Files

Julie Jeongeun Kim fbf3f1850a [printing] Use uint32_t for a page number and counts

This CL is a follow-up CL of converting
PrintHostMsg_DidGetPrintedPagesCount to mojo [1] and it updates the
type for the page number and counts with uint32_t as it couldn't
have a negative value.

It keeps using int for JNI and dictionary values and uses
'base::checked_cast<int>' to convert uint to int. In order to make
sure that the value is in the range to cast, this change also adds
the maximum limit for the page number and counts and checks the
value before passing it to JNI or dictionary. Given that the previous
type is int, the maximum limit is std::numeric_limits<int>::max().

[1] https://crrev.com/c/2326857

Bug: 1008939
Change-Id: I5c86514be4e7d549f888c9623136078a3b0c88c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351580
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Julie Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#807307}

2020-09-16 02:22:34 +00:00

app

Move content::WebPreferences struct to Blink

2020-09-11 03:32:51 +00:00

lib

[printing] Use uint32_t for a page number and counts

2020-09-16 02:22:34 +00:00

public

Move content::WebPreferences struct to Blink

2020-09-11 03:32:51 +00:00

test

Refactor OS_LINUX preprocessor directive for LaCrOS effort.

2020-08-20 02:11:09 +00:00

BUILD.gn

Headless: bring back HeadlessProtocolTests

2020-07-28 02:17:47 +00:00

DEPS

Move content::WebPreferences struct to Blink

2020-09-11 03:32:51 +00:00

headless_browsertest_resources.grd

…

headless.gni

…

OWNERS

…

protocol_config.json

…

README.md

…

README.md

Headless Chromium

Headless Chromium allows running Chromium in a headless/server environment. Expected use cases include loading web pages, extracting metadata (e.g., the DOM) and generating bitmaps from page contents -- using all the modern web platform features provided by Chromium and Blink.

There are two ways to use Headless Chromium:

Usage via the DevTools remote debugging protocol

Start a normal Chrome binary with the --headless command line flag (Linux-only for now):

$ chrome --headless --remote-debugging-port=9222 https://chromium.org

Currently you'll also need to use --disable-gpu to avoid an error from a missing Mesa library.

Navigate to http://localhost:9222 in another browser to open the DevTools interface or use a tool such as Selenium to drive the headless browser.

Usage from Node.js

For example, the chrome-remote-interface Node.js package can be used to extract a page's DOM like this:

const CDP = require('chrome-remote-interface');

CDP((client) => {
  // Extract used DevTools domains.
  const {Page, Runtime} = client;

  // Enable events on domains we are interested in.
  Promise.all([
    Page.enable()
  ]).then(() => {
    return Page.navigate({url: 'https://example.com'});
  });

  // Evaluate outerHTML after page has loaded.
  Page.loadEventFired(() => {
    Runtime.evaluate({expression: 'document.body.outerHTML'}).then((result) => {
      console.log(result.result.value);
      client.close();
    });
  });
}).on('error', (err) => {
  console.error('Cannot connect to browser:', err);
});

Usage as a C++ library

Headless Chromium can be built as a library for embedding into a C++ application. This approach is otherwise similar to controlling the browser over a DevTools connection, but it provides more customization points, e.g., for networking and mojo services.

Headless Example is a small sample application which demonstrates the use of the headless C++ API. It loads a web page and outputs the resulting DOM. To run it, first initialize a headless build configuration:

$ mkdir -p out/Debug
$ echo 'import("//build/args/headless.gn")' > out/Debug/args.gn
$ gn gen out/Debug

Then build the example:

$ ninja -C out/Debug headless_example

After the build completes, the example can be run with the following command:

$ out/Debug/headless_example https://www.google.com

Headless Shell is a more capable headless application. For instance, it supports remote debugging with the DevTools protocol. To do this, start the application with an argument specifying the debugging port:

$ ninja -C out/Debug headless_shell
$ out/Debug/headless_shell --remote-debugging-port=9222 https://youtube.com

Then navigate to http://localhost:9222 with your browser.

Embedder API

The embedder API allows developers to integrate the headless library into their application. The API provides default implementations for low level adaptation points such as networking and the run loop.

The main embedder API classes are:

HeadlessBrowser::Options::Builder - Defines the embedding options, e.g.:
- SetMessagePump - Replaces the default base message pump. See base::MessagePump.
- SetProxyServer - Configures an HTTP/HTTPS proxy server to be used for accessing the network.

Client/DevTools API

The headless client API is used to drive the browser and interact with loaded web pages. Its main classes are:

HeadlessBrowser - Represents the global headless browser instance.
HeadlessWebContents - Represents a single "tab" within the browser.
HeadlessDevToolsClient - Provides a C++ interface for inspecting and controlling a tab. The API functions corresponds to DevTools commands. See the client API documentation for more information.

Resources and Documentation

Mailing list: headless-dev@chromium.org

Bug tracker: Internals>Headless

File a new bug (bit.ly/2pP6SBb)