combobox.n

linux 下的源代码分析阅读器 red hat公司新版

'\"
'\" Copyright (c) 1995 John S. Sigler
'\" Copyright (c) 1997 Mitch Gorman
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" @(#) Combobox.n
'/" 
.so man.macros
.HS combobox iwid
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
combobox \- Create and manipulate combination box widgets
.SH SYNOPSIS
\fBcombobox\fI \fIpathName \fR?\fIoptions\fR?
.SH "INHERITANCE"
itk::Widget <- LabeledWidget <- Entryfield <- Combobox
.SH "STANDARD OPTIONS"
.LP
.ta 4c 8c 12c
.nf

\fB\fR
\fB
background	borderWidth	cursor	justify
exportSelection	foreground	highlightColor	highlightThickness
relief	width	insertWidth	insertBackground
insertOffTime	insertOnTime	insertWidth	insertBorderWidth
selectForeground	selectBackground
selectBorderWidth	textVariable
\fR
.fi
.LP
See the "options" manual entry for details on the standard options.
.SH "ASSOCIATED OPTIONS"
.LP
.nf
.ta 4c 8c 12c
\fBhscrollmode\fR	\fBtextBackground\fR	\fBtextFont\fR	\fBvscrollmode\fR
.fi
.LP
See the "scrolledlistbox" manual entry for details on the above inherited 
options.
.LP
.nf
.ta 4c 8c 12c
\fBshow\fR
.fi
.LP
See the "entry" manual entry for details on the above inherited option.
.SH "INHERITED OPTIONS"
.LP
.nf
.ta 4c 8c 12c
\fBchildSitePos\fR	\fBcommand\fR	\fBfixed\fR	\fBfocusCommand\fR
\fBinvalid\fR	\fBtextBackground\fR	\fBtextFont\fR	\fBvalidate\fR
.fi
.LP
See the "entryfield" class manual entry for details on the inherited options.
.LP
.nf
.ta 4c 8c 12c
\fBlabelBitmap\fR	\fBlabelFont\fR	\fBlabelImage\fR	\fBlabelMargin\fR
\fBlabelPos\fR	\fBlabelText\fR	\fBlabelVariable\fR
.fi
.LP
See the "labeledwidget" class manual entry for details on the 
inherited options.
.SH "WIDGET-SPECIFIC OPTIONS"
.LP
.nf
Name:	\fBarrowRelief\fR
Class:	\fBRelief\fR
Command-Line Switch:	\fB-arrowrelief\fR
.fi
.IP
Specifies the relief style to use for a dropdown Combobox's arrow
button in a normal (not depressed) state. Acceptable values 
are \fBraised\fR, \fBsunken\fR, \fBflat\fR, \fBridge\fR, and \fBgroove\fR.  
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.
.LP
.nf
Name:	\fBcompletion\fR
Class:	\fBCompletion\fR
Command-Line Switch:	\fB-completion\fR
.fi
.IP
Boolean given in any of the forms acceptable to \fBTcl_GetBoolean\fR which
determines whether insertions into the entry field, whether from the
keyboard or programmatically via the \fBinsert\fR method, are
automatically completed with the first matching item from the listbox.  The
default is true.
.LP
.nf
Name:	\fBdropdown\fR
Class:	\fBDropdown\fR
Command-Line Switch:	\fB-dropdown\fR
.fi
.IP
Boolean describing the Combobox layout style given in any of the forms
acceptable to \fBTcl_GetBoolean\fR. 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. 
.LP
.nf
Name:	\fBeditable\fR
Class:	\fBEditable\fR
Command-Line Switch:	\fB-editable\fR
.fi
.IP
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 \fBTcl_GetBoolean\fR. 
The default is true.
.LP
.nf
Name:	\fBgrab\fR
Class:	\fBGrab\fR
Command-Line Switch:	\fB-grab\fR
.fi
.IP
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.
.LP
.nf
Name:	\fBlistHeight\fR
Class:	\fBHeight\fR
Command-Line Switch:	\fB-listheight\fR
.fi
.IP
Height of the listbox specified in any of the forms acceptable to 
\fBTk_GetPixels\fR.  The default is 150 pixels.
.LP
.nf
Name:	\fBmargin\fR
Class:	\fBMargin\fR
Command-Line Switch:	\fB-margin\fR
.fi
.IP
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 
\fBTk_GetPixels\fR. This option has no effect on a simple Combobox. The
default is 1.
.LP
.nf
Name:	\fBpopupCursor\fR
Class:	\fBCursor\fR
Command-Line Switch:	\fB-popupcursor\fR
.fi
.IP
Specifies the cursor to be used for dropdown style listboxes. The value
may have any of the forms acceptable to \fBTk_GetCursor\fR. The default is
arrow. 
.LP
.nf
Name:	\fBselectionCommand\fR
Class:	\fBSelectionCommand\fR
Command-Line Switch:	\fB-selectioncommand\fR
.fi
.IP
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 {}.
.LP
.nf
Name:	\fBstate\fR
Class:	\fBState\fR
Command-Line Switch:	\fB-state\fR
.fi
.IP
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.
.LP
.nf
Name:	\fBunique\fR
Class:	\fBUnique\fR
Command-Line Switch:	\fB-unique\fR
.fi
.IP
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 \fBTcl_GetBoolean\fR. The default is true. 
.BE

.SH DESCRIPTION
.PP
The \fBcombobox\fR 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. 
.PP
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.
.SH "METHODS"
.PP
The \fBcombobox\fR command creates a new Tcl command whose
name is \fIpathName\fR. This
command may be used to invoke various
operations on the widget. It has the following general form:
.DS C
\fIpathName option \fR?\fIarg arg ...\fR?
.DE
\fIOption\fR and the \fIarg\fRs
determine the exact behavior of the command. The following
commands are possible for Combobox widgets:
.SH "ASSOCIATED METHODS"
.LP
.nf
.ta 4c 8c 12c
\fBicursor\fR	\fBscan\fR
.fi
.LP
See the "entry" manual entries for details on the above associated methods.
.LP
.nf
.ta 4c 8c 12c
\fBcurselection\fR	\fBindex\fR	\fBsee\fR	\fBsize\fR
\fBxview\fR	\fByview\fR
.fi
.LP
See the "listbox" manual entries for details on the above associated methods.
.LP
.nf
.ta 4c 8c 12c
\fBgetcurselection\fR	\fBjustify\fR	\fBsort\fR
.fi
.LP
See the "scrolledlistbox" manual entries for details on the above associated 
methods.
.LP
.SH "WIDGET-SPECIFIC METHODS"
.TP
\fIpathName \fBcget\fR \fIoption\fR
Returns the current value of the configuration option given
by \fIoption\fR.
\fIOption\fR may have any of the values accepted by the \fBcombobox\fR
command.
.TP
\fIpathName \fBclear\fR ?\fBcomponent\fR?
Clears the contents from one or both components. Valid component values
are \fBlist\fR, or \fBentry\fR.  With no component specified, both are cleared.
.TP
\fIpathName\fR \fBconfigure\fR ?\fIoption\fR? ?\fIvalue option value ...\fR?
Query or modify the configuration options of the widget.
If no \fIoption\fR is specified, returns a list describing all of
the available options for \fIpathName\fR (see \fBTk_ConfigureInfo\fR for
information on the format of this list).  If \fIoption\fR is specified
with no \fIvalue\fR, 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 \fIoption\fR is specified).  If
one or more \fIoption\-value\fR 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.
\fIOption\fR may have any of the values accepted by the \fBcombobox\fR
command.
.TP
\fIpathName \fBdelete \fIcomponent\fR \fIfirst\fR ?\fIlast\fR?
Delete one or more elements from a given component, \fBlist\fR or \fBentry\fR.
If a list item to be removed is currently selected (displayed in the entry 
field area), the entry field will be cleared.
.TP
\fIpathName \fBget ?\fIindex\fR? \fR
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.
.TP
\fIpathName \fBinsert\fR \fIcomponent\fR \fIindex\fR \fIelement\fR ?\fIelement element ...\fR?
Insert one or more new elements into the given component, \fBlist\fR or
\fBentry\fR, just before the element given by \fIindex\fR.
.TP
\fIpathName \fBselection\fR \fIoption\fR \fIfirst\fR ?\fIlast\fR?
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.
.SH "COMPONENTS"
.LP
.nf
Name:	\fBentry\fR
Class:	\fBEntry\fR
.fi
.IP
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.
.LP
.nf
Name:	\fBlist\fR
Class:	\fBScrolledlistbox\fR
.fi
.IP
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.
.SH "DEFAULT BINDINGS"
.PP
The Combobox generally has the same bindings as its primary component items -
the Scrolledlistbox and Entryfield. However it also adds these:
.PP
[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.
.PP
[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.
.PP
[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. 
.PP
[4] Escape keypress removes a dropdown list which has been popped up. 
.PP
[5] The <space> and <Return> keystrokes select the current item. They also
remove the popped up list for dropdown comboboxes.
.PP
[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.
.PP
[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.

.SH EXAMPLE
.DS
 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 
 .cb1 insert list end Jan Feb Mar Apr May June Jul Aug Sept Oct Nov Dec
	
 #
 # Editable Dropdown Combobox
 #
 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

.DE
.SH ORIGINAL AUTHOR
John S. Sigler
.SH CURRENT MAINTAINER
Mitch Gorman ([e-mail])
.SH KEYWORDS
combobox, entryfield, scrolledlistbox, itk::Widget, entry, listbox, widget,
iwidgets