Introduction

In this document ngui is introducted. Ngui uses many conventions commonly used in gui toolkits, so you may benefit from reviewing them. Here is a list of useful links in case you need them:

Useful Links

• MVC
• Event Loop
• List of graphical user interface elements
• Getting Started with GTK+

• NGUI

  • NGUI API
  • NGUI backend interface
  • Nim GTK3 Bindings

About NGUI

NGUI is an interface of user interfaces, or to put it simply, a thin layer over someone else's GUI toolkit code to program GUI's in a less cumbersome fashion. At the time of writting this document, only GTK3 is supported, but in the future more gui backends will follow, I assume.

let app = app()               # Lib initialization
app.add(window())             # Add Window Element
app[0].add(label("NGUI"))     # Add label to Window
app.run                       # Show app, block thread, listen to user events

Nomenclature

Your first application

In this example, a window will display a button which, upon clicking, will close the application:

# Lib initialization, first thing you need to do before using any element
let app = app()

# Add a new button with the given label. It will create a new 'Window' and
# 'Box' element under the hood for you
app.add(button("Close Now"))

# Attach onClick event to button. The button is inside a box, which is itself
# inside a window inside the app context variable. They were created for your
# convenience
# App[0] -> Window[0] -> Box[0] -> button
app[0][0][0].onClickDo:
  quit()

# This call will display the gui and block the thread, executing only user
# events (like the previously defined one) until a close event is sent
app.run

The app variable is a Container, that's why we can get the appended elements using array notation. However, conversion is needed. Window and Container elements were added the moment you added the button. That code is similar to this one:

let window = window()
let box = box()
let button = button("Close now")
box.add(button)
window.add(box)
app.add(window)

button.onClickDo:
  quit()

More

For more examples, have a look at the examples folder, or execute:

nim examples nguiscript.nims