gWidgets (version 0.0-27)

gtable: Constructor for widget to display tabular data

Description

This widget displays either a vector, matrix or data frame in a tabular format. The main usage is for user selection of a row or rows.

Usage

gtable(items, multiple = FALSE, chosencol = 1, icon.FUN = NULL, filter.column = NULL, filter.labels = NULL, filter.FUN = NULL, handler = NULL, action = NULL, container = NULL, ..., toolkit = guiToolkit())

Arguments

items

A vector, matrix or data frame to be displayed. A vector and matrix is coerced into a data frame.

multiple

A logical. If TRUE multiple lines can be selected

chosencol

By default, only the value in this column is returned by the svalue method.

icon.FUN

If given, this function is applied to the data frame to be shown. It should return a vector of stock icon names

filter.column

If not NULL a filter by droplist is given which can be used to filter the displayed values shown using the values in this column.

filter.labels

If filtering is desired, but by a more complicated means that just a columns value, then these labels are used for the drop list. These are used by filter.FUN

filter.FUN

A function with signature (obj, filter.by) to specify a vector of logical values indicating which rows should be shown.

handler

Called on a double click event

action

Passed to handler

container

Optional container to attach widget to

...

ignored

toolkit

Which GUI toolkit to use

Details

When no filtering is requested, the column headers can be clicked to sort the values.

The svalue method returns the selected value(s). By default, only the value(s) in the chosen column are returned. Use the argument drop=FALSE to return the entire row. To return the row index, use the argument index=TRUE. When filtering is being used, this index refers to the entire data frame, not just the visible data frame.

The "[" notion treats the object like a data frame. When filtering or sorting, this notation refers to the entire data frame, not the visible or rearranged data frame.

Assignment via "[<-" may be used. In gWidgetsRGtk there are limitations. The number of columns may not be reduced. Assignment with both row and column indices missing may be needed for some desired actions.

As with data frames, the data type of a variable is important. In particular, assignment with "[<-" for factors can cause warnings if the values are not in the factor's levels. When the value being assigned is a matrix there is a coercion to a data frame which may change the type.

The visible and visible<- methods refer to which rows of the data store are visible in the widget. These are specified by a vector of class logical. This may be used when there is filtering, not sorting.

The dim method returns the dimension of the data frame.

The dimnames method works, although you can't see the rownames, you can assigne to column names, although names is more convenient.

A single click is used for selection of a value.

The addhandlerdoubleclick handler responds to a double click event.

See Also

See also gtree for displaying tree-like data and gdf for tabular data meant to be edited

Examples

## example to select CRAN mirror
  m <- getCRANmirrors()[,c(1,4)]
  setCRAN <- function(URL) { ## see chooseCRANmirror
    repos = getOption("repos")
    repos["CRAN"] <- gsub("/$", "", URL)
    options(repos=repos)
  }
  w <- gwindow("gtable example",width=400)
  gp = ggroup(horizontal=FALSE, cont=w)
  tab <- gtable(m, chosencol = 2, cont=gp, expand=TRUE,
       handler = function(h,...) setCRAN(svalue(h$obj)))
  bg <- ggroup(cont=gp)
  addSpring(bg)
  gbutton("dismiss", cont=bg, handler = function(h,...) dispose(w))


  ## an example with icons.
  ## Select variables from a data frame

  ## find icons by class
  icon.FUN <- function(items) {
    dfName <- svalue(cb)
    df <- try(get(dfName, envir=.GlobalEnv), silent=TRUE)
    if(inherits(df,"try-error"))
      return(rep(NULL,dim(items)[1]))

    sapply(items[,1, drop=TRUE], function(i) {
      class(df[,i])[1]
    })
  }
  ## list data frames in an environment
  lsDF <- function(envir=.GlobalEnv) {
    varNames <- ls(envir=envir)
    dfs <- sapply(varNames, function(i) inherits(get(i,envir=envir),"data.frame"))
    varNames[dfs]
  }
  ## set up GUI
  w <- gwindow("Select variables",width=250)
  g <- ggroup(horizontal=FALSE, cont=w)
  l <- glabel("Data frame", cont=g)
  cb <- gcombobox(lsDF(), cont=g)
  tbl <- gtable(data.frame(variables=character(0)), icon.FUN=icon.FUN, cont=g,
    expand=TRUE)
  ## add handlers
  addHandlerChanged(cb, handler <- function(h,...) {
    dfName <- svalue(h$obj)
    dfNames <- names(get(dfName,envir=.GlobalEnv))
    tbl[,] <- data.frame(variables=dfNames, stringsAsFactors=FALSE)
  })
  addHandlerClicked(tbl, handler = function(h,...) {
    cat("Do something with",svalue(cb),"::", svalue(h$obj),"\n")
  })