Send Native Messages To External Apps With Vimium C

Ever wished you could seamlessly integrate your browser actions with external applications? Well, you're in luck! In this guide, we'll dive deep into how you can send native messages from your browser to an external application using the powerful Vimium C extension. This isn't just about sending a simple command; it's about unlocking a new level of browser automation and interaction. We'll cover the specifics of configuring Vimium C's Custom search engines to communicate with extensions like external-application-button, a handy tool that bridges the gap between your browser and your favorite desktop apps. Imagine opening YouTube videos directly in mpv with just a keyboard shortcut, or controlling other applications with browser-based commands. This article will walk you through the process, from understanding the chrome.runtime.sendMessage API to troubleshooting common issues. So, buckle up, and let's explore the exciting world of browser-to-application communication!

Understanding Native Messaging and Vimium C

Native messaging is a powerful feature that allows browser extensions to communicate with native applications installed on your computer. This opens up a world of possibilities, enabling you to extend your browser's functionality beyond its built-in capabilities. For instance, you might want to send the current URL to a desktop media player, control a smart home device, or interact with specialized software. Vimium C, a highly customizable browser extension that brings Vim-like keybindings to your browsing experience, can be instrumental in orchestrating these interactions. Its Custom search engines feature, while primarily designed for web searches, can be cleverly repurposed to send messages to native applications. This is particularly useful when you want to trigger specific actions in external programs based on your browsing context. The key to making this work lies in understanding how chrome.runtime.sendMessage functions and how to format the message correctly. The external-application-button extension, for example, listens for these messages and executes predefined commands. We'll be focusing on sending a message to this extension to launch a video in mpv in fullscreen and always on top, demonstrating a practical application of this technology. We'll also touch upon the importance of the unique message identifiers and the structured data required for the communication to be successful. By the end of this section, you'll have a solid grasp of the underlying concepts and the tools we'll be using.

The chrome.runtime.sendMessage API

The chrome.runtime.sendMessage API is the cornerstone of communication between browser components and, crucially for our purpose, between extensions and native applications. When you use this API, you're essentially sending a message that can be picked up by another part of your extension or, in this case, by a native application that has registered itself as a message listener. The API takes two primary arguments: a message string (often an ID for routing) and an optional object containing the message payload. In the context of interacting with an external application like one managed by the external-application-button extension, the message string usually serves as a unique identifier for the target application or service. The payload, an object, contains the specific instructions or data you want to send. For our example, the payload includes details like the path to the executable (mpv), the args to be passed to it (--fullscreen --ontop), and information about the current tab, such as its url. It's vital to get this structure exactly right, as the receiving application will parse this object to understand what action to perform. The example provided, chrome.runtime.sendMessage('{65b77238-bb05-470a-a445-ec0efe1d66c4}', {...});, illustrates this perfectly. The long string in curly braces is the ID that the external-application-button extension recognizes. The subsequent object specifies that we want to run mpv with certain arguments and provides the URL of the video. Understanding this API is fundamental to leveraging Vimium C for more than just navigation.

Configuring Vimium C Custom Search Engines

Vimium C's Custom search engines feature is a hidden gem that allows for powerful customization beyond simple web searches. While it might seem counterintuitive, this feature can be adapted to send messages to native applications. The way it works is by defining a URL pattern that, when matched, triggers a specific action. In our case, instead of a search engine URL, we'll configure it to execute JavaScript that utilizes the chrome.runtime.sendMessage API. To set this up, you'll navigate to Vimium C's options, find the Custom search engines section, and add a new entry. The