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)

Building the image-filter application

We can proceed to build the UI of the application. The idea is to open a picture from the filesystem and apply to it the various filters we developed in the filter-designer-plugin project. If you want to keep the result, you can save the resulting image.

We will start by designing the UI. Modify MainWindow.ui to look like the following:

Here is the Object Inspector content to help you build this layout:

There are three elements of this UI:

  • The menuFile element, which contains three possible actions: actionOpenPicture, actionExit, and actionSaveAs. You can see the details of these actions in the Action Editor window.
  • The pictureLabel element, which will display the loaded picture in the empty top section.
  • The filtersLayout element, which contains the three instances of our FilterWidget class in the bottom section.

As you add a FilterWidget...