Text

Text objects allow text input and output in your Swing program.

The JTextField class provides a single line of text and the JTextArea class provides a rectanglular area (rows and columns) of text.
Both classes are derived from the JTextComponent class, which has many useful methods. Here are a few:
getText() - returns the entire contents of the text object (i.e. what the user typed in.)

setText(String text) - set the contents of the text object. This can be used to re-set a text object to a default value.

setEditable(boolean canEdit) - if canEdit is true, the user can edit the text in the text object.

isEditable() - returns true if the user can edit the text object, false if they cannot.
Here are a few useful methods that belong to the JTextField class:
JTextField(String initText) - create the text field and initialize it to initText.

JTextField(int columns) - columns are "approximate".

setEchoCharacter(char c) - Show the specified character as the user types instead of the characters they are entering (used for passwords). In 1.1, this method has been renamed to setEchoChar().

echoCharacterIsSet(char c) - returns true if an echo character is being used, false if what the user types is echoed on the screen. In 1.1, this method has been renamed to echoCharIsSet().
Here are a few useful methods that belong to the JTextArea class:
JTextArea(int nrows, int ncols) - create the text area with the specified number of rows and columns.

JTextArea(String initText, int nrows, int ncols) - create the text area with the specified number of rows and columns and initialize it to initText.

appendText(String text) - add text to the end of the text area.

insertText(String text, int pos) - insert text into the character position specified. Note this is not a column position, but an index into the character array in the text area.
You typically create Label objects to label your text components.
The width argument (columns) simply sets the size of the display. It does not affect how many characters can be typed in.
As the user types in more characters, they are scrolled off the display.
The text classes support the standard text behavior such as selecting with the mouse, delete key, backspace, arrow keys, cut, paste, ...
To add custom behavior, such as validation, we will need to handle keystroke events.