NAME
combobox - Create and manipulate combination box widgets
SYNOPSIS
combobox pathName ?options?
INHERITANCE
itk::Widget <- LabeledWidget <- Entryfield <- Combobox
STANDARD OPTIONS
background borderWidth cursor exportSelection
ASSOCIATED OPTIONS
hscrollmode items textBackground textFont vscrollmode
See the "scrolledlistbox" manual entry for details on the above inherited options.
INHERITED OPTIONS
childSitePos command fixed focusCommand
labelBitmap labelFont labelImage labelMargin
DESCRIPTION
The 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 it's 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.
METHODS
The 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:
curselection index see size
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 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 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.
DEFAULT BINDINGS
The Combobox generally has the same bindings as it's 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.
EXAMPLE
proc selectCmd {} {
puts stdout "[.cb2 getcurselection]" }
#
# Non-editable Dropdown Combobox
#
combobox .cb1 -labeltext Month: \
-selectioncommand {puts "selected: [.cb1 getcurselection]"} \ -editable false -listheight 185 -popupcursor hand1 \ -items {Jan Feb Mar Apr May June Jul Aug Sept Oct Nov Dec}
#
# Editable Dropdown Combobox
#
combobox .cb2 -labeltext "Operating System:" \ -items {Linux HP-UX SunOS Solaris Irix} -selectioncommand selectCmd
#
# Simple Combobox
#
combobox .cb3 -labeltext Fonts: -labelpos nw \ -dropdown false -listheight 220 -items [exec xlsfonts]
pack .cb1 -padx 10 -pady 10 -fill x pack .cb2 -padx 10 -pady 10 -fill x pack .cb3 -padx 10 -pady 10 -fill x
AUTHOR
John S. Sigler
KEYWORDS
combobox, entryfield, scrolledlistbox, itk::Widget, entry, listbox, widget, iwidgets