# Controlling Animations

## Methods

‘Lottie’ offers several methods for controlling various aspects of animations, and ‘shinyLottie’ provides options for calling these methods when initialising the animation or updating them at a later point. The table below documents the most common methods:

Method | `lottie_animation()` argument | ‘shinyLottie’ Function
--- | --- | ---
Loop | `loop` | `lottie_setLoop()`
Autoplay | `autoplay` | `lottie_play()`, `lottie_pause()`, and `lottie_stop()`
Speed | `speed` | `lottie_setSpeed()`
Direction | `direction` | `lottie_setDirection()`
Play Segments | `playSegments` | `lottie_playSegments()`, `lottie_goToAndStop()`, and `lottie_goToAndPlay()`
Set Subframe Rendering | `setSubFrame` | `lottie_setSubFrame()`
Destroy | N/A | `lottie_destroy()`

To demonstrate this, the example below initialises an animation using `lottie_animation()` with a `speed` value of 2, causing the animation to play twice as fast as normal. We can then use a reactive event, triggered by clicking the button, to update the speed to a value of 0.5 (causing it to play twice as slow as normal) using `lottie_setSpeed()`.

    library(shiny)
    library(shinyLottie)

    ui <- fluidPage(
      include_lottie(),
      lottie_animation(
        path = "shinyLottie/example.json",
        name = "my_animation",
        speed = 2
      ),
      actionButton("updateSpeed", "Set Speed to 0.5")
    )

    server <- function(input, output, session) {
      observeEvent(input$updateSpeed, {
        lottie_setSpeed(speed = 0.5, name = "my_animation")
      })
    }

    shinyApp(ui, server)

Note that when calling `lottie_setSpeed()`, we reference the name of the animation we wish to target (in this case, `"my_animation"`). This is consistent across virtually all ‘shinyLottie’ functions, allowing for fine control over the animations in your ‘shiny’ app (i.e. being able to update the speed of a single animation, rather than all animations). Alternatively, the default default `name` value of `"all"` can be used to target all animations in the app.

Finally, if you want to call a ‘Lottie’ method for which ‘shinyLottie’ does not provide a function for, this can be achieved using `lottie_callMethod()`.

## Properties

‘Lottie’ animations have a number of properties that can be queried during runtime. The example below demonstrates how to query the ‘playCount’ property of an animation using `lottie_getProperty()`.

    library(shiny)
    library(shinyLottie)

    ui <- fluidPage(
      include_lottie(),
      lottie_animation(
        path = "shinyLottie/example.json",
        name = "my_animation"
      ),
      actionButton("getProperty", "Update Play Count"),
      textOutput("playCountOutput")
    )

    server <- function(input, output, session) {
      observeEvent(input$getProperty, {
        lottie_getProperty(name = "my_animation", property = "playCount")
      })

      observe({
        req(input$playCount)
        output$playCountOutput <- renderText({
          paste("Play Count:", input$playCount)
        })
      })
    }

     shinyApp(ui, server)