gova-declarative-gui
Gova Declarative GUI Framework
Skill by ara.so — Daily 2026 Skills collection.
Gova is a declarative GUI framework for Go that builds native desktop apps for macOS, Windows, and Linux from a single codebase. Views are plain Go structs, state is explicit via a Scope, and go build produces one static binary. Internally powered by Fyne (BSD-3), but the public API is stable and renderer-independent.
Install
go get github.com/nv404/gova@latest
Optional CLI:
go install github.com/nv404/gova/cmd/gova@latest
Prerequisites:
- Go 1.26+
- C toolchain: Xcode CLT (macOS),
build-essential+libgl1-mesa-dev(Linux), MinGW (Windows)
Key CLI Commands
| Command | Purpose |
|---|---|
gova dev ./path/to/app |
Hot reload — watch .go files, rebuild and relaunch on save |
gova build ./path/to/app |
Compile to ./bin/<name> static binary |
gova run ./path/to/app |
Build and launch once, no file watching |
go build -ldflags "-s -w" |
Stripped binary (~23 MB for simple apps) |
Core Concepts
1. Components as Structs
A component is a Go struct implementing Body(s *g.Scope) g.View. Fields on the struct are typed props; zero values are defaults.
package main
import g "github.com/nv404/gova"
type Greeting struct {
Name string // prop with zero-value default ""
}
func (c Greeting) Body(s *g.Scope) g.View {
name := c.Name
if name == "" {
name = "World"
}
return g.Text("Hello, " + name + "!").Font(g.Title)
}
2. Reactive State with Scope
State lives on the *g.Scope passed to Body. No hidden scheduler, no hook-ordering rules.
func (Counter) Body(s *g.Scope) g.View {
count := g.State(s, 0) // typed signal, initial value 0
return g.VStack(
g.Text(count.Format("Count: %d")).Font(g.Title),
g.HStack(
g.Button("-", func() { count.Set(count.Get() - 1) }),
g.Button("+", func() { count.Set(count.Get() + 1) }),
).Spacing(g.SpaceMD),
).Padding(g.SpaceLG)
}
3. Entry Point
func main() {
g.Run("My App", g.Component(MyComponent{}))
}
Layout Primitives
// Vertical stack
g.VStack(child1, child2, child3).Spacing(g.SpaceMD).Padding(g.SpaceLG)
// Horizontal stack
g.HStack(child1, child2).Spacing(g.SpaceSM)
// Layered/overlapping stack
g.ZStack(background, foreground)
// Scaffold (app shell with nav, toolbar, etc.)
g.Scaffold(
g.NavBar("Title"),
content,
)
Spacing Constants
| Constant | Use |
|---|---|
g.SpaceSM |
Small gaps |
g.SpaceMD |
Medium gaps |
g.SpaceLG |
Large padding |
Built-in Views
g.Text("Hello").Font(g.Title) // styled text
g.Text("body text").Font(g.Body)
g.Button("Click me", func() { /* handler */ })
g.TextField(value.Get(), func(s string) { value.Set(s) })
g.Toggle(enabled.Get(), func(b bool) { enabled.Set(b) })
g.Image("path/to/image.png")
g.Spacer() // flexible space
g.Divider()
Font Constants
g.Title, g.Headline, g.Body, g.Caption, g.Mono
State Patterns
Basic State
count := g.State(s, 0)
count.Get() // read
count.Set(42) // write, triggers re-render
count.Format("Value: %d") // returns formatted string signal
Derived / Computed State
doubled := g.Derived(s, func() int {
return count.Get() * 2
})
Effects (side effects on state change)
g.Effect(s, func() {
fmt.Println("count changed to", count.Get())
}, count) // dependencies
Persisted State (survives hot reload)
name := g.PersistedState(s, "user-name", "")
Full Example: Todo App
package main
import g "github.com/nv404/gova"
type Todo struct {
Text string
Done bool
}
type TodoApp struct{}
func (TodoApp) Body(s *g.Scope) g.View {
todos := g.State(s, []Todo{})
input := g.State(s, "")
addTodo := func() {
if input.Get() == "" {
return
}
todos.Set(append(todos.Get(), Todo{Text: input.Get()}))
input.Set("")
}
rows := make([]g.View, 0, len(todos.Get()))
for i, todo := range todos.Get() {
i, todo := i, todo // capture loop vars
rows = append(rows, g.HStack(
g.Toggle(todo.Done, func(v bool) {
list := todos.Get()
list[i].Done = v
todos.Set(list)
}),
g.Text(todo.Text),
).Spacing(g.SpaceSM))
}
return g.VStack(
g.Text("Todos").Font(g.Title),
g.VStack(rows...).Spacing(g.SpaceSM),
g.HStack(
g.TextField(input.Get(), func(v string) { input.Set(v) }),
g.Button("Add", addTodo),
).Spacing(g.SpaceSM),
).Padding(g.SpaceLG)
}
func main() {
g.Run("Todo", g.Component(TodoApp{}))
}
Native Dialogs (macOS: NSAlert / NSOpenPanel; other platforms: Fyne fallback)
// Alert dialog
g.Button("Alert", func() {
g.Alert(g.AlertOptions{
Title: "Warning",
Message: "Something happened.",
Style: g.AlertWarning,
})
})
// Open file dialog
g.Button("Open File", func() {
path, err := g.OpenFileDialog(g.OpenFileOptions{
Title: "Choose a file",
Extensions: []string{".txt", ".md"},
})
if err == nil && path != "" {
filePath.Set(path)
}
})
// Save file dialog
g.Button("Save", func() {
dest, err := g.SaveFileDialog(g.SaveFileOptions{
Title: "Save As",
DefaultFilename: "output.txt",
})
if err == nil && dest != "" {
// write to dest
}
})
Platform Integration (macOS Dock)
// Dock badge (macOS)
g.DockBadge("3")
g.DockBadge("") // clear badge
// Dock progress (macOS)
g.DockProgress(0.75) // 0.0–1.0
g.DockProgress(-1) // hide
// Dock menu (macOS)
g.SetDockMenu([]g.MenuItem{
{Label: "New Window", Action: func() { /* ... */ }},
{Label: "Preferences", Action: func() { /* ... */ }},
})
Theming and Colors
// Dark/light toggle
g.Button("Toggle Theme", func() {
if g.CurrentTheme() == g.ThemeDark {
g.SetTheme(g.ThemeLight)
} else {
g.SetTheme(g.ThemeDark)
}
})
// Semantic colors in custom views
g.Text("Primary").Color(g.ColorPrimary)
g.Text("Secondary").Color(g.ColorSecondary)
g.Text("Danger").Color(g.ColorDanger)
Component Composition with Viewable
type Card struct {
Title string
Content g.View
}
func (c Card) Body(s *g.Scope) g.View {
return g.VStack(
g.Text(c.Title).Font(g.Headline),
g.Divider(),
c.Content,
).Padding(g.SpaceMD)
}
// Usage
g.Component(Card{
Title: "My Card",
Content: g.Text("Card body text"),
})
Navigation / Multi-View
type NotesApp struct{}
func (NotesApp) Body(s *g.Scope) g.View {
selected := g.State(s, "list")
switch selected.Get() {
case "detail":
return g.Component(DetailView{OnBack: func() { selected.Set("list") }})
default:
return g.Component(ListView{OnSelect: func() { selected.Set("detail") }})
}
}
App Icon at Runtime
func main() {
app := g.NewApp("My App")
app.SetIcon("assets/icon.png") // set before Run
app.Run(g.Component(MyComponent{}))
}
Hot Reload with PersistedState
When using gova dev, use g.PersistedState to keep UI state across rebuilds:
func (MyApp) Body(s *g.Scope) g.View {
// survives hot reload, lost on full restart
activeTab := g.PersistedState(s, "active-tab", "home")
// ...
}
Project Structure (recommended)
myapp/
├── main.go # g.Run entry point
├── components/
│ ├── header.go
│ └── sidebar.go
├── views/
│ ├── home.go
│ └── settings.go
├── assets/
│ └── icon.png
└── go.mod
Platform Support Matrix
| Feature | macOS | Windows | Linux |
|---|---|---|---|
| Core UI | ✅ | ✅ | ✅ |
| Hot reload | ✅ | ✅ | ✅ |
| App icon | ✅ | ✅ | ✅ |
| Native dialogs | NSAlert/NSOpenPanel | Fyne fallback | Fyne fallback |
| Dock/taskbar | NSDockTile ✅ | Planned | Planned |
Troubleshooting
cgo: C compiler not found
- macOS:
xcode-select --install - Linux:
sudo apt install build-essential libgl1-mesa-dev - Windows: Install MinGW-w64 and add to PATH
go build fails with OpenGL errors on Linux
sudo apt install libgl1-mesa-dev xorg-dev
Hot reload not picking up changes
- Ensure you're using
gova dev, notgo run - Confirm
.gofiles are in a directory watched bygova dev ./path
Binary is large (~32 MB)
- Strip symbols:
go build -ldflags "-s -w" -o ./bin/myapp - Result: ~23 MB. This is expected — Fyne (OpenGL renderer) is bundled.
State not updating the UI
- Always call
count.Set(...)— mutating a slice/map in place withoutSetwon't trigger re-render - For slices: copy, modify, then set:
list := todos.Get(); list[i] = newVal; todos.Set(list)
API breakage (pre-1.0)
- Pin a specific tag:
go get github.com/nv404/gova@v0.x.y - Check the CHANGELOG before upgrading
Useful Links
- Docs: https://gova.dev
- Getting started: https://gova.dev/docs/getting-started/installation
- State & effects: https://gova.dev/docs/state/state
- Native dialogs: https://gova.dev/docs/overlays/native-dialogs
- CLI reference: https://gova.dev/docs/cli/overview
- pkg.go.dev: https://pkg.go.dev/github.com/nv404/gova