multi_window

A package for adding multi window support to Flutter on Desktop.

WARNING: This is an experimental package and is under heavy development. No guarantees can be giving that the API will stay the same.

Features

Feature	MacOS	Linux	Windows
Creating new windows	✔️	✔️
Closing existing windows	✔️	✔️
Receive window events¹	✔️	✔️
Communicate between windows	✔️	✔️

Notes:

1. For more info about implemented events see the Events table.

Getting Started

Required Flutter Setup

In your lib/main.dart change your main method to the following:

void main(List<String> args) {
  MultiWindow.init(args);

  ... // Rest of your code
}

Linux Setup

No setup is required for Linux.

MacOS Setup

Inside your application folder, go to macos\runner\MainFlutterWindow.swift and add this line after the one saying import FlutterMacOS:

import FlutterMacOS
import multi_window_macos // Add this line.

Then add the following line as the first line inside the awakeFromNib() function:

override func awakeFromNib() {
    MultiWindowMacosPlugin.registerGeneratedPlugins = RegisterGeneratedPlugins // Add this line.

And below that line change the FlutterViewController to MultiWindowViewController:

let flutterViewController = MultiWindowViewController()

Your code should now look something like this:

... // Your other imports
import multi_window_macos

class MainFlutterWindow: NSWindow {
    override func awakeFromNib() {
        MultiWindowMacosPlugin.registerGeneratedPlugins = RegisterGeneratedPlugins

        let flutterViewController = MultiWindowViewController.init()

        ... // Rest of your code

Usage

Creating a new window

To create a new window you can call the MultiWindow.create method:

final myWindow = await MultiWindow.create(
  'your_unique_key',
  size: Size(100, 100), // Optional size.
  title: 'Your Title', // Optional title.
  alignment: Alignment.center, // Optional alginment.
);

If a window with the given key already exists it will return a reference to that window.

NOTE: The first window that is created on startup will use the key main.

Accessing your current window

The instance of the current window (the window that your dart code is being executed on) is exposed for convencience sake:

final myWindow = MultiWindow.current; // Returns the current instance this code is running on.

CLosing a window

A window can be programmatically closed by calling it's close method:

final myWindow = await MultiWindow.create('myWindow');

// Close the window instance.
await myWindow.close();

When the window succesfully closes the windowClose event will be raised.

Get the count of the current existing windows

Retrieving the total amount of windows can be done using the MultiWindow.count method:

final totalWindows = await MultiWindow.count();

Setting and getting a window title

If you want to set or get the title of your window you can use the setTitle and getTitle methods respectively on your instance:

await myWindow.setTitle('My fancy title');
final currentTitle = await myWindow.getTitle(); // Returns 'My fancy title'.

Listening and emitting events

Listening to events

A MultiWindow instance also exposes an event stream for listening to events on a window instance:

final myWindow = await MultiWindow.create('myWindow');
myWindow.events.listen((event) {
  print('From: ${event.from}, of type ${event.type} with data ${event.data}');
});

An event exists out the following:

• The to is the key of the window that will receive this event, if you are listening on a window it will be that window's key.
• The sender is the key of the window that send the event, this can also be the window that you are listening on.
• The type is an enum that allows you to differentiate between system and user events.
• The data contains dynamic data that was emitted.

Emitting events

You can emit a user event by calling the .emit method on a MultiWindow instance:

await myWindow.emit('Hello world!');