#############################################################################
#
# XLConnect
# Copyright (C) 2010-2021 Mirai Solutions GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#############################################################################

#############################################################################
#
# Using cellstyles for specific selected cells
# 
# Author: Martin Studer, Mirai Solutions GmbH
#
#############################################################################

require(XLConnect)

# Excel workbook to write
demoExcelFile <- "cellstyles3.xlsx"

# Remove file if it already exists
if(file.exists(demoExcelFile)) file.remove(demoExcelFile)

# Load workbook (create if not existing)
wb <- loadWorkbook(demoExcelFile, create = TRUE)

# We don't set a specific style action in this demo, so the default 'XLConnect'
# will be used (XLC$"STYLE_ACTION.XLCONNECT")

# Create a sheet named 'mtcars'
createSheet(wb, name = "mtcars")

# Create a named region called 'mtcars' referring to the sheet called 'mtcars'
createName(wb, name = "mtcars", formula = "mtcars!$C$4")

# Write built-in data set 'mtcars' to the above defined named region.
# This will use the default style action 'XLConnect'.
writeNamedRegion(wb, mtcars, name = "mtcars")

# Now let's color all weight cells of cars with a weight > 3.5 in red
# (mtcars$wt > 3.5)

# First, create a corresponding (named) cellstyle
heavyCar <- createCellStyle(wb, name = "HeavyCar")
# Specify the cellstyle to use a solid foreground color
setFillPattern(heavyCar, fill = XLC$"FILL.SOLID_FOREGROUND")
# Specify the foreground color to be used
setFillForegroundColor(heavyCar, color = XLC$"COLOR.RED")

# Which cars have a weight > 3.5 ?
rowIndex <- which(mtcars$wt > 3.5)

# NOTE: The mtcars data.frame has been written offset with top left cell
# C4 - and we have also written a header row!
# So, let's take that into account appropriately. Obviously, the two steps
# could be combined directly into one ...
rowIndex <- rowIndex + 4

# The same holds for the column index
colIndex <- which(names(mtcars) == "wt") + 2

# Set the 'HeavyCar' cellstyle for the corresponding cells.
# Note: the row and col arguments are vectorized!
setCellStyle(wb, sheet = "mtcars", row = rowIndex, col = colIndex, 
	cellstyle = heavyCar)

# Save workbook (this actually writes the file to disk)
saveWorkbook(wb)

if(interactive()) {
	answer <- readline("Open the created Excel file (y/n)? ")
	if(answer == "y") browseURL(file.path(getwd(), demoExcelFile))
}
