## tixComboBox - Create and manipulate tixComboBox widgets

### SYNOPSIS

tixComboBox pathName ?options?

### SUPER-CLASS

The TixComboBox class is derived from the TixLabelWidget class and inherits all the commands, options and subwidgets of its super-class.

### STANDARD OPTIONS

TixComboBox supports all the standard options of a frame widget. See the options(n) manual entry for details on the standard options.

### WIDGET-SPECIFIC OPTIONS

    Name:		anchor
    Class:		Anchor
    Switch:		-anchor

Specifies how the string inside the entry subwidget should be aligned. Only the values "w" or "e" are allowed. When set the "w", the entry is aligned to its beginning. When set to "e", it is aligned to its end.

    Name:		arrowBitmap
    Class:		ArrowBitmap
    Switch:		-arrowbitmap

Specifies the bitmap to be used in the arrow button beside the entry widget. The default is an downward arrow bitmap in the file $tix_library/bitmaps/cbxarrow

    Name:		browseCmd
    Class:		BrowseCmd
    Switch:		-browsecmd

Specifies the command to be called when the user browses through the listbox. This command can be used to provide instant feedback when the user examines items in the listbox before committing a choice.

    Name:		command
    Class:		Command
    Switch:		-command

Specifies the command to be called when the ComboBox is invoked or when the -value of the ComboBox is changed.

    Name:		crossBitmap
    Class:		CrossBitmap
    Switch:		-crossbitmap

Specifies the bitmap to be used in the "cross" button to the left of the entry widget. The default is a bitmap in the file $tix_library/bitmaps/cross

    Name:		disableCallback
    Class:		DisableCallback
    Switch:		-disablecallback

A boolean value indicating whether callbacks should be disabled. When set to true, the TCL command specified by the -command option is not executed when the -value of the ComboBox. changes.

    Name:		disabledforeground
    Class:		DisabledForeground
    Switch:		-disabledforeground

Specifies the foreground color to be used when the ComboBox is disabled.

    Name:		dropdown
    Class:		Dropdown
    Switch:		-dropdown

A Boolean value specifying the style of the ComboBox. When set to "true", the listbox is only displayed temporarily when the arrow button is pressed. When set to "false", the listbox is always displayed.

    Name:		editable
    Class:		Editable
    Switch:		-editable

Specifies whether the user is allowed to type into the entry subwidget of the ComboBox.

    Name:		fancy
    Class:		Fancy
    Switch:		-fancy

A Boolean value specifying whether the cross and tick button subwidgets should be shown.

    Name:		grab
    Class:		Grab
    Switch:		-grab

Specifies the pointer grabbing policy when the listbox is popped up. Only values "global", "local" or "none" are allowed. By default global grab is used. However, when you are developing your application, you may want to use only local grabbing so that in the event of errors,

    Name:		historyLimit
    Class:		historyLimit
    Switch:		-historylimit
    Alias:		-histlimit

Specifies how many previous user inputs can be stored in the history list.

    Name:		history
    Class:		History
    Switch:		-history

A Boolean value specifying whether previous user inputs should be stored in the history list.

    Name:		label
    Class:		Label
    Switch:		-label

Specifies the string to display as the label of this ComboBox widget.

    Name:		labelSide
    Class:		LabelSide
    Switch:		-labelside

Specifies where the label should be displayed relative to the entry subwidget. Valid options are: top, left, right, bottom, none or acrosstop.

    Name:		listCmd
    Class:		listCmd
    Switch:		-listcmd

Specifies a TCL command to be called every time when the listbox pops up. This option allows you to fill up the listbox on-demand. This option is ignored when the listbox is not in the dropdown style.

    Name:		listWidth
    Class:		listWidth
    Switch:		-listwidth

If set, this option controls the width of the listbox subwidget when it is popped up. The option is ignored when the listbox is not in the dropdown style.

    Name:		prunehistory
    Class:		PruneHistory
    Switch:		-prunehistory

Specifies whether duplicated previous user inputs should be pruned from the the history list. Only Boolean values are allowed.

    Name:		selection
    Class:		Selection
    Switch:		-selection

Contains the selection in the ComboBox (the string displayed in the entry subwidget). Depending on the -selectmode, the selection of a ComboBox may be different than its -value.

    Name:		selection
    Class:		Selection
    Switch:		-selection

This option stores the temporary selection. When the user types in a text string inside the entry widget, that string is considered as a temporary input and is stored inside the -selection option. The -value option is updated only when the user presses the return key.

    Name:		selectMode
    Class:		SelectMode
    Switch:		-selectmode

Specifies the how the combobox responds to the mouse button events in the listbox subwidget; can eithet be "browse" or "immediate". The default -selectmode is "browse". See the BINDINGS section below.

    Name:		state
    Class:		State
    Switch:		-state

Specifies the whether the ComboBox is normal or disabled. Only the values "normal" and "disabled" are recognized.

    Name:		tickBitmap
    Class:		tickBitmap
    Switch:		-tickbitmap

Specifies the bitmap to be used in the "tick" button to the left of the entry widget. The default is a bitmap in the file $tix_library/bitmaps/tick

    Name:		validateCmd
    Class:		ValidateCmd
    Switch:		-validatecmd

Specifies a TCL command to be called when the -value of the ComboBox is about to change. This command is called with one parameter -- the new -value entered by the user. This command is to validate this new value by returning a value it deems valid.

    Name:		value
    Class:		Value
    Switch:		-value

Specifies the string to be displayed in the entry subwidget of the ComboBox. When queried, the returned value is the last value selected by the user. When the -value option is changed as a result of the config -value widget command, the TCL command specified by the -command option is called.

    Name:		variable
    Class:		Variable
    Switch:		-variable

Specifies the global variable in which the value of the ComboBox should be stored. The value of the ComboBox will be automatically updated when this variable is changed.

### SUBWIDGETS

    Name:		arrow
    Class:		Button

The down arrow button.

    Name:		cross
    Class:		Button

The cross button. Available only when -fancy is set.

    Name:		entry
    Class:		Entry

The entry that shows the value of this tixControl.

    Name:		label
    Class:		Label

The label subwidget.

    Name:		listbox
    Class:		Listbox

The listbox that holds all the list entries.

    Name:		slistbox
    Class:		TixScrolledListBox

The scrolled-listbox that provides the scrollbars.

    Name:		tick
    Class:		Button

The tick button. Available only when -fancy is set.

### DESCRIPTION

The tixComboBox command creates a new window (given by the pathName argument) and makes it into a tixComboBox widget. Additional options, described above, may be specified on the command line or in the option database to configure aspects of the ComboBox such as its cursor and relief. The Tix ComboBox widget is similar to the combo box control in MS Windows. The user can select a choice by either typing in the entry subwdget or selecting from the listbox subwidget.

### WIDGET COMMANDS

The tixComboBox command creates a new Tcl command whose name is the may be used to invoke various operations on the widget. It has the following general form:

    pathName option ?arg arg ...?

PathName is the name of the command, which is the same as the determine the exact behavior of the command. The following commands are possible for ComboBox widgets:

pathName addhistory string
  Add the string to the beinning of the listbox.

pathName appendhistory string
  Append the string to the end of the listbox.

pathName cget option
  Returns the current value of the configuration option given by option. Option may have any of the values accepted by the tixComboBox command.

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 tixComboBox command.

pathName flash index string
  Flashes the ComboBox. flash is usually called by a -command procedure to acknowledge to the user that he has selected a value for the ComboBox.

pathName insert index string
  Insert the string into the listbox at the specified index. index must be a valid listbox index.

pathName pick index
  Set the (index)th item in the listbox to be the current value of the ComboBox. As a result, the value of the ComboBox is changed and the TCL command sepcified by the -command option will be called.

pathName subwidget name ?args?
  When no options are given, returns the pathname of the subwidget of the specified name. When options are given, the widget command of the specified subwidget will be called with these options.

### BINDINGS

[1]
If the -selectmode is "immediate", when the user enters a keystroke, clicks on an item or drags the mouse pointer in the listbox, the -value of the ComboBox will be immediately set to this item and the -command procedure will be called.

[2]
If the -selectmode is "browse", when the user enters a keystroke, clicks on an item or drags the mouse pointer in the listbox, the -selection of the ComboBox will be immediately set to the new content of the entry subwidget; also the -browsecmd procedure will be called. The -value option will be changed only when the user invokes the ComboBox (see [3] below). If the user presses the <Escape> key at any time, any new -selection will be ignored and the text inside the entry subwidget will be restored to the current -value of the ComboBox.

[3]
If the -dropdown option is true, the user can invoke the ComboBox by releasing the left mouse button over the desired item in the listbox. If the -dropdown option is false, the user can invoke the ComboBox by double-clicking over the desired item in the listbox. In both cases, the user can also invoke the listbox by pressing the <Return> or <Tab> key inside the entry subwidget, or switching the input focus to another widget inside the same toplevel widget

### BUGS

Starting from Tix vetsion 4.0, the default -value of the ComboBox is the empty string. If you want the ComboBox to show a string by default, you must configure its -value option explicitly.

### KEYWORDS

Tix(n), ComboBox(n), listbox(n)

Last modified Sun Jan 19 22:34:20 EST 1997 --- Serial 853731296