electron/docs/development/source-code-directory-structure.md

Source Code Directory Structure

The source code of Electron is separated into a few parts, mostly following Chromium on the separation conventions.

You may need to become familiar with Chromium's multi-process architecture to understand the source code better.

Structure of Source Code

Electron
├── atom/ - C++ source code.
|   ├── app/ - System entry code.
|   ├── browser/ - The frontend including the main window, UI, and all of the
|   |   main process things. This talks to the renderer to manage web pages.
|   |   ├── ui/ - Implementation of UI stuff for different platforms.
|   |   |   ├── cocoa/ - Cocoa specific source code.
|   |   |   ├── win/ - Windows GUI specific source code.
|   |   |   └── x/ - X11 specific source code.
|   |   ├── api/ - The implementation of the main process APIs.
|   |   ├── net/ - Network related code.
|   |   ├── mac/ - Mac specific Objective-C source code.
|   |   └── resources/ - Icons, platform-dependent files, etc.
|   ├── renderer/ - Code that runs in renderer process.
|   |   └── api/ - The implementation of renderer process APIs.
|   └── common/ - Code that used by both the main and renderer processes,
|       including some utility functions and code to integrate node's message
|       loop into Chromium's message loop.
|       └── api/ - The implementation of common APIs, and foundations of
|           Electron's built-in modules.
├── chromium_src/ - Source code that copied from Chromium.
├── default_app/ - The default page to show when Electron is started without
|   providing an app.
├── docs/ - Documentations.
├── lib/ - JavaScript source code.
|   ├── browser/ - Javascript main process initialization code.
|   |   └── api/ - Javascript API implementation.
|   ├── common/ - JavaScript used by both the main and renderer processes
|   |   └── api/ - Javascript API implementation.
|   └── renderer/ - Javascript renderer process initialization code.
|       └── api/ - Javascript API implementation.
├── spec/ - Automatic tests.
├── electron.gyp - Building rules of Electron.
└── common.gypi - Compiler specific settings and building rules for other
    components like `node` and `breakpad`.

Structure of Other Directories

• script - Scripts used for development purpose like building, packaging, testing, etc.
• tools - Helper scripts used by gyp files, unlike script, scripts put here should never be invoked by users directly.
• vendor - Source code of third party dependencies, we didn't use third_party as name because it would confuse it with the same directory in Chromium's source code tree.
• node_modules - Third party node modules used for building.
• out - Temporary output directory of ninja.
• dist - Temporary directory created by script/create-dist.py script when creating a distribution.
• external_binaries - Downloaded binaries of third-party frameworks which do not support building with gyp.

Keeping Git Submodules Up to Date

The Electron repository has a few vendored dependencies, found in the /vendor directory. Occasionally you might see a message like this when running git status:

$ git status

	modified:   vendor/libchromiumcontent (new commits)
	modified:   vendor/node (new commits)

To update these vendored dependencies, run the following command:

git submodule update --init --recursive

If you find yourself running this command often, you can create an alias for it in your ~/.gitconfig file:

[alias]
	su = submodule update --init --recursive