M3 - Swing Components

• JOptionPane Class


  It is used to provide standard dialog boxes such as message dialog box, confirm dialog box, and input dialog box.
• Dialog Boxes


  Used to display information or get input from the user.
• The JOptionPane class inherits JComponent class.


  The JOptionPane class inherits JComponent class.
• ShowConfirmDialog


  Asks a confirming question, like yes/no/cancel.
• ShowInputDialog


  Prompt for some input.
• ShowMessageDialog


  Tell the user about something that has happened.
• ShowOptionDialog


  Allows you to display buttons containing the text of your choice.
• import javax.swing.JOptionPane;


  What is the import statement?
• Component


  The graphical widgets inside a frame, such as buttons or text input fields, are collectively called components.
• JComponent Class


  Provides the following functionality to its descendants.
• Abstract Button


  An abstract base class of button and menu objects.
• JButtons


  Act as push buttons which invoke some action when clicked. These are not buttons that are toggled on and off.
• add()


  Method of a content pane puts a JButton in the frame.
• getContentPane()


  Method of a frame is used to get the reference to the content pane.
• JText Component Class


  Provides a base class for Swing components that handle editable text.
• JText Component Class


  It provides the functionalities for entering and editing text information-nearly all the features of a text editor.
• ·TextComponent

  JTextField,JTextArea, andJEditorPane.TextComponent has three direct subclasses:
• int getColumns()


  Returns the number of columns in this TextField
• void setColumns(int columns)


  Sets the number of columns in this TextField, and then invalidate the layout
• int getHorizontalAlignment()


  Returns the horizontal alignment of the text
• void setHorizontalAlignment (int Alignment)


  Sets the horizontal alignment of the text
• void setFont(Font f)


  Sets the current font
• JTextArea Class


  Displays multiple lines of text in a single font and style and optionally allows the user to edit the text.
• JTextArea Class


  Uses the rows and columns properties to indicate the preferred size of the viewport when placed inside a JScrollPane to match the functionality provided by java.awt.TextArea.
• getText()


  Returns the text in the field
• setBackground(Color BackgroundColor)


  Sets the background color of the TextArea
• setEditable(boolean Editable)


  Sets the field as being editable or fixed
• setFont(Font TextFont)


  Sets the font for this component
• setLineWrap(boolean LineWrap)


  Sets the line-wrapping policy of the text area
• setText(String text)


  Sets the text for the field
• Text Fields


  A lightweight component that allows the editing of a single line of text.
• JLabel Class


  An object can display either text or an image, or both. It cannot react to input events but is instead commonly used to provide a label identifier for a nearby object that does.
• String getText()


  Returns the text string that the label displays
• void setText(String text)


  Defines the single line of text this component will display
• int getHorizontalAlignment()


  Returns the alignment of the label's contents along the X axis
• int getVerticalAlignment()


  Returns the alignment of the label's contents along the Y axis
• void setVerticalAlignment (int alignment)


  Sets the alignment of the label's contents along the Y axis
• Text Fields


  A display area for a short text string or an image or both.
• JCombo Class


  A component that combines display area showing an option, and a list box containing additional options.
• JCombo Box Class


  An array of Objects as the constructor argument.