l_bind_canvas {loon}

Create a Canvas Binding

Description

Canvas bindings are triggered by a mouse/keyboard gesture over the plot as a whole.

Usage

l_bind_canvas(widget, event, callback)

Arguments

widget

widget path as a string or as an object handle

event

event patterns as defined for Tk canvas widget https://www.tcl.tk/man/tcl8.6/TkCmd/bind.htm#M5.

callback

callback function is an R function which is called by the Tcl interpreter if the event of interest happens. Note that in loon the callback functions support different optional arguments depending on the binding type, read the details for more information

Details

Canvas bindings are used to evaluate callbacks at certain X events on the canvas widget (underlying widget for all of loon's plot widgets). Such X events include re-sizing of the canvas and entering the canvas with the mouse.

Bindings, callbacks, and binding substitutions are described in detail in loon's documentation webpage, i.e. run l_help("learn_R_bind")

Value

canvas binding id

See Also

l_bind_canvas_ids, l_bind_canvas_get, l_bind_canvas_delete, l_bind_canvas_reorder

Examples

# binding for when plot is resized
if(interactive()){
p <- l_plot(iris[,1:2], color=iris$Species)

printSize <- function(p) {
    size <- l_size(p)
    cat(paste('Size of widget ', p, ' is: ',
              size[1], 'x', size[2], ' pixels\n', sep=''))
}

l_bind_canvas(p, event='<Configure>', function(W) {printSize(W)})

id <- l_bind_canvas_ids(p)
id

l_bind_canvas_get(p, id)

}