Qt event model with signals/slots/MOC – an example

In this section, we will create an application to handle mouse events in QLabel. We will override the mouse events in a custom QLabel and handle them in the dialog where the custom label is placed. The approach to this application is as follows:

1. Create a custom my_QLabel class, inherited from the framework QLabel class, and override the mouse events, such as mouse-move, mouse-pressed, and mouse-leave.
2. Define the signals that correspond to these events in my_QLabel, and emit them from the corresponding event handlers.
3. Create a dialog class inherited from the QDialog class, and handcode the positions and layouts of all of the widgets, including the custom widget created to handle mouse events.
4. In the dialog class, define the slots to handle the emitted signals from the my_QLabel object, and display the appropriate results in the dialog.
5. Instantiate this dialog under the QApplication object, and execute.
6. Create the project file to build a widget...