David Faure

In this video, you will learn how to let the user drop files onto a Qt widget. The users of your application will appreciate being able to open a file by dragging it from a file manager (for instance), and dropping it onto your application.

To build parts of the code optionally, or to inject CMake variables into C++, you need pre-processor definitions like -DENABLE_FEATURE on the command-line or #define ENABLE_FEATURE 1 in code. This video shows 3 different ways of setting such pre-processor definitions with CMake. In addition, the video explains how and why you should use #if rather than #ifdef for on/off defines.

In this video, you will learn about a common programming pattern called the job pattern, useful for asynchronous operations (for instance, driven by the Qt event loop) such as socket communication, or any other operation that emits signals upon progress and completion.

In this video, you will learn how to debug a painting issue for a QWidget, using the detailed recording by GammaRay of all individual painting operations.

In this video, you will learn how to use GammaRay to find the slot executed by a QAction, when the user clicks on a menu item. This technique works even if you know nothing of the application code, all you have to do is find the action by its user-visible text.

In this video, you will learn how to use GammaRay to identify a context menu (QMenu) in a running application. The Pick Element feature won't let us see the context menu, but there are other solutions, like filtering for show events and finding the QWindow created for the menu.

In this video, you will learn how to use GammaRay to investigate the issue of a widget that can be squeezed down far too much horizontally. After testing the fix by changing a property dynamically at runtime, you will see how to find the corresponding line of C++ code in order to fix the bug for good.

In this video, you will learn how to use GammaRay to identify the widget responsible for a double margin issue, a frequent cause for misaligned widgets. After testing the removal of the margin in Gammaray, you will see how to make your IDE jump to the line of code that creates the widget, in order to find the corresponding layout and fix the bug there.

In this video, you will learn how to use GammaRay to visually select a widget in your Qt application, and from there find the class name of the widget, and make your IDE jump to the line of code that instanciated the widget.

This video introduces the series, defining the typical problems of Qt Widgets applications that we are going to try and solve using GammaRay.

This video shows how to implement a custom Qt widget, when none of the widgets provided by Qt match your needs. As an example, you'll be presented the code for a toggle switch, as is very common on mobile platforms, why not have something like that on the desktop too?

This video shows an example use of Qt stylesheets, to change the appearance of Qt widgets. We'll dig into the styling of the progressbar as example, the code for styling buttons is also provided.