createWin: Create a GUI Window

Description

Create a GUI window with widgets using instructions from a Window Description File (aka mark-up file) .

Usage

createWin( fname, astext=FALSE, env=NULL )

Arguments

fname: name of window description file or list returned from parseWinFile.
astext: logical: if TRUE, interpret fname as a vector of strings with each element representing a line in a window description file.
env: an environment in which to evaluate widget callback functions; see example.

Author

Alex Couture-Beil, Vancouver Island University, Nanaimo BC

Details

Generally, the markup file contains a single widget per line. However, widgets can span multiple lines by including a backslash ('\') character at the end of a line, prompting the suppression of the newline character.

For more details on widget types and markup file, see “PBSModelling-UG.pdf” in the R directory
.../library/PBSmodelling/doc.

It is possible to use a Window Description List produced by compileDescription rather than a file name for fname.

Another alternative is to pass a vector of characters to fname and set astext=T. This vector represents the file contents where each element is equivalent to a new line in the window description file.

Examples

Run this code

if (FALSE) {
# See file .../library/PBSmodelling/testWidgets/LissWin.txt
# Calculate and draw the Lissajous figure
local(envir=.PBSmodEnv,expr={
  drawLiss <- function() {
    oldpar = par(no.readonly=TRUE); on.exit(par(oldpar))
    getWinVal(scope="L"); ti=2*pi*(0:k)/k;
    x=sin(2*pi*m*ti);     y=sin(2*pi*(n*ti+phi));
    plot(x,y,type=ptype); invisible(NULL); };
  createWin(system.file("testWidgets/LissWin.txt",package="PBSmodelling"));
})

############################################################
# Environment example:
# function in global
local(envir=.PBSmodEnv,expr={
  hello <- function() {
    stop( "I shouldn't be called" )
  }

newNameGreeter <- function( name ) {
  # method to display window
  greet <- function() {
    createWin(c("button \"Say hello\" func=hello"), astext=TRUE,
      env=parent.env(environment()))
  }
  # hello method will refer to the name in this local scope
  hello <- function() {
    cat( "Hello", name, "\n" )
  }
  # return functions which the user can call directly
  return( list( greet=greet, hello=hello ) )
}
alex <- newNameGreeter( "Alex" )
jon  <- newNameGreeter( "Jon" )

alex$hello() # prints hello Alex
jon$hello()  # prints hello Jon
alex$greet() # creates a GUI with a button, which will print "hello Alex" when pushed
})
}