Chrome Runtime

[amaitland]

For historical reasons CEF browser windows are based on the “content” layer WebContents object.

CefSharp currently uses the Alloy Runtime by default. CEF has added support for the Chrome Runtime.

If we could create a CEF browser window based on the “chrome” Browser object we would get much of the “chrome” layer functionality “for free”

The Chrome runtime should support Chrome features that are currently missing from the Alloy Runtime. HTML5 Notifications, Geolocation, Full Extension API, etc.

Embedded non-Views windows (where the host application creates the top-level window), created with CefWindowInfo.SetAsChild.

Version 102 is the first version to support embedding the Chrome Runtime with a non-Views window. The WinForms and Wpf.HwndHost versions will be able to use the Chrome runtime. (disabled by default).

chrome: Add support for embedded non-Views windows

Implementation	Support
WinForms	✔️
Wpf	❌
Wpf.HwndHost	✔️
OffScreen	❌

The WPF and OffScreen versions cannot use the Chrome Runtime yet, see chromiumembedded/cef#3293

There are some limitations:

• Using a custom BrowserSubProcess via BrowserSubprocessPath is not supported yet. You can only self host the browser subprocess. (The Chrome runtime will launch multiple instances of your applications exe). See https://github.com/cefsharp/CefSharp/wiki/SelfHost-BrowserSubProcess for details on Self Hosting.
• Not all handlers are implemented
• Not all methods are implemented

Some of the open issues on the CEF issue tracker:

• chrome: Decide what to do with SetZoomLevel chromiumembedded/cef#3284
• chrome: Add generic solution for executing any Chrome command chromiumembedded/cef#3282
• chrome: Add support for CefDownloadHandler chromiumembedded/cef#3287
• chrome: Add support for CefAudioHandler chromiumembedded/cef#3286
• chrome: Add support for custom application structure: browser_subprocess_path, etc chromiumembedded/cef#3290
• chrome: Add support for off-screen rendering chromiumembedded/cef#3293
• chrome: Add support for programmatic extension management chromiumembedded/cef#3450
• Alloy extension handler should not be used when --enable-chrome-runtime is present chromiumembedded/cef#3529

If you find more issues then please create new discussion with a link so this list can be updated.

I'm seeing strange behaviour when CachePath is left empty with regards to default language.

[amaitland]

DevTools should be supported starting in M119 as par chromiumembedded/cef#3600

[amaitland]

IMPORTANT

Starting in M126 there will be some major changes to the Chrome Runtime. The Chrome bootstrap will be used by default, with browsers created using Alloy styling as their default.

For those wanting to use Chrome styled browsers you can, see #4835 (comment) for example.

Further details at chromiumembedded/cef#3681 Please make sure to read this in full before asking any questions here in the CefSharp repo.

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The alloy bootstrap will be removed in the near future see chromiumembedded/cef#3685

[amaitland]

For those wanting to use Chrome styled browsers you can, see #4835 (comment) for example.

For those upgrading from a previous version that are already using the Chrome Runtime then you will need to change to using CefRuntimeStyle.Chrome.