gtkAdjustmentValueChanged` and `gtkAdjustmentChanged` functions after changing the value and its bounds. This results in the emission of the "value_changed" or "changed" signal respectively.

### Structures

`GtkAdjustment`

  The `GtkAdjustment` struct contains the following fields.

  `numeric` lower; | the minimum value.
  `numeric` upper; | the maximum value.
  `numeric` value; | the current value.
  `numeric` step_increment; | the increment to use to make minor changes to the value. In a `GtkScrollbar` this increment is used when the mouse is clicked on the arrows at the top and bottom of the scrollbar, to scroll by a small amount.
  `numeric` page_increment; | the increment to use to make major changes to the value. In a `GtkScrollbar` this increment is used when the mouse is clicked in the trough, to scroll by a large amount.
  `numeric` page_size; | the page size. In a `GtkScrollbar` this is the size of the area which is currently visible.

### Convenient Construction

`gtkAdjustment` is the equivalent of `gtkAdjustmentNew`.

### Signals

`changed(adjustment, user.data)`

  Emitted when one or more of the `GtkAdjustment` fields have been changed, other than the value field.

  `adjustment`

    the object which received the signal.

  `user.data`

    user data set when the signal handler was connected.

`value-changed(adjustment, user.data)`

  Emitted when the `GtkAdjustment` value field has been changed.

  `adjustment`

    the object which received the signal.

  `user.data`

    user data set when the signal handler was connected.

### Properties

`lower` [numeric : Read / Write]

  The minimum value of the adjustment. Default value: 0 Since 2.4

`page-increment` [numeric : Read / Write]

  The page increment of the adjustment. Default value: 0 Since 2.4

`page-size` [numeric : Read / Write]

  The page size of the adjustment. Note that the page-size is irrelevant and should be set to zero if the adjustment is used for a simple scalar value, e.g. in a `GtkSpinButton`. Default value: 0 Since 2.4

`step-increment` [numeric : Read / Write]

  The step increment of the adjustment. Default value: 0 Since 2.4

`upper` [numeric : Read / Write]

  The maximum value of the adjustment. Note that values will be restricted by `upper - page-size` if the page-size property is nonzero. Default value: 0 Since 2.4

`value` [numeric : Read / Write]

  The value of the adjustment. Default value: 0 Since 2.4

### Author(s)

Derived by RGtkGen from GTK+ documentation

### References

https://developer.gnome.org/gtk2/stable/GtkAdjustment.html

[Package RGtk2 version 2.20.36.3 Index]