public function is_activity() {

		// Bail if not looking at a group.
		if ( ! bp_is_activity_component() )
			return;

		// Activity Directory.
		if ( ! bp_displayed_user_id() && ! bp_current_action() ) {
			bp_update_is_directory( true, 'activity' );

			/** This action is documented in bp-activity/bp-activity-screens.php */
			do_action( 'bp_activity_screen_index' );

			add_filter( 'bp_get_buddypress_template',                array( $this, 'directory_template_hierarchy' ) );
			add_action( 'bp_template_include_reset_dummy_post_data', array( $this, 'directory_dummy_post' ) );
			add_filter( 'bp_replace_the_content',                    array( $this, 'directory_content'    ) );

		// Single activity.
		} elseif ( bp_is_single_activity() ) {
			add_filter( 'bp_get_buddypress_template',                array( $this, 'single_template_hierarchy' ) );
			add_action( 'bp_template_include_reset_dummy_post_data', array( $this, 'single_dummy_post' ) );
			add_filter( 'bp_replace_the_content',                    array( $this, 'single_dummy_content'    ) );
		}
	}