02-button-callback

README

Example 02: Button with Callback

Demonstrates interactive widgets with callback functions that update the UI in response to user actions.

What It Does

• Creates a label and two buttons
• Tracks button click count
• Updates the label text when buttons are clicked
• Shows how to use closures to maintain state

Running

cd examples/02-button-callback
go run main.go

Key Concepts

Callbacks

Buttons accept callback functions that execute when clicked:

let button = widget.NewButton("Click me!", () => {
    // This code runs when the button is clicked
    label.Text = "Updated text"
})

State Management

Variables in the script maintain state across callback executions:

let clickCount = 0

let button = widget.NewButton("Click me!", () => {
    clickCount = clickCount + 1  // Increments each time
})

Widget Property Updates

Widget properties can be modified after creation:

let label = widget.NewLabel("Initial text")
// Later in a callback:
label.Text = "New text"  // Updates the displayed text

Container Layouts

The VBox container arranges widgets vertically:

let layout = container.NewVBox(label, button1, button2)

Status and Result Callbacks

This example demonstrates using callbacks in the Go code to monitor execution:

statusCallback := func(status string) {
    fmt.Printf("Status: %s\n", status)
}

fyneWindow := fynerisor.NewWindow(w, nil, statusCallback, resultCallback)

Files

• main.go: Go program with status monitoring
• button.risor: Risor script with interactive buttons
• README.md: This file