如何在 shiny 应用程序的平移和缩放功能中添加控件？

Question

I have used panzoom package in order to pan and zoom on my svg file in my shiny app. Is there a way to have controls like this ?

library(shiny)
library(DiagrammeR)
library(magrittr)

ui <- fluidPage(
  tags$head(
    tags$script(src = "https://unpkg.com/panzoom@9.4.0/dist/panzoom.min.js")
  ),

  grVizOutput("grr", width = "100%", height = "90vh"),

  tags$script(
    HTML('panzoom($("#grr")[0])')
  )
)

server <- function(input, output) {

  reactives <- reactiveValues()

  observe({
    reactives$graph <- render_graph(create_graph() %>%
                                      add_n_nodes(n = 2) %>%
                                      add_edge(
                                        from = 1,
                                        to = 2,
                                        edge_data = edge_data(
                                          value = 4.3)))
  })

  output$grr <- renderGrViz(reactives$graph)

}

shinyApp(ui, server)

Answer 1

Here is a way, but if you click too quickly on the +/- buttons, there's an undesirable effect.

library(shiny)
library(shinyWidgets)
library(DiagrammeR)
library(magrittr)

js <- '
$(document).ready(function(){
  var element = document.getElementById("grr");
  var instance = panzoom(element);
  $("#zoomout").on("click", function(){
    instance.smoothZoom(0, 0, 0.9);
  });
  $("#zoomin").on("click", function(){
    instance.smoothZoom(0, 0, 1.1);
  });
});
'

ui <- fluidPage(
  tags$head(
    tags$script(src = "https://unpkg.com/panzoom@9.4.0/dist/panzoom.min.js"),
    tags$script(HTML(js))
  ),

  grVizOutput("grr", width = "100%", height = "90vh"),

  actionGroupButtons(
    inputIds = c("zoomout", "zoomin"),
    labels = list(icon("minus"), icon("plus")),
    status = "primary"
  )

)

server <- function(input, output) {

  reactives <- reactiveValues()

  observe({
    reactives$graph <- render_graph(
      create_graph() %>%
        add_n_nodes(n = 2) %>%
        add_edge(
          from = 1,
          to = 2,
          edge_data = edge_data(
            value = 4.3
          )
        )
      )
  })

  output$grr <- renderGrViz(reactives$graph)

}

shinyApp(ui, server)