readium / r2-testapp-js

Did you test disabling the GPU? cf. electron/electron#6139 (comment) (cos’ yeah I’ve reinstalled Xubuntu from scratch this weekend and I had GPU issues for something else… and since Lubuntu ships with the minimal config possible…).

That or maybe electron/electron#8505.

Ah no, the empty BrowserWindow is not really a "bug", it is a "feature" :)

The r2-testapp-js user interface / UX is really basic, there is in fact no initial Electron BrowserWindow for a bookshelf / library view (only a system menu to choose publications from the filesystem). So on MacOS (platform darwin) we display a "welcome" native message box to let the user know about the existence of the top-level system menu, whereas on the other platforms we create a BrowserWindow to hosts the system menu and to display the "welcome" message that explains users what to do.

r2-testapp-js/src/electron/main/index.ts

Lines 682 to 720 in 3a3e325

    
           const detail = "Note that this is only a developer application (" + 
        
               "test framework) for the Readium2 NodeJS 'streamer' and Electron-based 'navigator'."; 
        
           const message = "Use the 'Electron' menu to load publications."; 
        
           if (process.platform === "darwin") { 
        
               const choice = dialog.showMessageBox({ 
        
                   buttons: ["&OK"], 
        
                   cancelId: 0, 
        
                   defaultId: 0, 
        
                   detail, 
        
                   message, 
        
                   noLink: true, 
        
                   normalizeAccessKeys: true, 
        
                   title: "Readium2 Electron streamer / navigator", 
        
                   type: "info", 
        
               }); 
        
               if (choice === 0) { 
        
                   debug("ok"); 
        
               } 
        
           } else { 
        
               const html = `<html><h2>${message}<hr>${detail}</h2></html>`; 
        
               const electronBrowserWindow = new BrowserWindow({ 
        
                   height: 300, 
        
                   webPreferences: { 
        
                       allowRunningInsecureContent: false, 
        
                       contextIsolation: false, 
        
                       devTools: false, 
        
                       nodeIntegration: false, 
        
                       nodeIntegrationInWorker: false, 
        
                       sandbox: false, 
        
                       webSecurity: true, 
        
                       webviewTag: false, 
        
                       // preload: __dirname + "/" + "preload.js", 
        
                   }, 
        
                   width: 400, 
        
               }); 
        
               electronBrowserWindow.webContents.loadURL("data:text/html," + html); 
        
           }

So, this issue is about the weird empty reader view in Lubuntu's LXDE X11-based window manager ( https://lxde.org ), instead of the "welcome" message.

Thanks for the Electron GPU heads-up though, good to know.

Ok OK sorry for the noise then.

On a somewhat related note, Lubuntu is currently transitioning to LXQt, see their explainer.

@JayPanoz I created this r2-navigator-js issue just in case GPU hardware-accelerated webview is problematic in our current Electron v2 implementations:
readium/r2-navigator-js#17

Eventually we will migrate to Electron v3+ which will bring its own set of breaking changes / integration challenges:
readium/r2-navigator-js#15
... but hopefully this will fix any potential GPU issues :)

Ah, my bad, I was trying to use the npm run electron CLI to open a custom root directory, when in fact the command line parameter is meant to be a file! (EPUB to open directly)
I added a directory check to the CLI to avoid this silly mistake in the future:
e5f2310

	const detail = "Note that this is only a developer application (" +
	"test framework) for the Readium2 NodeJS 'streamer' and Electron-based 'navigator'.";
	const message = "Use the 'Electron' menu to load publications.";

	if (process.platform === "darwin") {
	const choice = dialog.showMessageBox({
	buttons: ["&OK"],
	cancelId: 0,
	defaultId: 0,
	detail,
	message,
	noLink: true,
	normalizeAccessKeys: true,
	title: "Readium2 Electron streamer / navigator",
	type: "info",
	});
	if (choice === 0) {
	debug("ok");
	}
	} else {
	const html = `<html><h2>${message}<hr>${detail}</h2></html>`;
	const electronBrowserWindow = new BrowserWindow({
	height: 300,
	webPreferences: {
	allowRunningInsecureContent: false,
	contextIsolation: false,
	devTools: false,
	nodeIntegration: false,
	nodeIntegrationInWorker: false,
	sandbox: false,
	webSecurity: true,
	webviewTag: false,
	// preload: __dirname + "/" + "preload.js",
	},
	width: 400,
	});

	electronBrowserWindow.webContents.loadURL("data:text/html," + html);
	}

Linux Lubuntu (not Ubuntu, or Kubuntu), Electron BrowserWindow at app startup with empty contents (does not crash, but annoying)