Introduction to Design Patterns in C++ with Qt, 2nd Edition

Chapter 9: Widgets and Designer

This chapter provides an overview of the graphical user interface (GUI) building blocks in the Qt library, called widgets, and includes some simple examples of how to use them. We use QtCreator and Designer to explore the widgets and their features and to integrate forms with user code.

A widget is an object of a class derived from QWidget that has a visual representation on the screen. The structural origins of QWidget are shown in Figure 9.1.

Figure 9.1 QWidget’s Heritage

QWidget is a class that uses multiple inheritance (Section 22.3). A QWidget is a QObject, and thus can have a parent, signals, slots, and managed ...