Collections

Contiguous Arrays

• Arrays are great for storing data and accessing elements
• Arrays are stored in contiguous memory
• Adding and removing elements?
• Add and remove operations in the middle, or at the beginning can be inefficient
  • Requires element by element copying

Linked Structures

• Linked data structures are NOT stored in contiguous memory
• Linked list data structure has a node containing th e value of interest and a reference to the next node
• Inserting element in the middle does not require a complete reorganization

Java Collections

Using a Set

• When you don't need to store duplicate items multiple itimes and you don't care what order things are stored in, a Set is a good option
• Each element can only be added once.

Sorting Set Elements

A hashset order is defined by a hash function and is not related to: The order in which the items are inserted The natural order of the elements

Treeset

Tresset is the same as a hashset, but will return the items in order.

Swing's Event Dispatch Thread (EDT)

• The Event dispatch thread is the thread of execution in which Swing stuff occurs
• If your swing event handling code utilizes blocking calls, your GUI can lock up and act oddly

SwingWorker Implementation

• SwingWorked class in the API allows you to do work in a separate thread of execution
• To use SwingWorked, develop a clas that etends it

Using SwingWorker

• Make a new class that extends SwingWorker
• In the event handling code

Using JList

• A Jlist is simply a list of items that act as a Swing component

• Associate a list model with a list for easy modifications on the list

• DefaultListModel in the API provides useful functiaonlity to moify the List's contents

  • addELement(element)
  • getElementAt(index)
  • removeElementAt(index)
  • etc
• JList is a Swing component that can be interacted with
  • Select items via click
  • Multi-select via ctr-click( can be set to be single selection only)
  • Functions like:
    • getSelectedIndices

Using a Frame's Content Pane

• A frame consists of decoraions, borders, and a content pane
• The content pane is where the window's contents are displayed
• Jframe comes witha d efault content pane
  • Uses the BorderLayour by default
  • Can use different layout manager via setLayout
• Rather than add a bunch of components to the frame, can add to a JpPanel, and then replace the fram'e's contents

The Glass Pane

• The glass pane is another pane that can sit on top of the content pane
• It is often used to prevent events from being performed on the conetnt pane
• Set a JFRame's glass pane using setGlassPane

Internal Frames

• Internal frames, JInternalFrame, can be used to contain multiple farmes inside one overall frame
• • Mos common ctor:
  • JInternalFrame
• Used in conjunction with a JDesktopPane to contain the internal frames
• THe JdesktopPane is set to be the content pane for the main frame
• Good for apps wich need a lot of windwos for control