gtkfilechooser.sgml

This GTK+ version 2.12.3. GTK+ is a multi-platform toolkit for creating graphical user interfaces.

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GtkFileChooser

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File chooser interface used by GtkFileChooserWidget and GtkFileChooserDialog

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    <para>
      #GtkFileChooser is an interface that can be implemented by file
      selection widgets.  In GTK+, the main objects that implement this
      interface are #GtkFileChooserWidget, #GtkFileChooserDialog, and
      #GtkFileChooserButton.  You do not need to write an object that
      implements the #GtkFileChooser interface unless you are trying to
      adapt an existing file selector to expose a standard programming
      interface.
    </para>

    <para>
      #GtkFileChooser allows for shortcuts to various places in the filesystem.
      In the default implementation these are displayed in the left pane. It
      may be a bit confusing at first taht these shortcuts come from various 
      sources and in various flavours, so lets explain the terminology here:
    </para>
      <variablelist>
         <varlistentry>
           <term>Bookmarks</term>
           <listitem><para>
             are created by the user, by dragging folders from the 
             right pane to the left pane, or by using the "Add". Bookmarks
             can be renamed and deleted by the user.
           </para></listitem>
         </varlistentry>
         <varlistentry>
           <term>Shortcuts</term>
           <listitem><para> 
             can be provided by the application or by the underlying filesystem
             abstraction (e.g. both the gnome-vfs and the Windows filesystems 
             provide "Desktop" shortcuts). Shortcuts cannot be modified by the 
             user.
           </para></listitem>
         </varlistentry>
         <varlistentry> 
           <term>Volumes</term>
           <listitem><para>
             are provided by the underlying filesystem abstraction. They are
             the "roots" of the filesystem. 
           </para></listitem>
         </varlistentry>
      </variablelist>

    <refsect2 id="gtkfilechooser-encodings">
      <title>File Names and Encodings</title>

      <para>
	When the user is finished selecting files in a
	#GtkFileChooser, your program can get the selected names
	either as filenames or as URIs.  For URIs, the normal escaping
	rules are applied if the URI contains non-ASCII characters.
	However, filenames are <emphasis>always</emphasis> returned in
	the character set specified by the
	<envar>G_FILENAME_ENCODING</envar> environment variable.
	Please see the Glib documentation for more details about this
	variable.
      </para>

      <important>
	<para>
	  This means that while you can pass the result of
	  gtk_file_chooser_get_filename() to
	  <function>open(2)</function> or
	  <function>fopen(3)</function>, you may not be able to
	  directly set it as the text of a #GtkLabel widget unless you
	  convert it first to UTF-8, which all GTK+ widgets expect.
	  You should use g_filename_to_utf8() to convert filenames
	  into strings that can be passed to GTK+ widgets.
	</para>
      </important>
    </refsect2>

    <refsect2 id="gtkfilechooser-preview">
      <title>Adding a Preview Widget</title>

      <para>
	You can add a custom preview widget to a file chooser and then
	get notification about when the preview needs to be updated.
	To install a preview widget, use
	gtk_file_chooser_set_preview_widget().  Then, connect to the
	#GtkFileChooser::update-preview signal to get notified when
	you need to update the contents of the preview.
      </para>

      <para>
	Your callback should use
	gtk_file_chooser_get_preview_filename() to see what needs
	previewing.  Once you have generated the preview for the
	corresponding file, you must call
	gtk_file_chooser_set_preview_widget_active() with a boolean
	flag that indicates whether your callback could successfully
	generate a preview.
      </para>

      <example id="example-gtkfilechooser-preview">
	<title>Sample Usage</title>

	<programlisting>
{
  GtkImage *preview;

  ...

  preview = gtk_image_new (<!-- -->);

  gtk_file_chooser_set_preview_widget (my_file_chooser, preview);
  g_signal_connect (my_file_chooser, "update-preview",
		    G_CALLBACK (update_preview_cb), preview);
}

static void
update_preview_cb (GtkFileChooser *file_chooser, gpointer data)
{
  GtkWidget *preview;
  char *filename;
  GdkPixbuf *pixbuf;
  gboolean have_preview;

  preview = GTK_WIDGET (data);
  filename = gtk_file_chooser_get_preview_filename (file_chooser);

  pixbuf = gdk_pixbuf_new_from_file_at_size (filename, 128, 128, NULL);
  have_preview = (pixbuf != NULL);
  g_free (filename);

  gtk_image_set_from_pixbuf (GTK_IMAGE (preview), pixbuf);
  if (pixbuf)
    gobject_unref (pixbuf);

  gtk_file_chooser_set_preview_widget_active (file_chooser, have_preview);
}
	</programlisting>
      </example>
    </refsect2>

    <refsect2 id="gtkfilechooser-extra">
      <title>Adding Extra Widgets</title>

      <para>
	You can add extra widgets to a file chooser to provide options
	that are not present in the default design.  For example, you
	can add a toggle button to give the user the option to open a
	file in read-only mode.  You can use
	gtk_file_chooser_set_extra_widget() to insert additional
	widgets in a file chooser.
      </para>

      <example id="example-gtkfilechooser-extra">
	<title>Sample Usage</title>

	<programlisting>
{
  GtkWidget *toggle;

  ...

  toggle = gtk_check_button_new_with_label ("Open file read-only");
  gtk_widget_show (toggle);
  gtk_file_chooser_set_extra_widget (my_file_chooser, toggle);
}
	</programlisting>
      </example>

      <note>
	<para>
	  If you want to set more than one extra widget in the file
	  chooser, you can a container such as a GtkVBox or a GtkTable
	  and include your widgets in it.  Then, set the container as
	  the whole extra widget.
	</para>
      </note>
    </refsect2>

    <refsect2 id="gtkfilechooser-key-bindings">
      <title>Key Bindings</title>

      <para>
	Internally, GTK+ implements a file chooser's graphical user
	interface with the private
	<classname>GtkFileChooserDefaultClass</classname>.  This
	widget has several <link linkend="gtk-Bindings">key
	bindings</link> and their associated signals.  This section
	describes the available key binding signals.
      </para>

      <example id="gtkfilechooser-key-binding-example">
	<title>GtkFileChooser key binding example</title>

	<para>
	  The default keys that activate the key-binding signals in
	  <classname>GtkFileChooserDefaultClass</classname> are as
	  follows:
	</para>

	<informaltable>
	  <tgroup cols="2">
	    <tbody>
	      <row>
		<entry>Signal name</entry>
		<entry>Default key combinations</entry>
	      </row>
	      <row>
		<entry>location-popup</entry>
		<entry>
		  <keycombo><keycap>Control</keycap><keycap>L</keycap></keycombo> (empty path);
		  <keycap>/</keycap> (path of "/")<footnote>
		    <para>
		      Both the individual <keycap>/</keycap> key and the
		      numeric keypad's "divide" key are supported.
		    </para>
		  </footnote>;
		  <keycap>~</keycap> (path of "~")
		</entry>
	      </row>
	      <row>
		<entry>up-folder</entry>
		<entry>
		  <keycombo><keycap>Alt</keycap><keycap>Up</keycap></keycombo><footnote>
		    <para>
		      Both the individual Up key and the numeric
		      keypad's Up key are supported.
		    </para>
		  </footnote>
		  ;
		  <keycap>Backspace</keycap>
		</entry>
	      </row>
	      <row>
		<entry>down-folder</entry>
		<entry><keycombo><keycap>Alt</keycap><keycap>Down</keycap></keycombo></entry>
	      </row>
	      <row>
		<entry>home-folder</entry>
		<entry><keycombo><keycap>Alt</keycap><keycap>Home</keycap></keycombo></entry>
	      </row>
	      <row>
		<entry>desktop-folder</entry>
		<entry><keycombo><keycap>Alt</keycap><keycap>D</keycap></keycombo></entry>
	      </row>
	      <row>
		<entry>quick-bookmark</entry>
		<entry><keycombo><keycap>Alt</keycap><keycap>1</keycap></keycombo> through <keycombo><keycap>Alt</keycap><keycap>0</keycap></keycombo></entry>
	      </row>
	    </tbody>
	  </tgroup>
	</informaltable>

	<para>
	  You can change these defaults to something else.  For
	  example, to add a <keycap>Shift</keycap> modifier to a few
	  of the default bindings, you can include the following
	  fragment in your <filename>.gtkrc-2.0</filename> file:
	</para>

	<programlisting>
binding "my-own-gtkfilechooser-bindings" {
	bind "&lt;Alt&gt;&lt;Shift&gt;Up" {
		"up-folder" ()
	}
	bind "&lt;Alt&gt;&lt;Shift&gt;Down" {
		"down-folder" ()
	}
	bind "&lt;Alt&gt;&lt;Shift&gt;Home" {
		"home-folder" ()
	}
}

class "GtkFileChooserDefault" binding "my-own-gtkfilechooser-bindings"
	</programlisting>
      </example>

      <refsect3 id="GtkFileChooserDefault-location-popup">
	<title>The &quot;GtkFileChooserDefault::location-popup&quot; signal</title>

	<programlisting>
          void user_function (GtkFileChooserDefault *chooser,
                              const char            *path,
                              <link linkend="gpointer">gpointer</link> user_data);
	</programlisting>

	<para>
	  This is used to make the file chooser show a "Location"
	  dialog which the user can use to manually type the name of
	  the file he wishes to select.  The
	  <parameter>path</parameter> argument is a string that gets
	  put in the text entry for the file name.  By default this is bound to
	  <keycombo><keycap>Control</keycap><keycap>L</keycap></keycombo>
	  with a <parameter>path</parameter> string of "" (the empty
	  string).  It is also bound to <keycap>/</keycap> with a
	  <parameter>path</parameter> string of "<literal>/</literal>"
	  (a slash):  this lets you type <keycap>/</keycap> and
	  immediately type a path name.  On Unix systems, this is bound to
	  <keycap>~</keycap> (tilde) with a <parameter>path</parameter> string
	  of "~" itself for access to home directories.
	</para>

	<variablelist role="params">
	  <varlistentry>
	    <term><parameter>chooser</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		the object which received the signal.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>path</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		default contents for the text entry for the file name
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>user_data</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		user data set when the signal handler was connected.
	      </simpara>
	    </listitem>
	  </varlistentry>
	</variablelist>

	<tip>
	  <para>
	    You can create your own bindings for the
	    <symbol>location-popup</symbol> signal with custom
	    <parameter>path</parameter> strings, and have a crude form
	    of easily-to-type bookmarks.  For example, say you access
	    the path <filename>/home/username/misc</filename> very
	    frequently.  You could then create an <keycombo>
	    <keycap>Alt</keycap> <keycap>M</keycap> </keycombo>
	    shortcut by including the following in your
	    <filename>.gtkrc-2.0</filename>:
	  </para>

	  <programlisting>
binding "misc-shortcut" {
	bind "&lt;Alt&gt;M" {
		"location-popup" ("/home/username/misc")
	}
}

class "GtkFileChooserDefault" binding "misc-shortcut"
	  </programlisting>
	</tip>
      </refsect3>

      <refsect3 id="GtkFileChooserDefault-up-folder">
	<title>The &quot;GtkFileChooserDefault::up-folder&quot; signal</title>

	<programlisting>
          void user_function (GtkFileChooserDefault *chooser,
                              <link linkend="gpointer">gpointer</link> user_data);
	</programlisting>

	<para>
	  This is used to make the file chooser go to the parent of
	  the current folder in the file hierarchy.  By default this
	  is bound to <keycap>Backspace</keycap> and
	  <keycombo><keycap>Alt</keycap><keycap>Up</keycap></keycombo>
	  (the Up key in the numeric keypad also works).
	</para>

	<variablelist role="params">
	  <varlistentry>
	    <term><parameter>chooser</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		the object which received the signal.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>user_data</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		user data set when the signal handler was connected.
	      </simpara>
	    </listitem>
	  </varlistentry>
	</variablelist>
      </refsect3>

      <refsect3 id="GtkFileChooserDefault-down-folder">
	<title>The &quot;GtkFileChooserDefault::down-folder&quot; signal</title>

	<programlisting>
          void user_function (GtkFileChooserDefault *chooser,
                              <link linkend="gpointer">gpointer</link> user_data);
	</programlisting>

	<para>
	  This is used to make the file chooser go to a child of the
	  current folder in the file hierarchy.  The subfolder that
	  will be used is displayed in the path bar widget of the file
	  chooser.  For example, if the path bar is showing
	  "/foo/<emphasis>bar/</emphasis>baz", then this will cause
	  the file chooser to switch to the "baz" subfolder.  By
	  default this is bound to
	  <keycombo><keycap>Alt</keycap><keycap>Down</keycap></keycombo>
	  (the Down key in the numeric keypad also works).
	</para>

	<variablelist role="params">
	  <varlistentry>
	    <term><parameter>chooser</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		the object which received the signal.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>user_data</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		user data set when the signal handler was connected.
	      </simpara>
	    </listitem>
	  </varlistentry>
	</variablelist>
      </refsect3>

      <refsect3 id="GtkFileChooserDefault-home-folder">
	<title>The &quot;GtkFileChooserDefault::home-folder&quot; signal</title>

	<programlisting>
          void user_function (GtkFileChooserDefault *chooser,
                              <link linkend="gpointer">gpointer</link> user_data);
	</programlisting>

	<para>
	  This is used to make the file chooser show the user's home
	  folder in the file list.  By default this is bound to
	  <keycombo><keycap>Alt</keycap><keycap>Home</keycap></keycombo>
	  (the Home key in the numeric keypad also works).
	</para>

	<variablelist role="params">
	  <varlistentry>
	    <term><parameter>chooser</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		the object which received the signal.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>user_data</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		user data set when the signal handler was connected.
	      </simpara>
	    </listitem>
	  </varlistentry>
	</variablelist>
      </refsect3>

      <refsect3 id="GtkFileChooserDefault-desktop-folder">
	<title>The &quot;GtkFileChooserDefault::desktop-folder&quot; signal</title>

	<programlisting>
          void user_function (GtkFileChooserDefault *chooser,
                              <link linkend="gpointer">gpointer</link> user_data);
	</programlisting>

	<para>
	  This is used to make the file chooser show the user's Desktop
	  folder in the file list.  By default this is bound to
	  <keycombo><keycap>Alt</keycap><keycap>D</keycap></keycombo>.
	</para>

	<variablelist role="params">
	  <varlistentry>
	    <term><parameter>chooser</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		the object which received the signal.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>user_data</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		user data set when the signal handler was connected.
	      </simpara>
	    </listitem>
	  </varlistentry>
	</variablelist>
      </refsect3>

      <refsect3 id="GtkFileChooserDefault-quick-bookmark">
	<title>The &quot;GtkFileChooserDefault::quick-bookmark&quot; signal</title>

	<programlisting>
          void user_function (GtkFileChooserDefault *chooser,
                              gint bookmark_index,
                              <link linkend="gpointer">gpointer</link> user_data);
	</programlisting>

	<para>
	  This is used to make the file chooser switch to the bookmark
	  specified in the <parameter>bookmark_index</parameter> parameter.
	  For example, if you have three bookmarks, you can pass 0, 1, 2 to
	  this signal to switch to each of them, respectively.  By default this is bound to
	  <keycombo><keycap>Alt</keycap><keycap>1</keycap></keycombo>,
	  <keycombo><keycap>Alt</keycap><keycap>2</keycap></keycombo>, 
	  etc. until
	  <keycombo><keycap>Alt</keycap><keycap>0</keycap></keycombo>.  Note
	  that in the default binding,
	  that <keycombo><keycap>Alt</keycap><keycap>1</keycap></keycombo> is
	  actually defined to switch to the bookmark at index 0, and so on
	  successively;
	  <keycombo><keycap>Alt</keycap><keycap>0</keycap></keycombo> is
	  defined to switch to the bookmark at index 10.
	</para>

	<variablelist role="params">
	  <varlistentry>
	    <term><parameter>chooser</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		the object which received the signal.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>bookmark_indes</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		index of the bookmark to switch to; the indices start at 0.
	      </simpara>
	    </listitem>
	  </varlistentry>
	  <varlistentry>
	    <term><parameter>user_data</parameter>&nbsp;:</term>
	    <listitem>
	      <simpara>
		user data set when the signal handler was connected.
	      </simpara>
	    </listitem>
	  </varlistentry>
	</variablelist>
      </refsect3>
    </refsect2>

<!-- ##### SECTION See_Also ##### -->
    <para>
      #GtkFileChooserDialog, #GtkFileChooserWidget, #GtkFileChooserButton
    </para>

<!-- ##### SECTION Stability_Level ##### -->


<!-- ##### STRUCT GtkFileChooser ##### -->
<para>

</para>


<!-- ##### SIGNAL GtkFileChooser::confirm-overwrite ##### -->
    <para>
      This signal gets emitted whenever it is appropriate to present a
      confirmation dialog when the user has selected a file name that
      already exists.  The signal only gets emitted when the file
      chooser is in #GTK_FILE_CHOOSER_ACTION_SAVE mode.
    </para>

    <para>
      Most applications just need to turn on the <link
      linkend="GtkFileChooser--do-overwrite-confirmation">do-overwrite-confirmation</link>
      property (or call the
      gtk_file_chooser_set_do_overwrite_confirmation() function), and
      they will automatically get a stock confirmation dialog.
      Applications which need to customize this behavior should do
      that, and also connect to the <symbol>confirm-overwrite</symbol>
      signal.
    </para>

    <para>
      A signal handler for this signal must return a
      #GtkFileChooserConfirmation value, which indicates the action to
      take.  If the handler determines that the user wants to select a
      different filename, it should return
      #GTK_FILE_CHOOSER_CONFIRMATION_SELECT_AGAIN.  If it determines
      that the user is satisfied with his choice of file name, it
      should return #GTK_FILE_CHOOSER_CONFIRMATION_ACCEPT_FILENAME.
      On the other hand, if it determines that the stock confirmation
      dialog should be used, it should return
      #GTK_FILE_CHOOSER_CONFIRMATION_CONFIRM.  The following example
      illustrates this.
    </para>

    <example id="gtkfilechooser-confirmation">
      <title>Custom confirmation</title>

      <programlisting>
static GtkFileChooserConfirmation
confirm_overwrite_callback (GtkFileChooser *chooser, gpointer data)
{
  char *uri;

  uri = gtk_file_chooser_get_uri (chooser);

  if (is_uri_read_only (uri))
    {
      if (user_wants_to_replace_read_only_file (uri))
        return GTK_FILE_CHOOSER_CONFIRMATION_ACCEPT_FILENAME;
      else
        return GTK_FILE_CHOOSER_CONFIRMATION_SELECT_AGAIN;
    } else