root access – Is it possible to take pictures from both front and rear camera at the same time (like bothie)

There are apps that can do this but they are not exactly Bothie. The app allows the user to first take a picture from rear camera and then from the front camera (but not simultaneously). Nokia first came up with this idea in 2017.
More about Bothie

I am just wondering if this is a hardware feature or software. I can handle the software issue(with root) i think. And if this is not possible then can you please explain why and how it works?

Thanks a ton in advance : )

front end – What is the black-background Mathematica code editor in the movie Arrival?

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optics – Aperture iris in front of lenses (in object space)

In general putting the aperture at the front or outside is avoided because not good; best is to put the aperture more or less in the center of the objective. With the aperture in front you’ll have more aberrations and/or need bigger and more expensive design.
Only in two cases the front aperture design is used:

  1. if the lens is very small and simple, like, really just one group (see the Kodak vest camera and the Triplet), here you cannot put the aperture in the middle! Choose, in the front or in the back.
  2. Otherwise, you put the aperture in front only if you are absolutely forced to do that, typically for coupling with other optical systems.

Small & simple:
Mobile phone lenses; to make them so compact, the aperture is usually placed at the brim of the front lens. Not really outside, but on the brim.

Pinholes and many probe objectives, that need to peep from an hole; the hole is the natural aperture and the lens must be built to use all the light that goes through such hole; putting another aperture will cause vignetting. Nice example the SO spy lenses by Zeiss Jena:
Marco Cavina or see the catalog of Marshall Electronics.

Non-photographic lenses:

  • Laser scanning lenses, called F-theta Rogonar; the laser light is coming form the aperture position.
  • All eyepieces: the aperture is well outside, at the “exit pupil”, so I can place my eye with my iris in this place.

If you are curious about aberrations etc, the best short introduction I’ve found are those slides from Jena:
Gross Jena 2017; lecture 11/3, stop position.

user research – Is it a good idea for me (a freshman in college) to focus on front end web dev and UI/UX at the same time, essentially learning to be a hybrid?

I studied Human-Computer-Interaction, which was basically what you describe as hybrid. Though it was more in-depth and a very well mixed assortment of classes, like data structures in coding and SQL, but at the same time stuff like psychology, ergonomy, prototypes and user research.

I’m not sure how much more into the UX field you can or will go, besides this one specific topic that you mentioned. I’m also not sure if “just” doing this one specific UX research topic is already basis enough to completely go in that direction. You have to be the judge of that, I can only make assumtions.

But regarding the actual question if it is viable:
I will say it is literally comparable to multi-classing in RPG games. You learn 50/50 of both and, thus, can contribute to both sides equally when it’s necessary. But at the same time, you aren’t as qualified in either of the halves as someone who focuses only & specifically on that.

And oftentimes people are looking for someone to solve a specific problem or fill a specific role in their company, and they’d rather have two experts than to have one person who only knows half of each. On the contrary, a smaller company or a start-up is often more interested in that type of hybrid. Have the necessary fundamentals of both sides and only pay one salary? Great! Because they may not need the very deep expertise and are happy with the basics.
So it’s also a question about the size of the company; one that is huge and established won’t be interested in doing experiments with someone in both fields, whereas those with a very lenient and free structure very well might be.

My suggestion: This is based solely on my personal experience, maybe someone else can share others views on this, but I would suggest to not go strictly 50/50 on UX and coding. Instead, go for a major role with a complementing minor role. Like 70% UX and 30% frontend.
Because, as I said, oftentimes they want someone for a specific problem, and it’s easier to take someone who’s majorly focused on the topic they need AND has some extra knowledge of a related topic (“wow, valuable!”) than to have someone where they aren’t sure if you have enough expertise in this ONE topic they need to even hire you.

I, for example, have went with a 80% UX – 20% code representation of myself for my professional career, but do about 50/50 in personal projects on the side. So I still get to use both parts equally.

Personal note: I also have to add that when you’re planning on doing your own thing and going freelancer or starting your own project, it’s super valuable to have both skills, because you oftentimes only need the basics and can cover nearly everything by yourself. I am very glad to have both skills.

macbook pro – Communication apps “jumping” to front without user input on Big Sur

Since I updated to Big Sur on my MacBookPro MacBook Pro (13-inch, 2019, i5) I have this very inconvenient situation where my communication apps, specifically Zoom, Slack and Discord, jump to the front without any action on my part.

Usually I have the app in the back, meaning I am either actively using another application, like writing something on visual studio code, IntelliJ, pycharm, or just have something else like Firefox or Mail opened in front of it. Then suddenly it jumps to front as if I had clicked on it or brought it to the front in some arcane way like “hitting cmd+tab” very fast.

It has become common place to be showing something on zoom screen share to my colleagues and then discord or slack to jump to the front plane on top of what I am showing, or when just talking with video open the zoom landing/main/app jumps to front obscuring my screen in the middle of the call.

It is very disruptive and frustrating to my workflow and it is happening at an alarming rate. Yesterday I had it happen to me 7 times, today it already happened once.

I had other weird problems too with Big Sur like the zoom link to open a call not immediately opening a new tab in my browser (actually it may take up to 2 minutes to open a new tab), but this is showing signs that it is going back to normal now.

8 – Disable caching for a front page path processor

I’m working on a project where users can create a book (core functionality). In a simple text field they can connect a domain to this book. This way the book is only accessible via this domain.

For example I have Book A with path node1 and with domain I also have Book B with path node2 and connected to domain

What I want now is if a visitor goes to the frontpage is node/1. And if they go to the frontpage should be node/2? I created a custom module for this book_frontpage.

For this I used large parts of the PathProcessorFront.php from core.

The code of my is:

    class: Drupalbook_frontpagePathProcessorFrontPagePathProcessor
      - { name: path_processor_inbound, priority: 300 }

The code of my FrontPagePathProcessor.php is:


namespace Drupalbook_frontpagePathProcessor;

use DrupalCoreDatabaseDatabase;
use DrupalCorePathProcessorInboundPathProcessorInterface;
use SymfonyComponentHttpFoundationRequest;
use SymfonyComponentHttpKernelExceptionNotFoundHttpException;

 * Path processor to replace 'node' with 'content' in URLs.
class FrontPagePathProcessor implements InboundPathProcessorInterface{
   * {@inheritdoc}
  public function processInbound($path, Request $request)
    if ($path === '/') {
      //current domain
      $currentDomain = $_SERVER('SERVER_NAME');

      //get nid of reader where domain is set
      $nid = Database::getConnection()->select('node__field_domain', 'd')
        ->fields('d', ('entity_id'))
        ->condition('field_domain_value', $currentDomain, '=')

      //get path
      $path = Drupal::service('path_alias.manager')->getAliasByPath('/node/'. $nid);

      if (empty($path)) {
        // We have to return a valid path but / won't be routable and config
        // might be broken so stop execution.
        throw new NotFoundHttpException();
      $components = parse_url($path);

      // Remove query string and fragment.
      $path = $components('path');

      // Merge query parameters from front page configuration value
      // with URL query, so that actual URL takes precedence.
      if (!empty($components('query'))) {
        parse_str($components('query'), $parameters);
        array_replace($parameters, $request->query->all());

    return $path;

Now when going to I see node/1 but when I go to I also see node/1. When I clear cache and first go to I get node/2 but when going to I also get node/2. So this looks like a cache problem.

How can I disable caching of this front page path?

key management – Securing API keys for accessing Google APIs via Front End (UI)

This question is about how to secure API keys. Not sure if this is in the same category as Key management for Cryptography and should follow the same rules. See details below.

We currently have hybrid Mobile Apps. The apps are made using Angular and Ionic. Now, we have some functions where we would need to use some of Google’s APIs in order to implement the functions we want. No problem there.

The issue is how to securely store the API keys that we pass to Google APIs? It would seem not a good practice to hardcode it in the UI codes. Can anyone help us here and suggest a way to securely store the API keys? We already have thought of retrieving it from the back end but it would still expose it after we retrieve it from back end and pass to Google.

Different front page based on url

I’m working on a project where users can create a book (core functionality). In a simple text field they can connect a domain to this book. This way the book is only accessible via this domain.

For example I have Book A with path node1 and with domain I also have Book B with path node2 and connected to domain

Now with a custom module I set the access to these nodes that Book A is only accessible via and not via and vice versa.

What I want now is if a visitor goes to the frontpage is node/1.
And if they go to the frontpage should be node/2?

I know the Domain Acces module has functionalities like this but I find this module to big and complex for my project.

I want to create a custom module to solve this. Where to start?

Thanks in advance