web/wp-includes/media.php
branchwordpress
changeset 109 03b0d1493584
child 132 4d4862461b8d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/wp-includes/media.php	Wed Dec 23 17:55:33 2009 +0000
@@ -0,0 +1,796 @@
+<?php
+/**
+ * WordPress API for media display.
+ *
+ * @package WordPress
+ */
+
+/**
+ * Scale down the default size of an image.
+ *
+ * This is so that the image is a better fit for the editor and theme.
+ *
+ * The $size parameter accepts either an array or a string. The supported string
+ * values are 'thumb' or 'thumbnail' for the given thumbnail size or defaults at
+ * 128 width and 96 height in pixels. Also supported for the string value is
+ * 'medium' and 'full'. The 'full' isn't actually supported, but any value other
+ * than the supported will result in the content_width size or 500 if that is
+ * not set.
+ *
+ * Finally, there is a filter named, 'editor_max_image_size' that will be called
+ * on the calculated array for width and height, respectively. The second
+ * parameter will be the value that was in the $size parameter. The returned
+ * type for the hook is an array with the width as the first element and the
+ * height as the second element.
+ *
+ * @since 2.5.0
+ * @uses wp_constrain_dimensions() This function passes the widths and the heights.
+ *
+ * @param int $width Width of the image
+ * @param int $height Height of the image
+ * @param string|array $size Size of what the result image should be.
+ * @return array Width and height of what the result image should resize to.
+ */
+function image_constrain_size_for_editor($width, $height, $size = 'medium') {
+	global $content_width;
+
+	if ( is_array($size) ) {
+		$max_width = $size[0];
+		$max_height = $size[1];
+	}
+	elseif ( $size == 'thumb' || $size == 'thumbnail' ) {
+		$max_width = intval(get_option('thumbnail_size_w'));
+		$max_height = intval(get_option('thumbnail_size_h'));
+		// last chance thumbnail size defaults
+		if ( !$max_width && !$max_height ) {
+			$max_width = 128;
+			$max_height = 96;
+		}
+	}
+	elseif ( $size == 'medium' ) {
+		$max_width = intval(get_option('medium_size_w'));
+		$max_height = intval(get_option('medium_size_h'));
+		// if no width is set, default to the theme content width if available
+	}
+	elseif ( $size == 'large' ) {
+		// we're inserting a large size image into the editor.  if it's a really
+		// big image we'll scale it down to fit reasonably within the editor
+		// itself, and within the theme's content width if it's known.  the user
+		// can resize it in the editor if they wish.
+		$max_width = intval(get_option('large_size_w'));
+		$max_height = intval(get_option('large_size_h'));
+		if ( intval($content_width) > 0 )
+			$max_width = min( intval($content_width), $max_width );
+	}
+	// $size == 'full' has no constraint
+	else {
+		$max_width = $width;
+		$max_height = $height;
+	}
+
+	list( $max_width, $max_height ) = apply_filters( 'editor_max_image_size', array( $max_width, $max_height ), $size );
+
+	return wp_constrain_dimensions( $width, $height, $max_width, $max_height );
+}
+
+/**
+ * Retrieve width and height attributes using given width and height values.
+ *
+ * Both attributes are required in the sense that both parameters must have a
+ * value, but are optional in that if you set them to false or null, then they
+ * will not be added to the returned string.
+ *
+ * You can set the value using a string, but it will only take numeric values.
+ * If you wish to put 'px' after the numbers, then it will be stripped out of
+ * the return.
+ *
+ * @since 2.5.0
+ *
+ * @param int|string $width Optional. Width attribute value.
+ * @param int|string $height Optional. Height attribute value.
+ * @return string HTML attributes for width and, or height.
+ */
+function image_hwstring($width, $height) {
+	$out = '';
+	if ($width)
+		$out .= 'width="'.intval($width).'" ';
+	if ($height)
+		$out .= 'height="'.intval($height).'" ';
+	return $out;
+}
+
+/**
+ * Scale an image to fit a particular size (such as 'thumb' or 'medium').
+ *
+ * Array with image url, width, height, and whether is intermediate size, in
+ * that order is returned on success is returned. $is_intermediate is true if
+ * $url is a resized image, false if it is the original.
+ *
+ * The URL might be the original image, or it might be a resized version. This
+ * function won't create a new resized copy, it will just return an already
+ * resized one if it exists.
+ *
+ * A plugin may use the 'image_downsize' filter to hook into and offer image
+ * resizing services for images. The hook must return an array with the same
+ * elements that are returned in the function. The first element being the URL
+ * to the new image that was resized.
+ *
+ * @since 2.5.0
+ * @uses apply_filters() Calls 'image_downsize' on $id and $size to provide
+ *		resize services.
+ *
+ * @param int $id Attachment ID for image.
+ * @param string $size Optional, default is 'medium'. Size of image, can be 'thumbnail'.
+ * @return bool|array False on failure, array on success.
+ */
+function image_downsize($id, $size = 'medium') {
+
+	if ( !wp_attachment_is_image($id) )
+		return false;
+
+	$img_url = wp_get_attachment_url($id);
+	$meta = wp_get_attachment_metadata($id);
+	$width = $height = 0;
+	$is_intermediate = false;
+
+	// plugins can use this to provide resize services
+	if ( $out = apply_filters('image_downsize', false, $id, $size) )
+		return $out;
+
+	// try for a new style intermediate size
+	if ( $intermediate = image_get_intermediate_size($id, $size) ) {
+		$img_url = str_replace(basename($img_url), $intermediate['file'], $img_url);
+		$width = $intermediate['width'];
+		$height = $intermediate['height'];
+		$is_intermediate = true;
+	}
+	elseif ( $size == 'thumbnail' ) {
+		// fall back to the old thumbnail
+		if ( ($thumb_file = wp_get_attachment_thumb_file($id)) && $info = getimagesize($thumb_file) ) {
+			$img_url = str_replace(basename($img_url), basename($thumb_file), $img_url);
+			$width = $info[0];
+			$height = $info[1];
+			$is_intermediate = true;
+		}
+	}
+	if ( !$width && !$height && isset($meta['width'], $meta['height']) ) {
+		// any other type: use the real image
+		$width = $meta['width'];
+		$height = $meta['height'];
+	}
+
+	if ( $img_url) {
+		// we have the actual image size, but might need to further constrain it if content_width is narrower
+		list( $width, $height ) = image_constrain_size_for_editor( $width, $height, $size );
+
+		return array( $img_url, $width, $height, $is_intermediate );
+	}
+	return false;
+
+}
+
+/**
+ * An <img src /> tag for an image attachment, scaling it down if requested.
+ *
+ * The filter 'get_image_tag_class' allows for changing the class name for the
+ * image without having to use regular expressions on the HTML content. The
+ * parameters are: what WordPress will use for the class, the Attachment ID,
+ * image align value, and the size the image should be.
+ *
+ * The second filter 'get_image_tag' has the HTML content, which can then be
+ * further manipulated by a plugin to change all attribute values and even HTML
+ * content.
+ *
+ * @since 2.5.0
+ *
+ * @uses apply_filters() The 'get_image_tag_class' filter is the IMG element
+ *		class attribute.
+ * @uses apply_filters() The 'get_image_tag' filter is the full IMG element with
+ *		all attributes.
+ *
+ * @param int $id Attachment ID.
+ * @param string $alt Image Description for the alt attribute.
+ * @param string $title Image Description for the title attribute.
+ * @param string $align Part of the class name for aligning the image.
+ * @param string $size Optional. Default is 'medium'.
+ * @return string HTML IMG element for given image attachment
+ */
+function get_image_tag($id, $alt, $title, $align, $size='medium') {
+
+	list( $img_src, $width, $height ) = image_downsize($id, $size);
+	$hwstring = image_hwstring($width, $height);
+
+	$class = 'align' . esc_attr($align) .' size-' . esc_attr($size) . ' wp-image-' . $id;
+	$class = apply_filters('get_image_tag_class', $class, $id, $align, $size);
+
+	$html = '<img src="' . esc_attr($img_src) . '" alt="' . esc_attr($alt) . '" title="' . esc_attr($title).'" '.$hwstring.'class="'.$class.'" />';
+
+	$html = apply_filters( 'get_image_tag', $html, $id, $alt, $title, $align, $size );
+
+	return $html;
+}
+
+/**
+ * Calculates the new dimentions for a downsampled image.
+ *
+ * Same as {@link wp_shrink_dimensions()}, except the max parameters are
+ * optional. If either width or height are empty, no constraint is applied on
+ * that dimension.
+ *
+ * @since 2.5.0
+ *
+ * @param int $current_width Current width of the image.
+ * @param int $current_height Current height of the image.
+ * @param int $max_width Optional. Maximum wanted width.
+ * @param int $max_height Optional. Maximum wanted height.
+ * @return array First item is the width, the second item is the height.
+ */
+function wp_constrain_dimensions( $current_width, $current_height, $max_width=0, $max_height=0 ) {
+	if ( !$max_width and !$max_height )
+		return array( $current_width, $current_height );
+
+	$width_ratio = $height_ratio = 1.0;
+
+	if ( $max_width > 0 && $current_width > 0 && $current_width > $max_width )
+		$width_ratio = $max_width / $current_width;
+
+	if ( $max_height > 0 && $current_height > 0 && $current_height > $max_height )
+		$height_ratio = $max_height / $current_height;
+
+	// the smaller ratio is the one we need to fit it to the constraining box
+	$ratio = min( $width_ratio, $height_ratio );
+
+	return array( intval($current_width * $ratio), intval($current_height * $ratio) );
+}
+
+/**
+ * Retrieve calculated resized dimensions for use in imagecopyresampled().
+ *
+ * Calculate dimensions and coordinates for a resized image that fits within a
+ * specified width and height. If $crop is true, the largest matching central
+ * portion of the image will be cropped out and resized to the required size.
+ *
+ * @since 2.5.0
+ *
+ * @param int $orig_w Original width.
+ * @param int $orig_h Original height.
+ * @param int $dest_w New width.
+ * @param int $dest_h New height.
+ * @param bool $crop Optional, default is false. Whether to crop image or resize.
+ * @return bool|array False, on failure. Returned array matches parameters for imagecopyresampled() PHP function.
+ */
+function image_resize_dimensions($orig_w, $orig_h, $dest_w, $dest_h, $crop=false) {
+
+	if ($orig_w <= 0 || $orig_h <= 0)
+		return false;
+	// at least one of dest_w or dest_h must be specific
+	if ($dest_w <= 0 && $dest_h <= 0)
+		return false;
+
+	if ( $crop ) {
+		// crop the largest possible portion of the original image that we can size to $dest_w x $dest_h
+		$aspect_ratio = $orig_w / $orig_h;
+		$new_w = min($dest_w, $orig_w);
+		$new_h = min($dest_h, $orig_h);
+		if (!$new_w) {
+			$new_w = intval($new_h * $aspect_ratio);
+		}
+		if (!$new_h) {
+			$new_h = intval($new_w / $aspect_ratio);
+		}
+
+		$size_ratio = max($new_w / $orig_w, $new_h / $orig_h);
+
+		$crop_w = ceil($new_w / $size_ratio);
+		$crop_h = ceil($new_h / $size_ratio);
+
+		$s_x = floor(($orig_w - $crop_w)/2);
+		$s_y = floor(($orig_h - $crop_h)/2);
+	}
+	else {
+		// don't crop, just resize using $dest_w x $dest_h as a maximum bounding box
+		$crop_w = $orig_w;
+		$crop_h = $orig_h;
+
+		$s_x = 0;
+		$s_y = 0;
+
+		list( $new_w, $new_h ) = wp_constrain_dimensions( $orig_w, $orig_h, $dest_w, $dest_h );
+	}
+
+	// if the resulting image would be the same size or larger we don't want to resize it
+	if ($new_w >= $orig_w && $new_h >= $orig_h)
+		return false;
+
+	// the return array matches the parameters to imagecopyresampled()
+	// int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h
+	return array(0, 0, $s_x, $s_y, $new_w, $new_h, $crop_w, $crop_h);
+
+}
+
+/**
+ * Scale down an image to fit a particular size and save a new copy of the image.
+ *
+ * The PNG transparency will be preserved using the function, as well as the
+ * image type. If the file going in is PNG, then the resized image is going to
+ * be PNG. The only supported image types are PNG, GIF, and JPEG.
+ *
+ * Some functionality requires API to exist, so some PHP version may lose out
+ * support. This is not the fault of WordPress (where functionality is
+ * downgraded, not actual defects), but of your PHP version.
+ *
+ * @since 2.5.0
+ *
+ * @param string $file Image file path.
+ * @param int $max_w Maximum width to resize to.
+ * @param int $max_h Maximum height to resize to.
+ * @param bool $crop Optional. Whether to crop image or resize.
+ * @param string $suffix Optional. File Suffix.
+ * @param string $dest_path Optional. New image file path.
+ * @param int $jpeg_quality Optional, default is 90. Image quality percentage.
+ * @return mixed WP_Error on failure. String with new destination path. Array of dimensions from {@link image_resize_dimensions()}
+ */
+function image_resize( $file, $max_w, $max_h, $crop=false, $suffix=null, $dest_path=null, $jpeg_quality=90) {
+
+	$image = wp_load_image( $file );
+	if ( !is_resource( $image ) )
+		return new WP_Error('error_loading_image', $image);
+
+	list($orig_w, $orig_h, $orig_type) = getimagesize( $file );
+	$dims = image_resize_dimensions($orig_w, $orig_h, $max_w, $max_h, $crop);
+	if (!$dims)
+		return $dims;
+	list($dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h) = $dims;
+
+	$newimage = imagecreatetruecolor( $dst_w, $dst_h);
+
+	// preserve PNG transparency
+	if ( IMAGETYPE_PNG == $orig_type && function_exists( 'imagealphablending' ) && function_exists( 'imagesavealpha' ) ) {
+		imagealphablending( $newimage, false);
+		imagesavealpha( $newimage, true);
+	}
+
+	imagecopyresampled( $newimage, $image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h);
+
+	// we don't need the original in memory anymore
+	imagedestroy( $image );
+
+	// $suffix will be appended to the destination filename, just before the extension
+	if ( !$suffix )
+		$suffix = "{$dst_w}x{$dst_h}";
+
+	$info = pathinfo($file);
+	$dir = $info['dirname'];
+	$ext = $info['extension'];
+	$name = basename($file, ".{$ext}");
+	if ( !is_null($dest_path) and $_dest_path = realpath($dest_path) )
+		$dir = $_dest_path;
+	$destfilename = "{$dir}/{$name}-{$suffix}.{$ext}";
+
+	if ( $orig_type == IMAGETYPE_GIF ) {
+		if (!imagegif( $newimage, $destfilename ) )
+			return new WP_Error('resize_path_invalid', __( 'Resize path invalid' ));
+	}
+	elseif ( $orig_type == IMAGETYPE_PNG ) {
+		if (!imagepng( $newimage, $destfilename ) )
+			return new WP_Error('resize_path_invalid', __( 'Resize path invalid' ));
+	}
+	else {
+		// all other formats are converted to jpg
+		$destfilename = "{$dir}/{$name}-{$suffix}.jpg";
+		if (!imagejpeg( $newimage, $destfilename, apply_filters( 'jpeg_quality', $jpeg_quality, 'image_resize' ) ) )
+			return new WP_Error('resize_path_invalid', __( 'Resize path invalid' ));
+	}
+
+	imagedestroy( $newimage );
+
+	// Set correct file permissions
+	$stat = stat( dirname( $destfilename ));
+	$perms = $stat['mode'] & 0000666; //same permissions as parent folder, strip off the executable bits
+	@ chmod( $destfilename, $perms );
+
+	return $destfilename;
+}
+
+/**
+ * Resize an image to make a thumbnail or intermediate size.
+ *
+ * The returned array has the file size, the image width, and image height. The
+ * filter 'image_make_intermediate_size' can be used to hook in and change the
+ * values of the returned array. The only parameter is the resized file path.
+ *
+ * @since 2.5.0
+ *
+ * @param string $file File path.
+ * @param int $width Image width.
+ * @param int $height Image height.
+ * @param bool $crop Optional, default is false. Whether to crop image to specified height and width or resize.
+ * @return bool|array False, if no image was created. Metadata array on success.
+ */
+function image_make_intermediate_size($file, $width, $height, $crop=false) {
+	if ( $width || $height ) {
+		$resized_file = image_resize($file, $width, $height, $crop);
+		if ( !is_wp_error($resized_file) && $resized_file && $info = getimagesize($resized_file) ) {
+			$resized_file = apply_filters('image_make_intermediate_size', $resized_file);
+			return array(
+				'file' => basename( $resized_file ),
+				'width' => $info[0],
+				'height' => $info[1],
+			);
+		}
+	}
+	return false;
+}
+
+/**
+ * Retrieve the image's intermediate size (resized) path, width, and height.
+ *
+ * The $size parameter can be an array with the width and height respectively.
+ * If the size matches the 'sizes' metadata array for width and height, then it
+ * will be used. If there is no direct match, then the nearest image size larger
+ * than the specified size will be used. If nothing is found, then the function
+ * will break out and return false.
+ *
+ * The metadata 'sizes' is used for compatible sizes that can be used for the
+ * parameter $size value.
+ *
+ * The url path will be given, when the $size parameter is a string.
+ *
+ * @since 2.5.0
+ *
+ * @param int $post_id Attachment ID for image.
+ * @param array|string $size Optional, default is 'thumbnail'. Size of image, either array or string.
+ * @return bool|array False on failure or array of file path, width, and height on success.
+ */
+function image_get_intermediate_size($post_id, $size='thumbnail') {
+	if ( !is_array( $imagedata = wp_get_attachment_metadata( $post_id ) ) )
+		return false;
+
+	// get the best one for a specified set of dimensions
+	if ( is_array($size) && !empty($imagedata['sizes']) ) {
+		foreach ( $imagedata['sizes'] as $_size => $data ) {
+			// already cropped to width or height; so use this size
+			if ( ( $data['width'] == $size[0] && $data['height'] <= $size[1] ) || ( $data['height'] == $size[1] && $data['width'] <= $size[0] ) ) {
+				$file = $data['file'];
+				list($width, $height) = image_constrain_size_for_editor( $data['width'], $data['height'], $size );
+				return compact( 'file', 'width', 'height' );
+			}
+			// add to lookup table: area => size
+			$areas[$data['width'] * $data['height']] = $_size;
+		}
+		if ( !$size || !empty($areas) ) {
+			// find for the smallest image not smaller than the desired size
+			ksort($areas);
+			foreach ( $areas as $_size ) {
+				$data = $imagedata['sizes'][$_size];
+				if ( $data['width'] >= $size[0] || $data['height'] >= $size[1] ) {
+					$file = $data['file'];
+					list($width, $height) = image_constrain_size_for_editor( $data['width'], $data['height'], $size );
+					return compact( 'file', 'width', 'height' );
+				}
+			}
+		}
+	}
+
+	if ( is_array($size) || empty($size) || empty($imagedata['sizes'][$size]) )
+		return false;
+
+	$data = $imagedata['sizes'][$size];
+	// include the full filesystem path of the intermediate file
+	if ( empty($data['path']) && !empty($data['file']) ) {
+		$file_url = wp_get_attachment_url($post_id);
+		$data['path'] = path_join( dirname($imagedata['file']), $data['file'] );
+		$data['url'] = path_join( dirname($file_url), $data['file'] );
+	}
+	return $data;
+}
+
+/**
+ * Retrieve an image to represent an attachment.
+ *
+ * A mime icon for files, thumbnail or intermediate size for images.
+ *
+ * @since 2.5.0
+ *
+ * @param int $attachment_id Image attachment ID.
+ * @param string $size Optional, default is 'thumbnail'.
+ * @param bool $icon Optional, default is false. Whether it is an icon.
+ * @return bool|array Returns an array (url, width, height), or false, if no image is available.
+ */
+function wp_get_attachment_image_src($attachment_id, $size='thumbnail', $icon = false) {
+
+	// get a thumbnail or intermediate image if there is one
+	if ( $image = image_downsize($attachment_id, $size) )
+		return $image;
+
+	$src = false;
+
+	if ( $icon && $src = wp_mime_type_icon($attachment_id) ) {
+		$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/crystal' );
+		$src_file = $icon_dir . '/' . basename($src);
+		@list($width, $height) = getimagesize($src_file);
+	}
+	if ( $src && $width && $height )
+		return array( $src, $width, $height );
+	return false;
+}
+
+/**
+ * Get an HTML img element representing an image attachment
+ *
+ * @uses apply_filters() Calls 'wp_get_attachment_image_attributes' hook on attributes array
+ * @uses wp_get_attachment_image_src() Gets attachment file URL and dimensions
+ * @since 2.5.0
+ *
+ * @param int $attachment_id Image attachment ID.
+ * @param string $size Optional, default is 'thumbnail'.
+ * @param bool $icon Optional, default is false. Whether it is an icon.
+ * @return string HTML img element or empty string on failure.
+ */
+function wp_get_attachment_image($attachment_id, $size = 'thumbnail', $icon = false) {
+
+	$html = '';
+	$image = wp_get_attachment_image_src($attachment_id, $size, $icon);
+	if ( $image ) {
+		list($src, $width, $height) = $image;
+		$hwstring = image_hwstring($width, $height);
+		if ( is_array($size) )
+			$size = join('x', $size);
+		$attachment =& get_post($attachment_id);
+		$attr = array(
+			'src'	=> $src,
+			'class'	=> "attachment-$size",
+			'alt'	=> trim(strip_tags( $attachment->post_excerpt )),
+			'title'	=> trim(strip_tags( $attachment->post_title )),
+			);
+		$attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, $attachment );
+		$attr = array_map( 'esc_attr', $attr );
+		$html = rtrim("<img $hwstring");
+		foreach ( $attr as $name => $value ) {
+			$html .= " $name=" . '"' . $value . '"';
+		}
+		$html .= ' />';
+	}
+
+	return $html;
+}
+
+add_shortcode('wp_caption', 'img_caption_shortcode');
+add_shortcode('caption', 'img_caption_shortcode');
+
+/**
+ * The Caption shortcode.
+ *
+ * Allows a plugin to replace the content that would otherwise be returned. The
+ * filter is 'img_caption_shortcode' and passes an empty string, the attr
+ * parameter and the content parameter values.
+ *
+ * The supported attributes for the shortcode are 'id', 'align', 'width', and
+ * 'caption'.
+ *
+ * @since 2.6.0
+ *
+ * @param array $attr Attributes attributed to the shortcode.
+ * @param string $content Optional. Shortcode content.
+ * @return string
+ */
+function img_caption_shortcode($attr, $content = null) {
+
+	// Allow plugins/themes to override the default caption template.
+	$output = apply_filters('img_caption_shortcode', '', $attr, $content);
+	if ( $output != '' )
+		return $output;
+
+	extract(shortcode_atts(array(
+		'id'	=> '',
+		'align'	=> 'alignnone',
+		'width'	=> '',
+		'caption' => ''
+	), $attr));
+
+	if ( 1 > (int) $width || empty($caption) )
+		return $content;
+
+	if ( $id ) $id = 'id="' . esc_attr($id) . '" ';
+
+	return '<div ' . $id . 'class="wp-caption ' . esc_attr($align) . '" style="width: ' . (10 + (int) $width) . 'px">'
+	. do_shortcode( $content ) . '<p class="wp-caption-text">' . $caption . '</p></div>';
+}
+
+add_shortcode('gallery', 'gallery_shortcode');
+
+/**
+ * The Gallery shortcode.
+ *
+ * This implements the functionality of the Gallery Shortcode for displaying
+ * WordPress images on a post.
+ *
+ * @since 2.5.0
+ *
+ * @param array $attr Attributes attributed to the shortcode.
+ * @return string HTML content to display gallery.
+ */
+function gallery_shortcode($attr) {
+	global $post;
+
+	static $instance = 0;
+	$instance++;
+
+	// Allow plugins/themes to override the default gallery template.
+	$output = apply_filters('post_gallery', '', $attr);
+	if ( $output != '' )
+		return $output;
+
+	// We're trusting author input, so let's at least make sure it looks like a valid orderby statement
+	if ( isset( $attr['orderby'] ) ) {
+		$attr['orderby'] = sanitize_sql_orderby( $attr['orderby'] );
+		if ( !$attr['orderby'] )
+			unset( $attr['orderby'] );
+	}
+
+	extract(shortcode_atts(array(
+		'order'      => 'ASC',
+		'orderby'    => 'menu_order ID',
+		'id'         => $post->ID,
+		'itemtag'    => 'dl',
+		'icontag'    => 'dt',
+		'captiontag' => 'dd',
+		'columns'    => 3,
+		'size'       => 'thumbnail'
+	), $attr));
+
+	$id = intval($id);
+	$attachments = get_children( array('post_parent' => $id, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );
+
+	if ( empty($attachments) )
+		return '';
+
+	if ( is_feed() ) {
+		$output = "\n";
+		foreach ( $attachments as $att_id => $attachment )
+			$output .= wp_get_attachment_link($att_id, $size, true) . "\n";
+		return $output;
+	}
+
+	$itemtag = tag_escape($itemtag);
+	$captiontag = tag_escape($captiontag);
+	$columns = intval($columns);
+	$itemwidth = $columns > 0 ? floor(100/$columns) : 100;
+
+	$selector = "gallery-{$instance}";
+
+	$output = apply_filters('gallery_style', "
+		<style type='text/css'>
+			#{$selector} {
+				margin: auto;
+			}
+			#{$selector} .gallery-item {
+				float: left;
+				margin-top: 10px;
+				text-align: center;
+				width: {$itemwidth}%;			}
+			#{$selector} img {
+				border: 2px solid #cfcfcf;
+			}
+			#{$selector} .gallery-caption {
+				margin-left: 0;
+			}
+		</style>
+		<!-- see gallery_shortcode() in wp-includes/media.php -->
+		<div id='$selector' class='gallery galleryid-{$id}'>");
+
+	$i = 0;
+	foreach ( $attachments as $id => $attachment ) {
+		$link = isset($attr['link']) && 'file' == $attr['link'] ? wp_get_attachment_link($id, $size, false, false) : wp_get_attachment_link($id, $size, true, false);
+
+		$output .= "<{$itemtag} class='gallery-item'>";
+		$output .= "
+			<{$icontag} class='gallery-icon'>
+				$link
+			</{$icontag}>";
+		if ( $captiontag && trim($attachment->post_excerpt) ) {
+			$output .= "
+				<{$captiontag} class='gallery-caption'>
+				" . wptexturize($attachment->post_excerpt) . "
+				</{$captiontag}>";
+		}
+		$output .= "</{$itemtag}>";
+		if ( $columns > 0 && ++$i % $columns == 0 )
+			$output .= '<br style="clear: both" />';
+	}
+
+	$output .= "
+			<br style='clear: both;' />
+		</div>\n";
+
+	return $output;
+}
+
+/**
+ * Display previous image link that has the same post parent.
+ *
+ * @since 2.5.0
+ * @param string $size Optional, default is 'thumbnail'. Size of image, either array or string. 0 or 'none' will default to post_title or $text;
+ * @param string $text Optional, default is false. If included, link will reflect $text variable.
+ * @return string HTML content.
+ */
+function previous_image_link($size = 'thumbnail', $text = false) {
+	adjacent_image_link(true, $size, $text);
+}
+
+/**
+ * Display next image link that has the same post parent.
+ *
+ * @since 2.5.0
+ * @param string $size Optional, default is 'thumbnail'. Size of image, either array or string. 0 or 'none' will default to post_title or $text;
+ * @param string $text Optional, default is false. If included, link will reflect $text variable.
+ * @return string HTML content.
+ */
+function next_image_link($size = 'thumbnail', $text = false) {
+	adjacent_image_link(false, $size, $text);
+}
+
+/**
+ * Display next or previous image link that has the same post parent.
+ *
+ * Retrieves the current attachment object from the $post global.
+ *
+ * @since 2.5.0
+ *
+ * @param bool $prev Optional. Default is true to display previous link, true for next.
+ */
+function adjacent_image_link($prev = true, $size = 'thumbnail', $text = false) {
+	global $post;
+	$post = get_post($post);
+	$attachments = array_values(get_children( array('post_parent' => $post->post_parent, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => 'ASC', 'orderby' => 'menu_order ID') ));
+
+	foreach ( $attachments as $k => $attachment )
+		if ( $attachment->ID == $post->ID )
+			break;
+
+	$k = $prev ? $k - 1 : $k + 1;
+
+	if ( isset($attachments[$k]) )
+		echo wp_get_attachment_link($attachments[$k]->ID, $size, true, false, $text);
+}
+
+/**
+ * Retrieve taxonomies attached to the attachment.
+ *
+ * @since 2.5.0
+ *
+ * @param int|array|object $attachment Attachment ID, Attachment data array, or Attachment data object.
+ * @return array Empty array on failure. List of taxonomies on success.
+ */
+function get_attachment_taxonomies($attachment) {
+	if ( is_int( $attachment ) )
+		$attachment = get_post($attachment);
+	else if ( is_array($attachment) )
+		$attachment = (object) $attachment;
+
+	if ( ! is_object($attachment) )
+		return array();
+
+	$filename = basename($attachment->guid);
+
+	$objects = array('attachment');
+
+	if ( false !== strpos($filename, '.') )
+		$objects[] = 'attachment:' . substr($filename, strrpos($filename, '.') + 1);
+	if ( !empty($attachment->post_mime_type) ) {
+		$objects[] = 'attachment:' . $attachment->post_mime_type;
+		if ( false !== strpos($attachment->post_mime_type, '/') )
+			foreach ( explode('/', $attachment->post_mime_type) as $token )
+				if ( !empty($token) )
+					$objects[] = "attachment:$token";
+	}
+
+	$taxonomies = array();
+	foreach ( $objects as $object )
+		if ( $taxes = get_object_taxonomies($object) )
+			$taxonomies = array_merge($taxonomies, $taxes);
+
+	return array_unique($taxonomies);
+}
+
+?>