Yet another userChrome.js manager

The files in this repository create a toolkit to load arbitrary javascript files to be run in Firefox browser context. This method relies on autoconfig functionality available in Firefox.

Overview

Files in program folder tell Firefox to load an additional javascript module file from the current Profile directory. The boot.jsm is the one that implements loading and managing additional files.

Since the files in program go to the main program installation path, they will affect all profiles that are being run using that executable.

However, the bulk of the logic is located in profile folder with boot.jsm so if the file is not found there then the loader is simply not used.

Warning!

Please note that malicious external programs can now inject custom logic to Firefox even without elevated privileges just by modifying boot.jsm or adding their own scripts.

Install

Setting up config.js from "program" folder

Copy the contents of the directory called "program" (not the directory itself) into the directory of the Firefox binary you want it to apply to.

This means that if you want to affect multiple installations, like release, beta, ESR etc. you need to add the files to all of them.

Windows

Firefox is typically installed to C:\Program Files\Mozilla Firefox\

Copy defaults/ and config.js there from the program folder. config.js should end up in the same directory where firefox.exe is.

Linux

Firefox is typically installed to /usr/lib/firefox/ or /usr/lib64/firefox/

Copy defaults/ and config.js there from the program folder. config.js should end up in the same directory where firefox binary is.

MacOS

Unknown. Someone with mac should test how it goes.

Setting up profile

Copy the contents of the folder "profile" (not the folder itself) to the Firefox profile folder that you want to modify. If the profile already has a chrome folder (for userChrome.css or userContent.css) then the chrome folders should merge. Otherwise the chrome folder will be created. You should end up with chrome folder in the profile root, and three folders inside it - JS, resources and utils.

There will be two files in the chrome/utils/ folder:

chrome.manifest - registers file paths to chrome:// protocol
boot.jsm - implements user-script loading logic

Deleting startup-cache

Firefox caches some files to speed-up startup. But the files in utils/ modify the startup behavior so you might be required to clear the startup-cache.

If you modify boot.jsm and happen to break it, you will likely need to clear startup-cache again.

Clear startup-cache via about:support (recommended)

Load about:support
In the top-right corner should be a button to clear the startup-cache.
Click that button and confirm the popup that will show up.
Firefox will restart with startup-cache cleared, and now the scripts should be working.

Clear startup-cache manually

The startup-cache folder can be found as follows:

load the following url about:profiles
locate the profile you wish to set up and click the "Open Folder" of the Local directory - this should open the directory in File Manager
Close Firefox
Delete folder "StartupCache"
Run Firefox

(Note) If you wish to set up a profile that doesn't use normal profile directories (i.e one that was lauched with command-line such as firefox.exe -profile "C:\test\testprofile" or with portable-apps launcher) then the startupCache folder will be in the profile root folder.

Usage

The file extension for your custom scripts must be .uc.js, the loader script only looks for files with that extension.

Just put any such files into the JS directory. The JS directory should be in the same directory where userChrome.css would be. If you wish to change the directory name then you need to modify the chrome.manifest file inside utils directory. For example change ../JS/ to ../scripts/ to make Firefox load scripts from "scripts" folder.

At runtime, individual scripts can be toggled on/off from menubar -> tools -> userScripts. Note that toggling requires Firefox to be restarted, for which a "restart now" -button is provided. The button clears startup-cache so you don't need to worry about that.

A global preference to toggle all scripts is userChromeJS.enabled. This will disable all scripts but leaves the restart-button in the custom menu available.

API

This manager is NOT entirely compatible with all existing userScripts - specifically scripts that expect a global _uc object or something similar to be available.

Script scope

Each script normally runs once per document when the document is loaded. A window is a document, but a window may contain several "sub-documents" - kind of like iframes on web pages.

@include & @exclude

By default, the loader executes your script only in the main browser window document. Using any @include header will override the default - for example:

// ==UserScript==
// @include           chrome://browser/content/places/places.xhtml
// ==/UserScript==

The above would be executed only in the Library window.

// ==UserScript==
// @include           main
// @include           chrome://browser/content/places/places.xhtml
// ==/UserScript==

This would execute in both library and main window. "main" is an alias for chrome://browser/content/browser.xhtml.

A wildcard * can be used to target any window.

// ==UserScript==
// @include           *
// @exclude           main
// ==/UserScript==

This would execute in all documents, excecpt main window - notice "main" is excluded this time.

In addition, scripts can be marked as @backgroundmodule in which case they are executed "outside" of any document when the the loader reads the file. See backgroundmodule section below.

Some convenience functions are provided for scripts to use in global _ucUtils object available in windows.

@onlyonce

By default the script is executed once per document it applies to, but this can be changed with @onlyonce header in which case the script will only be run in the first document.

// ==UserScript==
// @name           example only-once file
// @onlyonce
// ==/UserScript==

console.log("Hello world!") // This is only run in the first window that opens.

@backgroundmodule

Scripts can be marked as background modules by including a @backgroundmodule line in script header. See example:

// ==UserScript==
// @name           example background module
// @note           Loading as background module
// @backgroundmodule
// ==/UserScript==

let EXPORTED_SYMBOLS = [];
...
// actual script here

Note that the EXPORTED_SYMBOLS array in module global scope is mandatory.

You should note that background modules do not have access to window objects when they are being run because they are executed before any window exists. They also do not get access to _ucUtils object.

General

_ucUtils.createElement(document,tagname,attributes,isHTML) -> Element

_ucUtils.createElement(document,"menuitem",{ id:"someid", class:"aClass", label:"some label" })

Attaches a new element with tagname to the given document and adds it attributes from attributes object. isHTML is a boolean indicating whether the element is XUL element or HTML element - defaults to false.

_ucUtils.createWidget(details) -> (or null on failure)

_ucUtils.createWidget({
  id: "funk-item",                // required
  type: "toolbaritem",            // ["toolbaritem","toolbarbutton"]  
  label: "funky2",                // opt (uses id when missing)
  tooltip: "noiseButton",         // opt (uses id when missing)
  class: "noiseButton",           // opt additional className (see below for more)
  image: "favicon.png",           // opt image filename from resources folder
  style: "width:30px;",           // opt additional css-text (see below for more)
  allEvents: true,                // opt trigger on all clicks (default false)
  callback: function(ev,win){     // Function to be called when the item is clicked
    console.log(ev.target.id)
  }
})

Widget is a wrapper for actual elements. Firefox tracks widget placements across windows meaning that you can create the widget once and then you can re-position it using customize mode and its new location will be shared in all windows. The wrapper contains information about the instances of that widget in windows.

The class of elements using this will by default be "toolbarbutton-1 chromeclass-toolbar-additional" and the value of the class property (when provided) will be added into that.

The style info will be added as inline style to all elements of that widget. The image will be loaded as centered background-image in toolbaritems and as list-style-image in toolbarbuttons.

The callback function will be stored in _ucUtils.sharedGlobal mapped to the provided id. Clicking the button will call the callback which will receive two arguments: event (click) and window which is a reference to the window object where that instance of the widget is.

If the callback property is not a function, then the widget will be just a passive element.

The allEvents property defines if the callback should be called for all clicks, not just left-clicks.

The image is loaded from resources folder so save your icon files there.

_ucUtils.registerHotkey(details,function) -> Boolean

// description for hotkey Ctrl + Shift + G
let details = {
  id: "myHotkey",
  modifiers: "ctrl shift",
  key: "G"
}

function onHotkey(window,hotkey){
  console.log(hotkey);
  // prints id, modifiers and key of the pressed hotkey.
  // window is the window-object that captured this hotkey
}

let success = _ucUtils.registerHotkey(details,onHotkey);

Register a hotkey handler to each browser window. registerHotkey returns true if the hotkey was registered correctly. false if there was a problem. id,modifiers and key fields are mandatory and must be String type.

The function only supports modifiers "alt", "shift", "ctrl", "meta" and "accel" modifiers. Valid key values are A-Z a-z - and function keys F1-F12.

The created hotkey will override built-in hotkeys.

The id field in the details object should have some unique value, but this is not enforced.

_ucUtils.getScriptdata() -> Array

let scripts = _ucUtils.getScriptdata();
for(let script of scripts){
  console.log(`${script.filename} - ${script.isRunning})
}

Returns the currently loaded script files with their metadata

_ucUtils.windows -> Object

Returns an object to interact with windows with two properties

_ucUtils.windows.get(onlyBrowsers) -> Array

Return a list of handles for each window object for this firefox instance. If onlyBrowsers is true then this only includes browser windows. If it's false then it also includes consoles, PiP, non-native notifications etc.

onlyBrowsers defaults to true.

_ucUtils.windows.forEach(function,onlyBrowsers)

_ucUtils.windows.forEach((document,window) => console.log(document.location), false)

Runs the specified function for each window. The function will be given two arguments - reference to the document of the window and reference to the window object itself.

Note! _ucUtils may not be available on all target window objects if onlyBrowsers is false. The callback function should check for it's availability when called that way.

_ucUtils.toggleScript(fileName or element)

filename:

_ucUtils.toggleScript("test.uc.js")

Element where this is a menuitem:

_ucUtils.toggleScript(this);

If the argument is an element the function reads a filename attribute from the element and uses that. Toggles the specified script, note that browser restart is required for changes to take effect.

_ucUtils.loadURI(window,details) -> boolean

_ucUtils.loadURI(window,{
  url:"about:config",
  where:"tab",        // one of ["current","tab","tabshifted","window"]
  private: true,      // should the window be private
  userContextId: 2    // numeric identifier for container
});

// "tabshifted" means background tab but it does not work for unknown reasons
// Private tabs cannot be created in non-private windows

Return a boolean indicating if the operation was successful. "url" and "where" properties are mandatory - others are optional.

_ucUtils.restart(clearCache)

Immediately restart the browser. If the boolean clearCache is true then Firefox will invalidate startupCache which allows changes to the enabled scripts to take effect.

_ucUtils.startupFinished() -> Promise

_ucUtils.startupFinished()
.then(()=>{
  console.log("startup done");
});

Returns a promise that will be resolved when all windows have been restored during session startup. If all windows have already been restored at the time of calling the promise will be resolved immediately.

_ucUtils.windowIsReady() -> Promise

_ucUtils.windowIsReady(window)
.then(()=>{
  console.log("this window has finished starting up");
});

This corresponds to browser-delayed-startup-finished event. Note that extension-engine initialization code may or may not have run when this promise resolves.

Difference of startupFinished and windowIsReady

Since scripts run per window, startupFinished will be resolved once in each window that called it when ALL those windows have been restored. But windowIsReady will be resolved whenever the particular window that calls it has started up.

Prefs

A shortcut for reading and writing preferences

_ucUtils.prefs.set(prefName,value) -> value

_ucUtils.prefs.set("some.pref.path","test");
_ucUtils.prefs.set("some.other.pref",300);

Returns a new value on success, undefined if pref couldn't be set

_ucUtils.prefs.get(prefName) -> value

Returns the value of the pref, undefined if it doesn't exist

_ucUtils.prefs.addListener(prefName,callback) -> Object

let callback = (value,pref) => (console.log(`${pref} changed to ${value}`))
let prefListener = _ucUtils.prefs.addListener("userChromeJS",callback);

Note that the callback will be invoked when any pref that starts with userChromeJS is changed. The pref in callback argument will be the actual pref whose value changed.

_ucUtils.prefs.removeListener(listener)

_ucUtils.prefs.removeListener(prefListener) // from above example

Filesystem

Scripts should generally use the resources folder for their files. The helper functions interacting with filesystem expect resources to be the root folder for script operations.

The resources folder is registered to chrome:// scheme so scripts and stylesheets can use the following URL to access files within it:

"chrome://userChrome/content/<filename>.txt"

Scripts folder is registered to: chrome://userScripts/content/

The loader module folder is registered to chrome://userchromejs/content/

_ucUtils.getFSEntry(fileName) -> fileHandle || enumerator for entries in a folder

Get file handle for resources/some.txt:

let fileHandle = _ucUtils.getFSEntry("some.txt");

Loop through filesystem entries in resources/path:

let contents = _ucUtils.getFSEntry("path");
while(contents.hasMoreElements()){
  let nextFile = contents.getNext().QueryInterface(Ci.nsIFile);
  console.log(nextFile.leafName);
}

_ucUtils.readFile(fileHandle,metaOnly) -> String

_ucUtils.readFile(aFile,false)

Attempts to read the content of the given fileHandle as text. Boolean metaOnly is used to parse only the metadata of userScripts when reading them from script directory.

_ucUtils.createFileURI(fileName) -> String

_ucUtils.createFileURI("path\some.png")

Return a valid file uri describing <profileDir>\chrome\resources\path\some.png

_ucUtils.chromeDir

Return an object with two properties

_ucUtils.chromeDir.uri // a file:/// uri

_ucUtils.chromeDir.files -> enumerator for entries in chrome folder

let entries = _ucUtils.chromeDir.files;
while(entries.hasMoreElements()){
  let nextFile = entries.getNext().QueryInterface(Ci.nsIFile);
  console.log(nextFile.leafName);
}

Shared global object

If scripts need to store information to a global object they can get reference to that as follows:

let global = _ucUtils.sharedGlobal

The information in the global object is available for all scripts

Startup directive

Scripts can define a function to be executed when they are loaded in the header portion of the script. Consider the following header:

// ==UserScript==
// @name            My Test Script
// @startup         myScriptObject

This tells the loader to execute a special function named _startup from globalShared.myScriptObject. The _startup function will receive one argument - reference to the window object where it was executed.

In short, to use startup directive you need to store an object named myScriptObject to the globalShared object and the myScriptObject must have a property called _startup.

_ucUtils.sharedGlobal.myScriptObject = {
  _startup: function(win){ console.log(win.location) }
}

NOTE This is behavior is completely incompatible with the way old userscripts implement startup - which generally was of form eval(<whatever_is_in_header_startup>)

BunnyIIIX/fx-autoconfig