Karl:

### R code from vignette source 'grobs.Rnw'

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### code chunk number 1: grobs.Rnw:30-34
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library(grDevices)
library(grid)
ps.options(pointsize = 12)
options(width = 60)


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### code chunk number 2: grobs.Rnw:48-50
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gl <- linesGrob()
gl <- editGrob(gl, gp = gpar(col = "green"))


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### code chunk number 3: grobs.Rnw:64-68
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grid.newpage()
grid.lines(name = "lines")
grid.edit(gPath("lines"), gp = gpar(col = "pink"))
grid.edit("lines", gp = gpar(col = "red"))


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### code chunk number 4: grobs.Rnw:84-91
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grid.newpage()
pushViewport(viewport(w = .5, h = .5))
grid.rect(gp = gpar(col = "grey"))
grid.xaxis(name = "myxaxis")
grid.edit("myxaxis", at = 1:4/5)
grid.edit(gPath("myxaxis", "labels"), y = unit(-1, "lines"))



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### code chunk number 5: grobs.Rnw:103-113
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grid.newpage()
pushViewport(viewport(w = .5, h = .5))
myplot <-
    gTree(name = "myplot",
          children = gList(rectGrob(name = "box", gp = gpar(col = "grey")),
                           xaxisGrob(name = "xaxis")))
grid.draw(myplot)
grid.edit("myplot::xaxis", at = 1:10/11)
grid.edit("myplot::xaxis::labels", label = round(1:10/11, 2))
grid.edit("myplot::xaxis::labels", y = unit(-1, "lines"))


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### code chunk number 6: grobs.Rnw:121-124
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grid.newpage()
gt <- grid.text("Hi there")
grid.rect(width = unit(1, "grobwidth", gt))


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### code chunk number 7: grobs.Rnw:133-137
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grid.newpage()
gt <- grid.text("Hi there", name = "sometext")
grid.rect(width = unit(1, "grobwidth", "sometext"))
grid.edit("sometext", label = "Something different")


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### code chunk number 8: grobs.Rnw:162-176
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grid.newpage()
mygrob <- grob(name = "mygrob", cl = "mygrob")
preDrawDetails.mygrob <- function(x)
    pushViewport(viewport(gp = gpar(fontsize = 20)))

drawDetails.mygrob <- function(x, recording = TRUE)
    grid.draw(textGrob("hi there"), recording = FALSE)

postDrawDetails.mygrob <- function(x) popViewport()

widthDetails.mygrob <- function(x) unit(1, "strwidth", "hi there")

grid.draw(mygrob)
grid.rect(width = unit(1, "grobwidth", mygrob))


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### code chunk number 9: grobs.Rnw:194-206
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grid.newpage()
mygtree <- gTree(name = "mygrob",
                 childrenvp = viewport(name = "labelvp",
                                       gp = gpar(fontsize = 20)),
                 children = gList(textGrob("hi there", name = "label",
                   vp = "labelvp")),
                 cl = "mygtree")
widthDetails.mygtree <- function(x)
    unit(1, "grobwidth", getGrob(x, "label"))

grid.draw(mygtree)
grid.rect(width = unit(1, "grobwidth", mygtree))


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### code chunk number 10: grobs.Rnw:214-219
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grid.newpage()
fg <- frameGrob(layout = grid.layout(1, 2))
fg <- placeGrob(fg, textGrob("Hi there"), col = 1)
fg <- placeGrob(fg, rectGrob(), col = 2)
grid.draw(fg)


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### code chunk number 11: grobs.Rnw:224-240
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grid.newpage()
pushViewport(viewport(layout = grid.layout(2, 2)))
drawIt <- function(row, col) {
    pushViewport(viewport(layout.pos.col = col, layout.pos.row = row))
    grid.rect(gp = gpar(col = "grey"))
    grid.draw(fg)
    upViewport()
}
fg <- frameGrob()
fg <- packGrob(fg, textGrob("Hi there"))
fg <- placeGrob(fg, rectGrob())
drawIt(1, 1)
fg <- packGrob(fg, textGrob("Hello again"), side = "right")
drawIt(1, 2)
fg <- packGrob(fg, rectGrob(), side = "right", width = unit(1, "null"))
drawIt(2, 2)


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### code chunk number 12: grobs.Rnw:252-261
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grid.newpage()
fg <- frameGrob()
fg <- packGrob(fg, textGrob("Hi there"))
fg <- placeGrob(fg, rectGrob())
fg <- packGrob(fg, textGrob("Hello again", name = "midtext"),
               side = "right", dynamic = TRUE)
fg <- packGrob(fg, rectGrob(), side = "right", width = unit(1, "null"))
grid.draw(fg)
grid.edit("midtext", label = "something much longer")


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### code chunk number 13: grobs.Rnw:285-309
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grid.newpage()
pushViewport(viewport(layout = grid.layout(2, 2)))
drawIt <- function(row, col) {
    pushViewport(viewport(layout.pos.col = col, layout.pos.row = row))
    grid.rect(gp = gpar(col = "grey"))
    grid.draw(gplot)
    upViewport()
}
gplot <- gTree(x = NULL, y = NULL,
               childrenvp = vpTree(
                 plotViewport(c(5, 4, 4, 2), name = "plotRegion"),
                 vpList(viewport(name = "dataRegion"))),
               children = gList(
                 xaxisGrob(vp = "plotRegion::dataRegion"),
                 yaxisGrob(vp = "plotRegion::dataRegion"),
                 rectGrob(vp = "plotRegion")))
drawIt(1, 1)
gplot <- addGrob(gplot, pointsGrob(vp = "plotRegion::dataRegion"))
drawIt(1, 2)
gplot <- addGrob(gplot, pointsGrob(name = "data1", pch = 2,
                                   vp = "plotRegion::dataRegion"))
drawIt(2, 1)
gplot <- removeGrob(gplot, "data1")
drawIt(2, 2)


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### code chunk number 14: grobs.Rnw:316-337
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gplot <- gTree(x = NULL, y = NULL,
               childrenvp = vpTree(
                 plotViewport(c(5, 4, 4, 2), name = "plotRegion"),
                   vpList(viewport(name = "dataRegion"))),
               children = gList(
                 xaxisGrob(vp = "plotRegion::dataRegion"),
                 yaxisGrob(vp = "plotRegion::dataRegion"),
                 rectGrob(vp = "plotRegion")))
save(gplot, file = "gplot1")
gplot <- addGrob(gplot, pointsGrob(vp = "plotRegion::dataRegion"))
save(gplot, file = "gplot2")
grid.newpage()
pushViewport(viewport(layout = grid.layout(1, 2)))
pushViewport(viewport(layout.pos.col = 1))
load("gplot1")
grid.draw(gplot)
popViewport()
pushViewport(viewport(layout.pos.col = 2))
load("gplot2")
grid.draw(gplot)
popViewport()


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### code chunk number 15: grobs.Rnw:348-359
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myplot <- gTree(name = "myplot",
                children = gList(
                  rectGrob(name = "box", gp = gpar(col = "grey")),
                  xaxisGrob(name = "xaxis")))
myplot <- editGrob(myplot, gPath = "xaxis", at = 1:10/11)
myplot <- editGrob(myplot, gPath = "xaxis::labels", label = round(1:10/11, 2))
myplot <- editGrob(myplot, gPath = "xaxis::labels", y = unit(-1, "lines"))
grid.newpage()
pushViewport(viewport(w = .5, h = .5))
grid.draw(myplot)



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### code chunk number 16: grobs.Rnw:365-378
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myplot <- gTree(name = "myplot",
                children = gList(
                  rectGrob(name = "box", gp = gpar(col = "grey")),
                  xaxisGrob(name = "xaxis")))
getGrob(myplot, "xaxis")
myplot <- editGrob(myplot, gPath="xaxis", at=1:10/11)
getGrob(myplot, "xaxis::labels")
grid.newpage()
pushViewport(viewport(w=.5, h=.5))
grid.draw(myplot)
grid.get("myplot")
grid.get("myplot::xaxis")
grid.get("myplot::xaxis::labels")


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### code chunk number 17: grobs.Rnw:399-415
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myplot <- gTree(name = "myplot",
                children = gList(rectGrob(name = "box", gp = gpar(col = "grey")),
                  xaxisGrob(name = "xaxis")))
myplot <- setGrob(myplot, "xaxis", rectGrob(name = "xaxis"))
grid.newpage()
pushViewport(viewport(w = .5, h = .5))
grid.draw(myplot)
grid.set("myplot::xaxis", xaxisGrob(name = "xaxis", at = 1:3/4))
grid.set("myplot::xaxis::labels",
         textGrob(name = "labels", x = unit(1:3/4, "native"),
                  y = unit(-1, "lines"), label = letters[1:3]))
myplot <- setGrob(grid.get("myplot"), "xaxis::labels",
                  circleGrob(name = "labels"))
grid.newpage()
pushViewport(viewport(w = .5, h = .5))
grid.draw(myplot)


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### code chunk number 18: grobs.Rnw:433-464
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drawIt <- function(row, col) {
  pushViewport(viewport(layout.pos.col = col, layout.pos.row = row))
  grid.rect(gp = gpar(col = "grey"))
  grid.draw(gplot)
  upViewport()
}
gplot <- gTree(name = "plot1",
               childrenvp = vpTree(
                 plotViewport(c(5, 4, 4, 2), name = "plotRegion"),
                 vpList(viewport(name = "dataRegion"))),
               children = gList(
                 xaxisGrob(name = "xaxis", vp = "plotRegion::dataRegion"),
                 yaxisGrob(name = "yaxis", vp = "plotRegion::dataRegion"),
                 rectGrob(name = "box", vp = "plotRegion")))
grid.newpage()
pushViewport(viewport(layout = grid.layout(2, 2)))
drawIt(1, 1)
grid.add("plot1", pointsGrob(0.5, 0.5, name = "data1",
                             vp = "plotRegion::dataRegion"))
grid.add("plot1::xaxis",
         textGrob("X Axis", y = unit(-2, "lines"), name = "xlab"))
grid.edit("plot1::xaxis::xlab", y = unit(-3, "lines"))
gplot <- grid.get("plot1")
gplot <- addGrob(gplot, gPath = "yaxis",
                 textGrob("Y Axis", x = unit(-3, "lines"), rot = 90,
                          name = "ylab"))
drawIt(1, 2)
gplot <- removeGrob(gplot, "xaxis::xlab")
drawIt(2, 1)
grid.remove("plot1::data1")
grid.remove("plot1")


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### code chunk number 19: grobs.Rnw:472-482
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grid.newpage()
grid.frame(name = "myframe", layout = grid.layout(1, 2))
grid.place("myframe", textGrob("Hi there"), col = 1)
grid.place("myframe", rectGrob(), col = 2)
grid.newpage()
grid.frame(name = "frame2")
grid.pack("frame2", textGrob("Hi there"))
grid.place("frame2", rectGrob())
grid.pack("frame2", textGrob("Hello again"), side = "right")
grid.pack("frame2", rectGrob(), side = "right", width = unit(1, "null"))