edrlab / thorium-reader

A cross platform desktop reading app, based on the Readium Desktop toolkit

Thorium Reader

Thorium Reader is an easy to use EPUB reading application for Windows 10/10S, MacOS and Linux. After importing e-books from a directory or OPDS feed, you'll be able to read on any screen size, customize layout settings, navigate via the table of contents or page list, set bookmarks ... A great care is taken to ensure the accessibility of the application for visual impaired people using NVDA, JAWS or Narrator.

Free application. No ads. No private data flowing anywhere.

This project is in constant evolution, corrections and new features will be added soon and your support is welcome for that. The application is based on the open-source Readium Desktop toolkit.

It is currently localized in following 25 languages:

• (en) English
• (fr) Français (French)
• (fi) Suomi (Finish)
• (de) Deutsch (German)
• (es) Español (Spanish)
• (nl) Nederlands (Dutch)
• (ja) 日本語 (Japanese)
• (ka) ქართული (Georgian)
• (lt) Lietuvių (Lithuanian)
• (pt-BR) Português Brasileiro (Portuguese - Brazil)
• (pt-PT) Português (Portuguese - Portugal)
• (zh-CN) 中文 - 中國/国 (Chinese trad.)
• (zh-TW) 中文 - **/灣 (Chinese simp.)
• (it) Italiano (Italian)
• (ru) Русский (Russian)
• (ko) 한국어 (Korean)
• (sv) Svenska (Swedish)
• (ca) Catalan
• (gl) Galician
• (eu) Euskadi (Basque)
• (el) ελληνικός (Greek)
• (bg) български (Bulgarian)
• (hr) Hrvatski (Croatian)
• (da) Dansk (Danish)
• (sl) Slovenščina (Slovene)

See: https://github.com/edrlab/thorium-reader/wiki/Localization-(l10n)-language-translations

Prerequisites

1. NodeJS 18 (check with node --version)
2. NPM 9 (check with npm --version)

Technologies

• typescript
• electron
• reactjs
• redux
• saga
• i18next

Quick start

Install dependencies

• npm install (or npm ci): initialize local node_modules packages from dependencies declared in package.json (this will also automatically call a long-running compilation stage in npm run postinstall)
• in case of failure to NPM "install" because of "Divina player" SHA integrity mismatch, please try running the following command in your shell: node scripts/package-lock-patch.js && cat package-lock.json | grep -i divina-player-js

Start application in development environment

(with hot-reload dev server, web inspectors / debuggers)

• npm run start:dev (or npm run start:dev:quick to bypass TypeScript checks / launch the app faster)

Start application in production environment

• npm start (or npm run start)

Build installers

• npm run package:win or npm run package:mac or npm run package:linux

Code Signing information: https://github.com/edrlab/thorium-reader/wiki/Code-Signing

Command line

thorium <cmd> [args]

Commands:
  thorium opds <title> <url>  import opds feed
  thorium import <path>       import epub or lpcl file
  thorium read <title>        searches already-imported publications with the
                              provided TITLE, and opens the reader with the
                              first match
  thorium [path]              import and read an epub or lcpl file     [default]
  thorium completion          generate bash completion script

Positionals:
  path  path of your publication, it can be an absolute, relative path  [string]

Options:
  --version  Show version number                                       [boolean]
  --help     Show help                                                 [boolean]

[DEV] Architecture

Thorium-reader is composed of 3 parts:

• One node.js main process (electron back-end)
• One library window (chromium renderer)
• One to N reader window(s) (chromium renderer)

Each part runs a model-controller and a view for the renderer process.

• the model is a state container with Redux. It's based on flux architecture
• the controller is a middleware from Redux named Redux-saga. It handles all side effects and application behaviour.
• the view for the rendering is React with class components

To link these 3 parts we use:

• IPC/RPC: we use an implementation from Electron
• React/Redux: We use connect from react-redux.

Diagram

Model View Controller Architecture

API Concept

To have a POST request from a renderer process to the main process, we use the notion of API. It's not an http API but an RPC encapsuled one, to redux/redux-saga logic with Action and Reducer.

Here is a diagram of the communication:

Src:

• src/main/redux/sagas/api/api.ts
• src/common/redux/actions/api/index.ts
• src/renderer/common/redux/reducers/api.ts

At the moment there are 17 API endpoints from (src/main/redux/sagas/api):

library:

• apiapp:
  • apiapp/search : search a library from apiapp protocol
• browser:
  • httpbrowser/browse : browse and parse an opds URL
• opds:
  • opds/getFeed : get an opdsFeed with its identifier
  • opds/findAllFeed: get all opdsFeed saved
  • opds/deleteFeed: delete an opdsFeed with its identifier
  • opds/addFeed: add an opdsFeed
  • opds/getUrlWithSearchLinks: get the search URL from an opdsFeed
• publication: (src/common/api/interface/publicationApi.interface.ts)
  • publication/get: get a publicationView from id
  • publication/delete: delete a publicationView from id
  • publication/findAll: get all publicationView
  • publication/findByTag: get all publicationView from a specific tag string
  • publication/updateTags: update tags list from a publication
  • publication/importFromLink: import a publication from an URL
  • publication/importFromFs: import a publication from a fileSystem path
  • publication/search: search publication from a query text
  • publication/searchEqTitrle: search publication by title matching
  • publication/exportPublication: export publication to the fileSystem

ACTION-REDUCER

From the main-process to the renderer-process, or from the renderer-process to the main-process.

List of all Actions in place (src/common/redux/actions):

• auth: opds authentication
  • cancel
  • done
  • wipeData
• catalog
  • getCatalog: ask to rehydrate catalogView in the libraryState
  • setCatalogView: response from getCatalog
  • setTagView: rehydrate tagStringView in the libraryState
• dialog: modal dialog view in library,reader
  • closeRequest
  • openRequest
  • updateRequest
• download: download queue in library
  • abort
  • done
  • progress
• history: history opds feed
  • pushFeed
  • refresh
• i18n
  • setLocale
• import
  • verify: import verification process
• keyboard: keyboard shortcut
  • reloadShortcut
  • setShortcut
  • showShortcut
• lcp
  • renewPublication
  • returnPublication
  • unlockPublicationWithPassphrase
  • userKeyCheckRequest
• load: main proceess busy or not
  • busy
  • iddle
• net (not used)
• reader
  • attachMode
  • clipboardCopy
  • closeRequest
  • closeRequestFromPublication
  • configSetDefault
  • detachModeRequest
  • detachModeSuccess
  • fullScreenRequest
  • openRequest
  • openError
  • setReduxState: trigger app persistence
• session: saved session
  • enable
• toast: toast notification library,reader
  • close
  • open

thorium-reader's Issues

keyboard navigation: no focus outline on cover image thumbnails (flip cards) and prev/next arrow buttons, user confused, no visual feedback about currently-focused widget

HTTPS header check sometimes fails because of short time window + slow webpack redux/react bootstrap

TODO in navigator: increase time window in DEBUG / DEV mode

React DropZone: dual CommonJS vs. ECMAScript module export => Node require() loader fails with WebPack renderer bundle and externalized react-dropzone package.

The react-dropzone package comes in two flavours: CommonJS (supported by the Node CommonJS loader, and indicated by package.json main: ./dist/index.js), and ECMAScript module (supported by the WebPack bundle loader, and indicated by package.json module: ./dist/es/index.js).
Due to @types/react-dropzone, VSCode (and more generally-speaking, the TypeScript compiler) is perfectly happy with either TSX syntaxes:

1. import { default as Dropzone } from "react-dropzone"; and <Dropzone />
2. import { Dropzone } from "react-dropzone"; and <Dropzone.default />

This works fine in the WebPack require/loader too, when the react-dropzone package is injected in the code bundle (naturally, WebPack prefers ES modules instead of CommonJS, as this is good for dynamic imports and tree shaking).

However the import breaks when the package remains external (inside node_modules), which is a desirable optimization in development mode to minimize the compile times and bundle size (in addition to using HMR Hot Module Reload for local code). The import breaks because default is not handled this way in CommonJS.

The solution that works for me is to ensure that Dropzone is imported as CommonJS in all cases.
TSX: import * as Dropzone from "react-dropzone/dist"; and <Dropzone />
typings.d.ts (or declarations.d.ts): declare module "react-dropzone/dist";

UI: previous/next buttons overlap EPUB document scroll bar, and other interactive elements in fixed layout or reflowable publications (e.g. hyperlinks)

EPUB landmarks UI (for list of illustrations, figures, etc.)

This is implemented in r2-testapp-js, but is currently missing in readium-desktop.
Note that there may be multiple types of landmarks, so this is more like a set of categorized lists.

Feature request: Implement targeting of a specific "topic" on reader startup

(I know, you're probably not looking for feature requests, but this should be really "easy", and will be a huge help to opening up the world of EPUB to the technical communication profession. Hoping I'm not overstepping here.)

Provide the ability to include a command line parameter that opens a specified EPUB and optionally a specified content document on application startup. This could be as basic as ..

<readium-app> book.epub#itemref-idref

• If the specified book is already open, switch to the specified idref rather than opening a new window.
• Preserve the application window size and position between instances.

A better implementation would be to provide a programmatic API (via DLL, etc) to this functionality rather than needing to use the CLI, but the CLI implementation is probably much easier and is quite sufficient (for an initial implementation).

Background:

The technical communication (techcomm) industry has made use of Online Help applications to deliver context sensitive documentation for many years. First with WinHelp and then HTML Help (CHM files). But Microsoft stopped supporting HTML Help many years ago, and techcomm has been scrambling for a replacement. Many companies are fine with delivering documentation as "web help" in a browser, but many still need to have a locally installed deliverable and still (for now) use HTML Help (on Windows only).

I see EPUB as a possible replacement for this deliverable. It fundamentally provides (or can provide) all of the necessary features, and is platform independent. I've developed prototypes for "EPUB Help" for a number of years and presented these at conferences. It mostly works. The main piece missing for a basic implementation is the ability for the main software application to launch a specific EPUB on the desired topic. Now that rendition:flow=scrolled-doc is available, I no longer need to do javascript hacks to get nice vertically scrolling topics (much better for reference documentation).

If a viable ereader was available that provided this basic functionality, I'd be able to encourage the tool vendors to update their publishing tools to provide better support for EPUB. Right now they say their clients aren't asking for it (which in my mind is because there are no readers that do what's needed to offer good techcomm deliverables)

There is reasonable interest in techcomm for use of EPUBs, but the ereaders and publishing tools are lacking in feature support. If Readium Desktop can provide more of these features, we may see more adoption.

Test for UI a11y

https://github.com/reactjs/react-a11y

dialogs (e.g. settings in reader view): escape key does not trigger "close" action, enter/return should "accept" / okay button

local nodeExternals() should have a simpler version JUST to fix the import alias problem (main process), and one for start:devex (renderer processes) with all the webpack, hotloader, etc. excludes

https://github.com/readium/readium-desktop/blob/develop/nodeExternals.js

Note that this is only used in DEV mode (NODE_ENV !== "production").

NPM dep Moment (date lib) 2.19.1 fixes bugs

We freeze v2.18.* because of critical bugs, but they are now fixed:
https://github.com/moment/moment/blob/develop/CHANGELOG.md#changelog

Library view, toolbar, keyboard tab navigation as well as screen reader: in toolbar, "add epub" button focusable twice

This is because the button contains both SVG icon and input HTML element.

LCP passphrase input HTML element should be automatically focused when dialog pops-up

...otherwise, typing requires extra user interaction to set the focus, and also TAB-navigation occurs "behind" the dialog because of lack of proper modal support

readiumCssOnOff() function is called before webview is ready in navigator => nil pointer

Suggestion: rather than force readium-desktop design to figure-out when it is legal to invoke readiumCssOnOff() (i.e. once a publication is loaded, and its webviews have been created), it would be better to do a sanity check in the r2-navigator-js's code. The initial ReadiumCSS state is always pulled from the navigator anyway, as soon as it loads a publication (to avoid FOUC Flash Of Unstyled Content).

store for "reading location", navigator API setReadingLocationSaver()

(ReaderApp.tsx)

Same "pull" model as setReadiumCssJsonGetter(), but with setReadingLocationSaver() the parameters to save into DB storage are doc (spine item path/href relative to publication / zip archive root), and loc (CSS selector).
This is a "pull" design in the sense that the navigator will invoke this app-level store fonction at arbitrary times during the reading experience, for example every time a page is turned, or when the user clicks a spot in the document (to narrow down / guess the current reading location).

The saved reading location can then be restored by passing the doc + loc parameters to installNavigatorDOM() when the user re-opens the EPUB.

when import EPUB (into library) with multilingual title: React crash (requires deleting database)

The Readium2 webpub manifest can contain metadata title with map object instead of single string value, for example:

{ "en": "Mahabharata" }

=> this kills the library view, and happens again after closing+reopening the application.

The Redux Store state that causes problems is store.catalog.publications[i].title (object type instead of string), or any React component that expect to consume string values but gets object instead.

reader view: left/right keystrokes to activate previous/next commands (page turn)

Redundancy in WebPack alias + TypeScript tsconfig compilerOptions.paths

const { TsConfigPathsPlugin } = require('awesome-typescript-loader');

resolve: {
  ...
  plugins: [
    new TsConfigPathsPlugin(/* { tsconfig, compiler } */)
  ],
  ...
},

https://github.com/edrlab/readium-desktop/blob/703d81e327fd9ecee409e5a705b1d6e6fe24fd79/webpack.config.main.js#L35

https://github.com/edrlab/readium-desktop/blob/703d81e327fd9ecee409e5a705b1d6e6fe24fd79/tsconfig.json#L13

"navigation" pane (TOC, and in the future: page-list, landmarks, etc.) currently pushes content sideways instead of overlay

I'm not sure what it best. So this is a question (not a feature request)

Electron / Chromium accessibility tree (rendering), screen reader support

API:

accessibility-support-changed:
https://electronjs.org/docs/all#event-accessibility-support-changed-macos-windows

isAccessibilitySupportEnabled() and setAccessibilitySupportEnabled():
https://electronjs.org/docs/all#appisaccessibilitysupportenabled-macos-windows

This can help us debug the a11y tree (also see #87 ) or to test edge cases / performance issues when accessible rendering is activated (processing overhead).

associative array with key = spineItem.title is not reliable

I posted a comment for review in this Pull Request:
#41 (review)

...but it seems the branch associated with the PR has already been merged into feature/next-v1.
So I am posting a separate issue to address this.

Direct code reference:
https://github.com/edrlab/readium-desktop/blob/5db60f8ac5b77c8d782ca9732dd41bd60f8f3cd6/src/renderer/components/ReaderApp.tsx#L552

navigator doc contains many dead links (moved files, various refactorings)

https://github.com/edrlab/readium-desktop/blob/feature/next-v1/docs/navigator.md

Randomize HTTP server port (streamer)

See: https://github.com/edrlab/readium-desktop/blob/feature/r2-navigator-refactor/docs/navigator.md#streamer-http-server

Font chooser / selector: ReadiumCSS built-in (inc. Dyslexic), and system

UI suggestion: https://github.com/reactjs/react-autocomplete

[UI/UX] Reading position

To be innovative we should have some kind of an indicator to display the current reading position (how much you have "read", depending on how far you have scrolled down an article).

Read this interesting post on the subject.
I found referece to this in another interesting post about pagination and word processors.

This is a place for your ideas about the best way to indicate his reading position to the user.

"Display Type" terminology (paginated vs. scroll)

The current terms are "Document" and "Continue", should be instead: "Paginated" and "Scrolling".

UI missing for`doTryLcpPass()` throw+catch / promise.reject error code

In both usages of doTryLcpPass() where the try+catch block captures Promise.reject (async/await syntax), the error code should be passed in the payload for lcpActions.ActionType.PassphraseSubmitError and lcpActions.ActionType.UserKeyCheckError.

Code references:
https://github.com/edrlab/readium-desktop/blob/feature/next-v1/src/main/redux/sagas/lcp.ts#L62
and
https://github.com/edrlab/readium-desktop/blob/feature/next-v1/src/main/redux/sagas/lcp.ts#L118

Then some UI should let the user know what the problem is. For example, 11 = "LICENSE_OUT_OF_DATE", as per the listing below:

            // DRMErrorCode (from r2-lcp-client)
            // 1 === NO CORRECT PASSPHRASE / UERKEY IN GIVEN ARRAY
            //     // No error
            //     NONE = 0,
            //     /**
            //         WARNING ERRORS > 10
            //     **/
            //     // License is out of date (check start and end date)
            //     LICENSE_OUT_OF_DATE = 11,
            //     /**
            //         CRITICAL ERRORS > 100
            //     **/
            //     // Certificate has been revoked in the CRL
            //     CERTIFICATE_REVOKED = 101,
            //     // Certificate has not been signed by CA
            //     CERTIFICATE_SIGNATURE_INVALID = 102,
            //     // License has been issued by an expired certificate
            //     LICENSE_SIGNATURE_DATE_INVALID = 111,
            //     // License signature does not match
            //     LICENSE_SIGNATURE_INVALID = 112,
            //     // The drm context is invalid
            //     CONTEXT_INVALID = 121,
            //     // Unable to decrypt encrypted content key from user key
            //     CONTENT_KEY_DECRYPT_ERROR = 131,
            //     // User key check invalid
            //     USER_KEY_CHECK_INVALID = 141,
            //     // Unable to decrypt encrypted content from content key
            //     CONTENT_DECRYPT_ERROR = 151

getMultiLangString() for publication metadata (author/contributor, title, etc.) is currently used with forced English, of default fallback (first in available list)

https://github.com/edrlab/readium-desktop/blob/feature/next-v1/src/common/models/language.ts#L8

reader view keyboard interaction: even when TOC is hidden/closed, tab-navigation focuses on TOC links

[UI/UX] Page numbers (`epub:type="pagebreak"`)

We’re collecting feedback for Readium CSS and some requests may exceed the project’s scope (designing a CSS baseline).

Managing page numbers is a critical issue, especially in education. Users may search for page numbers, check which page they are scanning/reading/referring to (so page number should be displayed), etc.

Something as simple as having the page number displayed inline would already be judged some kind of progress, extra points if displayed in the margin. I guess it shouldn’t reflow with font-size but I may be wrong.

The streamer is already taking care of the pagelist/navdoc so this is probably more of an UI/UX-focused issue that a dev issue. Correct me if I’m wrong.

EPUB page-list UI (for page-breaks)

This is implemented in r2-testapp-js, but is currently missing in readium-desktop.

dialogs (settings in reader view, OPDS in library) is mouse-modal, but cyclic keyboard traversal is not contained (user can navigate to UI "underneath" the dialog)

React unique iterator key should be on 'li', not 'a' element.

Warning: Each child in an array or iterator should have a unique "key" prop.

https://github.com/edrlab/readium-desktop/blob/3b6895e99619a5954ce2c21ab7fb67609d46ed49/src/renderer/components/ReaderApp.tsx#L307

@Scarsniik

Add a CNL logo in the "about" menu

The financial help of the CNL (Centre National du Livre) is instrumental in this work and we have to show it.

The initial text of the "About" screen will be:
"Copyright 2018 European Digital Reading Lab"
followed by the content of the BSD-3 license (https://opensource.org/licenses/BSD-3-Clause)
followed by some vertical spaces and an horizontal line then:
"Readium Desktop wouldn't have been developed without the financial help of the CNL (Centre National du Livre, France)."
followed by the logo of the CNL, found on http://www.centrenationaldulivre.fr/fr/usage_du_logo_du_cnl/.

Font size chooser / slider: stepped values rather than continuous

The ReadiumCSS documentation recommends the following enumeration:

https://github.com/readium/readium-css/blob/master/docs/CSS09-user_prefs.md#font-size-and-type-scale

75% | 87.5% | 100% | 112.5% | 137.5% | 150% | 162.5% | 175% | 200% | 225% | 250%

The r2-testapp-js Electron app utilizes a UI slider with stepped values at regular intervals, not exactly the same as the above enumeration, but close enough.

The current navigator implementation documents these values too (whilst allowing any arbitrary values, as this is not strictly enforced), but note that only --USER__fontSize is currently implemented, not --USER__typeScale (TODO?):

https://github.com/edrlab/r2-navigator-js/blob/develop/src/electron/renderer/webview/readium-css.ts#L452

Un/active button colors in main view

Currently active color is grey and unactive color is black
Switch this behaviour : grey color for unactive button and black color for active button

RangeError: Invalid time value for some EPUBs (date/time metadata)

RangeError: Invalid time value

Deprecation warning: value provided is not in a recognized RFC2822 or ISO format. moment construction falls back to js Date(), which is not reliable across all browsers and versions. Non RFC2822/ISO date formats are discouraged and will be removed in an upcoming major release. Please refer to http://momentjs.com/guides/#/warnings/js-date/ for more info.
Arguments:
[0] _isAMomentObject: true, _isUTC: false, _useUTC: false, _l: undefined, _i: --T00:00:00Z, _f: undefined, _strict: undefined, _locale: [object Object]
Error
    at Function.createFromInputFallback (r2-testapp-js/node_modules/moment/moment.js:324:94)
    at configFromString (r2-testapp-js/node_modules/moment/moment.js:2366:11)
    at configFromInput (r2-testapp-js/node_modules/moment/moment.js:2592:9)
    at prepareConfig (r2-testapp-js/node_modules/moment/moment.js:2575:9)
    at createFromConfig (r2-testapp-js/node_modules/moment/moment.js:2542:40)
    at createLocalOrUTC (r2-testapp-js/node_modules/moment/moment.js:2629:12)
    at createLocal (r2-testapp-js/node_modules/moment/moment.js:2633:12)
    at hooks (r2-testapp-js/node_modules/moment/moment.js:16:25)
    at fillPublicationDate (r2-testapp-js/node_modules/r2-shared-js/dist/es8-es2017/src/parser/epub.js:624:52)
    at Object.EpubParsePromise (r2-testapp-js/node_modules/r2-shared-js/dist/es8-es2017/src/parser/epub.js:332:5)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)

night/dark mode in ReadiumCSS (EPUB HTML content documents) should be matched in UI

navigator doc LCP / LSD info needs updating (contains IPC event bootstrapping specific to r2-testapp-js)

https://github.com/edrlab/readium-desktop/blob/feature/next-v1/docs/navigator.md

UI crashes (blank screen) when using escape key to close popup menus (toolbar), or enter/return to select menu item

Uncaught TypeError: iconButton.setKeyboardFocus is not a function, The above error occurred in the <IconMenu> component
(material UI)

WebPack bundle with external package references for Electron renderer process (compatible with Hot Module Reload server)

This optional optimization would minimizes the bundle size by an order of magnitude, and improves compile times.
To turn on the optional build feature, we could use an environment variable, for example WEBPACK=bundle-external npm run start:dev.

Keyboard interaction with React-MaterialUI: buttons onClick event called several times when pushed with space/enter key

This is a known bug in material-ui 0.20.0 (latest):
https://www.npmjs.com/package/material-ui

Issue:
mui/material-ui#9344

Pull Request (already merged in their master branch):
mui/material-ui#9439

v0.20.0 was published on December 4th:
https://github.com/mui-org/material-ui/commits/master

We will close this issue when a new release of material-ui is available.

PS: I personally check my NPM dependencies regularly using the ncu CLI:
https://www.npmjs.com/package/npm-check-updates
(alternatively, the David web app is great too, e.g.: https://david-dm.org/edrlab/r2-streamer-js )

navigator doc contains unnecessary info about IStore / ElectronStore (implementation detail in r2-testapp-js)

https://github.com/edrlab/readium-desktop/blob/feature/next-v1/docs/navigator.md

levelUP / levelDOWN runtime error with `npm run start:dev`

npm install concludes with a full successful rebuild to target Electron (1.7.9/1.7.10), but the app starts with an error (see console message below). Any idea? Are you experiencing the same at your end?

[1] App threw an error during load
[1] AssertionError: .status required, old abstract-leveldown
[1]     at new LevelUP (/Users/danielweck/Code/readium-desktop/dist/main.js:69273:10)
[1]     at LevelUP (/Users/danielweck/Code/readium-desktop/dist/main.js:69250:12)
[1]     at PouchDB$2.LevelPouch (/Users/danielweck/Code/readium-desktop/dist/main.js:67882:144)
[1]     at PouchDB$2.JsonDownPouch (/Users/danielweck/Code/readium-desktop/dist/main.js:67611:83)
[1]     at new PouchDB$2 (/Users/danielweck/Code/readium-desktop/dist/main.js:17751:36)
[1]     at Object.<anonymous> (/Users/danielweck/Code/readium-desktop/dist/main.js:5592:23)
[1]     at __webpack_require__ (/Users/danielweck/Code/readium-desktop/dist/main.js:21:30)
[1]     at Object.<anonymous> (/Users/danielweck/Code/readium-desktop/dist/main.js:47451:14)
[1]     at __webpack_require__ (/Users/danielweck/Code/readium-desktop/dist/main.js:21:30)
[1]     at /Users/danielweck/Code/readium-desktop/dist/main.js:64:18

Use FSA Flux Standard Actions (type and payload)

https://github.com/acdlite/flux-standard-action#example

Opt-in EPUB file extension association ("double-click from filesystem to open publication")

CBZ too?

This should work on all 3 target distribution platforms Windows, Linux and MacOS

Manage LCPL file (EPUB acquisition / download from LCP license rel=publication link)

Download publication linked to this LCPL file

Fetch LCP LSD info before start of reader view (from catalog / library view)

See: https://github.com/edrlab/readium-desktop/blob/feature/r2-navigator-refactor/docs/navigator.md#epub-parser

publication cover images are stretched (aspect ratio not preserved)

"loading" indicator (indefinitely spinning visuals) + blank overlay to hide EPUB content whilst loading / formating

In ReaderApp.tsx, the installNavigatorDOM() function attaches the navigator to an app-defined HTML "anchor" node (passed as a DOM element unique ID parameter).

The navigator emits a show/hide custom DOM event on this "anchor" element in order to let the app UI know that the EPUB content should be hidden/shown (for example during formatting operations, resizing, etc.).

The application can do whatever it likes with this event, or even ignore it (as is the case right now in readium-desktop). For example, the r2-testapp-js sample Electron app displays a white overlay with a spinning "loader" to let the user know that a long operation is taking place under the hood.

API:

import {
    DOM_EVENT_HIDE_VIEWPORT,
    DOM_EVENT_SHOW_VIEWPORT,
} from "@r2-navigator-js/electron/renderer/index";

anchorHtmlElement.addEventListener(DOM_EVENT_HIDE_VIEWPORT, () => {
    HIDE_WITH_LOADER();
});
anchorHtmlElement.addEventListener(DOM_EVENT_SHOW_VIEWPORT, () =>
    SHOW();
});

VSCode Electron "launch" debugger config does not work with externals in renderer process bundle

There's a weird "bug" (feature?) in the Electron CLI, whereby electron . (assuming package.json and a correct main property pointing to dist/main.js) is different than electron dist/main.js. The former works great, the latter breaks when Electron renderer process is launched from a code bundle that contains Node CommonJS require() calls to externalized packages.
Unfortunately, the VSCode launch configuration results in the latter. Thankfully, we can fix that by using an "attach" configuration to an existing Electron process.