Anatomy of exercise app

Our image viewer app uses several C++ classes to open, display, and control display of image. The following screenshot highlights major classes that are responsible for user interaction:

Let us see more about the classes listed in the following bullet list:

• The wxFrame class: This class represents main window. All other visual elements are displayed inside this class.

• The wxMenuBar class: This class shows the menu bar in our app.

• The wxToolBar class: This class shows a tool bar in our app.

• The wxScrolledWindow class: This class is used to display images. This class creates a resizable window to match window size.

• The wxStatusBar class: This class shows a status bar at the bottom of our app. We'll be using this to display menu item help and other information.

A tree of the classes and their relationship with the wxFrame derived class is shown in the following diagram:

In the preceding diagram wxMenuBar, wxToolBar, and wxStatusBar are derived classes and have been added directly...