Create and launch a native desktop application window from R.

Provides bidirectional native pipe communication between R and the UI.

Methods

Public methods

• App$new()

• App$on_ready()

• App$on_close()

• App$check_update()

• App$register_hotkey()

• App$set_tray_menu()

• App$clipboard_write()

• App$clipboard_read()

• App$on_message()

• App$send()

• App$load_ui()

• App$set_size()

• App$set_position()

• App$set_title()

• App$minimize()

• App$maximize()

• App$restore()

• App$fullscreen()

• App$always_on_top()

• App$set_menu()

• App$dialog_open()

• App$dialog_save()

• App$dialog_folder()

• App$message_box()

• App$dialog_color()

• App$notify()

• App$loading_start()

• App$loading_progress()

• App$loading_done()

• App$toast()

• App$set_tray()

• App$remove_tray()

• App$service()

• App$quit()

• App$get_dir()

• App$run()

• App$clone()

---

Method new()

Create a new RDesk application

Usage

App$new(title, width = 1200L, height = 800L, www = NULL, icon = NULL)

Arguments

title

Window title string

width

Window width in pixels (default 1200)

height

Window height in pixels (default 800)

www

Directory containing HTML/CSS/JS assets (default: built-in template)

icon

Path to window icon file

Returns

A new App instance

---

Method on_ready()

Register a callback to fire when the window is ready

Usage

App$on_ready(fn)

Arguments

fn

A zero-argument function called after the server starts and window opens

Returns

The App instance (invisible)

---

Method on_close()

Register a callback to fire when the user attempts to close the window

Usage

App$on_close(fn)

Arguments

fn

A zero-argument function. Should return TRUE to allow closing, FALSE to cancel.

Returns

The App instance (invisible)

---

Method check_update()

Check for application updates from a remote URL

Usage

App$check_update(version_url, current_version = NULL)

Arguments

version_url

URL to a JSON metadata file (e.g. {"version": "1.1.0", "url": "http://..."})

current_version

Optional version string to compare against. Defaults to app description version.

Returns

A list with update status and metadata

---

Method register_hotkey()

Register a global keyboard shortcut (hotkey)

Usage

App$register_hotkey(keys, fn)

Arguments

keys

Character string representing the key combination (e.g., "Ctrl+Shift+A")

fn

A zero-argument function to be called when the hotkey is pressed

Returns

The App instance (invisible)

---

Method set_tray_menu()

Set the native system tray menu

Usage

App$set_tray_menu(items)

Arguments

items

A named list of lists defining the menu structure

Returns

The App instance (invisible)

---

Method clipboard_write()

Write text to the system clipboard

Usage

App$clipboard_write(text)

Arguments

text

Character string to copy

Returns

The App instance (invisible)

---

Method clipboard_read()

Read text from the system clipboard

Usage

App$clipboard_read()

Returns

Character string from clipboard or NULL

---

Method on_message()

Register a handler for a UI -> R message type

Usage

App$on_message(type, fn)

Arguments

type

Unique message identifier string

fn

A function(payload) called when this message type arrives

Returns

The App instance (invisible)

---

Method send()

Send a message from R to the UI

Usage

App$send(type, payload = list())

Arguments

type

Character string message type (received by rdesk.on() in JS)

payload

A list or data.frame to serialise as JSON payload

Returns

The App instance (invisible)

---

Method load_ui()

Load an HTML file into the window

Usage

App$load_ui(path = "index.html")

Arguments

path

Path relative to the www directory (e.g. "index.html")

Returns

The App instance (invisible)

---

Method set_size()

Set the window size dynamically

Usage

App$set_size(width, height)

Arguments

width

New width (pixels)

height

New height (pixels)

Returns

The App instance (invisible)

---

Method set_position()

Set the window position dynamically

Usage

App$set_position(x, y)

Arguments

x

Horizontal position from left (pixels)

y

Vertical position from top (pixels)

Returns

The App instance (invisible)

---

Method set_title()

Set the window title dynamically

Usage

App$set_title(title)

Arguments

title

New title

Returns

The App instance (invisible)

---

Method minimize()

Minimize the window to the taskbar

Usage

App$minimize()

Returns

The App instance (invisible)

---

Method maximize()

Maximize the window to fill the screen

Usage

App$maximize()

Returns

The App instance (invisible)

---

Method restore()

Restore the window from minimize/maximize

Usage

App$restore()

Returns

The App instance (invisible)

---

Method fullscreen()

Toggle fullscreen mode

Usage

App$fullscreen(enabled = TRUE)

Arguments

enabled

If TRUE, enters fullscreen. If FALSE, exits.

Returns

The App instance (invisible)

---

Method always_on_top()

Set the window to stay always on top of others

Usage

App$always_on_top(enabled = TRUE)

Arguments

enabled

If TRUE, always on top.

Returns

The App instance (invisible)

---

Method set_menu()

Set the native window menu

Usage

App$set_menu(items)

Arguments

items

A named list of lists defining the menu structure

Returns

The App instance (invisible)

---

Method dialog_open()

Open a native file-open dialog

Usage

App$dialog_open(title = "Open File", filters = NULL)

Arguments

title

Dialog title

filters

List of file filters, e.g. list("CSV files" = "*.csv")

Returns

Selected file path (character) or NULL if cancelled

---

Method dialog_save()

Open a native file-save dialog

Usage

App$dialog_save(title = "Save File", default_name = "", filters = NULL)

Arguments

title

Dialog title

default_name

Initial filename

filters

List of file filters

Returns

Selected file path (character) or NULL if cancelled

---

Method dialog_folder()

Open a native folder selection dialog

Usage

App$dialog_folder(title = "Select Folder")

Arguments

title

Dialog title

Returns

Selected directory path (character) or NULL if cancelled

---

Method message_box()

Show a native message box / alert

Usage

App$message_box(message, title = "RDesk", type = "ok", icon = "info")

Arguments

message

The message text

title

The dialog title

type

One of "ok", "okcancel", "yesno", "yesnocancel"

icon

One of "info", "warning", "error", "question"

Returns

The button pressed (character: "ok", "cancel", "yes", "no")

---

Method dialog_color()

Open a native color selection dialog

Usage

App$dialog_color(initial_color = "#FFFFFF")

Arguments

initial_color

Optional hex color to start with (e.g. "#FF0000")

Returns

Selected hex color code or NULL if cancelled

---

Method notify()

Send a native desktop notification

Usage

App$notify(title, body = "")

Arguments

title

Notification title

body

Notification body text

Returns

The App instance (invisible)

---

Method loading_start()

Show a loading state in the UI

Usage

App$loading_start(
  message = "Loading...",
  progress = NULL,
  cancellable = FALSE,
  job_id = NULL
)

Arguments

message

Text shown under the spinner

progress

Optional numeric 0-100 for a progress bar

cancellable

If TRUE, shows a cancel button in the UI

job_id

Optional job_id from rdesk_async() to wire cancel button

---

Method loading_progress()

Update progress on an active loading state

Usage

App$loading_progress(value, message = NULL)

Arguments

value

Numeric 0-100

message

Optional updated message

---

Method loading_done()

Hide the loading state in the UI

Usage

App$loading_done()

---

Method toast()

Show a non-blocking toast notification in the UI

Usage

App$toast(message, type = "info", duration_ms = 3000L)

Arguments

message

Text to show

type

One of "info", "success", "warning", "error"

duration_ms

How long to show it (default 3000ms)

---

Method set_tray()

Set or update the system tray icon

Usage

App$set_tray(label = "RDesk App", icon = NULL, on_click = NULL)

Arguments

label

Tooltip text for the tray icon

icon

Path to .ico file (optional)

on_click

Character "left" or "right" or callback function(button)

Returns

The App instance (invisible)

---

Method remove_tray()

Remove the system tray icon

Usage

App$remove_tray()

Returns

The App instance (invisible)

---

Method service()

Service this app's pending native events

Usage

App$service()

Returns

The App instance (invisible)

---

Method quit()

Close the window and stop the app's event loop.

Usage

App$quit()

Returns

The App instance (invisible)

---

Method get_dir()

Get the application root directory (where www/ and R/ are located).

Usage

App$get_dir()

Returns

Character string path.

---

Method run()

Start the application - opens the window

Usage

App$run(block = TRUE)

Arguments

block

If TRUE (default), blocks with an event loop until the window is closed.

---

Method clone()

The objects of this class are cloneable with this method.

Usage

App$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

# Safe logical check (unwrapped)
app_dir <- system.file("templates/hello", package = "RDesk")
if (nzchar(app_dir)) {
  message("Built-in app directory: ", app_dir)
}
#> Built-in app directory: C:/Users/runneradmin/AppData/Local/R/cache/R/renv/library/RDesk-47d971e3/windows/R-4.5/x86_64-w64-mingw32/RDesk/templates/hello

if (interactive()) {
  app <- App$new(title = "Car Visualizer", width = 1200, height = 800)
  
  app$on_ready(function() {
    message("App is ready!")
  })
  
  # Handle messages from UI
  app$on_message("get_data", function(payload) {
    list(cars = mtcars[1:5, ])
  })
  
  # Start the app
  app$run()
}