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gimp/devel-docs/libgimpthumb/xml/gimpthumb-utils.xml
2010-08-11 01:21:23 -04:00

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
<refentry id="libgimpthumb-gimpthumb-utils">
<refmeta>
<refentrytitle role="top_of_page">gimpthumb-utils</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>LIBGIMPTHUMB Library</refmiscinfo>
</refmeta>
<refnamediv>
<refname>gimpthumb-utils</refname>
<refpurpose>Utility functions provided and used by libgimpthumb</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>
<refsynopsisdiv role="synopsis">
<title role="synopsis.title">Synopsis</title>
<synopsis>
<link linkend="gboolean">gboolean</link> <link linkend="gimp-thumb-init">gimp_thumb_init</link> (const <link linkend="gchar">gchar</link> *creator,
const <link linkend="gchar">gchar</link> *thumb_basedir);
<link linkend="gchar">gchar</link>* <link linkend="gimp-thumb-find-thumb">gimp_thumb_find_thumb</link> (const <link linkend="gchar">gchar</link> *uri,
<link linkend="GimpThumbSize">GimpThumbSize</link> *size);
<link linkend="GimpThumbFileType">GimpThumbFileType</link> <link linkend="gimp-thumb-file-test">gimp_thumb_file_test</link> (const <link linkend="gchar">gchar</link> *filename,
<link linkend="gint64">gint64</link> *mtime,
<link linkend="gint64">gint64</link> *size,
<link linkend="gint">gint</link> *err_no);
<link linkend="gchar">gchar</link>* <link linkend="gimp-thumb-name-from-uri">gimp_thumb_name_from_uri</link> (const <link linkend="gchar">gchar</link> *uri,
<link linkend="GimpThumbSize">GimpThumbSize</link> size);
<link linkend="gboolean">gboolean</link> <link linkend="gimp-thumb-ensure-thumb-dir">gimp_thumb_ensure_thumb_dir</link> (<link linkend="GimpThumbSize">GimpThumbSize</link> size,
<link linkend="GError">GError</link> **error);
const <link linkend="gchar">gchar</link>* <link linkend="gimp-thumb-get-thumb-dir">gimp_thumb_get_thumb_dir</link> (<link linkend="GimpThumbSize">GimpThumbSize</link> size);
<link linkend="void">void</link> <link linkend="gimp-thumbs-delete-for-uri">gimp_thumbs_delete_for_uri</link> (const <link linkend="gchar">gchar</link> *uri);
<link linkend="gchar">gchar</link>* <link linkend="gimp-thumb-name-from-uri-local">gimp_thumb_name_from_uri_local</link> (const <link linkend="gchar">gchar</link> *uri,
<link linkend="GimpThumbSize">GimpThumbSize</link> size);
<link linkend="gboolean">gboolean</link> <link linkend="gimp-thumb-ensure-thumb-dir-local">gimp_thumb_ensure_thumb_dir_local</link> (const <link linkend="gchar">gchar</link> *dirname,
<link linkend="GimpThumbSize">GimpThumbSize</link> size,
<link linkend="GError">GError</link> **error);
<link linkend="gchar">gchar</link>* <link linkend="gimp-thumb-get-thumb-dir-local">gimp_thumb_get_thumb_dir_local</link> (const <link linkend="gchar">gchar</link> *dirname,
<link linkend="GimpThumbSize">GimpThumbSize</link> size);
<link linkend="void">void</link> <link linkend="gimp-thumbs-delete-for-uri-local">gimp_thumbs_delete_for_uri_local</link> (const <link linkend="gchar">gchar</link> *uri);
</synopsis>
</refsynopsisdiv>
<refsect1 role="desc">
<title role="desc.title">Description</title>
<para>
</para>
</refsect1>
<refsect1 role="details">
<title role="details.title">Details</title>
<refsect2>
<title><anchor id="gimp-thumb-init" role="function"/>gimp_thumb_init ()</title>
<indexterm><primary>gimp_thumb_init</primary></indexterm><programlisting><link linkend="gboolean">gboolean</link> gimp_thumb_init (const <link linkend="gchar">gchar</link> *creator,
const <link linkend="gchar">gchar</link> *thumb_basedir);</programlisting>
<para>
This function initializes the thumbnail system. It must be called
before any other functions from libgimpthumb are used. You may call
it more than once if you want to change the <parameter>thumb_basedir</parameter> but if
you do that, you should make sure that no thread is still using the
library. Apart from this function, libgimpthumb is multi-thread
safe.
</para>
<para>
The <parameter>creator</parameter> string must be 7bit ASCII and should contain the name
of the software that creates the thumbnails. It is used to handle
thumbnail creation failures. See the spec for more details.
</para>
<para>
Usually you will pass <link linkend="NULL:CAPS"><literal>NULL</literal></link> for <parameter>thumb_basedir</parameter>. Thumbnails will
then be stored in the user's personal thumbnail directory as
defined in the spec. If you wish to use libgimpthumb to store
application-specific thumbnails, you can specify a different base
directory here.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>creator</parameter>&nbsp;:</term>
<listitem><simpara> an ASCII string that identifies the thumbnail creator
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>thumb_basedir</parameter>&nbsp;:</term>
<listitem><simpara> an absolute path or <link linkend="NULL:CAPS"><literal>NULL</literal></link> to use the default
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> <link linkend="TRUE:CAPS"><literal>TRUE</literal></link> if the library was successfully initialized.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-find-thumb" role="function"/>gimp_thumb_find_thumb ()</title>
<indexterm><primary>gimp_thumb_find_thumb</primary></indexterm><programlisting><link linkend="gchar">gchar</link>* gimp_thumb_find_thumb (const <link linkend="gchar">gchar</link> *uri,
<link linkend="GimpThumbSize">GimpThumbSize</link> *size);</programlisting>
<para>
This function attempts to locate a thumbnail for the given
<parameter>uri</parameter>. First it tries the size that is stored at <parameter>size</parameter>. If no
thumbnail of that size is found, it will look for a larger
thumbnail, then falling back to a smaller size.
</para>
<para>
If the user's thumbnail repository doesn't provide a thumbnail but
a local thumbnail repository exists for the folder the image is
located in, the same search is done among the local thumbnails (if
there are any).
</para>
<para>
If a thumbnail is found, it's size is written to the variable
pointer to by <parameter>size</parameter> and the file location is returned.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>uri</parameter>&nbsp;:</term>
<listitem><simpara> an escaped URI
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> pointer to a <link linkend="GimpThumbSize"><type>GimpThumbSize</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> a newly allocated string in the encoding of the
filesystem or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if no thumbnail for <parameter>uri</parameter> was found
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-file-test" role="function"/>gimp_thumb_file_test ()</title>
<indexterm><primary>gimp_thumb_file_test</primary></indexterm><programlisting><link linkend="GimpThumbFileType">GimpThumbFileType</link> gimp_thumb_file_test (const <link linkend="gchar">gchar</link> *filename,
<link linkend="gint64">gint64</link> *mtime,
<link linkend="gint64">gint64</link> *size,
<link linkend="gint">gint</link> *err_no);</programlisting>
<para>
This is a convenience and portability wrapper around <link linkend="stat"><function>stat()</function></link>. It
checks if the given <parameter>filename</parameter> exists and returns modification time
and file size in 64bit integer values.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>filename</parameter>&nbsp;:</term>
<listitem><simpara> a filename in the encoding of the filesystem
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>mtime</parameter>&nbsp;:</term>
<listitem><simpara> return location for modification time
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> return location for file size
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>err_no</parameter>&nbsp;:</term>
<listitem><simpara> return location for system "errno"
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> The type of the file, or <link linkend="GIMP-THUMB-FILE-TYPE-NONE:CAPS"><type>GIMP_THUMB_FILE_TYPE_NONE</type></link> if
the file doesn't exist.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-name-from-uri" role="function"/>gimp_thumb_name_from_uri ()</title>
<indexterm><primary>gimp_thumb_name_from_uri</primary></indexterm><programlisting><link linkend="gchar">gchar</link>* gimp_thumb_name_from_uri (const <link linkend="gchar">gchar</link> *uri,
<link linkend="GimpThumbSize">GimpThumbSize</link> size);</programlisting>
<para>
Creates the name of the thumbnail file of the specified <parameter>size</parameter> that
belongs to an image file located at the given <parameter>uri</parameter>.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>uri</parameter>&nbsp;:</term>
<listitem><simpara> an escaped URI
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="GimpThumbSize"><type>GimpThumbSize</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> a newly allocated filename in the encoding of the
filesystem or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if <parameter>uri</parameter> points to the user's
thumbnail repository.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-ensure-thumb-dir" role="function"/>gimp_thumb_ensure_thumb_dir ()</title>
<indexterm><primary>gimp_thumb_ensure_thumb_dir</primary></indexterm><programlisting><link linkend="gboolean">gboolean</link> gimp_thumb_ensure_thumb_dir (<link linkend="GimpThumbSize">GimpThumbSize</link> size,
<link linkend="GError">GError</link> **error);</programlisting>
<para>
This function checks if the directory that is required to store
thumbnails for a particular <parameter>size</parameter> exist and attempts to create it
if necessary.
</para>
<para>
You shouldn't have to call this function directly since
<link linkend="gimp-thumbnail-save-thumb"><function>gimp_thumbnail_save_thumb()</function></link> and <link linkend="gimp-thumbnail-save-failure"><function>gimp_thumbnail_save_failure()</function></link> will
do this for you.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> a GimpThumbSize
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>error</parameter>&nbsp;:</term>
<listitem><simpara> return location for possible errors
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> <link linkend="TRUE:CAPS"><literal>TRUE</literal></link> is the directory exists, <link linkend="FALSE:CAPS"><literal>FALSE</literal></link> if it could not
be created
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-get-thumb-dir" role="function"/>gimp_thumb_get_thumb_dir ()</title>
<indexterm><primary>gimp_thumb_get_thumb_dir</primary></indexterm><programlisting>const <link linkend="gchar">gchar</link>* gimp_thumb_get_thumb_dir (<link linkend="GimpThumbSize">GimpThumbSize</link> size);</programlisting>
<para>
Retrieve the name of the thumbnail folder for a specific size. The
returned pointer will become invalid if <link linkend="gimp-thumb-init"><function>gimp_thumb_init()</function></link> is used
again. It must not be changed or freed.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> a GimpThumbSize
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> the thumbnail directory in the encoding of the filesystem
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="gimp-thumbs-delete-for-uri" role="function" condition="since:GIMP 2.2"/>gimp_thumbs_delete_for_uri ()</title>
<indexterm role="GIMP 2.2"><primary>gimp_thumbs_delete_for_uri</primary></indexterm><programlisting><link linkend="void">void</link> gimp_thumbs_delete_for_uri (const <link linkend="gchar">gchar</link> *uri);</programlisting>
<para>
Deletes all thumbnails for the image file specified by <parameter>uri</parameter> from the
user's thumbnail repository.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>uri</parameter>&nbsp;:</term>
<listitem><simpara> an escaped URI
</simpara></listitem></varlistentry>
</variablelist><para role="since">Since GIMP 2.2
</para></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-name-from-uri-local" role="function" condition="since:GIMP 2.2"/>gimp_thumb_name_from_uri_local ()</title>
<indexterm role="GIMP 2.2"><primary>gimp_thumb_name_from_uri_local</primary></indexterm><programlisting><link linkend="gchar">gchar</link>* gimp_thumb_name_from_uri_local (const <link linkend="gchar">gchar</link> *uri,
<link linkend="GimpThumbSize">GimpThumbSize</link> size);</programlisting>
<para>
Creates the name of a local thumbnail file of the specified <parameter>size</parameter>
that belongs to an image file located at the given <parameter>uri</parameter>. Local
thumbnails have been introduced with version 0.7 of the spec.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>uri</parameter>&nbsp;:</term>
<listitem><simpara> an escaped URI
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="GimpThumbSize"><type>GimpThumbSize</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> a newly allocated filename in the encoding of the
filesystem or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if <parameter>uri</parameter> is a remote file or
points to the user's thumbnail repository.
</simpara></listitem></varlistentry>
</variablelist><para role="since">Since GIMP 2.2
</para></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-ensure-thumb-dir-local" role="function" condition="since:GIMP 2.2"/>gimp_thumb_ensure_thumb_dir_local ()</title>
<indexterm role="GIMP 2.2"><primary>gimp_thumb_ensure_thumb_dir_local</primary></indexterm><programlisting><link linkend="gboolean">gboolean</link> gimp_thumb_ensure_thumb_dir_local (const <link linkend="gchar">gchar</link> *dirname,
<link linkend="GimpThumbSize">GimpThumbSize</link> size,
<link linkend="GError">GError</link> **error);</programlisting>
<para>
This function checks if the directory that is required to store
local thumbnails for a particular <parameter>size</parameter> exist and attempts to
create it if necessary.
</para>
<para>
You shouldn't have to call this function directly since
<link linkend="gimp-thumbnail-save-thumb-local"><function>gimp_thumbnail_save_thumb_local()</function></link> will do this for you.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>dirname</parameter>&nbsp;:</term>
<listitem><simpara>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> a GimpThumbSize
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>error</parameter>&nbsp;:</term>
<listitem><simpara> return location for possible errors
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> <link linkend="TRUE:CAPS"><literal>TRUE</literal></link> is the directory exists, <link linkend="FALSE:CAPS"><literal>FALSE</literal></link> if it could not
be created
</simpara></listitem></varlistentry>
</variablelist><para role="since">Since GIMP 2.2
</para></refsect2>
<refsect2>
<title><anchor id="gimp-thumb-get-thumb-dir-local" role="function" condition="since:GIMP 2.2"/>gimp_thumb_get_thumb_dir_local ()</title>
<indexterm role="GIMP 2.2"><primary>gimp_thumb_get_thumb_dir_local</primary></indexterm><programlisting><link linkend="gchar">gchar</link>* gimp_thumb_get_thumb_dir_local (const <link linkend="gchar">gchar</link> *dirname,
<link linkend="GimpThumbSize">GimpThumbSize</link> size);</programlisting>
<para>
Retrieve the name of the local thumbnail folder for a specific
size. Unlike <link linkend="gimp-thumb-get-thumb-dir"><function>gimp_thumb_get_thumb_dir()</function></link> the returned string is not
constant and should be free'd when it is not any longer needed.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>dirname</parameter>&nbsp;:</term>
<listitem><simpara>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>size</parameter>&nbsp;:</term>
<listitem><simpara> a GimpThumbSize
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> the thumbnail directory in the encoding of the filesystem
</simpara></listitem></varlistentry>
</variablelist><para role="since">Since GIMP 2.2
</para></refsect2>
<refsect2>
<title><anchor id="gimp-thumbs-delete-for-uri-local" role="function" condition="since:GIMP 2.2"/>gimp_thumbs_delete_for_uri_local ()</title>
<indexterm role="GIMP 2.2"><primary>gimp_thumbs_delete_for_uri_local</primary></indexterm><programlisting><link linkend="void">void</link> gimp_thumbs_delete_for_uri_local (const <link linkend="gchar">gchar</link> *uri);</programlisting>
<para>
Deletes all thumbnails for the image file specified by <parameter>uri</parameter> from
the local thumbnail repository.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>uri</parameter>&nbsp;:</term>
<listitem><simpara> an escaped URI
</simpara></listitem></varlistentry>
</variablelist><para role="since">Since GIMP 2.2
</para></refsect2>
</refsect1>
</refentry>