keys 
The goal of keys is to add hotkeys to shiny applications using
Mousetrap. With keys, you
can:
- Assign hotkeys on app load
- Add and remove hotkeys from server
- Pause and unpause hotkeys from server
- Record keys from server
Installation
Install the released version of keys from CRAN:
install.packages("keys")Or install the development version from GitHub with:
# install.packages("devtools")
devtools::install_github("r4fun/keys")You can also install keys with conda-forge. More information here:
https://github.com/conda-forge/r-keys-feedstock
Usage
To use keys, start by adding a dependency to it using useKeys().
Then, you can add a keysInput to the UI:
library(shiny)
library(keys)
hotkeys <- c(
"1",
"command+shift+k",
"up up down down left right left right b a enter"
)
ui <- fluidPage(
useKeys(),
keysInput("keys", hotkeys)
)
server <- function(input, output, session) {
observeEvent(input$keys, {
print(input$keys)
})
}
shinyApp(ui, server)You can add binding after application launch using addKeys.
library(shiny)
library(keys)
ui <- fluidPage(
useKeys(),
actionButton("add", "Add keybinding")
)
server <- function(input, output, session) {
observeEvent(input$add, {
addKeys("keys", c("a", "b", "c"))
})
observeEvent(input$keys, {
print(input$keys)
})
}
shinyApp(ui, server)Bindings can be removed after application launch using removeKey.
library(shiny)
library(keys)
ui <- fluidPage(
useKeys(),
keysInput("keys", c("a", "b", "c")),
actionButton("rm", "Remove `a` keybinding")
)
server <- function(input, output, session) {
observeEvent(input$rm, {
removeKeys("a")
})
observeEvent(input$keys, {
print(input$keys)
})
}
shinyApp(ui, server)For more information about what types of hotkeys you can use, please take a look at the mousetrap github repository.
Acknowledgements
All credit goes to Craig Campbell who is
the author of Mousetrap.