Hello world tutorial

This tutorial makes a simple hello world example app:

package main

import "cogentcore.org/core/core"

func main() {
    b := core.NewBody()
    core.NewButton(b).SetText("Hello, World!")
    b.RunMainWindow()
}

Notice how you can see the result of the code above, a button with the text “Hello, World!”. Not only can you see the result of the code, you can edit the code live. Try changing “Hello, World!” to “Click me!” and you will see the button update accordingly.

Extending hello world

We can expand our hello world example app by displaying a message when a user clicks on the button:

core.NewButton(b).SetText("Hello, World!").OnClick(func(e events.Event) {
    core.MessageSnackbar(b, "Hello!")
})

We can customize the message based on the user’s name:

tf := core.NewTextField(b).SetPlaceholder("Name")
core.NewButton(b).SetText("Hello, World!").OnClick(func(e events.Event) {
    core.MessageSnackbar(b, "Hello, "+tf.Text()+"!")
})