Qt 5.0.0 introduced the QStandardPaths class. This expands on functionality that was in Qt 4 in the QDesktopServices class.

The QStandardPaths class provides methods for accessing standard paths on a system such as the location of the user's desktop directory or location of a program executable. The class provides only static methods, so it never needs to be instantiated as an object.

Introduction

A quick trivia quiz:

1. Does Qt use multiple inheritance?
2. If so, how many public Qt classes use it?
3. Does any Qt class directly inherit from more than two classes?
4. Does Qt let you multiply inherit (directly or indirectly) from QObject?

If you can correctly answer these questions off the top of your head you're definitely a Qt and C++ guru and can stop reading now. If not, then by the end of this article you will be able to answer these questions and impress your colleagues with your knowledge.

QMimeDatabase and QMimeType are new classes introduced in Qt 5. MIME, which stands for Multipurpose Internet Mail Extensions, is an Internet standard for identifying file formats. The MIME standard was originally created to support attachment of files in e-mail messages. A good reference for MIME can be found here.

The QMimeDatabase class returns information about the database of MIME types on a system. Instances of the QMimeType class describe the type of a file or data.

QScreen is a new class introduced in Qt 5.0.0 that returns information about screen properties, where screen here refers to a display, such as a monitor or LCD panel.

[Update: It was pointed out that Qt 4 has a class named QScreen. However, the QScreenclass in Qt 4 was entirely different from the one in Qt 5 with different APIs and used for a different purpose. So I really consider them to be different classes.]

Written by Alan Ezust and Paul Ezust
Foreword by Lars Knoll

This week was a little slow as some people were away for the holidays. The new callback-qtimplementation by Viras got committed to github and we are now working with that version.