Book Image

Mastering Qt 5 - Second Edition

By : Guillaume Lazar, Robin Penea
Book Image

Mastering Qt 5 - Second Edition

By: Guillaume Lazar, Robin Penea

Overview of this book

Qt 5.11 is an app development framework that provides a great user experience and develops full capability applications with Qt Widgets, QML, and even Qt 3D. Whether you're building GUI prototypes or fully-fledged cross-platform GUI applications with a native look and feel, Mastering Qt 5 is your fastest, easiest, and most powerful solution. This book addresses various challenges and teaches you to successfully develop cross-platform applications using the Qt framework, with the help of well-organized projects. Working through this book, you will gain a better understanding of the Qt framework, as well as the tools required to resolve serious issues, such as linking, debugging, and multithreading. You'll start off your journey by discovering the new Qt 5.11 features, soon followed by exploring different platforms and learning to tame them. In addition to this, you'll interact with a gamepad using Qt Gamepad. Each chapter is a logical step for you to complete in order to master Qt. By the end of this book, you'll have created an application that has been tested and is ready to be shipped.
Table of Contents (16 chapters)

Enhancing thumbnails with PictureDelegate

By default, a QListView class will request Qt::DisplayRole and Qt::DecorationRole to display text and a picture for each item. Thus, we already have a visual result, for free, that looks like this:

However, our Gallery application deserves better thumbnail rendering. Hopefully, we can easily customize it using the view's delegate concept. A QListView class provides a default item rendering. We can do our own item rendering by creating a class that inherits QStyledItemDelegate. The aim is to paint your dream thumbnails with a name banner, like in the following screenshot:

Let's take a look at PictureDelegate.h:

#include <QStyledItemDelegate> 
 
class PictureDelegate : public QStyledItemDelegate 
{ 
    Q_OBJECT 
public: 
    PictureDelegate(QObject* parent = 0); 
 
    void paint(QPainter* painter, const QStyleOptionViewItem...