gtk-0.14.3: Binding to the Gtk+ graphical user interface library.

Maintainer gtk2hs-users@lists.sourceforge.net provisional portable (depends on GHC) None Haskell98

Description

A Object representing an adjustable bounded value

Synopsis

# Detail

The 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 SpinButton, Viewport, and Range (which is a base class for HScrollbar, VScrollbar, HScale, and VScale).

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

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

# Class Hierarchy

| GObject
| +----Object


# Types

Instances

 Source # Methods Source # Methods Source # Methods Source # Source #

class ObjectClass o => AdjustmentClass o Source #

Instances

 Source #

# Constructors

Arguments

 :: Double value - the initial value. -> Double lower - the minimum value. -> Double upper - the maximum value. -> Double stepIncrement - the step increment. -> Double pageIncrement - the page increment. -> Double pageSize - the page size. -> IO Adjustment

Creates a new Adjustment.

The creation function take every value that is contained in the object: value is the initial value and should be between the upper and lower bounds of the slider. Clicking on the arrows increases this value by stepIncrement. Clicking in the slider advances by pageIncrement. The pageSize is needed to determine if the end of the slider is still in the range.

# Methods

Set the lower value.

Retrieve the lower value.

Set the page increment value.

Retrieve the pageincrement value.

Set the page size value.

Retrieve the page size value.

Set the step-increment value.

Retrieve the step-increment value.

Set the upper value.

Retrieve the upper value.

Sets the current value of the Adjustment object. The value is clamped to lie between the adjustment's lower and upper values. See adjustmentNew for details of these properties.

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

Gets the current value of the adjustment. See adjustmentSetValue.

Arguments

 :: Adjustment -> Double lower - the lower value. -> Double upper - the upper value. -> IO ()

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

Emit the onAdjChanged signal.

Emit the onValueChanged signal.

• When adjusting the or bounds, this function can be called to enforce a visual update of the containing widget.

# Attributes

Default value: 0

The minimum value of the adjustment.

Default value: 0

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

The step increment of the adjustment.

Default value: 0

The page increment of the adjustment.

Default value: 0

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 SpinButton.

Default value: 0

# Signals

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

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

Emitted when the Adjustment value field has been changed.

Emitted when the Adjustment value field has been changed.