combobox man page

iwidgets::combobox — Create and manipulate combination box widgets


iwidgets::combobox pathName ?options?


itk::Widget <- iwidgets::LabeledWidget <- iwidgets::Entryfield <- iwidgets::Combobox

Standard Options

background        borderWidth        cursor          justify
exportSelection   foreground         highlightColor  highlightThickness
insertWidth       insertBackground   insertOffTime   insertOnTime
insertWidth       insertBorderWidth  relief          selectForeground
selectBackground  selectBorderWidth  textVariable    width

See the "options" manual entry for details on the standard options.

Associated Options

hscrollmode	textBackground	textFont	vscrollmode

See the "scrolledlistbox" manual entry for details on the above inherited  options.


See the "entry" manual entry for details on the above inherited option.

Inherited Options

childSitePos command fixed focusCommand
invalid textBackground textFont validate

See the "entryfield" class manual entry for details on the inherited options.

labelBitmap labelFont labelImage labelMargin
labelPos labelText labelVariable sticky

See the "labeledwidget" class manual entry for details on the  inherited options.

Widget-Specific Options

Name: arrowRelief
Class: Relief
Command-Line Switch: -arrowrelief

Specifies the relief style to use for a dropdown Combobox's arrow button in a normal (not depressed) state. Acceptable values  are raised, sunken, flat, ridge, and groove.   Sunken is discouraged as this is the relief used to indicate a depressed  state. This option has no effect on simple Comboboxes. The default is raised.

Name: completion
Class: Completion
Command-Line Switch: -completion

Boolean given in any of the forms acceptable to Tcl_GetBoolean which determines whether insertions into the entry field, whether from the keyboard or programmatically via the insert method, are automatically completed with the first matching item from the listbox.  The default is true.

Name: dropdown
Class: Dropdown
Command-Line Switch: -dropdown

Boolean describing the Combobox layout style given in any of the forms acceptable to Tcl_GetBoolean. If true, the Combobox  will be a dropdown style widget which displays an entry field and an arrow button which when activated will pop up a scrollable list of items. If false, a simple Combobox style  will be used which has an entry field and a scrollable list beneath it  which is always visible. Both styles allow an optional label for the entry field area. The default is true.

Name: editable
Class: Editable
Command-Line Switch: -editable

Boolean describing whether or not the text entry area is editable by the user. If true the user can add items to the combobox by entering text into the entry area and then pressing Return. If false, the list of items is non-editable and can only be changed by calling the insert or delete methods. (The value in the entry field can still be modified by selecting from the list.)  Given in any of the forms acceptable to Tcl_GetBoolean.  The default is true.

Name: grab
Class: Grab
Command-Line Switch: -grab

This option sets the grab scope for the appearance of the listbox in drop-down comboboxes.  It can be either global or local.  The default is local.

Name: listHeight
Class: Height
Command-Line Switch: -listheight

Height of the listbox specified in any of the forms acceptable to  Tk_GetPixels.  The default is 150 pixels.

Name: margin
Class: Margin
Command-Line Switch: -margin

Specifies the width in pixels between the entry component and the arrow button for a dropdown Combobox given in any of the forms acceptable to  Tk_GetPixels. This option has no effect on a simple Combobox. The default is 1.

Name: popupCursor
Class: Cursor
Command-Line Switch: -popupcursor

Specifies the cursor to be used for dropdown style listboxes. The value may have any of the forms acceptable to Tk_GetCursor. The default is arrow.

Name: selectionCommand
Class: SelectionCommand
Command-Line Switch: -selectioncommand

Specifies a Tcl command procedure which is called when an item in the listbox area is selected. The item will be selected in the list, the listbox  will be removed if it is a dropdown Combobox, and the selected item's  text will be inserted into the entry field before the -selectioncommand proc is called. The default is {}.

Name: state
Class: State
Command-Line Switch: -state

Specifies the overall state of the Combobox megawidget.  Can be either normal or disabled.  If the Combobox is disabled, no text can be entered into the entry field, no selection can be made in the listbox, and the arrowBtn component is disabled.  The default is normal.

Name: unique
Class: Unique
Command-Line Switch: -unique

Boolean describing whether or not duplicate items are allowed in the combobox list. If true, then duplicates are not allowed to be inserted. If false, a duplicate entry causes selection of the item. Given in any of the forms acceptable to Tcl_GetBoolean. The default is true.


The iwidgets::combobox command creates an enhanced entry field widget with an optional associated label and a scrollable list. When an item is selected in the list area of a Combobox, its value is then displayed in the entry field text area. Functionally similar to an Optionmenu, the Combobox adds (optional) list scrolling and (optional) item editing and inserting capabilities.

There are two basic styles of Comboboxes (determined by the -dropdown option): dropdown and simple. The dropdown style adds an arrow button to the right of the entry field which when activated will pop up (and down) the scrolled listbox beneath the entry field. The simple (non-dropdown) Combobox  permanently displays the listbox beneath the entry field and has no  arrow button. Either style allows an optional entry field label.


The iwidgets::combobox command creates a new Tcl command whose name is pathName. This command may be used to invoke various operations on the widget. It has the following general form: pathName option ?arg arg ...? Option and the args determine the exact behavior of the command. The following commands are possible for Combobox widgets:

Associated Methods

icursor	scan

See the "entry" manual entries for details on the above associated methods.

curselection index see size
xview yview

See the "listbox" manual entries for details on the above associated methods.

getcurselection	justify	sort

See the "scrolledlistbox" manual entries for details on the above associated  methods.

Widget-Specific Methods

pathName cget option

Returns the current value of the configuration option given by option. Option may have any of the values accepted by the iwidgets::combobox command.

pathName clear ?component?

Clears the contents from one or both components. Valid component values are list, or entry.  With no component specified, both are cleared.

pathName configure ?option? ?value option value ...?

Query or modify the configuration options of the widget. If no option is specified, returns a list describing all of the available options for pathName (see Tk_ConfigureInfo for information on the format of this list).  If option is specified with no value, then the command returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified).  If one or more option-value pairs are specified, then the command modifies the given widget option(s) to have the given value(s);  in this case the command returns an empty string. Option may have any of the values accepted by the iwidgets::combobox command.

pathName delete component first ?last?

Delete one or more elements from a given component, list or entry. If a list item to be removed is currently selected (displayed in the entry  field area), the entry field will be cleared.

pathName get ?index?

With no arguments, returns the contents currently in the entry  field area. With a single argument, returns the contents of the  listbox item at the indicated index.

pathName insert component index element ?element element ...?

Insert one or more new elements into the given component, list or entry, just before the element given by index.

pathName selection option first ?last?

Adjust the selection within the listbox component and updates the contents of the entry field component to the value of the selected item. See the "listbox" manual entry for more details on parameter options.


Name: entry
Class: Entry

Text entry area where the current selection is displayed. If the  Combobox is editable and its state is normal, the user can edit the  contents of this item.

Name: list
Class: Scrolledlistbox

Scrollable list which stores all the items which the user can select from. For dropdown Comboboxes, this component is hidden until the user pops it up by pressing on the arrow button to the right of the entry component. For simple Comboboxes this component is always visible just beneath the entry component.

Default Bindings

The Combobox generally has the same bindings as its primary component items - the Scrolledlistbox and Entryfield. However it also adds these:

[1] Button-1 mouse press on the arrow key of a dropdown Combobox causes the list to be popped up. If the combobox is non-editable, a Button-1 press on the entry field area will also pop up the list.

[2] Button-1 mouse press anywhere on the display removes a dropdown listbox which has been popped up, unless the keypress is upon one of the Combobox scrollbars which scrolls the list. If it is pressed upon an item in the list area, that item will be selected before the list is removed.

[3] Button-3 mouse press on the arrow key of a dropdown Combobox causes the next item to be selected. Shift-Button-3 causes the previous item to be selected.

[4] Escape keypress removes a dropdown list which has been popped up.

[5] The <space> and <Return> keystrokes select the current item. They also remove the popped up list for dropdown comboboxes.

[6] Up and Down arrow keypresses from the entry field and arrow button component cause the previous and next items in the listbox to be selected  respectively. Ctl-P and Ctl-N are similarly mapped for emacs emulation.

[7] Entry field and arrow button component Shift-Up and Shift-Down arrow keys pop up and down the listbox of a dropdown Combobox. The arrow button component also maps <Return> and <space> similarly.


package require Iwidgets 4.0
proc selectCmd {} {
   puts stdout "[.cb2 getcurselection]"

# Non-editable Dropdown Combobox
iwidgets::combobox .cb1 -labeltext Month: \
    -selectioncommand {puts "selected: [.cb1 getcurselection]"} \
    -editable false -listheight 185 -popupcursor hand1
.cb1 insert list end Jan Feb Mar Apr May June Jul Aug Sept Oct Nov Dec
# Editable Dropdown Combobox
iwidgets::combobox .cb2 -labeltext "Operating System:" -selectioncommand selectCmd
.cb2 insert list end Linux HP-UX SunOS Solaris Irix
.cb2 insert entry end L

pack .cb1 -padx 10 -pady 10 -fill x
pack .cb2 -padx 10 -pady 10 -fill x

Original Author

John S. Sigler

Current Maintainer

Mitch Gorman (


combobox, entryfield, scrolledlistbox, itk::Widget, entry, listbox, widget, iwidgets