tk_getOpenFile, tk_getSaveFile - pop up a dialog box for the user to select a
file to open or save.
tk_getOpenFile ?option value ...?
tk_getSaveFile ?option value ...?
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.
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.
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.
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 ...
}