gimage: Container for an image

In jverzani/gWidgetsWWW2: Toolkit implementation of the gWidgets API for use with web pages

Description

The image shows a url. This url can be external. For local urls, the file must be accessible by the server. The function get_tempfile can be used to create a file that is so accessible. See the example.

Usage

gimage(filename = "", dirname = "", size = NULL, handler = NULL,
  action = NULL, container = NULL, ..., width = NULL, height = NULL,
  ext.args = NULL)

Arguments

filename	A url or file from get_tempfile.
dirname	ignored.
size	A vector passed to width and height arguments. Can also be set by the size<- method later.
handler	optional means (to addHandlerChanged) to specify a handler for the default signal. A handler is a function with signature (h,...) where h is a list with components obj referring to the object emitting the signal, action containing values passed to the action argument, and possible other values.
action	Passed to handler to parameterize a call
container	A parent container. In gWidgetsWWW2 a parent container is not optional (though it can be substituted with the parent argument in some circumstances). The parent specifies the widget heirarchy and the ... argument is used to pass along arguments to layout the child component in the parent container. Typically, these are passed to the add method of the parent container.
...	Used to pass along argument to the parent container's add method and possible other arguments to the underlying ference class constructors.
width	width in pixels of component. Sizing in gWidgetsWWW2 is sometimes necessary as the arguments expand and fill are not well implemented.
height	height in pixels of the component.
ext.args	The contructors of gWidgetsWWW2 ultimately call an Ext constructor. The options passed to the Ext constructor may be added to or overridden by use of this argument. Values are passed in as named list components and with values converted into JavaScript objects by asJSObject.

Value

an GImage reference object

Note

requires tempdir to be mapped to a specific url, as this is assumed by get_tempfile and get_tempfile_url

Examples

w <- gwindow("hello")
sb <- gstatusbar("Powered by gWidgetsWWW and Rook", cont=w)
g <- ggroup(cont=w, horizontal=FALSE)

f <- get_tempfile(ext=".png")
png(f)
hist(rnorm(100))
dev.off()

i <- gimage(f, container=g, size = c(400, 400))
b <- gbutton("click", cont=g, handler=function(h,...) {
  f <- get_tempfile(ext=".png")
  png(f)
  hist(rnorm(100))
  dev.off()
  svalue(i) <- f
})

jverzani/gWidgetsWWW2 documentation built on Feb. 9, 2020, 5:18 p.m.