MainWindow Class Implementation
The MainWindow's constructor invokes createActions() and createMenus() to set up the File menu and Help menu. Then, the Previewer object, centralWidget, is set to the main window's central widget. Also, we connect webView's loadFinished() signal to our updateTextEdit() slot. Finally, we call the setStartupText() function to display the description of the example.
Within the createActions() function, we instantiate all our private QAction objects which we declared in mainwindow.h. We set the short cut and status tip for these actions and connect their triggered() signal to appropriate slots.
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The createMenus() function instantiates the QMenu items, fileMenu and helpMenu and adds them to the main window's menu bar.
The example also provides an about() slot to describe its purpose.
The MainWindow class provides two types of Open functions: open() and openUrl(). The open() function opens an HTML file with fileName, and reads it with QTextStream. The function then displays the output on plainTextEdit. The file's name is obtained using QFileDialog's getOpenFileName() function.
The openUrl() function, on the other hand, displays a QInputDialog to obtain a URL, and displays it on webView.
In order to save a HTML file, the save() function first extracts the contents of plainTextEdit and displays a QFileDialog to obtain fileName. Then, we use a QTextStream object, in, to write to file.
Earlier, in MainWindow's constructor, we connected webView's loadFinished() signal to our private updateTextEdit() slot. This slot updates the contents of plainTextEdit with the HTML source of the web page's main frame, obtained using QWebFrame's toHtml() function.
To provide a description about the Previewer example, when it starts up, we use the setStartupText() function, as shown below:
The main() Function
The main() function instantiates a MainWindow object, mainWindow, and displays it with the show() function.
