XML, HTML

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XML, HTML Swing An Overview

• Inf 141
• Information Retrieval
• Winter 2007

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XML

• General purpose mark-up language
• Extensible because it allows users to define
  their own elements
• Example ltstartgtlt/startgt
• Follows a tree-like structure
• Must have exactly one root element

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XML

• Levels of correctness
• Well-formed if u start with a statement you must
  end with a statement or it will not be parsed
• Example ltstartgt blah blah blah lt/startgt
• Element names are case sensitive
• ltstart /gt
• Valid conforms to semantic rules (either user
  defined or schema included)
• Example if a document contains an undefined
  element, then it is not valid and will not be
  parsed

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HTML

• Predominant markup language for web pages.
• It provides a means to describe the structure of
  text-based information in a document by
  denoting certain text as headings, paragraphs,
  lists, and so on and to supplement that text
  with interactive forms, embedded images, and
  other objects.

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HTML

• Elements are the basic structure
• Properties
• Attributes contained in the start label
• ltfont size 8gtlt/fontgt
• Content - located between the labels
• ltpgt hello lt/pgt
• Types of markup
• Structural describes purpose most browsers have
  formatting standards
• Example
• lth2gtlt/h2gt
• Presentational describes appearance
• Example
• ltstronggt bold lt/stronggt
• ltemgt italics lt/emgt
• Hypertext links to other documents or pages
• Example
• lta href"http//en.wikipedia.org/"gtWikipedialt/agt

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HTML

• Must start with a document type which determines
  which rendering mode to use
• HTML documents transmitted from a web server to a
  web browser for viewing

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Swing

• GUIs are layed out as trees
• There is a toplevel container, usually a window
• Inside this are multiple panels (often
  invisible), used to control layout
• Swing Javas GUI programming toolkit

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Swing
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Common Swing Widgets

• JFrames, JPanels
• Layout Managers
• JLists
• JButtons
• JLabels, JTextFields, JTextAreas

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Swing JFrames and JPanels

• JFrames are top-level windows
• JPanels allow grouping of other widgets
• Each JFrame has a panel into which the frames
  contents must go the contentPane
• window swing.JFrame(FrameDemo)
• window.contentPane.add(new JButton())
• You must pack and show a JFrame to display it
• window.pack()
• window.show()

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Swing Layout Managers

• Layout Managers control the placement of widgets
  in a JPanel
• Simplest by far awt.BorderLayout
• window.contentPane.layout awt.BorderLayout()
• window.contentPane.add(Center,
  swing.JButton(Button 2 (CENTER)))
• Five regions
• North, South expand horizontally
• East, West expand vertically
• Center expands in both directions

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Swing JLists

• JLists are collections of widgets
• list swing.JList()
• Put JLists in a JScrollPane to make them
  scrollable
• window.contentPane.add(swing.JScrollPane(list))
• JLists contain a listData member with the
  contents
• list.listData January, February, March,
  ...
• selectedValue contains the selected item!
• gtgtgt print list.selectedValue
• March

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Swing JButtons

• JButtons have many fancy features...
• Images, labels, tooltips, etc.
• Basic use is very simple
• Supply a label when you construct the button
• button swing.JButton(This is my label!)
• Provide a function to use as a callback
• button.actionPerformed someCallback

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Swing JTextFields, JTextAreas, and JLabels

• JLabels are the worlds simplest widgets
• years swing.JLabel(Years)
• JTextFields are used for single-line text entry
• yearValue swing.JTextField()
• print yearValue.text
• JTextAreas are used for longer pieces of text
• area swing.JTextArea(24, 80)

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Resources

• XML
• Wikipedia
• Tutorial http//www.w3schools.com/xml/default.asp
  
• inside out http//www.xml.com/
• HTML
• Wikipedia
• Tutorial http//www.w3schools.com/html/default.as
  p
• Swing
• Wikipedia
• JComponent Class http//java.sun.com/docs/books/t
  utorial/uiswing/components/jcomponent.html

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Questions

• ?