flipPictographs: Pictograph htmlwidgets

Documented in pictoChart

#' pictoChart
#'
#' Function that computes dimensions for PictographChart. It should not be called directly.
#' The output is a JSON string for creating the widget
#'
#' @return Either a JSON string to create the widget or NA or a numeric value (see parameter \code{f.mspace}) if adjustment of dimensions is required to fit the floating labels in properly. The iterative adjustment is performed only when \code{graphic.width.inch} and \code{graphic.height.inch} is provided.
#' @param x Data for charting
#' @param fill.image URL of icon
#' @param base.image Optional URL of background image
#' @param total.icons Maximum icons in each table cell. Ignored if both \code{icon.nrow} and \code{icon.ncol} supplied.
#' @param fill.direction Accepts \code{horizontal}, \code{vertical}, \code{radial}, \code{scale}. (But \code{scale} may not be appropriate, especially if \code{total.icons} is important).
#' @param show.lines Add horizontal lines between each row
#' @param line.width Width of lines
#' @param line.color Line colour
#' @param show.legend Show legend (true or false).
#' @param legend.text Text to show beside legend icon.
#' @param legend.font.family.family Font of legend.
#' @param legend.font.size Text size of legend text.
#' @param legend.icon.color Color of icon shown in legend.
#' @param background.color Background colour of pictograph
#' @param icon.nrow Configuration of icons in each table cell. Can be a single value or a vector with length equal to the number of rows.
#' @param icon.ncol Configuration of icons in each table cell. Can be a single value or a vector with length equal to the number of columns.
#' @param label.left.pad,label.right.pad Horizontal spacing between row labels and icons.
#' @param label.left Length must be equal to length (if \code{x} is a vector) or number of rows (if \code{x} is matrix or data.frame) as x. If no value is supplied, labels will be read from names/rowname of \code{x}. To suppress labels, use \code{label.left  =  NULL}.
#' @param label.top By default, labels are read from column names of \code{x}.
#' @param label.bottom Optional labels below graphic cells. The length of the labels must be the same as the number of columns in \code{x}.
#' @param label.right Optional labels to the right of graphic cells. The length of the labels must be the same as the number of rows in \code{x}.
#' @param label.font.family Controls font-family of all labels. To modify only the font of one label use \code{label.left.font.family, label.top.font.family}, etc.
#' @param label.font.size Size of label text.
#' @param label.font.color Colour of labels. This can be a string or a 6-digit hex code.
#' @param label.top.height Height of top label row in pixels.
#' @param label.left.width Width of left label column in pixels.
#' @param label.left.align.horizontal,label.right.align.horizontal,label.top.align.horizontal,label.bottom.align.horizontal Horizontal alignment of row and column labels. One of \code{"left", "right"} or \code{"center"}.
#' @param label.left.align.vertical,label.right.align.vertical,label.top.align.vertical,label.bottom.align.vertical Vertical alignment of row and column labels. One of \code{"top", "bottom"} or \code{"center"}.
#' @param label.left.font.color,label.right.font.color,label.top.font.color,label.bottom.font.color Font color of row/column labels which overrides the global \code{label.font.color} setting.
#' @param label.left.font.size,label.right.font.size,label.top.font.size,label.bottom.font.size Font size of row/column labels which overrides the global \code{label.font.size} setting.
#' @param label.left.font.weight,label.right.font.weight,label.top.font.weight,label.bottom.font.weight Font weight of row/column labels which overrides the global \code{label.font.weight} setting.
#' @param label.data.font.family Font in which the data labels are displayed.
#' @param label.data.font.size Font size of data labels.
#' @param label.data.font.color Font color of data labels.
#' @param label.data.font.weight Weight of data labels, i.e. one of \code{"bold"} or \code{"normal"}.
#' @param label.data.align.horizontal Horizontal alignment of data labels.

#' @param row.height Height of graphic cells. Can be a single value or a character or numeric vector the same length as the number of rows in \code{x}.
#' @param column.width Width of graphic cells.
#' @param width.height.ratio Width-to-height ratio used to adjust row heights and column widths so they match the aspect ratio of the icon. Mis-specfication does not distort icon, but graphic will have extra spacing. When set to zero, row.height and column.width are unchanged, otherwise initial values are decreased to match \code{width.height.ratio}.
#' @param pad.row Single numeric specifying vertical spacing between graphic cells in the table.
#' @param pad.col Vertical spacing between cells in table.
#' @param pad.icon.row Numeric specifying vertical spacing between icons inside each table cell. May be a single value or a numeric matrix of the same dimensions as \code{x}.
#' @param pad.icon.ncol Horizontal spacing between icons inside each table cell.
#' @param pad.legend Horizontal spacing between the chart and the legend.
#' @param f.mspace Space in left/right margin left for floating labels. This parameter is adjusted iteratively by \code{PictographChart} when floating labels are used in bar pictographs.
#' @param font.whratio Numeric specifying the average aspect ratio of a single character, which usually varies around 0.4 - 0.6. It is used to calculate the minimum width of the labels.
#' @param graphic.width.inch Horizontal dimension of the chart output in inches. If these dimensions are not specified, the width-to-height ratio of the chart output may not match the desired dimensions.
#' @param graphic.height.inch Verical dimension of the chart output in inches.
#' @keywords internal
#' @importFrom utils tail
#' @importFrom verbs Sum
pictoChart <- function(x,
                       fill.image,
                       base.image = NA,
                       image.type = "url",
                       total.icons = max(ceiling(x)),
                       fill.icon.color = "",
                       base.icon.color = "",
                       fill.direction = "fromleft",
                       show.lines = FALSE,
                       show.legend = FALSE,
                       legend.text = "",
                       icon.nrow = 1,
                       icon.ncol = NA,
                       label.left = NA,
                       label.right = NA,
                       label.top = NA,
                       label.bottom = NA,
                       sublabel.left = NA,
                       sublabel.right = NA,
                       label.left.pad = 5,
                       label.right.pad = 5,
                       label.font.family = "arial",
                       label.font.size = 12,
                       label.font.color = "#2C2C2C",
                       label.top.font.family = label.font.family,
                       label.top.font.size = label.font.size,
                       label.top.font.weight = "normal",
                       label.top.font.color = label.font.color,
                       label.top.height = NA,
                       label.right.font.family = label.font.family,
                       label.right.font.size = label.font.size,
                       label.right.font.weight = "normal",
                       label.right.font.color = label.font.color,
                       label.right.width = NA,
                       label.bottom.font.family = label.font.family,
                       label.bottom.font.size = label.font.size,
                       label.bottom.font.weight = "normal",
                       label.bottom.font.color = label.font.color,
                       label.bottom.height = NA,
                       label.left.font.family = label.font.family,
                       label.left.font.size = label.font.size,
                       label.left.font.weight = "normal",
                       label.left.font.color = label.font.color,
                       label.left.width = NA,
                       label.left.align.horizontal = "right",
                       label.right.align.horizontal = "left",
                       label.top.align.horizontal = "center",
                       label.bottom.align.horizontal = "left",
                       label.left.align.vertical = "center",
                       label.right.align.vertical = "center",
                       label.top.align.vertical = "center",
                       label.bottom.align.vertical = "center",
                       sublabel.left.font.size = label.left.font.size,
                       sublabel.left.font.weight = label.left.font.weight,
                       sublabel.left.align.horizontal = label.left.align.horizontal,
                       sublabel.right.font.size = label.right.font.size,
                       sublabel.right.font.weight = label.right.font.weight,
                       sublabel.right.align.horizontal = label.right.align.horizontal,
                       legend.font.family = label.font.family,
                       legend.font.size = 0.8*label.font.size,
                       legend.font.weight = "normal",
                       legend.font.color = label.font.color,
                       legend.icon.color = fill.icon.color[1],
                       show.label.data = FALSE,
                       label.data.text = NULL,
                       label.data.position = "footer",
                       label.data.font.family = label.font.family,
                       label.data.font.size = 0.8*label.font.size,
                       label.data.font.weight = "normal",
                       label.data.font.color = label.font.color,
                       label.data.align.horizontal = "right",
                       show.label.float = FALSE,
                       label.float.text = NULL,
                       label.float.font.family = label.font.family,
                       label.float.font.size = 0.8*label.font.size,
                       label.float.font.weight = "normal",
                       label.float.font.color = label.font.color,
                       label.float.align.horizontal = "center",
                       label.float.align.vertical = "center",
                       row.height = NA,
                       column.width = NA,
                       width.height.ratio = NA,
                       background.color = "transparent",
                       line.color = "#A8A8A8",
                       line.width = 0.5,
                       pad.legend = 0.5*column.width[1],
                       pad.row = 2,
                       pad.col = 2,
                       pad.icon.row = 0.0,
                       pad.icon.col = 0.0,
                       label.vpad = 0, # deprecated - is ignored
                       f.mspace = 0,
                       #margin.top = 0,
                       #margin.right = 0,
                       #margin.bottom = 0,
                       #margin.left = 0,
                       graphic.width.inch = NA,
                       graphic.height.inch = NA,
                       graphic.resolution = 72,
                       font.whratio = 0.9,
                       print.config = FALSE
                       )
{
    n <- if (is.null(nrow(x))) length(x)
         else nrow(x)
    m <- if (is.null(ncol(x)) || is.na(ncol(x))) 1
         else ncol(x)

    # Errors that are commonly encountered by Displayr/Q users are in sentence case
    # (e.g. total icons instead of total.icons), but parameters which are less commonly used
    # are referred to by exact parameter name so they can be easily corrected
    if (is.na(width.height.ratio))
        width.height.ratio <- 1
    if (any(total.icons != ceiling(total.icons)))
        stop("Total icons must be a whole number\n")
    if (any(total.icons <= 0))
        stop("Total icons must be greater than zero\n")
    if (length(total.icons) != 1 && length(total.icons) != length(x))
        stop("total.icons must be either a single integer or a matrix with the same dimensions as x\n")
    if (all(total.icons == 0))
        stop("No non-zero entries in total.icons\n")
    if (length(icon.nrow) != 1 && length(icon.nrow) != n)
        stop("icon.nrow should be a single integer or a vector of length ", n, "\n")
    if (length(icon.ncol) != 1 && length(icon.ncol) != m)
        stop("icon.ncol should be a single integer or a vector of length ", m, "\n")
    if (pad.icon.row < 0 || pad.icon.row >= 1)
        stop("pad.icon.row must be smaller than 1 and greater or equal to 0\n")
    if (pad.icon.col < 0 || pad.icon.col >= 1)
        stop("pad.icon.col must be smaller than 1 and greater or equal to 0\n")

    total.icons <- matrix(total.icons, nrow=n, ncol=m)
    prop <- as.vector(unlist(x))/unlist(total.icons)
    prop[total.icons == 0] <- 0
    if (any(is.na(prop)))
    {
        warning("Non-numeric values set to zero\n")
        prop[is.na(prop)] <- 0
    }

    # Scale has already been checked for non-negativity in pictographchart
    if (any(prop < 0))
        stop("Input data cannot be negative\n")
    if (any(prop > 1))
        stop("Input data is too large. Try increasing the scale or total icons\n")

    # Determine layout
    layout.str <- ""
    if (any(!is.na(icon.nrow)))
    {
        if (any(!is.na(icon.ncol)))
            warnings("icon.ncol is ignored when icon.nrow is specified\n")
        if (length(icon.nrow) == 1)
            icon.nrow <- rep(icon.nrow, n)

        icon.nrow.matrix <- matrix(icon.nrow, n, m)
        icon.ncol <- apply(total.icons/icon.nrow.matrix, 2, max)
        layout.str <- paste("\"numRows\":", icon.nrow.matrix)

    } else
    {
        if (length(icon.ncol) == 1)
            icon.ncol <- rep(icon.ncol, m)
        icon.ncol.matrix <- matrix(icon.ncol, n, m, byrow=T)
        icon.nrow <- apply(total.icons/icon.ncol.matrix, 1, function(x){ceiling(max(x))})
        layout.str <- paste("\"numCols\":", icon.ncol.matrix)
    }
    tot.icon.nrow <- Sum(icon.nrow, remove.missing = FALSE)
    tot.icon.ncol <- Sum(icon.ncol, remove.missing = FALSE)

    # Fill row/column labels with defaults
    if (!is.null(label.left) && is.na(label.left) && m == 1 && is.null(row.names(x)) && !is.null(names(x)))
        label.left <- names(x)
    if (!is.null(label.left) && all(is.na(label.left)) && !is.null(rownames(x)))
        label.left <- rownames(x)
    if (!is.null(label.top) && all(is.na(label.top)) && !is.null(colnames(x)))
        label.top <- colnames(x)
    if (!is.null(label.right) && all(is.na(label.right)))
        label.right <- NULL
    if (!is.null(label.bottom) && all(is.na(label.bottom)))
        label.bottom <- NULL
    if (!is.null(label.right) && all(is.na(label.right)))
        label.right <- NULL

    if (!is.null(label.left) && all(is.na(label.left)))
        label.left <- NULL
    if (!is.null(label.top) && all(is.na(label.top)))
        label.top <- NULL

    if (!is.null(sublabel.left) && all(is.na(sublabel.left)))
        sublabel.left <- NULL
    if (!is.null(sublabel.right) && all(is.na(sublabel.right)))
        sublabel.right <- NULL

    if (!is.null(label.left) && length(label.left) != n)
        stop("label.left must be of length ", n, "\n")
    if (!is.null(label.right) && length(label.right) != n)
        stop("label.right must be of length ", n, "\n")
    if (!is.null(label.top) && length(label.top) != m)
        stop("label.top must be of length ", m, "\n")
    if (!is.null(label.bottom) && length(label.bottom) != m)
        stop("label.bottom must be of length ", m, "\n")

    if (length(row.height) !=  1 && length(row.height) !=  n)
        stop("row.height must be of length 1 or ", n, "\n")
    if (length(column.width) !=  1 && length(column.width) != m)
        stop ("column.width must be of length 1 or ", m, "\n")


    fill.icon.color.str <- ifelse(nchar(fill.icon.color) > 0, paste(fill.icon.color, ":", sep = ""), "")
    base.image.str <- ""
    if (any(!is.na(base.image)))
    {
        base.icon.color.str <- ifelse(nchar(base.icon.color) > 0, paste(base.icon.color, ":", sep = ""), "")
        base.image.str <- ifelse(!is.na(base.image), paste("\"baseImage\":\"", image.type, ":", base.icon.color.str, base.image, "\",", sep = ""), "")
    }

    # Calculate floating labels
    # We need to do this first in case we need to leave extra space in the margin
    label.float.str <- ""
    if (show.label.float)
    {
        #if (any(x >= total.icons))
        #    warning("Floating labels placed at invalid positions. Please increase total.icons\n")

        i.pos <- floor(x/icon.ncol)
        j.pos <- x %% icon.ncol
        ind.outside <- which(x >= icon.ncol)
        if (length(ind.outside) > 0)
        {
            i.pos[ind.outside] <- 0
            j.pos[ind.outside] <- icon.ncol
        }

        # extra space in margin
        pad.dir <- ifelse(fill.direction == "fromright", "padding-right", "padding-left")
        label.float.align.horizontal <- ifelse(fill.direction == "fromright", "right", "left")
        i.pos <- i.pos + 0.5
        j.pos <- j.pos
        #fstr.width <- font.whratio * (label.float.font.size * nchar(label.float.text))
        #f.mspace <- max(f.mspace, fstr.width[ind.outside])

        #if (length(ind.outside) > 0)
        #    cat("f.mspace increased to", f.mspace, "to fit labels of length", fstr.width[ind.outside], "\n")

        label.float.position <- sprintf("%.2f:%.2f", i.pos, j.pos)
        label.float.str <- sprintf("\"floatingLabels\":[{\"position\":\"%s\", \"text\":\"%s\",
                            \"font-size\":\"%fpx\",\"font-weight\":\"%s\", \"%s\": \"4em\",
                            \"font-family\":\"%s\", \"font-color\":\"%s\",
                            \"horizontal-align\":\"%s\", \"vertical-align\":\"center\"}],",
                            label.float.position, label.float.text,
                            label.float.font.size, label.float.font.weight, pad.dir,
                            label.float.font.family, label.float.font.color, label.float.align.horizontal)
    }

    # Calculate size of table cells
    # The units should roughly be equal to 1 px = 1/72 inch
    # Note that icons will resize automatically to fill table cell
    # But label font sizes are in fixed px
    if (is.null(label.left))
        label.left.font.size <- 0
    if (is.null(sublabel.left))
        sublabel.left.font.size <- 0
    if (is.null(label.right))
        label.right.font.size <- 0
    if (is.null(sublabel.right))
        sublabel.right.font.size <- 0
    if (is.null(label.top))
        label.top.font.size <- 0
    if (is.null(label.bottom))
        label.bottom.font.size <- 0
    if (!show.label.data || !(label.data.position %in% c("header","footer")))
        label.data.font.size <- 0

    max.font.size <- max(label.left.font.size + sublabel.left.font.size,
                         label.right.font.size + sublabel.right.font.size, 1)
    size.warning <- 0   # tracker so we only give one size warning


    if(is.na(label.top.height))
        label.top.height <- label.top.font.size*1.0
    if(is.na(label.bottom.height))
        label.bottom.height <- label.bottom.font.size*1.0

    if (any(is.na(row.height)))
        row.height <- paste0("\"proportion:", floor(icon.nrow/tot.icon.nrow*1000)/1000, "\"")
    if (any(is.na(column.width)))
        column.width <- rep("\"flexible:graphic\"", m)

    # Calculating padding/alignment
    pad.left <- matrix(0, n, m)
    pad.right <- matrix(0, n, m)
    pad.top <- matrix(0, n, m)
    pad.bottom <- matrix(0, n, m)
    #pad.right[,m] <- f.mspace

    # Compensating for rowGutters/pad.row
    # This additional padding is required to ensure that all rowheights are the same and
    # rowlabels on the top and bottom of the table remain vertically centered
    # It also ensures that lines are visible at the top and bottom of the table
    lab.tpad <- rep(0, n)
    lab.bpad <- rep(0, n)
    if (length(label.top) == 0 || all(nchar(label.top) == 0))
    {
        pad.top[1,] <- pad.top[1,] + pad.row/2
        lab.tpad[1] <- lab.tpad[1] + pad.row/2
    }
    if (length(label.bottom)  ==  0 || all(nchar(label.bottom) == 0))
    {
        pad.bottom[n,] <- pad.bottom[n,] + pad.row/2
        lab.bpad[n] <- lab.bpad[n] + pad.row/2
    }

    # Preparing labels
    # Dimensions of all table components are expected to be fixed by now
    if (length(label.top) > 0)
        label.top.str <- sprintf("{\"type\":\"label\", \"value\":{\"text\":\"%s\",
                         \"font-family\":\"%s\",\"font-size\":\"%fpx\",\"font-weight\":\"%s\",
                         \"font-color\":\"%s\", \"horizontal-align\":\"%s\", \"vertical-align\":\"%s\"}}",
                         label.top, label.top.font.family, label.top.font.size, label.top.font.weight,
                         label.top.font.color, label.top.align.horizontal, label.top.align.vertical)
    if (length(label.bottom) > 0)
        label.bottom.str <- sprintf("{\"type\":\"label\", \"value\":{\"text\":\"%s\",
                         \"font-family\":\"%s\",\"font-size\":\"%fpx\",\"font-weight\":\"%s\",
                         \"font-color\":\"%s\",\"horizontal-align\":\"%s\", \"vertical-align\":\"%s\"}}",
                         label.bottom, label.bottom.font.family, label.bottom.font.size, label.bottom.font.weight,
                         label.bottom.font.color, label.bottom.align.horizontal, label.bottom.align.vertical)
    if (length(label.left) > 0 || length(sublabel.left) > 0)
    {
        text.str <- ""
        config1.str  <- sprintf("\"font-size\": \"%fpx\", \"font-weight\":\"%s\", \"horizontal-align\":\"%s\"",
                               label.left.font.size, label.left.font.weight, label.left.align.horizontal)
        config2.str  <- sprintf("\"font-size\": \"%fpx\", \"font-weight\":\"%s\", \"horizontal-align\":\"%s\"",
                               sublabel.left.font.size, sublabel.left.font.weight, sublabel.left.align.horizontal)
        config12.str <- sprintf("\"font-family\":\"%s\",\"font-color\":\"%s\"",
                              label.left.font.family, label.left.font.color)

        if (length(label.left) > 0 && length(sublabel.left) == 0)
            text.str <- paste("\"text\":\"", label.left, "\",", config1.str, ",", config12.str, sep="")
        if (length(label.left) == 0 && length(sublabel.left) > 0)
            text.str <- paste("\"text\":\"", sublabel.left, "\",", config2.str,  ",", config12.str, sep="")
        if (length(label.left) > 0 && length(sublabel.left) > 0)
            text.str <- sprintf("\"labels\": [{\"text\":\"%s\", %s, %s},{\"text\": \"%s\", %s, %s}]",
                                label.left, config1.str, config12.str, sublabel.left, config2.str, config12.str)

        label.left.str <- sprintf("{\"type\":\"label\", \"value\":{\"padding-right\":%f,
                                    \"padding-top\":%f, \"padding-bottom\":%f, \"vertical-align\":\"%s\", %s}}",
                         label.left.pad, lab.tpad, lab.bpad, label.left.align.vertical, text.str)
    }
    if (length(label.right) > 0 || length(sublabel.right) > 0)
    {
        text.str <- ""
        config1.str  <- sprintf("\"font-size\": \"%fpx\", \"font-weight\":\"%s\", \"horizontal-align\":\"%s\"",
                               label.right.font.size, label.right.font.weight, label.right.align.horizontal)
        config2.str  <- sprintf("\"font-size\": \"%fpx\", \"font-weight\":\"%s\", \"horizontal-align\":\"%s\"",
                               sublabel.right.font.size, sublabel.right.font.weight, sublabel.right.align.horizontal)
        config12.str <- sprintf("\"font-family\":\"%s\",\"font-color\":\"%s\"",
                              label.right.font.family, label.right.font.color)

        if (length(label.right) > 0 && length(sublabel.right) == 0)
            text.str <- paste("\"text\":\"", label.right, "\",", config1.str, ",", config12.str, sep="")
        if (length(label.right) == 0 && length(sublabel.right) > 0)
            text.str <- paste("\"text\":\"", sublabel.right, "\",", config2.str,  ",", config12.str, sep="")
        if (length(label.right) > 0 && length(sublabel.right) > 0)
            text.str <- sprintf("\"labels\": [{\"text\":\"%s\", %s, %s},{\"text\": \"%s\", %s, %s}]",
                                label.right, config1.str, config12.str, sublabel.right, config2.str, config12.str)

        label.right.str <- sprintf("{\"type\":\"label\", \"value\":{\"padding-left\":%f,
                                     \"padding-top\":%f, \"padding-bottom\":%f, \"vertical-align\":\"%s\", %s}}",
                         label.right.pad, lab.tpad, lab.bpad, label.right.align.vertical, text.str)
    }

    # Preparing data labels
    label.data.str <- ""
    if (show.label.data)
        label.data.str <- sprintf("\"text-%s\":{\"text\":\"%s\", \"font-size\":\"%fpx\",\"font-weight\":\"%s\",
                             \"font-family\":\"%s\", \"font-color\":\"%s\", \"horizontal-align\":\"%s\"},",
                            label.data.position, label.data.text,
                            label.data.font.size, label.data.font.weight, label.data.font.family,
                            label.data.font.color, label.data.align.horizontal)

    row.str <- sprintf("{\"type\":\"graphic\", \"value\":{\"proportion\":%f,\"numImages\":%d,
                         \"variableImage\":\"%s:%s%s:%s\", %s %s, %s %s
                        \"columnGutter\":%f, \"rowGutter\":%f, \"padding\":\"%f %f %f %f\"}}",
                        prop, total.icons, image.type, fill.icon.color.str, fill.direction,
                        fill.image, base.image.str, layout.str, label.data.str, label.float.str,
                        pad.icon.col, pad.icon.row, pad.top, pad.right, pad.bottom, pad.left)
    row.str <- matrix(row.str, n, m)

    # Adding left/right labels
    empty.str <- "{\"type\":\"label\", \"value\":{\"text\":\"\"}}"
    corner.tl <- NULL
    corner.tr <- NULL
    corner.bl <- NULL
    corner.br <- NULL

    if (length(label.left) > 0 || length(sublabel.left) > 0)
    {
        row.str <- cbind(label.left.str, row.str)
        corner.tl <- empty.str
        corner.bl <- empty.str
        column.width <- c("\"flexible:label\"", column.width)
    }
    if (length(label.right) > 0 || length(sublabel.right) > 0)
    {
        row.str <- cbind(row.str, label.right.str)
        corner.tr <- empty.str
        corner.br <- empty.str
        column.width <- c(column.width, "\"flexible:label\"")
    }


    # Adding legend
    # Does not work because we need to calculate leg.vpad (based on icon.height)
    # Ask Kyle about aligning within a table cell
    # Or maybe play around with hidden base image + floating labels?
    #leg.rpad <- 0
    #if (nchar(legend.text) == 0)
    #    legend.text <- " "
    #if (show.legend)
    #{
    #    row.str <- cbind(row.str, matrix(empty.str, nrow(row.str), 3))
    #    leg.row <- ceiling(nrow(row.str)/2)
    #    leg.col <- ncol(row.str)
    #    legend.col.str <- ""
    #    if (nchar(legend.icon.color) > 0)
    #        legend.col.str <- paste(legend.icon.color[1], ":", sep="")
    #
    #    leg.vpad <- (row.height[leg.row]-icon.height)/2
    #    row.str[leg.row, leg.col] <-  sprintf("{\"type\":\"label\", \"value\":{\"text\":\"%s\",\"font-family\":\"%s\",
    #                                            \"font-size\":\"%fpx\",\"font-weight\":\"%s\",\"font-color\":\"%s\",
    #                                            \"horizontal-align\":\"left\", \"vertical-align\":\"center\"}}",
    #                                            legend.text, legend.font.family, legend.font.size, legend.font.weight, legend.font.color)
    #    row.str[leg.row, leg.col-1] <- sprintf("{\"type\":\"graphic\", \"value\":{\"proportion\":1,\"numImages\":1,
    #                     \"variableImage\":\"%s:%s:%s%s\", \"padding\":\"%f %f %f %f\"}}",
    #                                           image.type, legend.col.str, fill.direction[1], fill.image[1],
    #                                           leg.vpad, 0, leg.vpad, 0)
    #    column.width <- c(column.width, pad.legend, icon.width, font.whratio*legend.font.size*nchar(legend.text))
    #    leg.rpad <- sum(tail(column.width, 3))
    #}

    # Adding lines to make table
    lines.str <- ""
   # legendgap.str <- ""
    if (show.lines)
    {
       # if (show.legend)
       #     legendgap.str <- paste("\"padding-right\":", 3*pad.col+leg.rpad, ",")
        lines.str <- paste("\"lines\":{\"horizontal\":[", paste((0:n)+any(nchar(label.top)>0), collapse = ","), "],",
                           "\"vertical\":[0,1,2],",
       #                    legendgap.str,
                           "\"style\": \"stroke:", line.color, ";stroke-width:", line.width, "\"}, ", sep = "")
    }


    # Adding top/bottom labels
    if (any(nchar(label.top) > 0))
        row.height <- c(label.top.height, row.height)
    if (any(nchar(label.bottom) > 0))
        row.height <- c(row.height, label.bottom.height)
    row.str <- apply(row.str, 1, paste, collapse = ",")

    # Exact dimensions should not matter as long as aspect ratio is correct
    dim.str <- ""
    if (!is.na(graphic.width.inch) && !is.na(graphic.height.inch))
        dim.str <- paste0("\"width\":", graphic.width.inch * graphic.resolution,
                          ", \"height\":", graphic.height.inch * graphic.resolution, ",")
    json.str <- paste("{", dim.str,
             "\"background-color\":\"", background.color, "\",",
             "\"table\":{\"rowHeights\":[", paste(row.height, collapse = ","), "],",
             "\"rowGutterLength\":", pad.row, ",\"columnGutterLength\":", pad.col, ",",
             "\"colWidths\":[", paste(column.width, collapse = ","), "],",
             sep = "")
    json.str <- paste(json.str, lines.str, "\"rows\":[[", sep = "")
    if (any(nchar(label.top) > 0))
        json.str <- paste(json.str, paste(c(corner.tl, label.top.str, corner.tr), collapse = ","), "],[", sep = "")
    json.str <- paste(json.str, paste(row.str, collapse = "],["), sep = "")
    if (any(nchar(label.bottom) > 0))
        json.str <- paste(json.str, "],[", paste(c(corner.bl, label.bottom.str, corner.br), collapse = ","), sep = "")
    json.str <- paste(json.str, "]]}}", sep = "")

    if (print.config)
        cat(json.str, "\n")
    return(json.str)
}