"Hello, Captain Squirrels, sir!"
"Soldier, we have a secret mission for you. You will develop a tool for creating web pages."
"Cool, web pages. But why do we need our own editor?"
"What do you mean 'why'? Soldier, orders aren't for discussion. They're for execution."
"Yes, sir! Write a tool for creating web pages."
"Don't shout, soldier. Didn't they tell you this is a top secret mission."
"Contact Agent IntelliJ IDEA to begin. He'll bring you up to speed."
"He'll also provide all further instructions."
"May I proceed, sir?"
HTML Editor (part 1)
Today we'll write an HTML editor with a graphical user interface. We'll use Swing to create the GUI. And we'll use the MVC pattern as the architectural framework for our application. 1.1. Declare a Controller class and a View class.
HTML Editor (part 2)
2.1. Add init() methods, empty for now, to the controller and view. They will be responsible for initializing the controller and view. 2.2. Now we will write a main method in the Controller class. It must: 2.2.1. Create a view object. 2.2.2. Use the view to create a controller.
HTML Editor (part 3)
The graphical interface will be a window with a menu and a pane with two tabs. The first tab will be a text pane that will render an HTML page. Here it will be possible to format and edit the text of the page. The second tab will have an editor that will display the page's HTML code.
HTML Editor (part 4)
4.1. Declare initMenuBar() and initEditor() methods in the View class. They will be responsible for initializing the menus and editor panes. 4.2. Declare an initGui() method in the view. It will initialize the graphical interface.
HTML Editor (part 5)
5.1. In the listeners package, declare a TabbedPaneChangeListener class that implements the ChangeListener interface. This class will listen for and handle changes to the state of the tabbed pane.
HTML Editor (part 6)
Implement the initEditor() method, which initializes the editor panes. It must: 6.1. Set "text/html" as the content type for the htmlTextPane component. Find and use the appropriate method. 6.2. Create a new local JScrollPane component based on htmlTextPane.
HTML Editor (part 7)
Add a MenuHelper class. This will be a helper class for initializing and configuring the menu. The menu will have the following structure — File: New, Open, Save, Save as..., Exit; Edit: Undo, Redo, Cut, Copy, Paste.
HTML Editor (part 8)
It's time to add all the necessary menu items and write classes for the actions that are performed when the menu items are selected. This is quite time-consuming, routine work. You're a great student and we wouldn't want to upset you. So, as a bonus, you're getting a ready-made MenuHelper class!
HTML Editor (part 9)
9.1. Implement the initMenuBar() method. It must: 9.1.1. Create a new JMenuBar object. This will be our menu bar. 9.1.2. Use MenuHelper to initialize the menu in the following order: File, Edit, Style, Align, Color, Font, and Help.
HTML Editor (part 10)
Our editor will support undo/redo of actions performed in the editor. Implement the UndoMenuListener class. This listener will listen to the menu, or more accurately, it will listen for the moment when the edit menu is selected by the user.
HTML Editor (part 11)
11.1. Add an UndoManager undoManager field to the view. Figure out what this class is used for. Initialize the field with a new object. 11.2. In the listeners package, add an UndoListener class that implements the UndoableEditListener interface.
HTML Editor (part 12)
12.1. Implement the RedoAction class: 12.1.1. Add a View field to the class. Add its initialization in the constructor. 12.1.2. Implement the actionPerformed(ActionEvent actionEvent) method. It should call the redo() method on the view.
HTML Editor (part 13)
Let's implement the TextEditMenuListener class in the listeners package. This class will work like the UndoMenuListener class, but for other menu items. The menu items responsible for style, font, color, etc. should only be available when the first tab is selected in our editor.
HTML Editor (part 14)
14.1. Add a selectHtmlTab() method to the view class. It must: 14.1.1. Select the HTML tab (switch to it). 14.1.2. Reset all edits using the method you previously implemented. 14.2. Add a getter for the model to the controller class. In our case, this is the document field.
HTML Editor (part 15)
Add a resetDocument() method to the controller. It should reset the current document. It must: 15.1. Remove the undo/redo edit listener from the current document (find the appropriate method inherited from AbstractDocument). You need to ask the view for the listener (getUndoListener() method).
HTML Editor (part 16)
Add a setPlainText(String text) method to the controller. It will write the passed text with HTML tags to document. Implement it as follows: 16.1. Reset the document. 16.2. Create a new StringReader based on the passed text.
HTML Editor (part 17)
Add a String getPlainText() method to the controller. It should get text from the document with all the HTML tags. 17.1. Create a StringWriter object. 17.2. Copy all of the document's contents to the created object using the HTMLEditorKit class's write method.
HTML Editor (part 18)
Implement the view's selectedTabChanged() method. This method is called when the selected tab changes. Let's begin: 18.1. The method should check which tab is currently selected.
HTML Editor (part 19)
Implement the actionPerformed(ActionEvent actionEvent) method on the view. This method is inherited from the ActionListener interface and will be called upon selection of menu items that our view has been added to as an event listener.
HTML Editor (part 20)
20.1. Implement the createNewDocument() method in the controller. It must: 20.1.1. Select the HTML tab on the view. 20.1.2. Reset the current document. 20.1.3. Set a new window title, e.g. "HTML editor". Use the setTitle() method, which is inherited by our view.
HTML Editor (part 21)
To open and save the file, we'll use JFileChooser from the swing library. Objects of this type support filters that inherit FileFilter. Now we'll write our own filter: 21.1. Create a public HTMLFileFilter class that inherits FileFilter.
HTML Editor (part 22)
In the controller, let's implement the saveDocumentAs() method for saving the file under a new name. The implementation should: 22.1. Switch the view to the HTML tab. 22.2. Create a new JFileChooser object. 22.3. Set an HTMLFileFilter object as its filter.
HTML Editor (part 23)
23.1. Let's write the saveDocument() method for saving the current file. The method should work the same as saveDocumentAs(), but not ask the user for a file. Instead, it should use currentFile. If currentFile is null, then call the saveDocumentAs() method.
HTML Editor (part 24)
Your HTML editor is ready! You learned how to: - Create applications with a graphical interface. - Work with dialog boxes. - Use classes from the Swing library. - Implement interaction between program components with the help of events, listeners, and actions.