Today I want to talk about the usage of data models in Cascades. As you might know already, Cascades provides the abstract interface bb::cascades::DataModel, which is used by bb::cascades::ListView to retrieve and display arbitrary data. Cascades also provides a couple of convenience classes that implement this DataModel interface, namely ArrayDataModel GroupDataModel QListDataModel XmlDataModel While the […]

In the last episode of this series we discussed QAbstractItemModel::checkIndex(). QAbstractItemModel::checkIndex() is a function added in Qt 5.11 that allows developers of model classes to perform some validity checks on the QModelIndex objects passed to the model; specifically, on the indices passed to the APIs that model classes need to implement (rowCount(), columnCount(), data, setData(), […]

Introduction When someone with an OpenGL background begins using Vulkan, one of the very common outcomes - beyond the initial one of "OMG how much code does it take to draw a triangle?" - is that the resulting image is upside down. Searching the web for this will give many hits on discussions about coordinate […]

With QML as abstraction layer, we nowadays have a great way to separate the business logic (C++) of our application from the graphical user interface (QtQuick/QtWidgets/Cascades) on top of it. The interface between the two layers is well defined by the meta-object API, which essentially boils down to signals and slots for notifications and invocations, […]

This is the latest release of our powerful open-source Qt component, KD Chart, that allows you to create business charts and much more. Release Highlights Builds with modern Qt versions, at least up to Qt 5.10 Improves tooltip handling Fixes horizontal bar chart Uses @rpath for OSX dynamic libraries Fixes build on Qt4/ARM KD Chart […]

In this follow-up to our drag-and-drop guide, we explore how to move items between views in Qt’s model/view framework. Learn how to set up both drag and drop sides, handle MIME data, and implement key model methods. Whether you're working with model/view separation or with item widgets, this post provides practical examples to help you customize UI interactions effectively.

This post explores implementing drag-and-drop onto existing items in Qt, such as moving emails between folders. It covers both Model/View and Item Widget approaches, detailing key setup steps and improvements made to Qt along the way.

Common render issues and their solution -Part 3

If you are here from Part 1, you missed Part 2, somehow. You have tried everything from the first two parts that seemed applicable, and your screen is still a window to the void? No problem: we’ve gathered another five reasons black screen issues could be happening and how to go about fixing them. Issue […]

The Qt model/view APIs are used throughout Qt -- in Qt Widgets, in Qt Quick, as well as in other non-GUI code. As I tell my students when I deliver Qt trainings: mastering the usage of model/view classes and functions is mandatory knowledge, any non-trivial Qt application is going to be data-driven, with the data […]

In recent years, a lot has been happening to improve performance, maintainability and tooling of QML. Some of those improvements can only take full effect when your code follows modern best practices. Here are 10 things you can do in order to modernize your QML code and take full advantage of QML's capabilities. 1. Use […]

This blog post is the first in a series on implementing drag-and-drop in the Qt model/view framework. It covers how to reorder items within a single view, whether you're using QListView, QTableView, or QTreeView with a custom model, or QListWidget, QTableWidget, or QTreeWidget with items. The post includes code examples, checklists, and insights into improvements made in Qt 6.8 for smoother drag-and-drop functionality.

When using Qt's model/view framework, filtering has always been very easy with QSortFilterProxyModel. To filter a list using text typed by the user in a line-edit, you have certainly been applying the standard recipe: instantiate the proxy; insert it between view and source model; connect the lineedit's textChanged signal to the proxy's setFilterFixedString slot; done! […]

With this blog post we are going to kickstart our brand new blog series about KDToolBox. The first class we're exploring is KDTableToListProxyModel, a table-to-list proxy model. The main use case for KDTableToListProxyModel is exposing tabular models to Qt Quick. Qt Quick has a certain number of "view" elements that only support list models: for […]

If you missed Qt Desktop Days, you might be wondering what you missed. No need to worry! We’re going to give you a day-by-day summary of some of the cool things that were discussed, demoed, and explained. (We’re uploading all of the videos to our YouTube channel, but we’ll provide the direct links to each […]

This post is part of an ongoing series about developments and discussions in Qt. Some parts of this report are still under discussion and don’t necessarily reflect the final state of Qt 5. The target audience is people involved in Qt development itself, but without the time to follow everything that happens, and others with […]

During the last couple of months KDAB engineers have been working on improving CUPS printing support for Linux in Qt. This work has been sponsored by the LiMux project, a big thank you to them for allowing us to spend time improving Qt :). We started in early December with a series of small commits […]

At Qt World Summit in 2019, KDAB offered five Introductory courses (one was given by our partner, froglogic), and three advanced classes., as follows: Introductory Course descriptions Introduction to Qt 3D Studio, trainer: Nuno Pinheiro This training introduces designers and developers to 3D content workflows and concepts, giving them a solid grounding in creating content […]

Hello, and welcome to the usual appointment with a new release of Qt! Qt 5.7 has just been released, and once more, KDAB has been a huge part of it (we are shown in red on the graph): In this blog post I will show some of the outstanding contributions by KDAB engineers to the […]