dev/R_ggraph/layout.R

In kbodwin/longnet: What the Package Does (One Line, Title Case)

#' @rdname ggraph
#'
#' @aliases layout_ggraph
#'
#' @export
create_layout <- function(graph, layout, circular, ...) {
    UseMethod('create_layout', graph)
}
#' @rdname ggraph
#' @usage NULL
#' @export
createLayout <- function(...) {
    .Deprecated('create_layout')
    create_layout(...)
}
#' @rdname ggraph
#' @export
create_layout.default <- function(graph, layout, ...) {
    graph <- tryCatch(as_tbl_graph(graph), error = function(e) {
        stop('No layout function defined for objects of class ', class(graph), call. = FALSE)
    })
    create_layout(graph, layout, ...)
}
#' @rdname ggraph
#' @export
create_layout.layout_ggraph <- function(graph, ...) {
    graph
}
#' @export
as.data.frame.layout_ggraph <- function(x, ...) {
    extraAttr <- names(attributes(x))
    extraAttr <- extraAttr[!extraAttr %in% c('names', 'row.names')]
    attributes(x)[extraAttr] <- NULL
    class(x) <- 'data.frame'
    x
}
check_layout <- function(layout) {
    if (!is.data.frame(layout)) {
        stop('layout must be a data.frame', call. = FALSE)
    }
    if (!(is.numeric(layout$x) && is.numeric(layout$y))) {
        stop('layout must contain numeric `x` and `y` columns', call. = FALSE)
    }
    graph <- attr(layout, 'graph')
    if (!is.tbl_graph(graph)) {
        stop('layout must have a tbl_graph as the `graph` attribute', call. = FALSE)
    }
    if (nrow(layout) != gorder(graph)) {
        stop('layout must contain the same number of rows as nodes', call. = FALSE)
    }
    if (!'circular' %in% names(layout)) {
        layout$circular <- FALSE
    }
    if (!is.logical(layout$circular)) {
        stop('circular column must be logical', call. = FALSE)
    }
    layout
}