Book Image

Mastering Qt 5

By : Guillaume Lazar, Robin Penea
Book Image

Mastering Qt 5

By: Guillaume Lazar, Robin Penea

Overview of this book

Qt 5.7 is an application development framework that provides a great user experience and develops full-capability applications with Qt Widgets, QML, and even Qt 3D. This book will address challenges in successfully developing cross-platform applications with the Qt framework. Cross-platform development needs a well-organized project. Using this book, you will have a better understanding of the Qt framework and the tools to resolve serious issues such as linking, debugging, and multithreading. Your journey will start with the new Qt 5 features. Then you will explore different platforms and learn to tame them. Every chapter along the way is a logical step that you must take to master Qt. The journey will end in an application that has been tested and is ready to be shipped.
Table of Contents (20 chapters)
Mastering Qt 5
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface

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 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& 
        option, const QModelIndex& index) const override; 
 
    QSize sizeHint(const QStyleOptionViewItem& option...