Plain Text Editor

Develop a simple plain text editor using C# WPF. The following are the requirements for the application.

1. (5pt) Use a TextBox as the text input user interface element. The TextBox is to scale bigger/smaller when the window is made bigger/smaller.

2. (5pt) The TextBox is to have a vertical scroll bar appear when the content is bigger than the TextBox.

3. (5pt) The text in the TextBox is to wrap when a line is longer than the width of the TextBox. No horizontal scroll bar is to appear. Make sure the TextBox UI element allows the user to enter multiple lines (accepts line returns) and allows the user to enter tabs in the content.

4. (5pt) No interface elements (TextBox, Buttons) should disappear or become unusable when the window is made bigger/smaller.

5. (5pt) All files are to be saved as .txt files. The editor should only allow opening .txt files.

6. (40 points) Implement a menu bar as:

File

- New

- Open

- Save

- Save As

- Exit

Help

-About

Open and Save /Save as should have the functions of opening and saving the file using OpenFileDialog and SaveFileDialog.

The New menu item is to provide the user with a blank document to edit a new document.

The Exit menu item should cause the application to close.

The About menu item is to display a dialog that contains information about the application and/or developer.

(5pts) If a menu item does not apply when the document is in a particular state then it should be made inactive (greyed out and not selectable). For example, if there is

nothing to save, then Save should be made inactive. Apply this rule where needed.

(2pts) The New menu item is to provide the user with a blank document to edit a new document.

(5pts) The Open menu item is to allow the user to open an existing text document.

(5pts) The Save menu item is to quietly (no dialog) save the document to the place it was last saved or opened from OR if this a new document that was never saved a file dialog is to be displayed that allows the user to select the location and name for the file.

(5pts) The Save As menu item is to display a file save dialog that allows the user to select the location and name for the file.

(2pts) It should be possible for the user to save an empty document.

(5pts) Intelligently implement management of file paths so that the user goes to expected places when a file open or save dialog appears. For example when the user chooses Save As and if the document was previously saved or opened from an existing file the file save dialog should show the current name of the file at its current location in the file system. Apply this rule where needed.

(5pts) If the document has changed since the last time it was saved or since it was opened/created the user should be asked whether or not they want to save it if an action they are taking will cause the changes to be lost. They should have the option to save, not save, or cancel the action.

(2pts) The Exit menu item should cause the application to close.

(2pts) The About menu item is to display a dialog that contains information about the application and/or developer.

(2pts) Exception handling is to be implemented in the code where errors or exceptions could occur. If an error occurs the user is to be notified using an appropriate dialog.

(35pts) The text document should be represented in the application as an object. You are to create a class called TextDocument that holds the data and methods associated with the text document that is being edited. The class must contain methods for opening text files and saving text files. BUT, these methods are not to cause the file open or file save dialogs to appear. The methods for opening and saving the text document should only contain the code for doing the file IO. Separating interface from control and model code is the basis of the model-view-controller (MVC) software architecture. The right place to maintain information about the text document is in the TextDocument class. Make sure you use the Model-View-Controller paradigm and do not place user interface stuff in the TextDocument class.