State

A reactive value that automatically triggers UI redraw when changed.

Basic Usage

counter := NewState(0)
counter.Bind(window)

// In your UI
Text(fmt.Sprintf("Count: %d", counter.Get()))

// Update the value (triggers redraw)
counter.Set(counter.Get() + 1)

Creating State

// Create state with initial value
counter := NewState(0)
name := NewState("John")
isEnabled := NewState(true)

Methods

Method	Description	Example
`NewState[T](initial)`	Creates a new reactive state	`NewState(0)`
`Get()`	Returns the current value	`counter.Get()`
`Set(value)`	Sets a new value and triggers redraw	`counter.Set(5)`
`Update(fn)`	Applies a function to update the value	`counter.Update(func(n int) int { return n + 1 })`
`Bind(window)`	Binds state to a window for reactivity	`counter.Bind(w)`

Type Constraint

State works with any comparable type:

// Integers
count := NewState(0)

// Strings
name := NewState("")

// Booleans
visible := NewState(true)

// Custom types (must be comparable)
type Status int
status := NewState(Status(0))

Examples

// Counter example
func run(w *app.Window) error {
    counter := NewState(0).Bind(w)
    
    // ... in render loop
    Column([]any{
        Text(fmt.Sprintf("Count: %d", counter.Get())),
        Button("Increment", OnClick(func() {
            counter.Set(counter.Get() + 1)
        })),
        Button("Decrement", OnClick(func() {
            counter.Update(func(n int) int { return n - 1 })
        })),
    })
}

// Toggle example
func run(w *app.Window) error {
    isDark := NewState(false).Bind(w)
    
    // ... in render loop
    theme := Light
    if isDark.Get() {
        theme = Dark
    }
    
    Button("Toggle Theme", OnClick(func() {
        isDark.Set(!isDark.Get())
    }))
}

// Text input example
func run(w *app.Window) error {
    name := NewState("").Bind(w)
    
    Column([]any{
        TextField(
            Hint("Enter name"),
            OnChange(func(s string) {
                name.Set(s)
            }),
        ),
        Text(fmt.Sprintf("Hello, %s!", name.Get())),
    })
}

Thread Safety

State is thread-safe. You can safely call Get(), Set(), and Update() from any goroutine.