list_theme_updates

function list_theme_updates() {
	$themes = get_theme_updates();
	if ( empty( $themes ) ) {
		echo '<h2>' . __( 'Themes' ) . '</h2>';
		echo '<p>' . __( 'Your themes are all up to date.' ) . '</p>';
		return;
	}

	$form_action = 'update-core.php?action=do-theme-upgrade';
	?>
<h2><?php _e( 'Themes' ); ?></h2>
<p><?php _e( 'The following themes have new versions available. Check the ones you want to update and then click &#8220;Update Themes&#8221;.' ); ?></p>
<p>
	<?php
	printf(
		/* translators: %s: Link to documentation on child themes. */
		__( '<strong>Please Note:</strong> Any customizations you have made to theme files will be lost. Please consider using <a href="%s">child themes</a> for modifications.' ),
		__( 'https://developer.wordpress.org/themes/advanced-topics/child-themes/' )
	);
	?>
</p>
<form method="post" action="<?php echo esc_url( $form_action ); ?>" name="upgrade-themes" class="upgrade">
	<?php wp_nonce_field( 'upgrade-core' ); ?>
<p><input id="upgrade-themes" class="button" type="submit" value="<?php esc_attr_e( 'Update Themes' ); ?>" name="upgrade" /></p>
<table class="widefat updates-table" id="update-themes-table">
	<thead>
	<tr>
		<td class="manage-column check-column"><input type="checkbox" id="themes-select-all" /></td>
		<td class="manage-column"><label for="themes-select-all"><?php _e( 'Select All' ); ?></label></td>
	</tr>
	</thead>

	<tbody class="plugins">
	<?php
	$auto_updates = array();
	if ( wp_is_auto_update_enabled_for_type( 'theme' ) ) {
		$auto_updates       = (array) get_site_option( 'auto_update_themes', array() );
		$auto_update_notice = ' | ' . wp_get_auto_update_message();
	}

	foreach ( $themes as $stylesheet => $theme ) {
		$requires_wp  = isset( $theme->update['requires'] ) ? $theme->update['requires'] : null;
		$requires_php = isset( $theme->update['requires_php'] ) ? $theme->update['requires_php'] : null;

		$compatible_wp  = is_wp_version_compatible( $requires_wp );
		$compatible_php = is_php_version_compatible( $requires_php );

		$compat = '';

		if ( ! $compatible_wp && ! $compatible_php ) {
			$compat .= '<br>' . __( 'This update doesn&#8217;t work with your versions of WordPress and PHP.' ) . '&nbsp;';
			if ( current_user_can( 'update_core' ) && current_user_can( 'update_php' ) ) {
				$compat .= sprintf(
					/* translators: 1: URL to WordPress Updates screen, 2: URL to Update PHP page. */
					__( '<a href="%1$s">Please update WordPress</a>, and then <a href="%2$s">learn more about updating PHP</a>.' ),
					self_admin_url( 'update-core.php' ),
					esc_url( wp_get_update_php_url() )
				);

				$annotation = wp_get_update_php_annotation();

				if ( $annotation ) {
					$compat .= '</p><p><em>' . $annotation . '</em>';
				}
			} elseif ( current_user_can( 'update_core' ) ) {
				$compat .= sprintf(
					/* translators: %s: URL to WordPress Updates screen. */
					__( '<a href="%s">Please update WordPress</a>.' ),
					self_admin_url( 'update-core.php' )
				);
			} elseif ( current_user_can( 'update_php' ) ) {
				$compat .= sprintf(
					/* translators: %s: URL to Update PHP page. */
					__( '<a href="%s">Learn more about updating PHP</a>.' ),
					esc_url( wp_get_update_php_url() )
				);

				$annotation = wp_get_update_php_annotation();

				if ( $annotation ) {
					$compat .= '</p><p><em>' . $annotation . '</em>';
				}
			}
		} elseif ( ! $compatible_wp ) {
			$compat .= '<br>' . __( 'This update doesn&#8217;t work with your version of WordPress.' ) . '&nbsp;';
			if ( current_user_can( 'update_core' ) ) {
				$compat .= sprintf(
					/* translators: %s: URL to WordPress Updates screen. */
					__( '<a href="%s">Please update WordPress</a>.' ),
					self_admin_url( 'update-core.php' )
				);
			}
		} elseif ( ! $compatible_php ) {
			$compat .= '<br>' . __( 'This update doesn&#8217;t work with your version of PHP.' ) . '&nbsp;';
			if ( current_user_can( 'update_php' ) ) {
				$compat .= sprintf(
					/* translators: %s: URL to Update PHP page. */
					__( '<a href="%s">Learn more about updating PHP</a>.' ),
					esc_url( wp_get_update_php_url() )
				);

				$annotation = wp_get_update_php_annotation();

				if ( $annotation ) {
					$compat .= '</p><p><em>' . $annotation . '</em>';
				}
			}
		}

		$checkbox_id = 'checkbox_' . md5( $theme->get( 'Name' ) );
		?>
	<tr>
		<td class="check-column">
			<?php if ( $compatible_wp && $compatible_php ) : ?>
				<input type="checkbox" name="checked[]" id="<?php echo $checkbox_id; ?>" value="<?php echo esc_attr( $stylesheet ); ?>" />
				<label for="<?php echo $checkbox_id; ?>" class="screen-reader-text">
					<?php
					/* translators: %s: Theme name. */
					printf( __( 'Select %s' ), $theme->display( 'Name' ) );
					?>
				</label>
			<?php endif; ?>
		</td>
		<td class="plugin-title"><p>
			<img src="<?php echo esc_url( $theme->get_screenshot() ); ?>" width="85" height="64" class="updates-table-screenshot" alt="" />
			<strong><?php echo $theme->display( 'Name' ); ?></strong>
			<?php
			printf(
				/* translators: 1: Theme version, 2: New version. */
				__( 'You have version %1$s installed. Update to %2$s.' ),
				$theme->display( 'Version' ),
				$theme->update['new_version']
			);

			echo ' ' . $compat;

			if ( in_array( $stylesheet, $auto_updates, true ) ) {
				echo $auto_update_notice;
			}
			?>
		</p></td>
	</tr>
			<?php
	}
	?>
	</tbody>

	<tfoot>
	<tr>
		<td class="manage-column check-column"><input type="checkbox" id="themes-select-all-2" /></td>
		<td class="manage-column"><label for="themes-select-all-2"><?php _e( 'Select All' ); ?></label></td>
	</tr>
	</tfoot>
</table>
<p><input id="upgrade-themes-2" class="button" type="submit" value="<?php esc_attr_e( 'Update Themes' ); ?>" name="upgrade" /></p>
</form>
	<?php
}