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<H2><A NAME="sec:11.1"><SPAN class="sec-nr">11.1</SPAN> <SPAN class="sec-title">Library
``find_file''</SPAN></A></H2>
<A NAME="sec:findfile"></A>
<P><A NAME="idx:filepromptingfor:477"></A>The library <CODE>library(find_file)</CODE>
defines the class <B>finder</B>, representing a modal dialog window for
entering a filename. This class defines the method <A NAME="idx:findergetfile:478"></A>`<B>finder<CODE><-</CODE>file</B>':
<DL>
<DT><STRONG>finder <-file:</STRONG> <VAR>Exists:[bool],
Ext:[name|chain], Dir:[directory], Def:[file]</VAR></DT>
<DD class="defbody">
name Ask the user for a file. If <VAR>Exists</VAR> is <A NAME="idx:on:479"></A><B>@on</B>,
only existing files can be returned. <VAR>Ext</VAR> is either an atom
denoting a single extension or a chain of allowed extensions. Extensions
can be specified with or without the leading dot. I.e. both <CODE>pl</CODE>
and <CODE>'.pl'</CODE> are valid specifications of files ending in
<CODE>'.pl'</CODE>. <VAR>Dir</VAR> is the directory to start from. When
omitted, this is the last directory visited by this instance of <B>finder</B>
or the current working directory. <VAR>Def</VAR> is the default
file-name returned. When omitted there is no default.
<P>Below is the typical declaration and usage. In this example we ask
for an existing Prolog file.
<PRE class="code">
:- pce_autoload(finder, library(find_file)).
:- pce_global(@finder, new(finder)).
...,
get(@finder, file, @on, pl, PlFile),
...,
</PRE>
<P></DD>
</DL>
<P><A NAME="idx:filegetnameinWindows:480"></A>The Windows version of <font size=-1>XPCE</font>
implements the method
<A NAME="idx:displaygetwinfilename:481"></A>`<B>display<CODE><-</CODE>win_file_name</B>',
using the Win32 API standard functions GetOpenFileName() or
GetSaveFileName() to obtain a file-name for saving or loading. If this
method is defined, <A NAME="idx:findergetfile:482"></A>`<B>finder<CODE><-</CODE>file</B>'
uses it, showing the users familiar dialog.
<P>Names for the extensions (as `Prolog file' rather than '*.pl') can be
defined by extending the multifile predicate pce_finder:file_type/2. See
the library source for the standard definition.
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