WordPress/wp-admin/themes.php

<?php
require_once('admin.php');

if ( isset($_GET['action']) ) {
	check_admin_referer();

	if ('activate' == $_GET['action']) {
	  if (isset($_GET['template'])) {
	    update_option('template', $_GET['template']);
	  }

	  if (isset($_GET['stylesheet'])) {
	    update_option('stylesheet', $_GET['stylesheet']);
	  }

		do_action('switch_theme', get_current_theme());

	  header('Location: themes.php?activated=true');
	}
 }

$title = __('Manage Themes');
$parent_file = 'themes.php';
require_once('admin-header.php');
?>
<?php if ( ! validate_current_theme() ) : ?>
<div class="updated"><p><?php _e('The active theme is broken.  Reverting to the default theme.'); ?></p></div>
<?php elseif ( isset($activated) ) : ?>
<div class="updated"><p><?php _e('New theme activated'); ?></p></div>
<?php endif; ?>

<?php
$themes = get_themes();
$current_theme = get_current_theme();
$current_title = $themes[$current_theme]['Title'];
$current_version = $themes[$current_theme]['Version'];
$current_parent_theme = $themes[$current_theme]['Parent Theme'];
$current_template_dir = $themes[$current_theme]['Template Dir'];
$current_stylesheet_dir = $themes[$current_theme]['Stylesheet Dir'];
$current_template = $themes[$current_theme]['Template'];
$current_stylesheet = $themes[$current_theme]['Stylesheet'];
?>

<div class="wrap">
<h2><?php _e('Current Theme'); ?></h2>
<div id="currenttheme">
<h3><?php printf(__('%1$s %2$s by %3$s'), $current_title, $current_version, $themes[$current_theme]['Author']) ; ?></h3>
<p><?php echo $themes[$current_theme]['Description']; ?></p>
<?php if ($current_parent_theme) { ?>
	<p><?php printf(__('The active theme is <strong>%1$s</strong>.  The template files are located in <code>%2$s</code>.  The stylesheet files are located in <code>%3$s</code>.  <strong>%4$s</strong> uses templates from <strong>%5$s</strong>.  Changes made to the templates will affect both themes.'), $current_theme, $current_template_dir, $current_stylesheet_dir, $current_theme, $current_parent_theme); ?></p>
<?php } else { ?>
	<p><?php printf(__('The active theme is <strong>%1$s</strong>.  The template files are located in <code>%2$s</code>.  The stylesheet files are located in <code>%3$s</code>.'), $current_theme, $current_template_dir, $current_stylesheet_dir); ?></p>
<?php } ?>
</div>

<h2><?php _e('Other Themes'); ?></h2>
<p><?php _e('Themes are usually downloaded separately from WordPress. To install a theme you generally just need to put the theme file or files into your <code>wp-content/themes</code> directory. Once a theme is installed, you may select it here.'); ?></p>

<?php if ( 1 < count($themes) ) { ?>
<table width="100%" cellpadding="3" cellspacing="3">
	<tr>
		<th><?php _e('Name'); ?></th>
		<th><?php _e('Author'); ?></th>
		<th><?php _e('Description'); ?></th>
		<th></th>
	</tr>
<?php
	$style = '';

	$theme_names = array_keys($themes);
	natcasesort($theme_names);

	foreach ($theme_names as $theme_name) {
		$template = $themes[$theme_name]['Template'];
		$stylesheet = $themes[$theme_name]['Stylesheet'];
		$title = $themes[$theme_name]['Title'];
		$version = $themes[$theme_name]['Version'];
		$description = $themes[$theme_name]['Description'];
		$author = $themes[$theme_name]['Author'];

		if ($template == $current_template && $stylesheet == $current_stylesheet) {
			$action = '<strong>' . __('Active Theme') . '</strong>';
			$current = true;
		} else {
			$action = "<a href='themes.php?action=activate&amp;template=$template&amp;stylesheet=$stylesheet' title='" . __('Select this theme') . "' class='edit'>" . __('Select') . '</a>';
			$current = false;
		}

		$style = ('class="alternate"' == $style|| 'class="alternate active"' == $style) ? '' : 'alternate';
		if ($current) $style .= $style == 'alternate' ? ' active' : 'active';
		if ($style != '') $style = 'class="' . $style . '"';

		echo "
	  <tr $style>";
if ( $current )
	echo "<td><strong>$title $version</strong></td>";
else
	echo "<td>$title $version</td>";
echo "
	     <td class=\"auth\">$author</td>
	     <td class=\"desc\">$description</td>
	     <td class=\"togl\">$action</td>
	  </tr>";
	}
?>

</table>
<?php
}
?>

<?php
// List broken themes, if any.
$broken_themes = get_broken_themes();
if (count($broken_themes)) {
?>

<h2><?php _e('Broken Themes'); ?></h2>
<p><?php _e('The following themes are installed but incomplete.  Themes must have a stylesheet and a template.'); ?></p>

<table width="100%" cellpadding="3" cellspacing="3">
	<tr>
		<th><?php _e('Name'); ?></th>
		<th><?php _e('Description'); ?></th>
	</tr>
<?php
	$theme = '';
	
	$theme_names = array_keys($broken_themes);
	natcasesort($theme_names);

	foreach ($theme_names as $theme_name) {
		$title = $broken_themes[$theme_name]['Title'];
		$description = $broken_themes[$theme_name]['Description'];

		$theme = ('class="alternate"' == $theme) ? '' : 'class="alternate"';
		echo "
	  <tr $theme>
	     <td>$title</td>
	     <td>$description</td>
	  </tr>";
	}
?>
</table>
<?php
}
?>

</div>

<?php
include('admin-footer.php');
?>