## Start a program and rearrange the geometry of its window
## (assume program creates EXACTLY ONE window)

## This is based on python script from
## http://askubuntu.com/questions/613973/how-can-i-start-up-an-application-with-a-pre-defined-window-size-and-position

run <- function(program, x, y, w, h, args="") {

    ## List current windows
    getWindows <- function() {
        wl <- system("wmctrl -lp", intern=TRUE)
        if (!is.null(attr(wl, "status"))) {
            # Try again
            while (!is.null(attr(wl, "status"))) {
                wl <- system("wmctrl -lp", intern=TRUE)
            }
        }
        nf <- max(count.fields(textConnection(wl)))
        windows <- read.table(textConnection(wl), fill=TRUE,
                              col.names=paste0("V", 1:nf))
        windows$name <- gsub(" *$", "",
                             apply(windows[-(1:4)], 1, paste, collapse=" "))
        windows
    }
    w1 <- getWindows()

    ## Run the program 
    system(paste(program, args))
    ## Get process id of program
    ## (NOTE that all firefox windows have same pid)
    pid <- system(paste("pidof", program), intern=TRUE)
    ## Get multiple pids if run immediately after execution, but the
    ## last one is the common pid for gnome-terminal and firefox
    pid <- gsub(".+ ", "", pid)

    ## Loop (waiting for program window to open)
    time <- proc.time()
    found <- FALSE
    while (!found && (proc.time() - time)[3] < 10) {
        ## Check the window list again
        w2 <- getWindows()
        if (nrow(w2) > nrow(w1)) {
            wall <- rbind(w1, w2)
            wnew <- w2[! w2$V1 %in% w1$V1,]
            wprog <- wnew[grepl(pid, wnew$V3), ]
            if (nrow(wprog) > 0) {
                if (nrow(wprog) > 1)
                    stop("More than one window matched")
                windowID <- wprog$V1
                found <- TRUE
            }
        }
    }

    if (!found) stop("Failed to detect program window")

    ## Set geometry for the program window
    system(paste0("wmctrl -ir ", windowID, " -b remove,maximized_horz"))
    system(paste0("wmctrl -ir ", windowID, " -b remove,maximized_vert"))
    system(paste0("wmctrl -ir ", windowID, " -e 0,", x, ",", y, ",", w, ",", h))
    
    return(windowID)
}