Basic Qt5 Slots, Signals and Menus Example

In case the reader is an aspiring programmer, but yet a hobbyist, one of the facts which he or she will already know is that, in order to design applications which have a Graphical User Interface, some predefined GUI Library is commonly used, and one example of a GUI Library which can be used is Qt 5. Therefore, in order to become proficient at using this library, like me, the reader might want a working example of:

  • Signals and Slots – The way in which Qt connects user-actions on the GUI, to actions which should be triggered from the actual program,
  • The use of the ‘QLabel’ class to display an image instead of more-common text,
  • The design of a very basic command-menu and a keyboard shortcut,
  • A QRC Resource Script.

Even though this example was created with ‘Qt Creator’ and Qt version 5.7, one of the main features of Qt Creator, its GUI Layout Designer, has been cut from the project, so that the means by which such mechanisms can be set up entirely via code, can be explored better. Also, while Qt5 maintains backwards-compatibility with Qt4 -style Signals and Slots, that are based on macros, this project makes use of the newer Qt5 semantics, that are based on function pointers, for the sake of favouring new features over old.

I can say that on my Debian 9 / Stretch computer, the example works. However, the Qt Library is designed to be cross-platform, and so the example should also work under Windows. What some people have suggested is that, in order to get such code to work under OS/X, ‘ccmake’ should be used with the ‘Unix Makefiles’ generator. This will assume that ‘XCode’ is already installed. (:1)

The Link where the compressed files, containing only source code, can be found (along some other compressed files that also contain precompiled binaries, belonging to other projects) is here:

https://dirkmittler.homeip.net/binaries/

In that Gopher-Hole, the files of interest would be ‘Creator_Test2.tar.gz‘ or ‘Creator_Test2.zip‘.

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