astrum wiki

Start by making ~/.config/astrum/config.lua

Astrum = require("astrum")
App = Astrum:application()
-- you can make windows with App:window()

return App

You will see nothing happening if you run astrum, mainly because its an empty config
You have to make a window in order for astrum to display something

Making windows

Windows are toplevel containers that hold widgets and signals (More on signals later).

App:window("window_name", {
 -- window model goes here
})

Windows have a mandatory view field, which defines what widgets to display
The view field gets ran after signals get processed.

App:window("window_name", {
    view = function()
         return Astrum.widgets:text("hello world!")
    end
})

This will display a window that has a text widget containing "hello world!"

Signals and states

Windows also have an optional signals field, which is a dictionary of signal names and logic that will be processed when the signal is fired

App:window("window_name", {
    view = function()
         return Astrum.widgets:button({
             child = Astrum.widgets:text("press me!")
             on_press = "button_pressed" -- the name of the signal
         })
    end,
    -- the syntax for signals is this
    -- signal_name = function(signal_data) end
    signals = {
        button_pressed = function() -- signal data is unnecessary since we do not send any yet
            print("hello world!")
        end
    }
})

This example will make a window, that has a button which when pressed will print hello world!

Signals are also the main way you change the state within astrum
And view logic is where you define widgets based on state

local state = {
    widget_text = "false"
}

App:window("window_name", {
    view = function()
         return Astrum.widgets:button({
             child = Astrum.widgets:text(state.widget_text)
             on_press = "button_pressed"
         })
    end,

    signals = {
        button_pressed = function()
            if state.widget_text == "false" then
                state.widget_text = "true"
            else
                state.widget_text = "false"
            end
        end
    }
})

This will make a window that has a button with text that toggles between false and true