swing programming

8/2/2019 Swing Programming

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What's Swing?What's Swing?

Swing is Suns alternate WindowingSwing is Suns alternate WindowingFrameworkFramework

Part of the JFC (Java FoundationPart of the JFC (Java Foundation

Classes)Classes)

Standard part of Java 2Standard part of Java 2

A full replacement/alternative to AWTA full replacement/alternative to AWT

Found in packages starting withFound in packages starting with

javax.swingjavax.swing

Key Features of SwingKey Features of Swing

Not based on windowing systemNot based on windowing system

all Swing components are lightweightall Swing components are lightweight

Pluggable Look and Feel (PLAF)Pluggable Look and Feel (PLAF)

Richer component set than AWTRicher component set than AWT

Doesnt take the least commonDoesnt take the least common

denominator approachdenominator approachincludes components not found in *any*includes components not found in *any*

windowing systemwindowing system

adds functionality to components thatadds functionality to components that

already have counterparts in the AWTalready have counterparts in the AWT


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Using SwingUsing Swing

Swing should not be combined withSwing should not be combined withAWTAWT

Each Window should be fully Swing orEach Window should be fully Swing or

fully AWTfully AWT

Since Swing matches the AWTsSince Swing matches the AWTs

functionality, thats not hardfunctionality, thats not hard

Most Swing components areMost Swing components are

upwards-compatible with their AWTupwards-compatible with their AWT

counterpartscounterpartseasy to change code from AWT to Swingeasy to change code from AWT to Swing

Swing ArchitectureSwing ArchitectureSwing follows theSwing follows the

MVC paradigmMVC paradigm

for building userfor building user

interfacesinterfaces

Each UIEach UI

Component has aComponent has a

modelmodel

We will oftenWe will often

customize certaincustomize certain

Swing modelsSwing models

data changechange

notificationdata access

gesturesand

events

View Controller

Model


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Basic Swing ProgrammingBasic Swing Programming

As noted previously, Swing adds anAs noted previously, Swing adds anentirely new set of components to Javaentirely new set of components to Java

Upward-compatible with their AWTUpward-compatible with their AWT

counterpartscounterparts

We wont deeply cover those similar toWe wont deeply cover those similar to

their AWT counterpartstheir AWT counterparts

We will start at the bottomWe will start at the bottom

JFrameJFrame

JappletJapplet

Top-level hierarchyTop-level hierarchy

Each top-levelEach top-level

class adds newclass adds new

behavior tobehavior to

existing AWTexisting AWT

componentscomponents

Frame

JFrame

Dialog

JDialog

Applet

JApplet

Window


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Comparing Swing & AWTComparing Swing & AWT

import java.awt.*;

public class ExampleAWTFrame extends java.awt.Frame {

public ExampleAWTFrame ( ) {

super();

Panel aPanel = new Panel();

aPanel.setLayout(new BorderLayout());

add(aPanel);

Label hello = new Label("Hello World");

aPanel.add(hello, BorderLayout.NORTH);

}

public static void main(String args[]) {

ExampleAWTFrame aFrame = new ExampleAWTFrame();

aFrame.setVisible(true);

}}

Comparing Swing & AWTComparing Swing & AWTimport java.awt.*;

import com.sun.java.swing.*;

public class ExampleSwingJFrame extends com.sun.java.swing.JFrame {

public ExampleSwingJFrame() {

super();

JPanel aPanel = new JPanel();


getContentPane().add(aPanel);

JLabel hello = new JLabel("Hello World");

aPanel.add(hello, BorderLayout.NORTH);

}


ExampleSwingJFrame aFrame = new ExampleSwingJFrame();

aFrame.setVisible(true);

}}


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JFramesJFrames

A JFrame acts like an AWT FrameA JFrame acts like an AWT FrameExcept it handles Swing componentExcept it handles Swing component

nestingnesting

A JFrame is really two panesA JFrame is really two panes

A LayeredPane that has an optionalA LayeredPane that has an optional

menu bar and a content panemenu bar and a content pane

A GlassPane that sits transparently inA GlassPane that sits transparently in

front of the LayeredPanefront of the LayeredPane

Partial Swing HierarchyPartial Swing Hierarchy

JComponent

AbstractButton

JButton JToggleButtonJMenuItem

JComboBox JPanelJLabel JList JSlider JTreeJTable

JTabbedPane JScrollPane

Container


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BordersBorders

Any JComponent can have a BorderAny JComponent can have a Borderplaced on itplaced on it

Usually only used on JPanelsUsually only used on JPanels

Specify the border withSpecify the border with

aJComponent.setBorder(Border aBorder)aJComponent.setBorder(Border aBorder)

Common Borders include BevelBorder,Common Borders include BevelBorder,

TitledBorderTitledBorder

Normally built with a BorderFactoryNormally built with a BorderFactory

JTitledBorder ExampleJTitledBorder Example

public ExampleWithGroupBox ( ) {

super();



TitledBorder border =

BorderFactory.createTitledBorder(BorderFactory.createBevelBorder(2), "Group");

aPanel.setBorder(border);


JLabel hello = new JLabel("Hello World");

aPanel.add(hello, BorderLayout.CENTER);

}


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JTabbedPaneJTabbedPane

A JTabbedPane represents a notebookA JTabbedPane represents a notebookAny JComponent can be a page in aAny JComponent can be a page in a

JTabbedPaneJTabbedPane

JPanels are usually usedJPanels are usually used

Tabs can be added, inserted at runtime,Tabs can be added, inserted at runtime,

deleted and selecteddeleted and selected

Creating TabsCreating Tabs

public ExampleWithTabbedPane ( ) {

super();

JTabbedPane tabs = new JTabbedPane();

tabs.addTab("Page1", buildTabOne());

tabs.addTab("Page2", buildTabTwo());

tabs.addTab("Page3", buildTabThree());

getContentPane().add(tabs);

}

public JPanel buildTabOne() {


JLabel first = new JLabel("This is the first tab");

aPanel.add(first, BorderLayout.CENTER);

return aPanel;

}


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JTabbedPane DetailsJTabbedPane Details

Tabs are indexed from 0Tabs are indexed from 0JTabbedPane.getTabCount();JTabbedPane.getTabCount();

Can remove tabs withCan remove tabs with

JTabbedPane.removeTabAt(index);JTabbedPane.removeTabAt(index);

Can select a tab withCan select a tab with

JTabbedPane.setSelectedIndex(index)JTabbedPane.setSelectedIndex(index)

JTabbedPane EventsJTabbedPane Events

The JTabbedPane supports theThe JTabbedPane supports the

ChangedEvent notificationChangedEvent notification

Clients must implement theClients must implement the

ChangeListener interfaceChangeListener interface

void stateChanged(ChangeEvent e)void stateChanged(ChangeEvent e)

No state information is passed inNo state information is passed inquery the source for the new statequery the source for the new state


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JScrollPaneJScrollPane

A JScrollPane manages scrolling over aA JScrollPane manages scrolling over alarger viewlarger view

It manages a viewport on the viewIt manages a viewport on the view

Viewport

View

JScrollPane exampleJScrollPane example

/*

* Add a Scroll pane to the Jframe. Put a JLabel having

* the numbers 0 - 49 into the scrollPanes viewport

*

*/

public ExampleScrolling ( ) {

super();

JScrollPane scroller = new JScrollPane();

getContentPane().add(scroller);StringBuffer bigBuffer = new StringBuffer();

for (int i=0; i


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Scrollable InterfaceScrollable Interface

Components that will be scrolled by aComponents that will be scrolled by aJScrollPane should implement theJScrollPane should implement the

Interface ScrollableInterface Scrollable

Most Swing components implement thisMost Swing components implement this

alreadyalready

This Interface defines methods toThis Interface defines methods to

return the preferred size of the viewportreturn the preferred size of the viewport

get the increment in pixels to scroll by unitget the increment in pixels to scroll by unit

and blockand block

JSplitPaneJSplitPane

A JSplitPane is a splitter pane thatA JSplitPane is a splitter pane that

allows the user to resize two componentsallows the user to resize two components

dynamicallydynamically

Can split horizontally or verticallyCan split horizontally or vertically

Use the constantUse the constant

JSplitPane.VERTICAL_SPLIT orJSplitPane.VERTICAL_SPLIT orJSplitPane.HORIZONTAL_SPLIT inJSplitPane.HORIZONTAL_SPLIT in

the constructorthe constructor


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JSplitPane ExampleJSplitPane Example

public ExampleWithSplitPane ( ) {

JSplitPane splitter = new JSplitPane(JSplitPane.VERTICAL_SPLIT);

splitter.setLeftComponent(new JTextArea());

splitter.setRightComponent(new JTextArea());

getContentPane().add(splitter);

}


ExampleWithSplitPane example = new ExampleWithSplitPane();

example.pack();

example.setVisible(true);

}

JProgressBarJProgressBar

A JProgressBar is a standardA JProgressBar is a standard

Windows-like progress indicatorWindows-like progress indicator

LED-like display like a Stereo systemLED-like display like a Stereo system

It is usually used in its own Frame orIt is usually used in its own Frame or

dialogdialog

Often combined with one or more labelsOften combined with one or more labels


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JSliderJSlider

A JSlider is a volume-control sliderA JSlider is a volume-control slidercomponentcomponent

Familiar in many Windows applicationsFamiliar in many Windows applications

Jsliders have a variety of attributesJsliders have a variety of attributes

Major and Minor TicksMajor and Minor Ticks

LabelsLabels

Minimum & Maximum valuesMinimum & Maximum values

Clients watch for the ChangeEventClients watch for the ChangeEvent

notificationnotification

Similar to JTabbedPaneSimilar to JTabbedPane

JSlider ExampleJSlider Example

public ExampleWithSlider ( ) {




counterLabel = new JLabel("0");

aPanel.add(counterLabel, BorderLayout.SOUTH);

JSlider slider = new

JSlider(SwingConstants.HORIZONTAL, 0, 100, 0);

slider.setMajorTickSpacing(20);

slider.setMinorTickSpacing(10);

slider.setPaintTicks(true);

slider.setPaintLabels(true);

slider.addChangeListener(this);aPanel.add(slider, BorderLayout.NORTH);

}

public void stateChanged(ChangeEvent e) {

int value = ((JSlider) e.getSource()).getValue();

counterLabel.setText(Integer.toString(value));

}


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AbstractButton HierarchyAbstractButton Hierarchy

Swing has a number ofSwing has a number ofbutton componentsbutton components

push buttons, radiopush buttons, radio

buttons, check boxesbuttons, check boxes

Usually each will use anUsually each will use an

ActionListener to hookActionListener to hook

into UI actionsinto UI actions

actionPerformed( )

AbstractButton ActionListener

JButton JToggleButt on

JCheckBox JRadioButton

JButton ExampleJButton Examplepublic ExampleJButton() {

super();




JBut ton push = new JBut ton(" Push Me" );

push.addActionListener(new ActionListener() {

public void act ionPerform ed(ActionEvent evt) {

buttonPushed();

}});

aPanel.add(push, BorderLayout.NORTH);

this.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0);

}

});

}

public void buttonPushed() {

System.out.println("The button was pushed");

}


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JMenu HierarchyJMenu Hierarchy

Swing Menus are similarSwing Menus are similarto Buttonsto Buttons

JMenuItems also haveJMenuItems also have

ActionListenersActionListeners

This is because they areThis is because they are

AbstractButtonsAbstractButtons

JComponent

JMenuBar AbstractButton

JCheckBoxMenuItem JRadioButtonMenuItem

JMenuItem

JMenu

JPopupMenu

JMenu ExampleJMenu Example

JMenuBar menuBar = new JMenuBar();

setJMenuBar(menuBar); // method of JFrame

JMenu testMenu = new JMenu("Test");

JMenuItem menuItem = new JMenuItem("Select Me");

menuItem.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent evt) {

menuSelected();

}});

testMenu.add(menuItem);

menuBar.add(testMenu);


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Text HandlingText Handling

Swing has text handlingSwing has text handlingcapabilities similar tocapabilities similar to

AWTAWT

JTextField,JTextField,

JPasswordField,JPasswordField,

JTextAreaJTextArea

However, it also hasHowever, it also has

sophisticated support forsophisticated support for

viewing HTML and RTFviewing HTML and RTFJEditorPaneJEditorPane

JTextComponent Document

JTextField JTextArea JEditorPane

DocumentListener

JListJList

JList is the primary Swing list classJList is the primary Swing list class

Its like the AWT List widget except:Its like the AWT List widget except:

The widget doesnt support adding &The widget doesnt support adding &

removing elements directlyremoving elements directly

Adds customized data modelsAdds customized data models

Adds custom element renderingAdds custom element rendering


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Simple JList ExampleSimple JList Example

/*

* You must place a Jlist inside a JScrollPane to get scroll bars!

*/

public ExampleSimpleList ( ) {

String[] strings = {"Bob", "Carol", "Ted", "Alice", "Jane", "Fred", "Sue"};


JList aList = new JList(strings);

scroller.getViewport().add(aList);

getContentPane().add(scroller);

}

JList ConstructorsJList Constructors

Jlist has four constructorsJlist has four constructors

JList()JList()

JList(Object[])JList(Object[])

JList(Vector)JList(Vector)

JList(ListModel)JList(ListModel)

Use the array and Vector versions onlyUse the array and Vector versions onlyfor simple, static listsfor simple, static lists

For more complex lists, use a ListModelFor more complex lists, use a ListModel


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ListModelListModel

A ListModelA ListModel

represents a list ofrepresents a list of

elements to a JListelements to a JList

SubclassSubclass

AbstractListModelAbstractListModel

to override getSize()to override getSize()

and getElementAt()and getElementAt()

contentsChanged( )

ListModel

getSize( )getElementAt( )addListDataListener( )

removeListDataListener( )

AbstractListModel

addListDataListener( )

removeListDataListener( )

ListDataListener

intervalAdded( )

intervalRemoved( )

fireContentsChanged( )

fireIntervalAdded( )

fireIntervalRemoved( )

ListModelsListModels

There would be several reasons youThere would be several reasons you

might make a ListModelmight make a ListModel

Loading database information as it isLoading database information as it is

requestedrequested

Synthetic lists of calculated itemsSynthetic lists of calculated items

As our example well store informationAs our example well store informationin a hashtable, and display the keys asin a hashtable, and display the keys as

they were added to the hashtablethey were added to the hashtable


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Example ListModelExample ListModelpublic class CustomListModel extends AbstractListModel {

Hashtable data = new Hashtable();

Vector orderedKeys = new Vector();

public void put(Object key, Object value) {

data.put(key, value);

if (!orderedKeys.contains(key))

orderedKeys.addElement(key);

fireContentsChanged(this, -1, -1);

}

public Object get(Object key) { return data.get(key);}

public Object getElementAt(int index) { return orderedKeys.elementAt(index);}

public int getSize() { return orderedKeys.size();}

}

ListModel ExampleListModel Example

public ExampleCustomListModelList ( ) {

JPanel outerPanel = new JPanel();

outerPanel.setLayout(new BorderLayout());


JList aList = new JList(buildCustomListModel());

scroller.getViewport().add(aList);

JButton button = new JButton("Add");

button.addActionListener(this);

outerPanel.add(scroller, BorderLayout.NORTH);

outerPanel.add(button, BorderLayout.SOUTH);

getContentPane().add(outerPanel);

}

public void actionPerformed(ActionEvent e) {

model.put("As", "If");

}


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JList EventsJList Events

JLists support the ListSelection eventJLists support the ListSelection eventnotificationnotification

Clients implement theClients implement the

ListSelectionListener interfaceListSelectionListener interface

void valueChanged(ListSelectionEvent e)void valueChanged(ListSelectionEvent e)

A ListSelectionEvent knows severalA ListSelectionEvent knows several

thingsthings

first selected indexfirst selected index

last selected indexlast selected index

getValueIsAdjusting()getValueIsAdjusting()

JList Event ExampleJList Event Example

public class ExampleListListening extends JFrame implements ListSelectionListener {

ExampleListListening() {

JList aList = new JList(someModel);

aList.addListSelectionListener(this);

public void valueChanged(ListSelectionEvent e) {if (!event.getValueIsAdjusting()) {

String value = event.getSource().getSelectedValue();

System.out.println(Selection is + value);

}

}

}


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List Cell RenderingList Cell Rendering

JList gives you the option to display notJList gives you the option to display notjust Strings, but graphical icons as welljust Strings, but graphical icons as well

You need to create a new cell rendererYou need to create a new cell renderer

implement the ListCellRenderer interfaceimplement the ListCellRenderer interface

set the custom text and icon (image) in thisset the custom text and icon (image) in this

classclass

JTableJTable

JTable is a Tabular (row-column) view withJTable is a Tabular (row-column) view with

read-only or editable cellsread-only or editable cells

Can create a JTable on:Can create a JTable on:

Two ArraysTwo Arrays

2d array of data, 1d array of column headings2d array of data, 1d array of column headings

Two VectorsTwo Vectors(data of length row X columns), column(data of length row X columns), column

headingsheadings

TableModel, (optionally) ListSelectionModel andTableModel, (optionally) ListSelectionModel and

TableColumnModelTableColumnModel


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Table ModelsTable Models

TableModel is anTableModel is aninterface that definesinterface that defines

the row/columnthe row/column

behaviorbehavior

AbstractTableModelAbstractTableModel

implements most of theimplements most of the

behaviorbehavior

you implementyou implement

getColumnCount(),getColumnCount(),getRowCount(),getRowCount(),

getValueAt()getValueAt()

TableModel

getColumnCount( )

getRowCount( )

getValueAt( )isCellEditable( )

AbstractTableModel

JDBCAdapterYourTableModel

Example Table ModelExample Table Model

public ExampleTableCustomModel() {

super();

JTable table = new JTable(new CustomDataModel());

createColumnHeadings(table);

getContentPane().add(table.createScrollPaneForTable(table));

}

public void createColumnHeadings(JTable table) {

String headers[] = {"Zero", "One", "Two", "Three", "Four"};

table.setAutoCreateColumnsFromModel(false);

for (int i=0; i


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Example Custom ModelExample Custom Model

public class CustomDataModel extends AbstractTableModel {

/**

* getColumnCount returns 0 since we will create columns ourselves

*/

public int getColumnCount() { return 0;}

public int getRowCount() {return 5;}

/**

* getValueAt is semi-bogus; it returns a string of row * column.

*/

public Object getValueAt(int row, int col) {

return Integer.toString(row * col);}

}

Table SelectionTable Selection

There are several selection attributes ofThere are several selection attributes of

JTable you can setJTable you can set

setRowSelectionAllowed(boolean value)setRowSelectionAllowed(boolean value)

setColumnSelectionAllowed(booleansetColumnSelectionAllowed(booleanvalue)value)

setSelectionForeground(Color value)setSelectionForeground(Color value)setSelectionBackground(Color value)setSelectionBackground(Color value)

You can also turn horizontal and verticalYou can also turn horizontal and vertical

lines on and offlines on and off


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List SelectionList Selection

JTables support ListSelectionJTables support ListSelectionnotificationnotification


ListSelectionListener interfaceListSelectionListener interface

Just like JLists in that respectJust like JLists in that respect

The Event doesnt carry the necessaryThe Event doesnt carry the necessary

selection informationselection information

You need to query the table for selectionYou need to query the table for selection

informationinformationUse getSelectedRow(),Use getSelectedRow(),

getSelectedColumn(), getValueAt()getSelectedColumn(), getValueAt()

TableSelectionListenerTableSelectionListenerExampleExamplepublic class ExampleTableSelection extends JFrame implements ListSelectionListener {

ExampleTableSelection() {

JTable table = new JTable(someModel);

ListSelectionModel selectionModel = table.getSelectionModel();

selectionModel.addListSelectionListener(this);

}

public void valueChanged(ListSelectionEvent e) {JTable table = (JTable) e.getSource();

DefaultTableModel model = (DefaultTableModel) table.getModel();

int row = table.getSelectedRow();

int column = table.getSelectedColumn();

String value = (String) model.getValueAt(row, column);

System.out.println(Selected value is + value);

}

}


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Swing TreesSwing Trees

JTree is a hierarchical display componentJTree is a hierarchical display componentallows expansion, contraction, editing ofallows expansion, contraction, editing of

nodesnodes

JTree displays a TreeModelJTree displays a TreeModel

TreeModel is built from TreeNodesTreeModel is built from TreeNodes

MutableTreeNodes hold arbitrary objectsMutableTreeNodes hold arbitrary objects

TreeModel HierarchyTreeModel Hierarchy

TreeNode is an interfaceTreeNode is an interface

that describes nodethat describes node

behaviorbehavior

MutableTreeNode is anMutableTreeNode is an

interface that allowsinterface that allows

addition/removal ofaddition/removal ofchildrenchildren

DefaultMutableTreeNodeDefaultMutableTreeNode

implementsimplements

MutableTreeNodeMutableTreeNode

TreeNode

getParent( )children( )getChildAt( )

isLeaf( )

MutableTreeNode

remove(MutableTreeNode )insert(MutableTreeNode, int )

setParent( MutableTreeNode)setUserObject(Object )

DefaultMutableTreeNode

getUserObject( )

add( MutableTreeNode)


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TreeNode ExampleTreeNode Example

public DefaultMutableTreeNode buildTree() {DefaultMutableTreeNode root = new DefaultMutableTreeNode("Classes");

DefaultMutableTreeNode level1a = new DefaultMutableTreeNode("Java");

DefaultMutableTreeNode level1b = new DefaultMutableTreeNode("Smalltalk");

root.add(level1a);

root.add(level1b);

level1a.add(new DefaultMutableTreeNode("Introduction to Java"));

level1a.add(new DefaultMutableTreeNode("Advanced Java"));

level1a.add(new DefaultMutableTreeNode("Enterprise Java Programming"));

return root;

}

public ExampleSimpleTree() {

JScrollPane scroller = new JScrollPane();JTree tree = new JTree(buildTree());

scroller.getViewport().add(tree);

getContentPane().add(scroller);

}

Tree SelectionTree Selection

JTrees support the TreeSelectionEventJTrees support the TreeSelectionEvent

notificationnotification


TreeSelectionListener interfaceTreeSelectionListener interface

void valueChanged(TreeSelectionEvent e)void valueChanged(TreeSelectionEvent e)

Use the JTree method getSelectionPath()Use the JTree method getSelectionPath()to get a TreePath that gives theto get a TreePath that gives the

selection(s)selection(s)


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Tree ExpansionTree Expansion

JTrees also support theJTrees also support theTreeExpansionEvent notificationTreeExpansionEvent notification

Clients implement TreeExpansionListenerClients implement TreeExpansionListener

void treeExpanded(TreeExpansionEvent e)void treeExpanded(TreeExpansionEvent e)

void treeCollapsed(TreeExpansionEvent e)void treeCollapsed(TreeExpansionEvent e)

You can ask the TreeExpansionEvent toYou can ask the TreeExpansionEvent to

getPath() and return the affected pathgetPath() and return the affected path

SummarySummary

Swing is a comprehensive expansion andSwing is a comprehensive expansion and

replacement for AWTreplacement for AWT

You've seen some basic and advancedYou've seen some basic and advanced

concepts in Swing Programmingconcepts in Swing Programming


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More InformationMore Information

For more information, see the SwingFor more information, see the Swingtutorials on the Sun Java Developer'stutorials on the Sun Java Developer's

Connection websiteConnection website

(http://developer.java.sun.com)(http://developer.java.sun.com)

requires registration (free)requires registration (free)

Steven Gutz, "Up to Speed With Swing,Steven Gutz, "Up to Speed With Swing,

2nd Edition", Manning, 20002nd Edition", Manning, 2000

swing programming

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