library(shiny)
library(ggvis)
options(shiny.launch.browser=TRUE)

## Scaled and unscaled values
dat <- data.frame(x = 1:3, y = 1:3,
                  f = c("red", "green", "black"))
dat

dat %>%
  ggvis(x = ~x, y = ~y, fill = ~f) %>%
  layer_points(size := 1000)


dat %>%
  ggvis(x = ~x, y = ~y, fill := ~f) %>%
  layer_points(size := 1000)


## A simple shiny app demonstrating reactivity
runApp(list(
  ui = basicPage(
    sliderInput('n', 'Number', 1, 100, value = 50),
    textOutput('text')
  ),
  server = function(input, output) {
    output$text <- renderText({
      paste("The value of n is ", input$n)
    })
  }
))


## Reactive computation parameters
faithful %>%
  ggvis(x = ~waiting) %>%
  layer_histograms(binwidth = input_slider(min=1, max=20, value=11))

## Reactive properties
mtcars %>%
  ggvis(x = ~wt, y = ~mpg) %>%
  layer_points(
    size := input_slider(10, 400, value=50, label="size"),
    fill := input_select(c("red", "blue"), label="color")
  )


## Reactive data source
dat <- data.frame(time = 1:10, value = runif(10))
# Add a new data point every 2 seconds
ddat <- reactive({
  invalidateLater(2000, NULL)
  dat$time  <<- c(dat$time[-1], dat$time[length(dat$time)] + 1)
  dat$value <<- c(dat$value[-1], runif(1))
  dat
})
ddat %>% ggvis(x = ~time, y = ~value, key := ~time) %>%
  layer_points() %>%
  layer_paths()


## Reactive data source 2
library(tourr)
aps <- 2
fps <- 30
mat <- rescale(as.matrix(flea[1:6]))
tour <- new_tour(mat, grand_tour(), NULL)
start <- tour(0)

proj_data <- reactive({
  invalidateLater(1000 / fps, NULL);
  step <- tour(aps / fps)
  data.frame(center(mat %*% step$proj), species = flea$species)
})

proj_data %>% ggvis(~X1, ~X2, fill = ~species) %>%
  layer_points() %>%
  scale_numeric("x", domain = c(-1, 1)) %>%
  scale_numeric("y", domain = c(-1, 1)) %>%
  set_options(duration = 0)


## Direct interaction
# This function receives information about the hovered
# point and returns a string to display
all_values <- function(x) {
  if(is.null(x)) return(NULL)
  paste0(names(x), ": ", format(x), collapse = "<br />")
}

mtcars %>% ggvis(x = ~wt, y = ~mpg) %>%
  layer_points() %>%
  add_tooltip(all_values, "hover")


## Movies app
runApp('movies')

## Brushing app
runApp('brush-summary')