inst/doc/Grid-based_flowcharts.R

In Gmisc: Descriptive Statistics, Transition Plots, and More

## ----setup, include = FALSE---------------------------------------------------
knitr::opts_chunk$set(echo = TRUE)

library(Gmisc, quietly = TRUE)
library(glue)
library(htmlTable)
library(grid)

## ----flowchart-example, fig.height = 7, fig.width = 8-------------------------
grid.newpage()
flowchart(source = glue("Stockholm population",
                        "n = {pop}",
                        pop = txtInt(1632798),
                        .sep = "\n"),
          eligible = glue("Eligible",
                          "n = {pop}",
                          pop = txtInt(10032),
                          .sep = "\n"),
          included = glue("Randomized",
                         "n = {incl}",
                         incl = txtInt(122),
                         .sep = "\n"),
          groups = list(
            glue("Treatment A",
                 "n = {recr}",
                 recr = txtInt(43),
                 .sep = "\n"),
            glue("Treatment B",
                 "n = {recr}",
                 recr = txtInt(122 - 43 - 30),
                 .sep = "\n")
          )) |>
  spread(axis = "y") |>
  spread(subelement = "groups", axis = "x") |>
  insert(list(excluded = boxHeaderGrob(header = glue("Excluded (n = {tot}):", tot = 30),
                          body = glue(" - not interested: {uninterested}",
                                      " - contra-indicated: {contra}",
                                      uninterested = 12,
                                      contra = 30 - 12,
                                      .sep = "\n"),
                          bjust = "left",
                          header_gp = getOption("boxGrobTxt", default = gpar(
                            color = "black",
                            cex = 1
                          )))),
         after = "eligible",
         name = "excluded") |>
  move(name = "excluded", x = .8) |>
  connect("source", "eligible", type = "vert") |>
  connect("eligible", "included", type = "vert") |>
  connect("included", "groups", type = "N") |>
  connect("eligible", "excluded", type = "L", label = "Excluded")

## ----basic_box, fig.height = 1.5, fig.width = 3, message = FALSE--------------
grid.newpage()
txt <-
"Just a plain box
with some text
- Note that newline is OK"
boxGrob(txt)

## ----styled_box, fig.height = 3, fig.width = 3--------------------------------
grid.newpage()
boxGrob("A large\noffset\nyellow\nbox",
        width = .8, height = .8,
        x = 0, y = 0,
        bjust = c("left", "bottom"),
        txt_gp = gpar(col = "darkblue", cex = 2),
        box_gp = gpar(fill = "lightyellow", col = "darkblue"))

## ----prop_box, fig.height = 2, fig.width = 4----------------------------------
grid.newpage()
boxPropGrob("A box with proportions",
            "Left side", "Right side",
            prop = .7)

## ----fig.height = 3, fig.width = 4--------------------------------------------
grid.newpage()
smpl_bx <- boxGrob(
  label = "A simple box",
  x = .5,
  y = .9,
  just = "center")

prop_bx <- boxPropGrob(
  label = "A split box",
  label_left = "Left side",
  label_right = "Right side",
  x = .5,
  y = .3,
  prop = .3,
  just = "center")

plot(smpl_bx)
plot(prop_bx)

smpl_bx_coords <- coords(smpl_bx)
grid.circle(y = smpl_bx_coords$y,
            x = smpl_bx_coords$x,
            r = unit(2, "mm"),
            gp = gpar(fill = "#FFFFFF99", col = "black"))
grid.circle(y = smpl_bx_coords$bottom,
            x = smpl_bx_coords$right,
            r = unit(1, "mm"),
            gp = gpar(fill = "red"))
grid.circle(y = smpl_bx_coords$top,
            x = smpl_bx_coords$right,
            r = unit(1, "mm"),
            gp = gpar(fill = "purple"))
grid.circle(y = smpl_bx_coords$bottom,
            x = smpl_bx_coords$left,
            r = unit(1, "mm"),
            gp = gpar(fill = "blue"))
grid.circle(y = smpl_bx_coords$top,
            x = smpl_bx_coords$left,
            r = unit(1, "mm"),
            gp = gpar(fill = "orange"))

prop_bx_coords <- coords(prop_bx)
grid.circle(y = prop_bx_coords$y,
            x = prop_bx_coords$x,
            r = unit(2, "mm"),
            gp = gpar(fill = "#FFFFFF99", col = "black"))
grid.circle(y = prop_bx_coords$bottom,
            x = prop_bx_coords$right_x,
            r = unit(1, "mm"),
            gp = gpar(fill = "red"))
grid.circle(y = prop_bx_coords$top,
            x = prop_bx_coords$right_x,
            r = unit(1, "mm"),
            gp = gpar(fill = "purple"))
grid.circle(y = prop_bx_coords$bottom,
            x = prop_bx_coords$left_x,
            r = unit(1, "mm"),
            gp = gpar(fill = "blue"))
grid.circle(y = prop_bx_coords$top,
            x = prop_bx_coords$left_x,
            r = unit(1, "mm"),
            gp = gpar(fill = "orange"))

grid.circle(y = prop_bx_coords$bottom,
            x = prop_bx_coords$right,
            r = unit(2, "mm"),
            gp = gpar(fill = "red"))
grid.circle(y = prop_bx_coords$top,
            x = prop_bx_coords$right,
            r = unit(2, "mm"),
            gp = gpar(fill = "purple"))
grid.circle(y = prop_bx_coords$bottom,
            x = prop_bx_coords$left,
            r = unit(2, "mm"),
            gp = gpar(fill = "blue"))
grid.circle(y = prop_bx_coords$top,
            x = prop_bx_coords$left,
            r = unit(2, "mm"),
            gp = gpar(fill = "orange"))

## ----extra_shapes, fig.height = 3, fig.width = 6------------------------------
# --- Branch labels + sharp diamond variant ---
grid.newpage()

# rounded and sharp diamond examples
d_rounded <- boxDiamondGrob("Decision", box_gp = gpar(fill = "#FFF4E6"))
d_sharp   <- boxDiamondGrob("Decision\n(sharp)", rounded = FALSE, box_gp = gpar(fill = "#FFF4E6"))

# outcomes
e <- boxEllipseGrob("Local", box_gp = gpar(fill = "#E6FFF4"))
r <- boxServerGrob("Server", box_gp = gpar(fill = "#E8F0FF"))

# arrange and draw
boxes <- list(decision = d_rounded, outcomes = list(e, r)) |>
  spreadHorizontal(from = unit(.1, "npc"), to = unit(.9, "npc"), subelement = "outcomes") |>
  spreadVertical() |>
  print()

# 1) quick many-to-many style connector (no labels)
con <- connectGrob(boxes$decision, boxes$outcomes, type = "N")
print(con)

# 2) explicit per-branch connectors with labels (preferred when you want text)
connectGrob(boxes$decision, boxes$outcomes[[1]], type = "N", label = "Local") |> print()
connectGrob(boxes$decision, boxes$outcomes[[2]], type = "N", label = "Server") |> print()

# 3) If you prefer the single connector and want labels on each branch:
#    place text at the midpoint of each returned grob (example)
con_list <- connectGrob(boxes$decision, boxes$outcomes, type = "N")
# Preferred: attach labels and let `print()` handle rendering
con_list <- setConnectorLabels(con_list, c("Local", "Server"))
print(con_list)

## ----standard_shapes, fig.height = 3.5, fig.width = 8-------------------------
# Arrange shapes in three rows for better readability
# 1) Grid-based objects (basic boxGrob / boxPropGrob / rect)
row1 <- list(
  boxGrob("Box (default)", box_gp = gpar(fill = "#EFEFEF"), y = unit(.85, "npc")),
  boxPropGrob("Prop", "Left", "Right", prop = .4, box_left_gp = gpar(fill = "#EFEFAF"), box_right_gp = gpar(fill = "#EFAFEF"), y = unit(.85, "npc")),
  boxGrob("Rectangle", box_fn = rectGrob, box_gp = gpar(fill = "#EFEFEF"), y = unit(.85, "npc"))
)

# 2) Gmisc row 1 (rounded/sharp diamond + ellipse + rack + server)
row2 <- list(
  boxDiamondGrob("Diamond\n(rounded)", box_gp = gpar(fill = "#FFF4E6"), y = unit(.55, "npc")),
  boxDiamondGrob("Diamond\n(sharp)", rounded = FALSE, box_gp = gpar(fill = "#FFF4E6"), y = unit(.55, "npc")),
  boxEllipseGrob("Ellipse", box_gp = gpar(fill = "#E6FFF4"), y = unit(.55, "npc")),
  boxRackGrob("Rack", box_gp = gpar(fill = "#E8F0FF"), y = unit(.55, "npc")),
  boxServerGrob("Server", box_gp = gpar(fill = "#E8F0FF"), y = unit(.55, "npc"))
)

# 3) Gmisc row 2 (database, document, documents, tape)
row3 <- list(
  boxDatabaseGrob("Database", box_gp = gpar(fill = "#DFF4E6"), y = unit(.25, "npc")),
  boxDocumentGrob("Document", box_gp = gpar(fill = "#FFF6E6"), y = unit(.25, "npc")),
  boxDocumentsGrob("Documents", box_gp = gpar(fill = "#FFF6E6"), y = unit(.25, "npc")),
  boxTapeGrob("Tape", box_gp = gpar(fill = "#E6F0FF"), y = unit(.25, "npc"))
)

# Spread each row across the horizontal span
spreadHorizontal(row1, from = unit(.05, "npc"), to = unit(.95, "npc"))
spreadHorizontal(row2, from = unit(.05, "npc"), to = unit(.95, "npc"))
spreadHorizontal(row3, from = unit(.05, "npc"), to = unit(.95, "npc"))

## ----"Connected boxes", fig.width = 7, fig.height = 5-------------------------
grid.newpage()
# Initiate the boxes that we want to connect
side <- boxPropGrob("Side", "Left", "Right",
                    prop = .3,
                    x = 0, y = .9,
                    bjust = c(0,1))
start <- boxGrob("Top",
                 x = .6, y = coords(side)$y,
                 box_gp = gpar(fill = "yellow"))
bottom <- boxGrob("Bottom",
                  x = .6, y = 0,
                  bjust = "bottom")


sub_side_left <- boxGrob("Left",
                         x = coords(side)$left_x,
                         y = 0,
                         bjust = "bottom")
sub_side_right <- boxGrob("Right",
                          x = coords(side)$right_x,
                          y = 0,
                          bjust = "bottom")

odd <- boxGrob("Odd\nbox",
               x = coords(side)$right,
               y = .5)

odd2 <- boxGrob("Also odd",
               x = coords(odd)$right +
                 distance(bottom, odd, type = "h", half = TRUE) -
                 unit(2, "mm"),
               y = 0,
               bjust = c(1,0))

exclude <- boxGrob("Exclude:\n - Too sick\n - Prev. surgery",
                   x = 1,
                   y = coords(bottom)$top +
                     distance(start, bottom, type = "v", half = TRUE),
                   just = "left", bjust = "right")

# Connect the boxes and print/plot them
connectGrob(start, bottom, "vertical")
connectGrob(start, side, "horizontal")
connectGrob(bottom, odd, "Z", "l")
connectGrob(odd, odd2, "N", "l")
connectGrob(side, sub_side_left, "v", "l")
connectGrob(side, sub_side_right, "v", "r")
connectGrob(start, exclude, "-",
            lty_gp = gpar(lwd = 2, col = "darkred", fill = "darkred"))

# Print the grobs
start
bottom
side
exclude
sub_side_left
sub_side_right
odd
odd2

## ----connect_multi, fig.width = 4, fig.height = 4-----------------------------
grid.newpage()

# Three upstream boxes + one side box
a_boxes <- paste("A", 1:3) |>
  lapply(\(x) boxGrob(x, box_gp = gpar(fill = "#E6F2FF"))) |>
  spreadHorizontal(from = unit(.1, "npc"), to = unit(1, "npc") - unit(1, "cm")) |>
  alignVertical(position="top",
                reference = unit(1, "npc")) |>
  print()

b_side <- boxGrob("B",  y = .70, box_gp = gpar(fill = "#FFF3BF")) |>
  moveBox(x = unit(1, "npc"),
          just = 1) |>
  print()

# Target box
c <- boxGrob("C", x = .50, box_gp = gpar(fill = "#D3F9D8"), width = unit(4, "cm")) |>
  moveBox(y = unit(0, "npc"),
          just = "bottom") |>
  print()


# Many -> one: merge on top with evenly distributed attachment points + margin
connectGrob(c(a_boxes, list(b_side)), c,
            type = "fan_in_top",
            margin = 4)

## ----horizontal_alignment, fig.width=10, fig.height=6-------------------------
align_1 <- boxGrob("Align 1",
                   y = .9,
                   x = 0,
                   bjust = c(0),
                   box_gp = gpar(fill = "#E6E8EF"))

align_2 <- boxPropGrob("Align 2",
                       "Placebo",
                       "Treatment",
                       prop = .7,
                       y = .8,
                       x = .5)

align_3 <- boxGrob("Align 3\nvertical\ntext",
                   y = 1,
                   x = 1,
                   bjust = c(1, 1),
                   box_gp = gpar(fill = "#E6E8EF"))

b1 <- boxGrob("B1",
              y = .3,
              x = .1,
              bjust = c(0))
b2 <- boxGrob("B2 with long\ndescription",
              y = .6,
              x = .5)
b3 <- boxGrob("B3",
              y = .2,
              x = .8,
              bjust = c(0, 1))

grid.newpage()
align_1
alignHorizontal(reference = align_1,
                b1, b2, b3,
                position = "left")

align_2
alignHorizontal(reference = align_2,
                b1, b2, b3,
                position = "center",
                sub_position = "left")
alignHorizontal(reference = align_2,
                b1, b2, b3,
                position = "left",
                sub_position = "right")

align_3
alignHorizontal(reference = align_3,
                b1, b2, b3,
                position = "right")

## ----vertical_alignment, fig.width=10, fig.height=6---------------------------
align_1 <- boxGrob("Align 1\nvertical\ntext",
                   y = 1,
                   x = 1,
                   bjust = c(1, 1),
                   box_gp = gpar(fill = "#E6E8EF"))

align_2 <- boxPropGrob("Align 2",
                       "Placebo",
                       "Treatment",
                       prop = .7,
                       y = .5,
                       x = .6)

align_3 <- boxGrob("Align 3",
                   y = 0,
                   x = 0,
                   bjust = c(0, 0),
                   box_gp = gpar(fill = "#E6E8EF"))


b1 <- boxGrob("B1",
              y = .3,
              x = 0.1,
              bjust = c(0, 0))
b2 <- boxGrob("B2 with long\ndescription",
              y = .6,
              x = .3)
b3 <- boxGrob("B3",
              y = .2,
              x = .85,
              bjust = c(0, 1))

grid.newpage()
align_1
alignVertical(reference = align_1,
              b1, b2, b3,
              position = "top")

align_2
alignVertical(reference = align_2,
              b1, b2, b3,
              position = "center")

align_3
alignVertical(reference = align_3,
              b1, b2, b3,
              position = "bottom")

## ----horizontal_spread, fig.width = 11, fig.height = 8------------------------
b1 <- boxGrob("B1", y = .85, x = .1, bjust = c(0, 0))
b2 <- boxGrob("B2", y = .65, x = .6)
b3 <- boxGrob("B3", y = .45, x = .6)
b4 <- boxGrob("B4 with long\ndescription", y = .7, x = .8)

from <- boxGrob("from",
                y = .25,
                x = .05,
                box_gp = gpar(fill = "darkgreen"),
                txt_gp = gpar(col = "white"))
to <- boxGrob("to this wide box",
              y = coords(from)$y,
              x = .95,
              bjust = "right",
              box_gp = gpar(fill = "darkred"),
              txt_gp = gpar(col = "white"))
txtOut <- function(txt, y_top) {
  grid.text(txt,
            x = unit(2, "mm"),
            y = y_top + unit(2, "mm"),
            just = c("left", "bottom"))
  grid.lines(y = y_top + unit(1, "mm"),
             gp = gpar(col = "grey"))
}

drawRow <- function(label, row_y, spread_args = list()) {
  row <- alignVertical(reference = row_y, b1, b2, b3, b4, position = "top")
  txtOut(label, coords(row[[1]])$top)
  do.call(spreadHorizontal, c(list(row), spread_args))
}

rowYs <- unit(c(.93, .76, .59, .42, .25, .12), "npc")

grid.newpage()

drawRow("Basic (viewport)", rowYs[1])
drawRow("From–to + margin (numeric = npc)", rowYs[2],
        spread_args = list(from = .2, to = .7, margin = .05))
drawRow("Only to (defaults from = 0)", rowYs[3],
        spread_args = list(to = .7))
drawRow("Only from (defaults to = 1)", rowYs[4],
        spread_args = list(from = .2))

# Row 5: Between boxes (box-to-box span)
row5_y <- rowYs[5]
row5 <- alignVertical(reference = row5_y, b1, b2, b3, b4, position = "top")
txtOut("Between boxes", coords(row5[[1]])$top)

span <- alignVertical(reference = row5_y, from  = from, to = to, position = "top")
span
spreadHorizontal(row5, .from = span$from, .to = span$to)

# Row 6: Reverse box order + center distribution
row6_y <- unit(.10, "npc")

bottom_from <- moveBox(from, x = coords(to)$right, y = 0, just = c(1, 0))
bottom_to <- moveBox(to, x = coords(from)$left, y = 0, just = c(0, 0))
bottom_from
bottom_to

row6 <- alignVertical(reference = bottom_from, b1, b2, b3, b4, position = "bottom")
txtOut("Reverse box order + center", coords(row6[[4]])$top)

spreadHorizontal(row6,
                 from = bottom_from,
                 to = bottom_to,
                 type = "center")



## ----vertical_spread, fig.width=6, fig.height=6-------------------------------
b1 <- boxGrob("B1",
              y = .8,
              x = 0.1,
              bjust = c(0, 0))
b2 <- boxGrob("B2 with long\ndescription",
              y = .5,
              x = .5)
b3 <- boxGrob("B3",
              y = .2,
              x = .8)
b4 <- boxGrob("B4",
              y = .7,
              x = .8)


txtOut <- function(txt, refBx) {
  grid.text(txt,
            x = coords(refBx)$left - unit(2, "mm"),
            y = .5,
            just = c("center", "bottom"),
            rot = 90)
  grid.lines(x = coords(refBx)$left - unit(1, "mm"),
             gp = gpar(col = "grey"))
}

grid.newpage()
txtOut("Basic", b1)
alignHorizontal(reference = b1,
                b1, b2, b3, b4,
                position = "left") |>
  spreadVertical()

txtOut("From-to", b2)
alignHorizontal(reference = b2,
                b1, b2, b3, b4,
                position = "left") |>
  spreadVertical(from = .2,
                 to = .7)

txtOut("From-to with center and reverse the box order", b3)
alignHorizontal(reference = b3,
                b1, b2, b3, b4,
                position = "left") |>
  spreadVertical(from = .7,
                 to = .2,
                 type = "center")

## ----complex_nested, fig.width = 7, fig.height = 8----------------------------
# Helper function to convert nested structure to grobs
make_boxes <- function(x) {
  if (is.list(x) && !inherits(x, "box_header")) {
    return(lapply(x, make_boxes))
  }

  if (inherits(x, "box_header")) {
    return(do.call(boxHeaderGrob, x))
  }

  # Simple text box fallback
  args <- attr(x, "args")
  if (is.null(args)) return(boxGrob(label = x))

  args$label <- x
  do.call(boxGrob, args)
}

# Define styling for different elements
arm_a_style <- list(
  header = gpar(fill = "#E8F5E9", col = "#2E7D32", lwd = 1.4),
  box = gpar(fill = "#F1F8E9", col = "#43A047")
)

arm_b_style <- list(
  header = gpar(fill = "#FFF8E1", col = "#EF6C00", lwd = 1.4),
  box = gpar(fill = "#FFFDE7", col = "#F9A825")
)

# Build flowchart structure
flowchart <- list(
  # Shared inclusion criteria
  criteria = structure(
    list(
      header = "Inclusion Criteria",
      body = paste(
        "• Adults aged 18-65",
        "• Confirmed diagnosis",
        "• Written informed consent",
        "• No contraindications",
        "• Available for 6-month follow-up",
        sep = "\n"
      ),
      box_gp = gpar(fill = "#E3F2FD", col = "#1E88E5", lwd = 1.4),
      body_gp = gpar(fontsize = 10)
    ),
    class = "box_header"
  ),

  # Two treatment arms
  arms = list(
    arm_a = list(
      # Arm header
      structure("Intensive Protocol", args = list(
        box_gp = arm_a_style$header,
        txt_gp = gpar(fontsize = 11, fontface = "bold")
      )),

      # Timeline boxes
      structure(list(
        header = "Week 0-1",
        body = "• Daily sessions\n• Supervised therapy\n",
        box_gp = arm_a_style$box,
        body_gp = gpar(fontsize = 9.5)
      ), class = "box_header"),

      structure(list(
        header = "Week 2-4",
        body = "• 3× weekly sessions\n• Progressive loading",
        box_gp = arm_a_style$box,
        body_gp = gpar(fontsize = 9.5)
      ), class = "box_header"),

      structure(list(
        header = "Week 5-8",
        body = "• Home program\n• Monthly check-ins\n• Return to activity",
        box_gp = arm_a_style$box,
        body_gp = gpar(fontsize = 9.5)
      ), class = "box_header")
    ),

    arm_b = list(
      # Arm header
      structure("Standard Care", args = list(
        box_gp = arm_b_style$header,
        txt_gp = gpar(fontsize = 11, fontface = "bold")
      )),

      # Timeline boxes - different schedule
      structure(list(
        header = "Month 0",
        body = "• Initial consultation\n• Exercise booklet",
        box_gp = arm_b_style$box,
        body_gp = gpar(fontsize = 9.5)
      ), class = "box_header"),

      structure(list(
        header = "Month 3",
        body = "• Follow-up visit\n• Progress review",
        box_gp = arm_b_style$box,
        body_gp = gpar(fontsize = 9.5)
      ), class = "box_header"),

      structure(list(
        header = "Month 6",
        body = "• Final assessment\n• Discharge planning",
        box_gp = arm_b_style$box,
        body_gp = gpar(fontsize = 9.5)
      ), class = "box_header")
    )
  )
)

# Convert to grobs and layout
grid.newpage()
boxes <- flowchart |>
  make_boxes() |>
  spreadVertical() |>
  spreadHorizontal(subelement = "arms", from = 0.15, to = 0.85) |>
  spreadVertical(subelement = c("arms", "arm_a"), from = 0.65) |>
  spreadVertical(subelement = c("arms", "arm_b"), from = 0.65) |>
  print()

# Connect criteria to both arms
connectGrob(boxes$criteria, boxes$arms, type = "N")

# Connect timeline within each arm
for (arm_name in names(boxes$arms)) {
  arm_boxes <- boxes$arms[[arm_name]]
  for (i in 2:length(arm_boxes)) {
    connectGrob(arm_boxes[[i-1]], arm_boxes[[i]], type = "v") |> print()
  }
}

## ----s3_api_example, fig.height=8, fig.width=6, eval=FALSE--------------------
#  grid.newpage()
#  
#  # Define the nodes
#  b1 <- boxGrob("Start", y = 0.8)
#  b2 <- boxGrob("Process", y = 0.5)
#  b3 <- boxGrob("End", y = 0.2)
#  
#  # Pipeline: list -> align -> connect -> print
#  list(start = b1, process = b2, end = b3) |>
#    align(axis = "y") |>
#    spread(axis = "x") |>
#    connect("start", "process", type = "horizontal") |>
#    connect("process", "end", type = "horizontal") |>
#    print()

## ----math_expressions, fig.width=6, fig.height=3------------------------------
grid.newpage()
###############
# Expressions #
###############
# Font style
list(expression(bold("Bold text")),
     expression(italic("Italics text")),
     expression(paste("Mixed: ", italic("Italics"), " and ", bold("bold")))) |>
  lapply(boxGrob) |>
  alignVertical(reference = unit(1, "npc"),
                position = "top") |>
  spreadHorizontal()

# Math
list(expression(paste("y = ", beta[0], " + ", beta[1], X[1], " + ", beta[2], X[2]^2)),
     expression(paste(hat(mu) == sum(frac(x[i], n), i == 1, n))),
     expression(paste(int(a, b, f(x) * dx) == F(b) - F(a)))) |>
  lapply(boxGrob) |>
  alignVertical(reference = unit(0.5, "npc"),
                position = "center") |>
  spreadHorizontal()

##########
# Quotes #
##########
a = 5
list(bquote(alpha == theta[1] * .(a) + ldots),
     paste("argument", sQuote("x"), "\nmust be non-zero")) |>
  lapply(boxGrob) |>
  alignVertical(reference = unit(0, "npc"),
                position = "bottom") |>
  spreadHorizontal(from = .2, to = .8)

## ----basic_plot, fig.height = 2, fig.width = 2--------------------------------
# Load the grid library
# part of standard R libraries so no need installing
library(grid)

# Create a new graph
grid.newpage()

pushViewport(viewport(width = .5, height = .8))

grid.rect(gp = gpar(fill = "#D8F0D1"))

popViewport()

## ----relative_lines, fig.height = 3, fig.width = 3----------------------------
grid.newpage()
pushViewport(viewport(width = .5, height = .8, clip = "on"))
grid.rect(gp = gpar(lty = 2, fill = "lightyellow"))
lg <- linesGrob(x = unit(c(.2, 1), "npc"),
                y = unit(c(.2, 1), "npc"),
                gp = gpar(lwd = 2))
grid.draw(lg)
pushViewport(viewport(x = 0, y = .6, just = "left", width = .4, height = .4, angle = 20))
grid.rect(gp = gpar(fill = "lightblue")) # A translucent box to indicate the new viewport
grid.draw(lg)
popViewport()

## ----absolute_lines, fig.height = 3, fig.width = 3----------------------------
grid.newpage()
pushViewport(viewport(width = .5, height = .8, clip = "on"))
grid.rect(gp = gpar(lty = 2, fill = "lightyellow"))
lg <- linesGrob(x = unit(c(2, 10), "mm"),
                y = unit(c(2, 10), "mm"),
                gp = gpar(lwd = 2))
grid.draw(lg)
pushViewport(viewport(x = 0, y = .6, just = "left", width = .4, height = .4, angle = 20))
grid.rect(gp = gpar(fill = "lightblue")) # A translucent box to indicate the new viewport
grid.draw(lg)
popViewport()

## ----complex_example, fig.height = 9, fig.width = 9---------------------------
# Define the boxes
org_cohort <- glue("Proximal humerus fracture",
                   "  - \u2265 18 years",
                   "  - \u2264 4 weeks of trauma",
                   "  - Not pathological",
                   .sep = "\n") |>
  boxGrob(just = "left",
          box_gp = gpar(fill = "#E3F2FD"))

surgery <- glue("Surgery",
                "  - Direct (\u2248 4%)",
                "  - Delayed (\u2248 4%)",
                .sep = "\n") |>
  boxGrob(just = "left",
          box_gp = gpar(fill = "#F8BBD0"))

randomize <- boxGrob("Non-surgical\nRandomise",
                     box_gp = gpar(fill = "#FFF3E0"))

treatments <- list(early = boxGrob("Early rehab",
                                   box_gp = gpar(fill = "#DCEDC8")),
                   late = boxGrob("Late rehab",
                                  box_gp = gpar(fill = "#DCEDC8")),
                   obs = boxGrob("Observation",
                                 box_gp = gpar(fill = "#E0E0E0")))

early_followup <- glue("Early follow-up",
                       "  - 2 weeks [PNRS]",
                       "  - 4 weeks [PNRS]",
                       .sep = "\n") |>
  boxGrob(just = "left",
          box_gp = gpar(fill = "#E0F7FA"))

late_followup <- glue("Late follow-up",
                      "  - 2-10 months (random) [OSS, PNRS]",
                      "  - 1 year [OSS, PNRS, accelerometer]",
                      "  - 2 years [OSS, PNRS]",
                      "  - 5 years [OSS, PNRS]",
                      .sep = "\n") |>
  boxGrob(just = "left",
                       box_gp = gpar(fill = "#E0F7FA"))

# Create the flowchart
grid.newpage()
flowchart(start = org_cohort,
          step_1 = list(surgery = surgery,
                        `non-surgical` = randomize),
          treatment = treatments,
          early_followup = early_followup,
          followup = late_followup) |>
  spread(axis = "y") |>
  spread(axis = "x", subelement = "step_1") |>
  spread(axis = "x", subelement = "treatment", from = 0.35) |>
  align(axis = "x",
        reference = c("treatment", "late"),
        subelement = c("step_1", "non-surgical")) |>
  connect(from = "start", to = "step_1", type = "N") |>
  connect(from = "step_1$non-surgical", to = "treatment", type = "N") |>
  connect(from = "treatment", to = "early_followup", type = "fan_in_center") |>
  connect(from = "early_followup", to = "followup", type = "v") |>
  connect(from = "early_followup", to = "step_1$surgery", type = "Z",
          label = "Crossover\nto surgery") |>
  connect(from = "step_1$surgery", to = "followup", type = "L") |>
  print()