Layouts
Qt is cross-platform application framework, hence it supports concepts such as layouts for developing applications that look consistent in all platforms, irrespective of the different screen resolutions. When we develop GUI/HMI-based Qt applications, an application developed in one system shouldn't appear different on another system with a different screen size and resolution. This is achieved in the Qt Framework via layouts. Layouts come in different flavors. This helps a developer design a professional-looking HMI/GUI by organizing various widgets within a window or dialog. Layouts differ in the way they arrange their child widgets. While one arranges its child widgets in a horizontal fashion, another will arrange them in a vertical or grid fashion. When a window or dialog gets resized, the layouts resize their child widgets so they don't get truncated or go out of focus.
Writing a GUI application with a horizontal layout
Let's write a Qt application that has a couple of buttons...