Actions/Menus – Using Designer

I discovered a much better and easier way to create actions and menus for the application without having to write all the lines of code by using Designer within QtCreator.  The UI form for the main window is opened in Designer by double-clicking on mainwindow.ui from the project files area.

Main menus are added by double-clicking on the "Type Here" text at the top of the edit area and entering the text.  Hot keys are entered by preceding the desired character with an '&' ampersand character.  The menus can be repositioned by dragging them as desired.

Menu items are added is a similar way, by selecting the main menu and again double-clicking the "Type Here" text.  Separators are added by double-clicking the "Add Separator" text.  Status tips are entered in the statusTip field on the lower-right side properties after selecting the desired action from the upper-right side object tree list.  Shortcut keys can be entered in the shortcut field in the properties area or can be entered using the Action Editor tab at the bottom of Designer.

Designer automatically names the actions with the name "actionXxx" where Xxx is the text entered for the menu item.  The under-bar character is used for spaces, so these were removed to follow the camel casing naming convention.  Qt will make connections between actions and functions automatically if the functions are named correctly.  For the menu item actions, the functions are named on_actionXxx_triggered() where actionXxx is the name of the action and triggered is the name of the signal to connect.  All of the dummy program functions were renamed to this form so that the needed connections are made automatically.

However, this does not work for connecting the actionExit triggered signal to the MainWindow::close() function, since this does not follow the automatic naming convention.  This was accomplished by using Signal & Slots Editor tab at the bottom of Designer.  A new signal/slot is added by clicking the large plus icon.  For this new entry, the Sender was set to actionExit, the Signal was set to triggered(), the Receiver was set to MainWindow, and the Slot was set to close().

The actionAboutQt action could not be setup in Designer since there is no way to connect to the application's aboutQt() function using the Signal & Slots Editor because the application object is not an available Receiver.  This was instead accomplished by adding a new on_actionAboutQt_triggered() function to MainWindow, which simply calls qApp‑>aboutQt().

Now that all the actions and menus are in the UI form for MainWindow, the action enumeration, action pointers and menu pointers were removed from the class definition.  The pointers are now contained in the Ui::MainWindow class that is automatically generated from the mainwindow.ui form file by the UIC (Qt User-Interface Compiler), which MainWindow contains a member pointer to.  Since the setupUi() function, called in the constructor, now creates the actions and sets up the menus, the createActions() and createMenus() functions are no longer needed and were removed.

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