NAME¶
tk_getOpenFile, tk_getSaveFile - pop up a dialog box for the user to select a
file to open or save.
SYNOPSIS¶
tk_getOpenFile ?option value ...?
tk_getSaveFile ?option value ...?
DESCRIPTION¶
The procedures
tk_getOpenFile and
tk_getSaveFile pop up a dialog
box for the user to select a file to open or save. The
tk_getOpenFile
command is usually associated with the
Open command in the
File
menu. Its purpose is for the user to select an existing file
only. If
the user enters a non-existent file, the dialog box gives the user an error
prompt and requires the user to give an alternative selection. If an
application allows the user to create new files, it should do so by providing
a separate
New menu command.
The
tk_getSaveFile command is usually associated with the
Save
as command in the
File menu. If the user enters a file that
already exists, the dialog box prompts the user for confirmation whether the
existing file should be overwritten or not.
The following
option-value pairs are possible as command line arguments
to these two commands:
- -confirmoverwrite boolean
- Configures how the Save dialog reacts when the selected
file already exists, and saving would overwrite it. A true value requests
a confirmation dialog be presented to the user. A false value requests
that the overwrite take place without confirmation. Default value is
true.
- -defaultextension extension
- Specifies a string that will be appended to the filename if
the user enters a filename without an extension. The default value is the
empty string, which means no extension will be appended to the filename in
any case. This option is ignored on Mac OS X, which does not require
extensions to filenames, and the UNIX implementation guesses reasonable
values for this from the -filetypes option when this is not
supplied.
- -filetypes filePatternList
- If a File types listbox exists in the file dialog on
the particular platform, this option gives the filetypes in this
listbox. When the user choose a filetype in the listbox, only the files of
that type are listed. If this option is unspecified, or if it is set to
the empty list, or if the File types listbox is not supported by
the particular platform then all files are listed regardless of their
types. See the section SPECIFYING FILE PATTERNS below for a
discussion on the contents of filePatternList.
- -initialdir directory
- Specifies that the files in directory should be
displayed when the dialog pops up. If this parameter is not specified,
then the files in the current working directory are displayed. If the
parameter specifies a relative path, the return value will convert the
relative path to an absolute path.
- -initialfile filename
- Specifies a filename to be displayed in the dialog when it
pops up.
- -message string
- Specifies a message to include in the client area of the
dialog. This is only available on Mac OS X.
- -multiple boolean
- Allows the user to choose multiple files from the Open
dialog.
- -parent window
- Makes window the logical parent of the file dialog.
The file dialog is displayed on top of its parent window. On Mac OS X,
this turns the file dialog into a sheet attached to the parent
window.
- -title titleString
- Specifies a string to display as the title of the dialog
box. If this option is not specified, then a default title is
displayed.
- -typevariable variableName
- The global variable variableName is used to
preselect which filter is used from filterList when the dialog box
is opened and is updated when the dialog box is closed, to the last
selected filter. The variable is read once at the beginning to select the
appropriate filter. If the variable does not exist, or its value does not
match any filter typename, or is empty ( {}), the dialog box will
revert to the default behavior of selecting the first filter in the list.
If the dialog is canceled, the variable is not modified.
If the user selects a file, both
tk_getOpenFile and
tk_getSaveFile
return the full pathname of this file. If the user cancels the operation, both
commands return the empty string.
SPECIFYING FILE PATTERNS¶
The
filePatternList value given by the
-filetypes option is a list
of file patterns. Each file pattern is a list of the form
typeName {extension ?extension ...?} ?{macType ?macType ...?}?
typeName is the name of the file type described by this file pattern and
is the text string that appears in the
File types listbox.
extension is a file extension for this file pattern.
macType is
a four-character Macintosh file type. The list of
macTypes is optional
and may be omitted for applications that do not need to execute on the
Macintosh platform.
Several file patterns may have the same
typeName, in which case they
refer to the same file type and share the same entry in the listbox. When the
user selects an entry in the listbox, all the files that match at least one of
the file patterns corresponding to that entry are listed. Usually, each file
pattern corresponds to a distinct type of file. The use of more than one file
pattern for one type of file is only necessary on the Macintosh platform.
On the Macintosh platform, a file matches a file pattern if its name matches at
least one of the
extension(s) AND it belongs to at least one of the
macType(s) of the file pattern. For example, the
C Source Files
file pattern in the sample code matches with files that have a
.c
extension AND belong to the
macType TEXT. To use the OR rule
instead, you can use two file patterns, one with the
extensions only
and the other with the
macType only. The
GIF Files file type in
the sample code matches files that
either have a
.gif extension
OR belong to the
macType GIFF.
On the Unix and Windows platforms, a file matches a file pattern if its name
matches at least one of the
extension(s) of the file pattern. The
macTypes are ignored.
SPECIFYING EXTENSIONS¶
On the Unix and Macintosh platforms, extensions are matched using glob-style
pattern matching. On the Windows platform, extensions are matched by the
underlying operating system. The types of possible extensions are:
- (1)
- the special extension “*” matches any
file;
- (2)
- the special extension “” matches any files that
do not have an extension (i.e., the filename contains no full stop
character);
- (3)
- any character string that does not contain any wild card
characters (* and ?).
Due to the different pattern matching rules on the various platforms, to ensure
portability, wild card characters are not allowed in the extensions, except as
in the special extension “*”. Extensions without a full stop
character (e.g. “~”) are allowed but may not work on all
platforms.
EXAMPLE¶
set types {
{{Text Files} {.txt} }
{{TCL Scripts} {.tcl} }
{{C Source Files} {.c} TEXT}
{{GIF Files} {.gif} }
{{GIF Files} {} GIFF}
{{All Files} * }
}
set filename [tk_getOpenFile -filetypes $types]
if {$filename != ""} {
# Open the file ...
}
SEE ALSO¶
tk_chooseDirectory
KEYWORDS¶
file selection dialog