fpCEF3

Chromium Embedded Framework for Free Pascal

How to get started on

Windows

Download CEF3 from here and copy all .dll files from either Debug or Release to the directory your .exe is / will be in.

Install cef3.lpk into Lazarus

Look into the examples

Linux

Download CEF3 from here and copy / link libcef.so (and maybe libffmpegsumo.so),
a) to a default library location, eg. /usr/lib(64), /usr/local/lib(64) OR
b) somewhere and set LD_LIBRARY_PATH accordingly

Install cef3.lpk into Lazarus

Look into the examples

Notes

Important: make sure you have cthreads as the first unit in your main program.

Also libcef.so needs the resources (folder locales and cef.pak, you can find them in the CEF package) in the directory your executable is in.

Hints

Don't use --single-process and don't change CefSingleProcess to True.
This will trigger a SIGSEGV in pthread_mutex_lock, which is a bug in either CEF3 or Chromium itself: You can find more details here

If crashes occur too often, you might try to turn off runtime checks in the project settings (mainly -Ct and -CR).

If you're using openSUSE (maybe some other distros, too) and your program crashes immidiately after being started, you could try to execute

echo 1073741824 > /proc/sys/kernel/shmmax

and see if the crash goes away.
That is a known bug in Chromium, which still isn't fixed.

If the browser goes "blank" (e.g. when loading a page), the render process crashed. Most ot the time it seems to be related to JavaScript/V8, see Debugging on how to debug the render process.
Please note, that the render process will be automatically restarted on the next page request.

SubProcess

When initialising CEF for the first time (mostly in your main app) a subprocess is started. By default a second instance of the main program is used as the subprocess. The preferred way however is to define an own (minimal) subprocess executable.

You can achive this in fpCEF3 by setting CefBrowserSubprocessPath to the path of your subprocess executable. In the LCLSimple example this can be done by changing TMainform.FormCreate at the end of main.pas.

A minimal subprocess can be found in /Examples/SubProcess. It should work for any use case. Note, that the subprocess also needs the CEF3 library and resources in its path, so the easiest way is to put the subprocess executable in the same folder as the main exe.

More details here

Debugging

Sometimes it is useful to debug the subprocesses spawned by cef. On Linux this can be done by adding

--renderer-cmd-prefix='xterm -title renderer -e gdb --args'

to the command line.
Further details can be found here.

FAQ:

Which versions of CEF are supported?

fpCEF3 only supports CEF3, no support for CEF1. Version 3.1650 (and newer) should work.

Which platforms are supported?

Windows
Linux with GTK2

The plain header should be ready for Mac (maybe with small changes), but the component needs to be adopted.

How stable is fpCEF?

Overall it looks good now, especially the Windows part. Unfortunately there seem to be bugs in Chromium / CEF3 itself as far as Linux is concerned.

Is there a documentation for fpCEF?

No, but you can find information in

cef3lib.pas / cef3api.pas
the sample programs (admittedly very basic ones)
the official api docs here
the official cefclient example program here

If you feel like contributing some more Pascal examples - please do.

What are the differences to dcef3?

compatibility with Free Pascal / Lazarus
reworked unit layout - more modular
slightly changed mechanism for loading the library
cef3api_static unit
removed VLC and FMX component

Can I help?

Of course - patches are always welcome :)

Can you help?

To a certain amount - yes, but don't expect too much.

ARADTech/fpCEF3