Book Image

Cross-Platform Development with Qt 6 and Modern C++

By : Nibedit Dey
Book Image

Cross-Platform Development with Qt 6 and Modern C++

By: Nibedit Dey

Overview of this book

Qt is a cross-platform application development framework widely used for developing applications that can run on a wide range of hardware platforms with little to no change in the underlying codebase. If you have basic knowledge of C++ and want to build desktop or mobile applications with a modern graphical user interface (GUI), Qt is the right choice for you. Cross-Platform Development with Qt 6 and Modern C++ helps you understand why Qt is one of the favorite GUI frameworks adopted by industries worldwide, covering the essentials of programming GUI apps across a multitude of platforms using the standard C++17 and Qt 6 features. Starting with the fundamentals of the Qt framework, including the features offered by Qt Creator, this practical guide will show you how to create classic user interfaces using Qt Widgets and touch-friendly user interfaces using Qt Quick. As you advance, you'll explore the Qt Creator IDE for developing applications for multiple desktops as well as for embedded and mobile platforms. You will also learn advanced concepts about signals and slots. Finally, the book takes you through debugging and testing your app with Qt Creator IDE. By the end of this book, you'll be able to build cross-platform applications with a modern GUI along with the speed and power of native apps.
Table of Contents (17 chapters)
Section 1: The Basics
Section 2: Cross-Platform Development
Section 3: Advanced Programming, Debugging, and Deployment

The working mechanism of Qt signals and slots

In the previous sections, we learned about signal and slot syntaxes and how to connect them. Now, we will understand how it works.

While creating a connection, Qt looks for the index of the signal and the slot. Qt uses a lookup string table to find the corresponding indexes. Then, a QObjectPrivate::Connection object is created and added to the internal linked lists. Since one signal can be connected to multiple slots, each signal can have a list of the connected slots. Each connection contains the receiver's name and the index of the slot. Each object has a connection vector that associates with each signal in a linked list of QObjectPrivate::Connection.

The following diagram illustrates how ConnectionList creates connections between sender and receiver objects:

Figure 6.1 – Illustration of the connection mechanism between the sender and receiver

ConnectionList is a singly linked list that contains...