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gWidgets2 (version 1.0-9)

gcombobox: constructor for a combobox

Description

A combobox can be either a drop down list (editable=FALSE), or a drop-down list and edit area (a combobox).

Non exported helper function to coerce items into a data frame. First column contains the values, second stock icons, third tooltips

Ensure that value is a data frame. One can pass a vector or a one-column data frame to inidicate the possible values for selection, a second column is used for an icons (if possible), a third for a tooltip (if possible).

Change handler for a non-editabe combobox is called when a new value is selected. For editable comboboxes, the handler is also called when the text entry box is activated.

The svalue method for a combobox object refers to its main property, the selected value. When index=FALSE (or NULL) the value is returned. If index=TRUE the index of the object within the set of items is used.

Usage

gcombobox(
  items,
  selected = 1,
  editable = FALSE,
  coerce.with = NULL,
  handler = NULL,
  action = NULL,
  container = NULL,
  ...,
  toolkit = guiToolkit()
)
.gcombobox(
  toolkit,
  items,
  selected = 1,
  editable = FALSE,
  coerce.with = NULL,
  handler = NULL,
  action = NULL,
  container = NULL,
  ...
)
gdroplist(...)
.make_gcombobox_items(value)
# S3 method for GComboBox
[ (x, i , j, ...) <- value
# S3 method for GComboBox
addHandlerChanged(obj, handler, action = NULL, ...)
# S3 method for GComboBox
svalue(obj, index = NULL, drop = NULL, ...)

Arguments

items

Items to select from. A vector or a data frame. If a data frame, then first column is values. Second is optional, but can specify a stock icon name, third is optional and can be used to specify a tooltip. These may not be supported in all toolkits.

selected

integer. Which item (by index) is selected. Use -1 for no selection

editable

logical. Is user allowed to edit value

coerce.with

A function of function name to be called before selected value is returned by svalue

handler

Called when combobox value is changed.

action

passed to handler

container

parent container

...

passed to parent container's add method

toolkit

toolkit

value

new items for selection

x

combobox object

i

item index

j

ignored

obj

object receiving event and emitting a signal to the handler

index

NULL or logical. If TRUE and widget supports it an index, instead of a value will be returned.

drop

NULL or logical. If widget supports it, drop will work as it does in a data frame or perhaps someother means.

Value

Returns an object of class GComboBox for which the following methods are overriden:

  1. svalue Return selected value by name or (if index=TRUE by index). The latter only if editable=FALSE.

  2. svalue<- Set the selected value by value or if index=TRUE by index.

  3. [ return items to select from

  4. [<- Set items to select from.