When we build internal pages (e.g. about:settings), there is currently
quite a lot of boilerplate needed to communicate between the browser and
the page. This includes creating IDL for the page and the IPC for every
message sent between the processes.
These internal pages are also special in that they have privileged
access to and control over the browser process.
The framework introduced here serves to ease the setup of new internal
pages and to reduce the access that WebContent processes have to the
browser process. WebUI pages can send requests to the browser process
via a `ladybird.sendMessage` API. Responses from the browser are passed
through a WebUIMessage event. So, for example, an internal page may:
ladybird.sendMessage("getDataFor", { id: 123 });
document.addEventListener("WebUIMessage", event => {
if (event.name === "gotData") {
console.assert(event.data.id === 123);
}
});
To handle these messages, we set up a new IPC connection between the
browser and WebContent processes. This connection is torn down when
the user navigates away from the internal page.
Our existing WebContentConsoleClient is very specific to our home-grown
Inspector. It renders console output to an HTML string. For DevTools, we
will not want this behavior; we will want to send representations of raw
JS values.
This patch makes WebContentConsoleClient a base class to handle console
input from the user, either from the Inspector or from DevTools. It then
moves the HTML rendering needed for the Inspector to a new class,
InspectorConsoleClient. And we add a DevToolsConsoleClient (currently
just stubbed) to handle needs specific to DevTools.
We choose at runtime which console client to install, based on the
--devtools command line flag.
The "WebContent" service provides a very restricted instance of LibWeb
running as an unprivileged user account. This will be used to implement
process separation in Browser, among other things.
This first cut of the service only spawns a single WebContent process
when someone connects to /tmp/portal/webcontent. We will soon switch
this over to spawning a new process for each connection.
Since this feature is very immature, we'll be bringing it up inside of
Demos/WebView as a separate demo program. Eventually this will become
a reusable widget that anyone can embed and easily get out-of-process
web content in their GUI.
This is pretty, pretty cool! :^)
