Bai 5 GUI JAVA

Bi 5:

GRAPHICAL USER INTERFACE

1

Ni dung

2

Tng quan v Graphical User Interface (GUI)

Containment Hierarchy

Layout Manager

Swing components

Tng quan GUI

AWT: cung cp cc gi c bn lp trnh giao din, c s dng trong cc phin bn trc jdk1.2 (java2)

Swing: c nhiu chc nng hn AWT, xy dng chng trnh d dng mm do hn. c a vo t jdk1.2

Swt: c pht trin bi IBM

Swing Components thng c tn bt u vi 'J'

o AWT c lp Panel

o Swing c lp tng ng l JPanel

C th s dng plug-in h tr:

o Eclipse: WindowsBuilder Pro

o Netbean: tch hp3

Tng quan GUI (tt)

Th vin h tr lp trnh giao din trong Java

AWT (Abstract Windows Toolkits)

import java.awt.*;

Swing (Java Foundation Classes Package)

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

Tt c Swing component c tn bt u vi J

4

Swing API

Java Foundation Classes (JFC) cung cp mt tp cc

chc nng gip xy dng cc ng dng GUI.

Gi Swing l 1 thnh phn ca JFC

S dng lnh: import javax.swing.*

u im ca Swing so vi AWT:

o Cung cp thm cc i tng mi xy dng giao din

ha

o look-and-feel: ty bin cc thnh phn giao din ca

Swing nhn ging nh cc thnh phn giao din ca HH

o H tr cc thao tc s dng bn phm thay chut

o S dng ti nguyn hiu qu hn5

6Java GUI hierarchy

Object

Color

ContainerComponent

LayoutManager

Panel

Window

Applet

Frame

Dialog

JComponent

JApplet

JFrame

JDialog

Swing

AWT

lightweight heavyweight

Dimension

Font

FontMetrics

Graphics

6

7Java GUI hierarchy (tt)

JComponent

JMenuBar

AbstractButton

JScrollPane

JPanel

JTextComponent

JLabel

JComboBox

JMenuItem

JButton

JTextArea

JTextField JPasswordField

etc. Swing

lightweight heavyweight

7

Swing Components

Swing Components c nhiu mc khc nhau:o frame, cn gi main window (JFrame)

o panel, hoc pane (JPanel)

o button (JButton)

o label (JLabel)

Cc mc ny qui nh cc Component trong 1 ng dng GUI kt hp vi nhau.

Cch kt hp ny gi l Swing Containment Hierarchy

8

Khi nim container

L thnh phn m c th cha cc thnh phn khc, c th v v t mu.

o Frame/JFrame, Panel/JPanel, Dialog/JDialog,

ScrollPane/JScrollPane,

Gn component vo khung cha

o containerObj.add(compObj);

Ly thng tin ca component

o objectName.get( );

Gn thng tin cho component

o objectName.set( );9

Nguyn tc xy dng GUI trong java

La chn 1 container: Frame/JFrame, Window/JWindow, Dialog/JDialog,

To cc iu khin: (buttons, text areas..)

a cc iu khin vo vng cha

Sp xp cc iu khin(layout)

Thm cc x l s kin (Listeners)

10

Containment Hierarchy

Frame: Top-level container: JFrame, JDialog, JApplet

11

Containment Hierarchy (tt)

Top Level

Container

Intermediate

Container

Atomic Component NAtomic Component N Atomic Component N

12


Top Level

(JFrame)

Intermediate

(JPanel)

Atomic

(JButton)

Atomic

(JLabel)

13


Top Level Containers

o L ni hin th cc Component khc

o V d:

JFrame: s dng cho cc ca s chnh ca chng trnh

JDialog: ca s thng bo

JApplet: s dng trn trnh duyt

14


Top Level Containers: JFrameo L ca s chnh, dng cha cc thnh phn giao din khc.

ng vai tr l mt container

o Hm khi to JFrame() JFrame(String title)

o Cc thnh phn ha c a vo content pane, khng a

trc tip vo JFrame. V d:frame.getContentPane().add(b);

o JFrame cung cp 2 phng thc: getContentPane() tr li mt i tng ContentPane thuc lp

Container

setContentPane(JPanel): thit lp ni dung cho Content Pane15

V D JFrame

import javax.swing.*;

class Frame1 extends JFrame {

/* Construction of the frame */

public Frame1() {

this.setSize(350, 250);

this.setTitle("My First Java Frame");

}

}

public class AppFrame1 {

public static void main(String[ ] args) {

Frame1 frame = new Frame1();

frame.setVisible(true);

}

}

Ap

pF

ram

e1.j

av

a

closing window

350

25

016


Intermediate Containers

o Dng xc nh v tr ca cc Atomic Components

o Hoc cung cp c ch tng tc vi khung cha.

o V d:

JPanel

JScrollPane

JTabbedPane

17


Intermediate Containers: JPanel

o L container trung gian cha cc Atomic

Components

o Thng dng chia cc component trong ng dng

o Hm khi to:

JPanel();

JPanel(LayoutManager lm);

18


Atomic Componentso Khng cha cc Components khc

o Dng cung cp thng tin n ngi s dng

o Hoc ly thng tin t ngi s dng

o V d:

JButton JLabel JComboBox JTextField JTable

19


Mi Top Level Container c 1 intermediate Container gi l Content Pane

Cc atomic component phi gn vo content paneo V d

JFrame frame = new JFrame(...);

JPanel pane = new JPanel();

frame.getContentPane().add(pane);

20

Layout Manager

Khi nim: c dng iu khin cch trnh by vt l ca cc phn t GUI nh l button, textbox, option button

Cc loi layout khc nhau:

o Flow Layout

o Border Layout

o Grid Layout

o GridBag Layout

o Null Layout

o

Trnh qun l layout c thit lp bng cch gi phng thc setLayout( )21

Layout Manager: FlowLayout

L trnh qun l layout mc nh cho cc panel

Vi FlowLayout cc thnh phn s c xp xp t gctri trn n gc phi di ca mn hnh.

Cc hm khi to - constructor:

o public FlowLayout();

o public FlowLayout(int align); // Canh l bn phi

o public FlowLayout(int align, int hgap, int vgap);

align: c cc gi tr FlowLayout.LEFT, FlowLayout.CENTER, FlowLayout.RIGHT, FlowLayout.LEADING, hoc

FlowLayout.TRAILING

hgap, vgap: khong trng gia cc thnh phn22

FlowLayout (tt)

Flow Layout Left and Right Aligned

23

Layout Manager: BorderLayout

L trnh qun l layout mc nh cho Window, Frame vDialog

Trnh qun l ny c th xp xp n 5 thnh phn trongcontainer

Cc thnh phn c th c t vo 5 hng NORTH,EAST, SOUTH, WEST v CENTER ca container

V d: thm mt thnh phn vo vng North cacontainerJButton b1= new JButton(North Button); setLayout(new BorderLayout( )); add(b1, BorderLayout.NORTH);

24

BorderLayout (tt)

25

public void showBorderLayout(){

JFrame frame = new JFrame("Border Layout Demo");

frame.setSize(400,400);

JPanel panel = new JPanel(new BorderLayout());

panel.add(new JButton("North Button"),BorderLayout.NORTH);

panel.add(new JButton("South Button"),BorderLayout.SOUTH);

panel.add(new JButton("West Button"),BorderLayout.WEST);

panel.add(new JButton("East Button"),BorderLayout.EAST);

panel.add(new JButton("Center Button"),BorderLayout.CENTER);

//frame.getContentPane().add(panel);

frame.add(panel);


}

BorderLayout (tt)

26

Layout Manager: GridLayout

27

H tr vic chia container thnh mt li Cc thnh phn c b tr trong cc dng v ct Mt li nn cha t nht mt thnh phn Kiu layout ny c s dng khi tt c cc thnh phn

c cng kch thc

GridLayout layout = new GridLayout(no. of rows, no. of columns);

containerObj.setLayout(layout);

GridLayout

28

public void showGridLayout(){

JFrame frame = new JFrame("Border Layout Demo");

frame.setSize(400,400);

JPanel panel = new JPanel();

GridLayout gridLayout = new GridLayout(2,2);

panel.setLayout(gridLayout);

panel.add(new JButton("Button 1"));




//frame.getContentPane().add(panel);

frame.add(panel);


}

Layout Manager: GridBagLayout

B tr cc thnh phn mt cch chnh xc Cc thnh phn khng cn c cng kch thc Cc thnh phn c xp xp trong mt li cha cc

dng v cc ct Th t t cc thnh phn khng tun theo hng t tri-

sang-phi v trn-xung-di Hm constructor

GridBagLayout gb = new GridBagLayout( );

Lp GridBagLayoutConstraints lu tr tt c cc thngtin m lp GridLayout yu cu: V tr v kch thuc mithnh phn

29

GridBagLayout

30

Layout Manager: NullLayout

T do trong vic nh v tr v kch thc ca cc components

Gii php ny dng xc nh hon ton kch thc v v v tr ca component.

Frame fr = new Frame("NullLayout Demo");

fr.setLayout(null);

31

Swing Components

32

S Dng Swing Component

33

C cc phng thc add, set, get

Phng thc dng gn components:

o objectName.add( );

Phng thc dng ly thuc tnh:

o objectName.getxxx( );

Phng thc dng gn thuc tnh:

o objectName.setxxx( );

S dng Swing Components

34

JLabel

Label dng hin th mt chui vn bn, hnh nh

nhm m t thm thng tin cho cc i tng khc.

Cc constructor ca JLabel:JLabel()

JLabel(String text)

JLabel(String text,int hAlignment)

JLabel(Icon icon)

JLabel(Icon icon, int hAlignment)

JLabel(String text,Icon icon,int hAlignment)

hAlignment: c cc gi tr LEFT, CENTER, RIGHT,LEADING, hoc

TRAILING35

Cc thuc tnh JLabel

o text

o icon

o horizontalAlignment

o verticalAlignment

Using Labels

36

V D

37

JTextComponent

38

y l lp cha ca tt c cc lp hin th vn bn trong Swing

JTextField

Textfield l nhp d liu dng vn bn trn 1 dng.

Cc constructor ca JTextField:

JTextField()

o To mt text field trng c s ct xc nh.

JTextField(int columns)

o To mt text field vi vn bn c sn.

JTextField(String text)

o To mt text field vi vn bn c sn v s ct xc nh.

JTextField(String text, int columns)39

Cc thuc tnh JTextField

o text


o editable

o columns

40

Cc phng thc JTextField

o getText()

Tr v chui k t trong text field. o setText(String text)

t chui k t trong text field.o setEditable(boolean editable)

Cho php hoc v hiu ha son tho trong text field. Mc nh editable l true.

o setColumns(int)

Thit lp s ct trong textfield. Chiu di ca textfield c th thay i.

41

JTextArea

TextArea l khung cho php ngi s dng nhp vo

nhiu dng vn bn.

Cc constructor ca JTextArea:

JTextArea()

JTextArea(String s)

JTextArea(int rows, int columns)

JTextArea(String s, int rows, int columns)

42

Cc thuc tnh JTextArea

o text

o editable

o columns

o lineWrap

o wrapStyleWord

o rows

o lineCount

o tabSize

43

Cc phng thc JTextArea

o getColumns()

Tr v s ct trong textarea. o getLineCount()

Tr v s dng trong textareao insert(String str, int pos)

t chui vo mt v tr xc nh.o append(String str)

Thm chui vo cui textareao paramString()

Tr v on vn bn trong textarea

44

Swing Button Classes

JComponent

AbstractButton

JButton JToggleButton

JCheckBox JRadioButton

45

JButton

Button l mt thnh phn gy ra mt s kin hnh ng

khi c kch chut.

Cc constructor ca JButton:

JButton()

JButton(String text)

JButton(String text, Icon icon)

JButton(Icon icon)

46

Cc thuc tnh JButton

o text

o icon

o mnemonic


o verticalAlignment

o horizontalTextPosition

o verticalTextPosition

47

p ng cc s kin JButton

public void actionPerformed(ActionEvent e)

{

// Get the button label

String actionCommand = e.getActionCommand();

// Make sure the event source is Left button

if (e.getSource() instanceof JButton)

// Make sure it is the right button

if ("Left".equals(actionCommand))

System.out.println ("Button pressed!");

}

48

JToggleButton

Cc nt lnh thay i trng thi

o Nhn cc gi tr on/off hoc true/false

o Swing h tr cc kiu:

JCheckBox

JRadioButton

50

Item Event

c to ra khi ngi dng chn cc mc khc nhau trn JCheckBox, JRadioButton,..

Cc phng thc

o Object getItem(): tr v mc c chn

o int getStateChange():tr v trng thi trng thi ca

mc chn (DESELECTED/SELECTED)

51

Item Listener

o void itemStateChanged(ItemEvent e):c gi

thi hnh khi ngi dng chn hoc b chn 1 mc.

52

JCheckBox

Checkbox c dng cung cp cho ngi dng kh nng la chn

Cc contructor JCheckBox:JCheckBox()

JCheckBox(Icon icon)

JCheckBox(Icon icon, boolean selected)

JCheckBox(String text)

JCheckBox(String text, boolean selected)

JCheckBox(String text, Icon icon)

JCheckBox(String text, Icon icon, boolean selected)

JCheckBox(Action a)

53

JCheckBox (tt)

54

1 // Fig. 12.11: CheckBoxTest.java

2 // Creating Checkbox buttons.

3

4 // Java core packages

5 import java.awt.*;

6 import java.awt.event.*;

7

8 // Java extension packages

9 import javax.swing.*;

10

11 public class CheckBoxTest extends JFrame {

12 private JTextField field;

13 private JCheckBox bold, italic;

14

15 // set up GUI

16 public CheckBoxTest()

17 {

18 super( "JCheckBox Test" );

19

20 // get content pane and set its layout

21 Container container = getContentPane();

22 container.setLayout( new FlowLayout() );

23

24 // set up JTextField and set its font

25 field =

26 new JTextField( "Watch the font style change", 20 );

27 field.setFont( new Font( "Serif", Font.PLAIN, 14 ) );

28 container.add( field );

29

30 // create checkbox objects

31 bold = new JCheckBox( "Bold" );

32 container.add( bold );

33

34 italic = new JCheckBox( "Italic" );

35 container.add( italic );

CheckBoxTest.java

Line 13

Line 27

Lines 31-35

Declare two JCheckBox instances

Set JTextField font

to Serif, 14-point plain

Instantiate JCheckBoxs for bolding and

italicizing JTextField text, respectively

5

4

36

37 // register listeners for JCheckBoxes

38 CheckBoxHandler handler = new CheckBoxHandler();

39 bold.addItemListener( handler );

40 italic.addItemListener( handler );

41

42 setSize( 275, 100 );

43 setVisible( true );

44 }

45

46 // execute application

47 public static void main( String args[] )

48 {

49 CheckBoxTest application = new CheckBoxTest();

50

51 application.setDefaultCloseOperation(

52 JFrame.EXIT_ON_CLOSE );

53 }

54

55 // private inner class for ItemListener event handling

56 private class CheckBoxHandler implements ItemListener {

57 private int valBold = Font.PLAIN;

58 private int valItalic = Font.PLAIN;

59

60 // respond to checkbox events

61 public void itemStateChanged( ItemEvent event )

62 {

63 // process bold checkbox events

64 if ( event.getItem() == bold )

65

66 if ( event.getStateChange() == ItemEvent.SELECTED )

67 valBold = Font.BOLD;

68 else

69 valBold = Font.PLAIN;

70

CheckBoxTest.java

Lines 38-40

Line 61

Register JCheckBoxs to receive

events from CheckBoxHandler

When user selects JCheckBox,

CheckBoxHandler invokes

method itemStateChanges of all

registered listeners

5

4

71 // process italic checkbox events

72 if ( event.getSource() == italic )

73


75 valItalic = Font.ITALIC;

76 else

77 valItalic = Font.PLAIN;

78

79 // set text field font

80 field.setFont(

81 new Font( "Serif", valBold + valItalic, 14 ) );

82 }

83

84 } // end private inner class CheckBoxHandler

85

86 } // end class CheckBoxTest

CheckBoxTest.java

Lines 80-81Change JTextField font, depending on

which JCheckBox was selected

5

4

JRadioButton

Mt tp cc nt cho php ch la chn c mt ti mt thi im

Dng lp ButtonGroup to ra nhm

Cc contructor JRadioButton:o JRadioButton(Icon icon)

o JRadioButton(Icon icon, boolean selected)

o JRadioButton(String text)

o JRadioButton(String text, boolean selected)

o JRadioButton(String text, Icon icon)

o JRadioButton(String text, Icon icon, boolean selected)

o JRadioButton(Action a)

58

JRadioButton (tt)

59

1 // Fig. 12.12: RadioButtonTest.java

2 // Creating radio buttons using ButtonGroup and JRadioButton.

3




7



10

11 public class RadioButtonTest extends JFrame {

12 private JTextField field;

13 private Font plainFont, boldFont, italicFont, boldItalicFont;

14 private JRadioButton plainButton, boldButton, italicButton,

15 boldItalicButton;

16 private ButtonGroup radioGroup;

17

18 // create GUI and fonts

19 public RadioButtonTest()

20 {

21 super( "RadioButton Test" );

22




26

27 // set up JTextField

28 field =

29 new JTextField( "Watch the font style change", 25 );

30 container.add( field );

31

32 // create radio buttons

33 plainButton = new JRadioButton( "Plain", true );

34 container.add( plainButton );

35

RadioButtonTest.java

Lines 14-15

Line 16

JRadioButtons normally

appear as a ButtonGroup

Declare four JRadioButton instances

5

4

36 boldButton = new JRadioButton( "Bold", false);

37 container.add( boldButton );

38

39 italicButton = new JRadioButton( "Italic", false );

40 container.add( italicButton );

41

42 boldItalicButton = new JRadioButton(

43 "Bold/Italic", false );

44 container.add( boldItalicButton );

45

46 // register events for JRadioButtons

47 RadioButtonHandler handler = new RadioButtonHandler();

48 plainButton.addItemListener( handler );

49 boldButton.addItemListener( handler );

50 italicButton.addItemListener( handler );

51 boldItalicButton.addItemListener( handler );

52

53 // create logical relationship between JRadioButtons

54 radioGroup = new ButtonGroup();

55 radioGroup.add( plainButton );

56 radioGroup.add( boldButton );

57 radioGroup.add( italicButton );

58 radioGroup.add( boldItalicButton );

59

60 // create font objects

61 plainFont = new Font( "Serif", Font.PLAIN, 14 );

62 boldFont = new Font( "Serif", Font.BOLD, 14 );

63 italicFont = new Font( "Serif", Font.ITALIC, 14 );

64 boldItalicFont =

65 new Font( "Serif", Font.BOLD + Font.ITALIC, 14 );

66 field.setFont( plainFont );

67

68 setSize( 300, 100 );


70 }


Lines 36-44

Lines 47-51

Lines 54-58

Instantiate JRadioButtons for

manipulating JTextField text font

Register JRadioButtons to

receive events from RadioButtonHandler

JRadioButtons belong to

ButtonGroup

5

4

71



74 {

75 RadioButtonTest application = new RadioButtonTest();

76



79 }

80

81 // private inner class to handle radio button events

82 private class RadioButtonHandler implements ItemListener {

83

84 // handle radio button events


86 {

87 // user clicked plainButton

88 if ( event.getItem() == plainButton )

89 field.setFont( plainFont );

90

91 // user clicked boldButton

92 else if (event.getItem() == boldButton )

93 field.setFont( boldFont );

94

95 // user clicked italicButton

96 else if (event.getItem() == italicButton )

97 field.setFont( italicFont );

98

99 // user clicked boldItalicButton

100 else if (event.getItem() == boldItalicButton )

101 field.setFont( boldItalicFont );

102 }

103

104 } // end private inner class RadioButtonHandler

105

106 } // end class RadioButtonTest


Lines 85-104

Lines 88-102

When user selects JRadioButton,

RadioButtonHandler invokes

method itemStateChanged of all


Set font corresponding to

JRadioButton selected

5

4

JComboBox

JComboBox

oDng lit k danh sch cc mc m ngi dng c th

chn

oCn c gi l drop-down list

o Pht sinh s kin ItemEvent khi ngi s dng chn 1 mc

trong danh sch

Cc constructor Jcomboboxo JComboBox()

o JComboBox(ComboBoxModel asModel)

o JComboBox(Object []item)

6

3

JComboBox (tt)

6

4

2002 Prentice Hall, Inc. All rights reserved.

Outline1 // Fig. 12.13: ComboBoxTest.java2 // Using a JComboBox to select an image to display.

3




7



10

11 public class ComboBoxTest extends JFrame {

12 private JComboBox imagesComboBox;

13 private JLabel label;

14

15 private String names[] =

16 { "bug1.gif", "bug2.gif", "travelbug.gif", "buganim.gif" };

17 private Icon icons[] = { new ImageIcon( names[ 0 ] ),

18 new ImageIcon( names[ 1 ] ), new ImageIcon( names[ 2 ] ),

19 new ImageIcon( names[ 3 ] ) };

20

21 // set up GUI

22 public ComboBoxTest()

23 {

24 super( "Testing JComboBox" );

25




29

30 // set up JComboBox and register its event handler

31 imagesComboBox = new JComboBox( names );

32 imagesComboBox.setMaximumRowCount( 3 );

33

34 imagesComboBox.addItemListener(

35

ComboBoxTest.java

Lines 31-32

Line 34

Register JComboBox to receive events

from anonymous ItemListener

Instantiate JComboBox to

show three Strings from

names array at a time

5

4


Outline36 // anonymous inner class to handle JComboBox events37 new ItemListener() {

38

39 // handle JComboBox event


41 {

42 // determine whether check box selected


44 label.setIcon( icons[

45 imagesComboBox.getSelectedIndex() ] );

46 }

47

48 } // end anonymous inner class

49

50 ); // end call to addItemListener

51

52 container.add( imagesComboBox );

53

54 // set up JLabel to display ImageIcons

55 label = new JLabel( icons[ 0 ] );

56 container.add( label );

57

58 setSize( 350, 100 );


60 }

61



64 {

65 ComboBoxTest application = new ComboBoxTest();

66



69 }

70

71 } // end class ComboBoxTest

ComboBoxTest.java

Lines 40-46

Lines 43-45

When user selects item in JComboBox,

ItemListener invokes method

itemStateChanged of all registered listeners

Set appropriate Icon

depending on user selection

5

4

JList

Jlist

oDanh sch cc mc chn

oC th chn 1 hoc nhiu mc

oCho php sp xp d liu hin th, phn nhm

oC th hin th chui v icon

oKhng h tr doublclik chut

o Pht sinh ListSelectionEvent khi ngi dng chn

Cc constructor Jlisto JList()

o JList(ListModel dataModel)

o JList(Object []listData)6

7

Jlist (tt)

Cc phng thco JList(Object[] listData)

o int getSelectedIndex()

o Object[] getSelectedValues()

o void setListData(Object[] listData)

o void setSelectedIndex(int idx)

ListSelectionListenero void valueChanged(ListSelectionEvent e)

6

8

Jlist Demo

5

4


Outline1 // Fig. 12.14: ListTest.java

2 // Selecting colors from a JList.

3



6



9 import javax.swing.event.*;

10

11 public class ListTest extends JFrame {

12 private JList colorList;

13 private Container container;

14

15 private String colorNames[] = { "Black", "Blue", "Cyan",

16 "Dark Gray", "Gray", "Green", "Light Gray", "Magenta",

17 "Orange", "Pink", "Red", "White", "Yellow" };

18

19 private Color colors[] = { Color.black, Color.blue,

20 Color.cyan, Color.darkGray, Color.gray, Color.green,

21 Color.lightGray, Color.magenta, Color.orange, Color.pink,

22 Color.red, Color.white, Color.yellow };

23

24 // set up GUI

25 public ListTest()

26 {

27 super( "List Test" );

28


30 container = getContentPane();


32

33 // create a list with items in colorNames array

34 colorList = new JList( colorNames );

35 colorList.setVisibleRowCount( 5 );

ListTest.java

Line 34

Use colorNames array to

populate JList

5

4


Outline36 37 // do not allow multiple selections

38 colorList.setSelectionMode(

39 ListSelectionModel.SINGLE_SELECTION );

40

41 // add a JScrollPane containing JList to content pane

42 container.add( new JScrollPane( colorList ) );

43

44 // set up event handler

45 colorList.addListSelectionListener(

46

47 // anonymous inner class for list selection events

48 new ListSelectionListener() {

49

50 // handle list selection events

51 public void valueChanged( ListSelectionEvent event )

52 {

53 container.setBackground(

54 colors[ colorList.getSelectedIndex() ] );

55 }

56


58

59 ); // end call to addListSelectionListener

60

61 setSize( 350, 150 );


63 }

64



67 {

68 ListTest application = new ListTest();

69

ListTest.java

Lines 38-39

Lines 45-59

Lines 51-55

Lines 53-54

JList allows single selections

Register JList to receive events from

anonymous ListSelectionListener

When user selects item in JList,

ListSelectionListener invokes

method valueChanged of all


Set appropriate background

depending on user selection

5

4


Outline70 application.setDefaultCloseOperation(71 JFrame.EXIT_ON_CLOSE );

72 }

73

74 } // end class ListTest ListTest.java

5

4

Multiple-Selection Lists

Multiple-selection list

oChn nhiu mc trn Jlist

5

4


Outline1 // Fig. 12.15: MultipleSelection.java

2 // Copying items from one List to another.

3




7



10

11 public class MultipleSelection extends JFrame {

12 private JList colorList, copyList;

13 private JButton copyButton;

14

15 private String colorNames[] = { "Black", "Blue", "Cyan",

16 "Dark Gray", "Gray", "Green", "Light Gray",

17 "Magenta", "Orange", "Pink", "Red", "White", "Yellow" };

18

19 // set up GUI

20 public MultipleSelection()

21 {

22 super( "Multiple Selection Lists" );

23




27

28 // set up JList colorList

29 colorList = new JList( colorNames );

30 colorList.setVisibleRowCount( 5 );

31 colorList.setFixedCellHeight( 15 );

32 colorList.setSelectionMode(

33 ListSelectionModel.MULTIPLE_INTERVAL_SELECTION );

34 container.add( new JScrollPane( colorList ) );

35

MultipleSelection.j

ava

Line 29

Lines 32-33

Use colorNames array to

populate JList

JList colorList allows

multiple selections

5

4


Outline36 // create copy button and register its listener

37 copyButton = new JButton( "Copy >>>" );

38

39 copyButton.addActionListener(

40

41 // anonymous inner class for button event

42 new ActionListener() {

43

44 // handle button event

45 public void actionPerformed( ActionEvent event )

46 {

47 // place selected values in copyList

48 copyList.setListData(

49 colorList.getSelectedValues() );

50 }

51


53

54 ); // end call to addActionListener

55

56 container.add( copyButton );

57

58 // set up JList copyList

59 copyList = new JList();

60 copyList.setVisibleRowCount( 5 );

61 copyList.setFixedCellWidth( 100 );

62 copyList.setFixedCellHeight( 15 );

63 copyList.setSelectionMode(

64 ListSelectionModel.SINGLE_INTERVAL_SELECTION );

65 container.add( new JScrollPane( copyList ) );

66

67 setSize( 300, 120 );


69 }

70

MultipleSelection.j

ava

Lines 48-49

Lines 63-64

When user presses JButton, JList

copyList adds items that user selected

from JList colorList

JList colorList

allows single selections

5

4


Outline71 // execute application


73 {

74 MultipleSelection application = new MultipleSelection();

75



78 }

79

80 } // end class MultipleSelection

MultipleSelection.j

ava

5

4

Menus

Java cung cp mt s lp - JMenuBar, JMenu,

JMenuItem, JCheckBoxMenuItem, v

JRadioButtonMenuItem - thc thi menu trong

mt frame.

Mt JFrame hoc JApplet c th cha mt menu bar trn

c gn cc pull-down menu. Cc menu cha cc menu

item ngi dng la chn (hoc bt/tt). Menu bar c

th c xem nh mt cu trc h tr cc menu.

77

Menus (tt)

78

Lp JMenuBar

Menu bar cha cc menu; menu bar ch c th c thm vo 1 frame. on code sau to v thm mt JMenuBar

vo 1 frame:

JFrame f = new JFrame();

f.setSize(300, 200);

f.setVisible(true);

JMenuBar mb = new JMenuBar();

f.setJMenuBar(mb);

79

Lp JMenu

Gn cc menu vo mt JMenuBar. on code sau to 2 menu File v Help, v thm chng vo JMenuBar mb:

JMenu fileMenu = new JMenu("File", false);

JMenu helpMenu = new JMenu("Help", true);

mb.add(fileMenu);

mb.add(helpMenu);

80

Lp JMenuItem

on code sau thm cc mc chn (menu item) v cc separator trong menu fileMenu:

fileMenu.add(new JMenuItem("New"));

fileMenu.add(new JMenuItem("Open"));

fileMenu.addSeparator();

fileMenu.add(new JMenuItem("Print"));

fileMenu.addSeparator();

fileMenu.add(new JMenuItem("Exit"));

81

Menu Demo

82

Submenus

Thm cc submenus vo cc menu item. on code sau thm cc submenu Unix, NT, v Win95 vo trong mc chn Software.

JMenu softwareHelpSubMenu = new JMenu("Software");

JMenu hardwareHelpSubMenu = new JMenu("Hardware");

helpMenu.add(softwareHelpSubMenu);

helpMenu.add(hardwareHelpSubMenu);

softwareHelpSubMenu.add(new JMenuItem("Unix"));

softwareHelpSubMenu.add(new JMenuItem("NT"));

softwareHelpSubMenu.add(new JMenuItem("Win95"));

83

Submenu Demo

84

Documents

Bai 5 GUI JAVA