gurkengewuerz / cefgo

Go bindings for the Chromium Embedded Framework (CEF)

cefgo

These are simple bindings for CEF C API in Go. It's not documented yet, but you can follow the example to figure out how to use. It's pretty simple.
In order to run the examples, the CEF supporting files must be placed beside the executable.

Features

• JS to Go callbacks
• Go to JS eval
• frameless window
• single and sub executable support
• Tested on Windows and Linux (macOS should work using seperate processes)
• window functions (maximize, minimize, show, always on top, etc)
• application icon

CEF Version and Compatibility

This lib is compiled against CEF 94.4.9+g09ee681+chromium-94.0.4606.71 / Chromium 94.0.4606.71 from https://cef-builds.spotifycdn.com/index.html

Installation

1. Download the CEF SDK for your system from Spotify.
2. Locate your installation of cefgo (typically in $GOPATH/src/github.com/Gurkengewuerz/cefgo or $GOPATH/pkg/mod/github.com/Gurkengewuerz/cefgo), and extract the CEF SDK.
   Copy include/* to cefgo/include
   Copy Release/* to cefgo/Release
   Copy Resources/* to cefgo/Release
3. Run your binaries inside the Release folder

Usage on macOS

Because i don't have the opportunity to test cefgo on a mac i need your help. Theoretically cefgo should compile on macOS. Because macOS is different the application needs a bit more preperation.
Please read the CEF Wiki carefully and set up your enviroment. Feel free to share your experience.

About JS callbacks

Callbacks need to be registered before browsers are created. Currently only basic type conversions are supported (undefined/null, bool, int/uint, double, string). Objects and Arrays are possible, but not done. If you are running in multi-process mode (the default - as opposed to single-process) keep in mind the callback will be executed in the browser process and not in the main process.

DevTools

Set the a RemoteDebuggingPort in the Settings struct. Start your application and point your browser to http://127.0.0.1:<port>.

Updating the CEF Version

The process for updating CEF to a newer version is relatively simple.

1. Download a new version from Spotify and extract.
2. Update the headers inside the include folder
3. Extract the new cef resources and libs to the Release folder
4. Try to compile the test application: go clean -cache -testcache && CGO_ENABLED=1 go build -o Release/test.exe examples/main.go
5. Fix any incompatibilities with new APIs until the application compiles.
6. Push the new version, and update the version listed in this README.

cefgo's Issues

More compact libcef.so?

I was looking through the release directory and it looks like the libcef.so that I downloaded is 1012 MB.... I'm surprised it's so big!

Is there a more compact version of this library?

support linux and windows

Build Issue - Couldn't mmap icu data file

Hello!

I found your cefgo project via your post on the go-ultralight issue tracker
maneac/go-ultralight#9 (comment)

I was doing some testing with Ultralight and noticed that some very simple Vue.js wasn't even working... Curious to see how CEF compares... Definitely excellent that it's actually open source!

I am trying to build the example on Ubuntu 20.04, but I'm getting a core dump...

I was able to get the release to build, though note the Readme.md says to use examples/main.go but I think it's updated to examples/mainthead/main.go.

go clean -cache -testcache && CGO_ENABLED=1 go build -o Release/test examples/mainthread/main.go

Once it builds though, I'm unable to get the test app to launch:

❯ ./test
[example app]fillMainArgs [./test] 1
[example app]ExecuteProcess
[example app]Initialize Settings
[example app]ResourcesDirPath= /home/ryan/Dev/cefgo/Release
[example app]LocalesDirPath= /home/ryan/Dev/cefgo/Release/locales
[example app]RemoteDebuggingPort= 6696
[example app]IgnoreCertificateErrors= false
[example app]CommandLineArgsDisabled= false
[example app]fillMainArgs [./test] 1
init_gui
cef_initialize
on_before_command_line_processing
on_register_custom_schemes
[0904/203439.702504:ERROR:icu_util.cc(247)] Couldn't mmap icu data file
zsh: trace trap (core dumped)  ./test

I'm using:

cef_binary_85.3.1+g1306235+chromium-85.0.4183.83_linux64_minimal
go version go1.13.8 linux/amd64
Ubuntu 20.04.1 LTS (Focal Fossa)

Managing window from GO

Hey,

I have played with JS functions exposed in your example to affect the window and it worked fine, but when I tried from the side of GO, seems like it's not working. Added this code right after this line https://github.com/Gurkengewuerz/cefgo/blob/master/examples/mainthread/main.go#L72:

		time.AfterFunc(time.Second*5, func() {
			client.WindowHide()
		})

To hide the window after 5 seconds. Nothing happens, no error, nothing. Any ideas?

how to increase the memory usage

hi, the application will be crash in single-process mode while the memory usage over 3.5G, and the application will be blank in not single-process mode. so how to fix it?

Doesn't work on a mac

[example app]fillMainArgs [./.app/Contents/MacOS/app --enable-logging --v=10] 3
[example app]ExecuteProcess
[example app]Initialize Settings
[example app]RemoteDebuggingPort= 6696
[example app]IgnoreCertificateErrors= false
[example app]CommandLineArgsDisabled= false
[example app]File /Users/aman/Projects/gomvc/icon.png does not exist
[example app]fillMainArgs [./.app/Contents/MacOS/app --enable-logging --v=10] 3
init_gui
cef_initialize
on_before_command_line_processing
on_register_custom_schemes
[0915/113659.510557:VERBOSE1:pref_proxy_config_tracker_impl.cc(185)] 0xce58da0: set chrome proxy config service to 0xce5a4c0
[0915/113659.512004:VERBOSE1:webrtc_internals.cc(119)] Could not get the download directory.
get_browser_process_handler
[0915/113659.513443:WARNING:gpu_process_host.cc(1217)] The GPU process has crashed 1 time(s)
get_resource_bundle_handler
[0915/113659.520208:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_cookies_allowed_for_urls
[0915/113659.520248:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_cookies_blocked_for_urls
[0915/113659.520270:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_cookies_sessiononly_for_urls
[0915/113659.520289:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_images_allowed_for_urls
[0915/113659.520306:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_images_blocked_for_urls
[0915/113659.520323:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_insecure_content_allowed_for_urls
[0915/113659.520340:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_insecure_content_blocked_for_urls
[0915/113659.520357:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_javascript_allowed_for_urls
[0915/113659.520374:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_javascript_blocked_for_urls
[0915/113659.520391:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_notifications_allowed_for_urls
[0915/113659.520408:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_notifications_blocked_for_urls
[0915/113659.520425:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_plugins_allowed_for_urls
[0915/113659.520441:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_plugins_blocked_for_urls
[0915/113659.520458:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_popups_allowed_for_urls
[0915/113659.520474:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_popups_blocked_for_urls
[0915/113659.520491:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_web_usb_ask_for_urls
[0915/113659.520508:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_web_usb_blocked_for_urls
[0915/113659.520525:VERBOSE2:content_settings_policy_provider.cc(245)] Skipping unset preference: profile.managed_legacy_cookie_access_allowed_for_domains
[0915/113659.520542:VERBOSE2:content_settings_policy_provider.cc(313)] Skipping unset preference: profile.managed_auto_select_certificate_for_urls
initialize_window_delegate
cef_run_message_loop
[0915/113659.562396:WARNING:gpu_process_host.cc(1217)] The GPU process has crashed 2 time(s)
[0915/113659.563684:WARNING:gpu_process_host.cc(1217)] The GPU process has crashed 3 time(s)
[0915/113659.565045:WARNING:gpu_process_host.cc(1217)] The GPU process has crashed 4 time(s)
[0915/113659.566373:WARNING:gpu_process_host.cc(1217)] The GPU process has crashed 5 time(s)
[0915/113659.567625:WARNING:gpu_process_host.cc(1217)] The GPU process has crashed 6 time(s)
[0915/113659.567658:FATAL:gpu_data_manager_impl_private.cc(439)] GPU process isn't usable. Goodbye.

How to set the Window Position (Top, Left)?

I can see from the source and examples how to set the Width and Height of the browser window, but I don't see anything on setting the Top and Left position of the window...?