I can sympathize that GPG (a free and toolset to encrypt and sign digital data) has not been used by the wide public in the past. It was complex to set up, the concept of private/public keys was a bit flaky to most people, PGP (not GPG!) costs precious money, and integration with mail clients was not trivial.

With the spreading of Mozilla Thunderbird this has changed drastically however. With enigmail (a mozilla-addon to use GPG with the mail client), things are becoming much easier and accessible. It offers most of the functionalities you wish to see in such a tool. It allows you to create a new private/public key pair, has a simple management tool for keys, and lets you very transparently sign and/or encrypt e-mails.

In my opinion, the main reason why GPG is still a thing for “geeks” or “professionals” is the ignorance (or naiveté) of people about how easy mails can be intercepted. Yesterday I demonstrated somebody this exact fact. And him still being quite computer-literate, he was still baffled that I could show him the text of a mail he sent with his password along the lines (All done with his consent of course). And I do not consider myself a hacker. Just a few minutes of googling, downloading and installing the right tool did it for me. And if I can do this, so can many other people as well. With a little bit more effort, it’s even possible to alter the text of a mail in transit. Needless to say, the emails are stored on somebody else’s server. An this in plain text! Even if the server does support SSL, TLS or whatnot. This only means that the transmission between mail-client and mail-server is secured. Not the storage. And you never know who sit’s behind the screen of that server.

Granted, most of the time, people managing servers like this are most likely geeks themselves, which usually share the concern about security, and thus keep things safe.

Considering this, it can become easy to demonstrate the advantages of mail encryption/signing. And usability is increasing steadily. With the mozilla suit (and thunderbird) now having a user-friendly tool at the ready, people are not yet easily convinced to keep security in mind. Other mail-clients offer easy user-interfaces as well. The KDE-Suite (with KMail and KGPG) had brilliant supoprt for this already a long time ago. And there are more free tools available to make it a user-friendly experience. The Swiss-Army-Knife for a Windows environment would probably be GPGShell. It still resorts to the GPG-Cli application from time-to-time, but it keeps it to a minimum. It also offers easy file-encryption via Windows Explorer shell entries. Another alternative is Evolution, which has built-in supoprt for GPG.

Suffice it to say, there is widespread support for GPG (and PGP) in mail-application across all OS’es. To become more widespread in use, people should be made aware of the risks that are posed by e-mails and how easy it can be made to keep personal information really personal.

And here’s the same thing as plpgsql function for Postgres:

This results in more accurate distances than simply using

You could also use plpython as function language and copy/paste the earlier post, but plpgsql is more portable.

This function uses the Haversine formula to calculate the distance which takes into account the spherical nature of the earth.
As the earth is not a perfect sphere, this function approximates this by using the average radius.

Yet another thing that’s not automagic in Qt.
Here’s a python solution:

This will also resize the window, adapting to the desktop size.
Found and adapted from the Qt interest archive.

Many things are very easy to accomplish in Qt. Qt’s designer is a great help with that. But the is no option to simply “enable” scrollbars for a frame. Also, the QScrollArea can nowhere be found in the designer. The solution is actually quite simple:

1. Add the component you want to be scrollable (QFrame, QLabel, …) in the designer as usual
2. In the application code:
   1. Create a new QScrollArea
   2. Set the parent of the widget you created in the designer to “None”
   3. Set the widget of the QScrollArea to the widget from step 1
   4. Insert the QScrollArea to you ui

And here’s some example code (boiled down to the essentials):

You would probably write this somewhere in you application-constructor right after you call setupUi.

This will insert the scroll area at the top of vboxlayout1 (see the doc for insertWidget). You can of course also use addWidget.

It’s a shame that there’s no direct support for QScrollArea in designer. Maybe we will see it in some future release.

An example for C++ can be found in the Qt Forums.

I never cared about which terminal to chose. I usually ended up with aterm on non-KDE boxes and Konsole on KDE boxes. This comparison (and the attached comments) is actually quite interesting.

The results were quite surprising 😉