astilectron

Thanks to go-astilectron build cross platform GUI apps with GO and HTML/JS/CSS. It is the official GO bindings of astilectron and is powered by Electron.

Real-life examples

Here's a list of awesome projects using go-astilectron (if you're using go-astilectron and want your project to be listed here please submit a PR):

• go-astivid Video tools written in GO
• GroupMatcher Program to allocate persons to groups while trying to fulfill all the given wishes as good as possible

Quick start

WARNING: the code below doesn't handle errors for readibility purposes. However you SHOULD!

Import go-astilectron

To import go-astilectron run:

$ go get -u github.com/asticode/go-astilectron

Start go-astilectron

// Initialize astilectron
var a, _ = astilectron.New(astilectron.Options{
    AppName: "<your app name>",
    AppIconDefaultPath: "<your .png icon>",
    AppIconDarwinPath:  "<your .icns icon>",
    BaseDirectoryPath: "<where you want the provisioner to install the dependencies>",
})
defer a.Close()

// Start astilectron
a.Start()

For everything to work properly we need to fetch 2 dependencies : astilectron and Electron. .Start() takes care of it by downloading the sources and setting them up properly.

In case you want to embed the sources in the binary to keep a unique binary you can use the NewDisembedderProvisioner function to get the proper Provisioner and attach it to go-astilectron with .SetProvisioner(p Provisioner). Check out the example to see how to use it with go-bindata.

Beware when trying to add your own app icon as you'll need 2 icons : one compatible with MacOSX (.icns) and one compatible with the rest (.png for instance).

If no BaseDirectoryPath is provided, it defaults to the executable's directory path.

The majority of methods are synchrone which means that when executing them go-astilectron will block until it receives a specific Electron event or until the overall context is cancelled. This is the case of .Start() which will block until it receives the app.event.ready astilectron event or until the overall context is cancelled.

Create a window

// Create a new window
var w, _ = a.NewWindow("http://127.0.0.1:4000", &astilectron.WindowOptions{
    Center: astilectron.PtrBool(true),
    Height: astilectron.PtrInt(600),
    Width:  astilectron.PtrInt(600),
})
w.Create()

When creating a window you need to indicate a URL as well as options such as position, size, etc.

This is pretty straightforward except the astilectron.Ptr* methods so let me explain: GO doesn't do optional fields when json encoding unless you use pointers whereas Electron does handle optional fields. Therefore I added helper methods to convert int, bool and string into pointers and used pointers in structs sent to Electron.

Add listeners

// Add a listener on Astilectron
a.On(astilectron.EventNameAppCrash, func(e astilectron.Event) (deleteListener bool) {
    astilog.Error("App has crashed")
    return
})

// Add a listener on the window
w.On(astilectron.EventNameWindowEventResize, func(e astilectron.Event) (deleteListener bool) {
    astilog.Info("Window resized")
    return
})

Nothing much to say here either except that you can add listeners to Astilectron as well.

Play with the window

// Play with the window
w.Resize(200, 200)
time.Sleep(time.Second)
w.Maximize()

Check out the Window doc for a list of all exported methods

Send messages between GO and your webserver

In your webserver add the following javascript to any of the pages you want to interact with:

<script>
    // This will wait for the astilectron namespace to be ready
    document.addEventListener('astilectron-ready', function() {
    
        // This will listen to messages sent by GO
        astilectron.listen(function(message) {
                            
            // This will send a message back to GO
            astilectron.send("I'm good bro")
        });
    })
</script>

In your GO app add the following:

// Listen to messages sent by webserver
w.On(astilectron.EventNameWindowEventMessage, func(e astilectron.Event) (deleteListener bool) {
    var m string
    e.Message.Unmarshal(&m)
    astilog.Infof("Received message %s", m)
    return
})

// Send message to webserver
w.Send("What's up?")

And that's it!

NOTE: needless to say that the message can be something other than a string. A custom struct for instance!

Handle several screens/displays

// If several displays, move the window to the second display
var displays = a.Displays()
if len(displays) > 1 {
    time.Sleep(time.Second)
    w.MoveInDisplay(displays[1], 50, 50)
}

Menus

// Init a new app menu
// You can do the same thing with a window
var m = a.NewMenu([]*astilectron.MenuItemOptions{
    {
        Label: astilectron.PtrStr("Separator"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Label: astilectron.PtrStr("Normal 1")},
            {
                Label: astilectron.PtrStr("Normal 2"),
                OnClick: func(e astilectron.Event) (deleteListener bool) {
                    astilog.Info("Normal 2 item has been clicked")
                    return
                },
            },
            {Type: astilectron.MenuItemTypeSeparator},
            {Label: astilectron.PtrStr("Normal 3")},
        },
    },
    {
        Label: astilectron.PtrStr("Checkbox"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Checked: astilectron.PtrBool(true), Label: astilectron.PtrStr("Checkbox 1"), Type: astilectron.MenuItemTypeCheckbox},
            {Label: astilectron.PtrStr("Checkbox 2"), Type: astilectron.MenuItemTypeCheckbox},
            {Label: astilectron.PtrStr("Checkbox 3"), Type: astilectron.MenuItemTypeCheckbox},
        },
    },
    {
        Label: astilectron.PtrStr("Radio"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Checked: astilectron.PtrBool(true), Label: astilectron.PtrStr("Radio 1"), Type: astilectron.MenuItemTypeRadio},
            {Label: astilectron.PtrStr("Radio 2"), Type: astilectron.MenuItemTypeRadio},
            {Label: astilectron.PtrStr("Radio 3"), Type: astilectron.MenuItemTypeRadio},
        },
    },
    {
        Label: astilectron.PtrStr("Roles"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Label: astilectron.PtrStr("Minimize"), Role: astilectron.MenuItemRoleMinimize},
            {Label: astilectron.PtrStr("Close"), Role: astilectron.MenuItemRoleClose},
        },
    },
})

// Retrieve a menu item
// This will retrieve the "Checkbox 1" item
mi, _ := m.Item(1, 0)

// Add listener manually
// An OnClick listener has already been added in the options directly for another menu item
mi.On(astilectron.EventNameMenuItemEventClicked, func(e astilectron.Event) bool {
    astilog.Infof("Menu item has been clicked. 'Checked' status is now %t", *e.MenuItemOptions.Checked)
    return false
})

// Create the menu
m.Create()

// Manipulate a menu item
mi.SetChecked(true)

// Init a new menu item
var ni = m.NewItem(&astilectron.MenuItemOptions{
    Label: astilectron.PtrStr("Inserted"),
    SubMenu: []*astilectron.MenuItemOptions{
        {Label: astilectron.PtrStr("Inserted 1")},
        {Label: astilectron.PtrStr("Inserted 2")},
    },
})

// Insert the menu item at position "1"
m.Insert(1, ni)

// Fetch a sub menu
s, _ := m.SubMenu(0)

// Init a new menu item
ni = s.NewItem(&astilectron.MenuItemOptions{
    Label: astilectron.PtrStr("Appended"),
    SubMenu: []*astilectron.MenuItemOptions{
        {Label: astilectron.PtrStr("Appended 1")},
        {Label: astilectron.PtrStr("Appended 2")},
    },
})

// Append menu item dynamically
s.Append(ni)

// Pop up sub menu as a context menu
s.Popup(&astilectron.MenuPopupOptions{PositionOptions: astilectron.PositionOptions{X: astilectron.PtrInt(50), Y: astilectron.PtrInt(50)}})

// Close popup
s.ClosePopup()

// Destroy the menu
m.Destroy()

A few things to know:

• when assigning a role to a menu item, go-astilectron won't be able to capture its click event
• on MacOS there's no such thing as a window menu, only app menus therefore my advice is to stick to one global app menu instead of creating separate window menus

Tray

// New tray
var t = a.NewTray(&astilectron.TrayOptions{
    Image:   astilectron.PtrStr("/path/to/image.png"),
    Tooltip: astilectron.PtrStr("Tray's tooltip"),
})

// New tray menu
var m = t.NewMenu([]*astilectron.MenuItemOptions{
    {
        Label: astilectron.PtrStr("Root 1"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Label: astilectron.PtrStr("Item 1")},
            {Label: astilectron.PtrStr("Item 2")},
            {Type: astilectron.MenuItemTypeSeparator},
            {Label: astilectron.PtrStr("Item 3")},
        },
    },
    {
        Label: astilectron.PtrStr("Root 2"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Label: astilectron.PtrStr("Item 1")},
            {Label: astilectron.PtrStr("Item 2")},
        },
    },
})

// Create the menu
m.Create()

// Create tray
t.Create()

Dialogs

In your webserver add one of the following javascript to achieve any kind of dialog.

Error box

<script>
    // This will wait for the astilectron namespace to be ready
    document.addEventListener('astilectron-ready', function() {
        // This will open the dialog
        astilectron.showErrorBox("My Title", "My content")
    })
</script>

Message box

<script>
    // This will wait for the astilectron namespace to be ready
    document.addEventListener('astilectron-ready', function() {
        // This will open the dialog
        astilectron.showMessageBox({message: "My message", title: "My Title"})
    })
</script>

Open dialog

<script>
    // This will wait for the astilectron namespace to be ready
    document.addEventListener('astilectron-ready', function() {
        // This will open the dialog
        astilectron.showOpenDialog({properties: ['openFile', 'multiSelections'], title: "My Title"}, function(paths) {
            console.log("chosen paths are ", paths)
        })
    })
</script>

Save dialog

<script>
    // This will wait for the astilectron namespace to be ready
    document.addEventListener('astilectron-ready', function() {
        // This will open the dialog
        astilectron.showSaveDialog({title: "My title"}, function(filename) {
            console.log("chosen filename is ", filename)
        })
    })
</script>

Final code

// Set up the logger
var l <your logger type>
astilog.SetLogger(l)

// Start an http server
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte(`<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Hello world</title>
    </head>
    <body>
        <span id="message">Hello world</span>
        <script>
            // This will wait for the astilectron namespace to be ready
            document.addEventListener('astilectron-ready', function() {
                // This will listen to messages sent by GO
                astilectron.listen(function(message) {
                    document.getElementById('message').innerHTML = message
                    // This will send a message back to GO
                    astilectron.send("I'm good bro")
                });
            })
        </script>
    </body>
    </html>`))
})
go http.ListenAndServe("127.0.0.1:4000", nil)

// Initialize astilectron
var a, _ = astilectron.New(astilectron.Options{
    AppName: "<your app name>",
    AppIconDefaultPath: "<your .png icon>",
    AppIconDarwinPath:  "<your .icns icon>",
    BaseDirectoryPath: "<where you want the provisioner to install the dependencies>",
})
defer a.Close()

// Handle quit
a.HandleSignals()
a.On(astilectron.EventNameAppCrash, func(e astilectron.Event) (deleteListener bool) {
    astilog.Error("App has crashed")
    return
})

// Start astilectron: this will download and set up the dependencies, and start the Electron app
a.Start()

// Init a new app menu
// You can do the same thing with a window
var m = a.NewMenu([]*astilectron.MenuItemOptions{
    {
        Label: astilectron.PtrStr("Separator"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Label: astilectron.PtrStr("Normal 1")},
            {
                Label: astilectron.PtrStr("Normal 2"),
                OnClick: func(e astilectron.Event) (deleteListener bool) {
                    astilog.Info("Normal 2 item has been clicked")
                    return
                },
            },
            {Type: astilectron.MenuItemTypeSeparator},
            {Label: astilectron.PtrStr("Normal 3")},
        },
    },
    {
        Label: astilectron.PtrStr("Checkbox"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Checked: astilectron.PtrBool(true), Label: astilectron.PtrStr("Checkbox 1"), Type: astilectron.MenuItemTypeCheckbox},
            {Label: astilectron.PtrStr("Checkbox 2"), Type: astilectron.MenuItemTypeCheckbox},
            {Label: astilectron.PtrStr("Checkbox 3"), Type: astilectron.MenuItemTypeCheckbox},
        },
    },
    {
        Label: astilectron.PtrStr("Radio"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Checked: astilectron.PtrBool(true), Label: astilectron.PtrStr("Radio 1"), Type: astilectron.MenuItemTypeRadio},
            {Label: astilectron.PtrStr("Radio 2"), Type: astilectron.MenuItemTypeRadio},
            {Label: astilectron.PtrStr("Radio 3"), Type: astilectron.MenuItemTypeRadio},
        },
    },
    {
        Label: astilectron.PtrStr("Roles"),
        SubMenu: []*astilectron.MenuItemOptions{
            {Label: astilectron.PtrStr("Minimize"), Role: astilectron.MenuItemRoleMinimize},
            {Label: astilectron.PtrStr("Close"), Role: astilectron.MenuItemRoleClose},
        },
    },
})

// Retrieve a menu item
// This will retrieve the "Checkbox 1" item
mi, _ := m.Item(1, 0)

// Add listener manually
// An OnClick listener has already been added in the options directly for another menu item
mi.On(astilectron.EventNameMenuItemEventClicked, func(e astilectron.Event) bool {
    astilog.Infof("Menu item has been clicked. 'Checked' status is now %t", *e.MenuItemOptions.Checked)
    return false
})

// Create the menu
m.Create()

// Create a new window with a listener on resize
var w, _ = a.NewWindow("http://127.0.0.1:4000", &astilectron.WindowOptions{
    Center: astilectron.PtrBool(true),
    Height: astilectron.PtrInt(600),
    Icon:   astilectron.PtrStr(<your icon path>),
    Width:  astilectron.PtrInt(600),
})
w.On(astilectron.EventNameWindowEventResize, func(e astilectron.Event) (deleteListener bool) {
    astilog.Info("Window resized")
    return
})
w.On(astilectron.EventNameWindowEventMessage, func(e astilectron.Event) (deleteListener bool) {
    var m string
    e.Message.Unmarshal(&m)
    astilog.Infof("Received message %s", m)
    return
})
w.Create()

// Play with the window
w.Resize(200, 200)
time.Sleep(time.Second)
w.Maximize()

// If several displays, move the window to the second display
var displays = a.Displays()
if len(displays) > 1 {
    time.Sleep(time.Second)
    w.MoveInDisplay(displays[1], 50, 50)
}

// Send a message to the server
time.Sleep(time.Second)
w.Send("What's up?")

// Manipulate a menu item
time.Sleep(time.Second)
mi.SetChecked(true)

// Init a new menu item
var ni = m.NewItem(&astilectron.MenuItemOptions{
    Label: astilectron.PtrStr("Inserted"),
    SubMenu: []*astilectron.MenuItemOptions{
        {Label: astilectron.PtrStr("Inserted 1")},
        {Label: astilectron.PtrStr("Inserted 2")},
    },
})

// Insert the menu item at position "1"
time.Sleep(time.Second)
m.Insert(1, ni)

// Fetch a sub menu
s, _ := m.SubMenu(0)

// Init a new menu item
ni = s.NewItem(&astilectron.MenuItemOptions{
    Label: astilectron.PtrStr("Appended"),
    SubMenu: []*astilectron.MenuItemOptions{
        {Label: astilectron.PtrStr("Appended 1")},
        {Label: astilectron.PtrStr("Appended 2")},
    },
})

// Append menu item dynamically
time.Sleep(time.Second)
s.Append(ni)

// Pop up sub menu as a context menu
time.Sleep(time.Second)
s.Popup(&astilectron.MenuPopupOptions{PositionOptions: astilectron.PositionOptions{X: astilectron.PtrInt(50), Y: astilectron.PtrInt(50)}})

// Close popup
time.Sleep(time.Second)
s.ClosePopup()

// Destroy the menu
time.Sleep(time.Second)
m.Destroy()

// Blocking pattern
a.Wait()

Bootstrap

For convenience purposes I've added a bootstrap to help first timers and avoid code duplications.

NOTE: you DON'T have to use the bootstrap, it's entirely up to you whether to use it or not.

The bootstrap allows you to quickly create a one-window application.

Using static files and remote messaging (the best way)

In order to use the bootstrap with static files and remote messaging you must:

• follow the following project organization:

    |--+ resources
        |
        |--+ app (contains your static files such as .html, .css, .js, .png, etc.)
    |--+ main.go
  

• use the MessageHandler bootstrap option in order to handle remote messaging

• use remote messaging in your static files

Using a web server

In order to use the bootstrap with a web server you must:

• follow the following project organization:

    |--+ resources
          |
          |--+ static (contains your static files such as .css, .js, .png, etc.)
          |
          |--+ templates (contains your templates .html files)
    |--+ main.go
  

• use the AdaptRouter and TemplateData bootstrap options in order to handle the server routes

Common

• if you're using the RestoreAssets bootstrap option, add the following comment on top of your main() method:

    //go:generate go-bindata -pkg $GOPACKAGE -o resources.go resources/...
  

  and run the following command before building your binary:

    $ go generate main.go
  

• use the bootstrap.Run() method

Check out the example for a detailed working example (see the Examples section below for the specific commands to run).

I want to see it in actions!

To make things clearer I've tried to split features in different examples.

To run any of the examples, run the following commands:

$ go run examples/<name of the example>/main.go -v

Here's a list of the examples:

• 1.basic_window creates a basic window that displays a static .html file
• 2.basic_window_events plays with basic window methods and shows you how to set up your own listeners
• 3.webserver_app sets up a basic webserver app
• 4.remote_messaging sends a message to the webserver and listens for any response
• 5.single_binary_distribution shows how to use go-astilectron in a unique binary. For this example you have to run one of the previous examples (so that the .zip files exist) and run the following commands:

$ go generate examples/5.single_binary_distribution/main.go
$ go run examples/5.single_binary_distribution/main.go examples/5.single_binary_distribution/vendor.go -v

• 6.screens_and_displays plays around with screens and displays
• 7.menus creates and manipulates menus
• 8.bootstrap shows how to use the bootstrap. For this example you have to run the following commands:

$ go generate examples/8.bootstrap/main.go
$ go run examples/8.bootstrap/main.go examples/8.bootstrap/resources.go -v

• 9.tray creates a tray

Features and roadmap

• custom branding (custom app name, app icon, etc.)
• window basic methods (create, show, close, resize, minimize, maximize, ...)
• window basic events (close, blur, focus, unresponsive, crashed, ...)
• remote messaging (messages between GO and the JS in the webserver)
• single binary distribution
• multi screens/displays
• menu methods and events (create, insert, append, popup, clicked, ...)
• bootstrap
• dialogs (open or save file, alerts, ...)
• tray
• loader
• bundle helper
• accelerators (shortcuts)
• file methods (drag & drop, ...)
• clipboard methods
• power monitor events (suspend, resume, ...)
• notifications (macosx)
• desktop capturer (audio and video)
• session methods
• session events
• window advanced options (add missing ones)
• window advanced methods (add missing ones)
• window advanced events (add missing ones)
• child windows

Cheers to

go-thrust which is awesome but unfortunately not maintained anymore. It inspired this project.