Aula 4

Transcrição

Aula 4

Aula 4 – Programando Interfaces
Gráficas Orientadas a Objeto - Parte 2
Planejamento
•
•
•
Classe, Objeto, Método,Herança, polimorfismo, Encapsulamento
•
Introdução a linguagem Java
•
•
•
Introdução a Ambientes Integrados de Desenvolvimento
Introdução ao Ambiente Eclipse
Desenvolvimento de Programas básicos (modo texto)
Aula 2
Comandos de controle: if, while,forClasses: String, Integer, DateBibliotecas Básicas: System, java,
•
•
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
Introdução
Conceitos Básicos
•
•
Sumário
Aula 1
Aula 3
•
Programando Interfaces Gráficas com Java – Parte I
• Aula 4
• Programando Interfaces Gráficas com Java – Parte II
•
Introdução
Componente JTextArea
Criando uma classe customizada de JPanel
Uma subclasse JPanel que trata seus próprios eventos
JSlider
Windows: Additional Notes
Usando Menus com Frames
JPopupMenu
Pluggable Look-and-Feel
JDesktopPane and JInternalFrame
JTabbedPane
Layout Managers: BoxLayout and GridBagLayout
Aula 5
5.1. Introdução a Design Patterns
5.2. Programação concorrente (Threads)
Paulo André Castro
ITA – Stefanini
POO
Paulo André Castro
1
POO
ITA – Stefanini
2
ITA – Stefanini
4
4.2 JTextArea
4.1 Introdução
• Componentes GUI Avançados
• JTextArea
– Text areas
– Sliders
– Menus
– Area for manipulating multiple lines of text
– extends JTextComponent
• Multiple Document Interface (MDI)
• Layout Managers Avançados
– BoxLayout
– GridBagLayout
Paulo André Castro
1
2
3
4
5
6
7
8
9
10
11
12
13
4
15
16
17
18
19
20
21
22
23
24
25
ITA – Stefanini
POO
// Fig. 4.1: TextAreaDemo.java
// Copying selected text from one textarea to another.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
public class TextAreaDemo extends JFrame {
private JTextArea textArea1, textArea2;
private JButton copyButton;
// set up GUI
public TextAreaDemo()
{
super(
super
( "TextArea Demo" );
Create Box container for
organizing GUI components
Box box = Box.createHorizontalBox();
String string = "This is a demo string to\
to\n" +
"illustrate copying text\
text\nfrom one textarea to \n" +
"another textarea using an\
an\nexternal event\
event\n";
n";
// set up textArea1
textArea1 = new JTextArea( string, 10,
10, 15 );
box.add( new JScrollPane( textArea1 ) );
Paulo André Castro
POO
Populate JTextArea with
String, then add to Box
ITA – Stefanini
Paulo André Castro
3
5
POO
// set up copyButton
copyButton = new JButton( "Copy >>>" );
box.add( copyButton );
copyButton.addActionListener(
new ActionListener() {
// anonymous inner class
// set text in textArea2 to selected text from textArea1
public void actionPerformed( ActionEvent event )
{
textArea2.setText( textArea1.getSelectedText() );
}
When user presses JButton,
textArea1’s highlighted text
is copied into textArea2
} // end anonymous inner class
); // end call to addActionListener
// set up textArea2
textArea2 = new JTextArea( 10,
10, 15 );
textArea2.setEditable( false );
box.add( new JScrollPane( textArea2 ) );
Instantiate uneditable JTextArea
// add box to content pane
Container container = getContentPane();
// place in BorderLayout.CENTER
container.add( box );
Paulo André Castro
POO
ITA – Stefanini
6
1
52
53
54
55
56
57
58
59
60
61
62
63
4.3 Criando uma classe customizada de JPanel
setSize( 425,
425, 200 );
setVisible( true );
} // end constructor TextAreaDemo
public static void main( String args[] )
{
TextAreaDemo application = new TextAreaDemo();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}
• Extend JPanel to create new components
– Dedicated drawing area
• Method paintComponent of class JComponent
} // end class TextAreaDemo
Paulo André Castro
ITA – Stefanini
POO
1
// Fig. 4.2: CustomPanel.java
2
// A customized JPanel class.
3
import java.awt.*;
4
5
6
public class CustomPanel extends JPanel {
7
public final static int CIRCLE = 1, SQUARE = 2;
Store integer representing
8
private int shape;
shape to draw
9
// use shape to draw an oval or rectangle
10
11
public void paintComponent( Graphics g )
12
{
13
super.paintComponent(
super.paintComponent( g );
Override method
14
paintComponent of
if ( shape == CIRCLE )
15
class JComponent to
16
g.fillOval( 50,
50, 10,
10, 60,
60, 60 );
17
else if ( shape == SQUARE )
draw oval or rectangle
18
g.fillRect( 50,
50, 10,
10, 60,
60, 60 );
19
}
20
21
// set shape value and repaint CustomPanel
22
public void draw( int shapeToDraw )
23
{
24
shape = shapeToDraw;
25
repaint();
Method repaint calls method paintComponent
26 }
27
28 } // end class CustomPanel
Paulo André Castro
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
ITA – Stefanini
POO
When user presses squareButton,
draw square on CustomPanel
circleButton = new JButton( "Circle" );
circleButton.addActionListener(
// draw a circle
{
myPanel.draw( CustomPanel.CIRCLE );
}
When user presses circleButton,
draw circle on CustomPanel
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
ITA – Stefanini
POO
8
// Fig. 4.3: CustomPanelTest.java
// Using a customized Panel object.
import java.awt.*;
public class CustomPanelTest extends JFrame {
private JPanel buttonPanel;
private CustomPanel myPanel;
private JButton circleButton, squareButton;
// set up GUI
public CustomPanelTest()
{
super(
super
( "CustomPanel Test" );
// create custom drawing area
myPanel = new CustomPanel();
myPanel.setBackground( Color.GREEN );
Instantiate CustomPanel object
and set background to green
// set up squareButton
squareButton = new JButton( "Square" );
squareButton.addActionListener(
Paulo André Castro
9
// draw a square
{
myPanel.draw( CustomPanel.SQUARE );
}
Paulo André Castro
7
ITA – Stefanini
POO
// set up panel containing buttons
buttonPanel = new JPanel();
buttonPanel.setLayout( new GridLayout( 1, 2 ) );
buttonPanel.add( circleButton );
buttonPanel.add( squareButton );
10
Use GridLayout to organize buttons
// attach button panel & custom drawing area to content pane
container.add( myPanel, BorderLayout.CENTER );
container.add( buttonPanel, BorderLayout.SOUTH );
setSize( 300,
300, 150 );
setVisible( true );
} // end constructor CustomPanelTest
{
CustomPanelTest application = new CustomPanelTest();
}
} // end class CustomPanelTest
Paulo André Castro
POO
ITA – Stefanini
11
Paulo André Castro
POO
ITA – Stefanini
12
2
4.4 Uma subclasse JPanel que trata seus
próprios eventos
Exercício
• Pergunta: Porquê inicialmente não surge nenhuma
forma (círculo ou quadrado) dentro do painel?
• Fazer com que o painel seja apresentado
inicialmente com o círculo no seu interior
• Fazer inicialização de cor de fundo do painel na
classe do próprio painel.
•
ITA – Stefanini
POO
• e.g., events offered by buttons, text areas, etc.
– Capable of recognizing lower-level events
• e.g., mouse events, key events, etc.
– Self-contained panel
• Listens for its own mouse events
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
import java.awt.*;
public class SelfContainedPanel extends JPanel {
private int x1, y1, x2, y2;
// set up mouse event handling for SelfContainedPanel
public SelfContainedPanel()
{
Self-contained JPanel
// set up mouse listener
addMouseListener(
listens for MouseEvents
new MouseAdapter() {
// handle mouse press event
public void mousePressed( MouseEvent event )
{
x1 = event.getX();
Save coordinates where user
y1 = event.getY();
pressed mouse button
}
POO
ITA – Stefanini
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
} // end constructor SelfContainedPanel
// return preferred width and height of SelfContainedPanel
public Dimension getPreferredSize()
{
150,
return new Dimension( 150
, 100 );
}
// paint an oval at the specified coordinates
{
super
.paintComponent( g );
Draw oval
}
} // end class SelfContainedPanel
Paulo André Castro
POO
ITA – Stefanini
17
ITA – Stefanini
POO
14
// handle mouse release event
public void mouseReleased( MouseEvent event )
{
x2 = event.getX();
Save coordinates where user released
y2 = event.getY();
mouse button, then repaint
repaint();
}
); // end call to addMouseListener
Self-contained JPanel listens
for when mouse moves
// set up mouse motion listener
addMouseMotionListener(
new MouseMotionAdapter() {
// handle mouse drag event
public void mouseDragged( MouseEvent event )
{
x2 = event.getX();
y2 = event.getY();
repaint();
}
Paulo André Castro
15
); // end call to addMouseMotionListener
g.drawOval( Math.min( x1, x2 ), Math.min( y1, y2 ),
Math.abs( x1 - x2 ), Math.abs( y1 - y2 ) );
Paulo André Castro
13
// Fig. 4.4: SelfContainedPanel.java
// A selfself-contained JPanel class that handles its own mouse events.
Paulo André Castro
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
– Does not support conventional events
Lembrar do conceito de encapsulamento, comportamento específico de
uma classe deve estar definido na própria classe e não externamente
Paulo André Castro
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
• JPanel
Save coordinates where user
dragged mouse, then repaint
POO
ITA – Stefanini
16
// Fig. 4.5: SelfContainedPanelTest.java
// Creating a selfself-contained subclass of JPanel that processes
// its own mouse events.
import java.awt.*;
public class SelfContainedPanelTest extends JFrame {
private SelfContainedPanel myPanel;
// set up GUI and mouse motion event handlers for application window
public SelfContainedPanelTest()
{
// set up a SelfContainedPanel
Instantiate SelfContaintedPanel
myPanel = new SelfContainedPanel();
object and set background to yellow
myPanel.setBackground( Color.YELLOW );
container.setLayout( new FlowLayout() );
container.add( myPanel );
Paulo André Castro
POO
ITA – Stefanini
18
3
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
// set up mouse motion event handling
addMouseMotionListener(
new MouseMotionListener() {
Register anonymous-inner-class object
to handle mouse motion events
// handle mouse drag event
public void mouseDragged( MouseEvent event )
{
setTitle( "Dragging: x=" + event.getX() +
"; y=" + event.getY() );
}
// handle mouse move event
public void mouseMoved( MouseEvent event )
{
setTitle( "Moving: x=" + event.getX() +
"; y=" + event.getY() );
}
51
52
53
54
55
56
57
58
{
SelfContainedPanelTest application = new SelfContainedPanelTest();
}
} // end class SelfContainedPanelTest
Display String in title bar
indicating x-y coordinate where
mouse-motion event occurred
); // end call to addMouseMotionListener
setSize( 300,
300, 200 );
setVisible( true );
} // end constructor SelfContainedPanelTest
Paulo André Castro
POO
ITA – Stefanini
19
Paulo André Castro
Perguntas
POO
ITA – Stefanini
Exercício
• Porque a barra de status não apresenta a
informação de posição do mouse quando, este
encontra-se sobre a parte amarela
• Como seria possível criar várias elipses ao invés
de apenas uma ?
• Criar ao invés de uma elipse um círculo, caso
esteja sendo presionado a tecla Shift durante o
“dragging” do mouse
Paulo André Castro
Paulo André Castro
POO
20
ITA – Stefanini
21
POO
ITA – Stefanini
22
Fig. 4.6 JSlider component with horizontal
orientation
4.5 JSlider
• JSlider
– Enable users to select from range of integer values
– Several features
thumb
tick mark
• Tick marks (major and minor)
• Snap-to ticks
• Orientation (horizontal and vertical)
Paulo André Castro
POO
ITA – Stefanini
23
Paulo André Castro
POO
ITA – Stefanini
24
4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
// Fig. 4.7: OvalPanel.java
// A customized JPanel class.
import java.awt.*;
public class OvalPanel extends JPanel {
private int diameter = 10;
10;
// draw an oval of the specified diameter
{
super
.paintComponent( g );
g.fillOval( 10,
10, 10,
10, diameter, diameter );
// validate and set diameter, then repaint
public void setDiameter( int newDiameter )
Set
{
// if diameter invalid, default to 10
diameter = ( newDiameter >= 0 ? newDiameter : 10 );
repaint();
}
52
53
54
55
56
57
58
ITA – Stefanini
POO
} // end class OvalPanel
Instantiate OvalPanel object
and set background to yellow
// set up OvalPanel
myPanel = new OvalPanel();
myPanel.setBackground( Color.YELLOW );
Instantiate horizontal JSlider object
with min. value of 0, max. value of 200
initial thumb location at 10
and
// set up JSlider to control diameter value
diameterSlider =
SwingConstants.HORIZONTAL,
new JSlider( SwingConstants.HORIZONTAL
, 0, 200,
200, 10 );
diameterSlider.setMajorTickSpacing( 10 );
diameterSlider.setPaintTicks( true );
POO
ITA – Stefanini
Paulo André Castro
25
public class SliderDemo extends JFrame {
private JSlider diameterSlider;
private OvalPanel myPanel;
Paulo André Castro
// used by layout manager to determine minimum size
public Dimension getMinimumSize()
{
return getPreferredSize();
}
diameter, then repaint
// Fig. 4.8: SliderDemo.java
// Using JSliders to size an oval.
import java.awt.*;
import javax.swing.event.*;
// set up GUI
public SliderDemo()
{
super(
super
( "Slider Demo" );
// used by layout manager to determine preferred size
{
200,
return new Dimension( 200
, 200 );
}
Draw filled oval of diameter
}
Paulo André Castro
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
25
26
27
28
29
30
31
32
33
34
35
36
37
27
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
26
Register anonymous
ChangeListener object
to handle JSlider events
// register JSlider event listener
diameterSlider.addChangeListener(
new ChangeListener() {
ITA – Stefanini
POO
// handle change in slider value
public void stateChanged( ChangeEvent e )
{
myPanel.setDiameter( diameterSlider.getValue() );
}
When user accesses JSlider,
set OvalPanel’s diameter
according to JSlider value
); // end call to addChangeListener
// attach components to content pane
container.add( diameterSlider, BorderLayout.SOUTH );
container.add( myPanel, BorderLayout.CENTER );
setSize( 220,
220, 270 );
setVisible( true );
} // end constructor SliderDemo
Paulo André Castro
POO
ITA – Stefanini
28
4.6 Caixas de Diálogo Simples JOptionPane
{
SliderDemo application = new SliderDemo();
}
• Utilização da classe
} // end class SliderDemo
– javax.swing.JOptionPane
• Caixa de Diálogo para Informação ao Usuário
– JOptionPane.showMessageDialog
• Parâmetros:
– (Component parentComponent, Object message, String title,
int messageType );
– Dois últimos argumentos podem ser omitidos
• Tipo de Mensagem (messageType)
–
–
–
–
–
Paulo André Castro
POO
ITA – Stefanini
29
JOptionPane.PLAIN_MESSAGE - nenhum ícone
JOptionPane.ERROR_MESSAGE - ícone de erro
JOptionPane.INFORMATION_MESSAGE - ícone de informação
JOptionPane.WARNING_MESSAGE - ícone de aviso
JOptionPane.QUESTION_MESSAGE - ícone de interrogação
Paulo André Castro
POO
ITA – Stefanini
30
5
Caixas de Diálogo Simples - JOptionPane
Caixas de Diálogo Úteis - JOptionPane
• Caixa de Diálogo para Captar informação do Usuário
– JOptionPane.showInputDialog
– Parâmetros: (Component parentComponent, Object message,
String title, int messageType );
– Dois últimos argumentos podem ser omitidos
• Caixa de Diálogo para obter confirmação do Usuário
JOPtionPane.showInputDialog
– JOptionPane. showConfirmDialog
– Parâmetros: (Component parentComponent, Object message,
String title, int optionType, int messageType );
– optionType: JOptionPane.YES_NO_OPTION ou
YES_NO_CANCEL_OPTION
– Três últimos argumentos podem ser omitidos
– Retorna um inteiro indicando o valor digitado pelo usuário:
JOPtionPane.showMessageDialog
JOPtionPane.showConfirmDialog
• JOptionPane.YES_OPTION, JOptionPane.NO_OPTION,
JOptionPane.CANCEL_OPTION
Paulo André Castro
POO
ITA – Stefanini
Paulo André Castro
31
Exemplo
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
POO
ITA – Stefanini
// set up GUI
public MenuTest()
{
super(
super
( "Using JMenus" );
Instantiate File JMenu
POO
– Allows for performing actions with cluttering GUI
– Contained by menu bar
• JMenuBar
– Comprised of menu items
• JMenuItem
Paulo André Castro
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
public class MenuTest extends JFrame {
private final Color colorValues[] =
Color.BLACK,
{ Color.BLACK
, Color.BLUE,
Color.BLUE, Color.RED,
Color.RED, Color.GREEN };
private JRadioButtonMenuItem colorItems[], fonts[];
private JCheckBoxMenuItem styleItems[];
private JLabel displayLabel;
private ButtonGroup fontGroup, colorGroup;
private int style;
Paulo André Castro
• Menus
33
// Fig. 4.9: MenuTest.java
// Demonstrating menus
import java.awt.*;
// set up File menu and its menu items
JMenu fileMenu = new JMenu( "File" );
fileMenu.setMnemonic( 'F' );
32
4.7 Usando Menus com Frames
1 import javax.swing.JOptionPane;
2
3 public class Dialogos {
4
5
public static void main(String args[]) {
6
int continua;
7
do {
8
String resposta;
9
resposta = JOptionPane.showInputDialog(null,
JOptionPane.showInputDialog(null, "Qual o seu nome?",
10
"Nome...",JOptionPane.QUESTION_MESSAGE);
11
12
JOptionPane.showMessageDialog(null,"Olá,
JOptionPane.showMessageDialog(null,"Olá, "+resposta);
13
continua=JOptionPane.showConfirmDialog
continua=JOptionPane.showConfirmDialog(null,
JOptionPane.showConfirmDialog(null,
14
"Deseja executar novamente?","Pergunta",
15
JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE);
16
17
18
} while(continua==JOptionPane.YES_OPTION);
19 }
20
21 }
Paulo André Castro
ITA – Stefanini
POO
ITA – Stefanini
35
ITA – Stefanini
POO
34
// set up About... menu item
JMenuItem aboutItem = new JMenuItem( "About..." );
aboutItem.setMnemonic( 'A' );
Instantiate About… JMenuItem
fileMenu.add( aboutItem );
to be placed in fileMenu
aboutItem.addActionListener(
// display message dialog when user selects About...
{
JOptionPane.showMessageDialog( MenuTest.this
MenuTest.this,
this,
example\
menus",
"This is an example
\nof using menus"
,
"About",
"About"
, JOptionPane.PLAIN_MESSAGE );
When
}
}
user selects About…
JMenuItem, display message
dialog with appropriate text
// end anonymous inner class
// set up Exit menu item
JMenuItem exitItem = new JMenuItem( "Exit" );
exitItem.setMnemonic( 'x' );
fileMenu.add( exitItem );
exitItem.addActionListener(
Paulo André Castro
POO
Instantiate Exit JMenuItem
to be placed in fileMenu
ITA – Stefanini
36
6
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
selects Exit
JMenuItem, exit system
}
// end anonymous inner class
// create menu bar and attach it to MenuTest window
JMenuBar bar = new JMenuBar();
Instantiate JMenuBar
setJMenuBar( bar );
bar.add( fileMenu );
to contain JMenus
// create Format menu, its submenus and menu items
JMenu formatMenu = new JMenu( "Format" );
Instantiate Format
formatMenu.setMnemonic( 'r' );
ITA – Stefanini
POO
fonts = new JRadioButtonMenuItem[ fontNames.length ];
fontGroup = new ButtonGroup();
// create Font radio button menu items
for ( int count = 0; count < fonts.length; count++ ) {
fonts[ count ] = new JRadioButtonMenuItem( fontNames[ count ] );
fontMenu.add( fonts[ count ] );
fontGroup.add( fonts[ count ] );
Instantiate
fonts[ count ].addActionListener( itemHandler );
JRadioButtonMenuItems
}
for
Font JMenu and ensure that only
one menu item is selected at a time
// select first Font menu item
fonts[ 0 ].setSelected( true );
fontMenu.addSeparator();
// set up style menu items
String styleNames[] = { "Bold",
"Bold", "Italic" };
styleItems = new JCheckBoxMenuItem[ styleNames.length ];
StyleHandler styleHandler = new StyleHandler();
ITA – Stefanini
POO
Invoked when user selects JMenuItem
// inner class to handle action events from menu items
private class ItemHandler implements ActionListener {
// process color and font selections
Determine which font or color
{
menu generated event
// process color selection
for ( int count = 0; count < colorItems.length; count++ )
// process font selection
for ( int count = 0; count < fonts.length; count++ )
Set font or color of JLabel,
respectively
if ( event.getSource() == fonts[ count ] ) {
displayLabel.setFont(
new Font( fonts[ count ].getText(), style, 72 ) );
break;
break
;
}
Paulo André Castro
POO
ITA – Stefanini
41
colorItems = new JRadioButtonMenuItem[ colors.length ];
colorGroup = new ButtonGroup();
ItemHandler itemHandler = new ItemHandler();
// create color radio button menu items
for ( int count = 0; count < colors.length; count++ ) {
colorItems[ count ] =
Instantiate
new JRadioButtonMenuItem( colors[ count ] );
JRadioButtonMenuItems for
colorMenu.add( colorItems[ count ] );
Color JMenu and ensure that only
colorGroup.add( colorItems[ count ] );
one );
menu item is selected at a time
colorItems[ count ].addActionListener( itemHandler
}
// select first Color menu item
colorItems[ 0 ].setSelected( true );
// add format menu to menu bar
formatMenu.add( colorMenu );
formatMenu.addSeparator();
Separator places line
between JMenuItems
// create Font submenu
String fontNames[] = { "Serif",
"Serif", "Monospaced",
"Monospaced", "SansSerif" };
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
ITA – Stefanini
POO
38
// create style checkbox menu items
for ( int count = 0; count < styleNames.length; count++ ) {
styleItems[ count ] =
new JCheckBoxMenuItem( styleNames[ count ] );
fontMenu.add( styleItems[ count ] );
styleItems[ count ].addItemListener( styleHandler );
}
// put Font menu in Format menu
formatMenu.add( fontMenu );
// add Format menu to menu bar
bar.add( formatMenu );
// set up label to display text
displayLabel = new JLabel( "Sample Text",
Text", SwingConstants.CENTER );
displayLabel.setForeground( colorValues[ 0 ] );
"Serif",
displayLabel.setFont( new Font( "Serif"
, Font.PLAIN,
Font.PLAIN, 72 ) );
getContentPane().setBackground( Color.CYAN );
getContentPane().add( displayLabel, BorderLayout.CENTER );
setSize( 500,
500, 200 );
setVisible( true );
} // end constructor
Paulo André Castro
39
{
MenuTest application = new MenuTest();
}
if ( colorItems[ count ].isSelected() ) {
displayLabel.setForeground( colorValues[ count ] );
break;
break
;
}
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
Instantiate Color JMenu
(submenu of Format JMenu)
JMenu colorMenu = new JMenu( "Color" );
colorMenu.setMnemonic( 'C' );
Paulo André Castro
37
Instantiate Font JMenu
(submenu of Format JMenu)
JMenu fontMenu = new JMenu( "Font" );
fontMenu.setMnemonic( 'n' );
Paulo André Castro
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
JMenu
// create Color submenu
String colors[] = { "Black",
"Black", "Blue",
"Blue", "Red",
"Red", "Green" };
Paulo André Castro
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
// terminate application when user clicks exitItem
{
System.exit( 0 );
When user
}
ITA – Stefanini
POO
40
repaint();
} // end method actionPerformed
} // end class ItemHandler
Invoked when user selects
menu items
// inner class to handle item events from check boxJCheckBoxMenuItem
private class StyleHandler implements ItemListener {
// process font style selections
public void itemStateChanged( ItemEvent e )
{
style = 0;
// check for bold selection
if ( styleItems[ 0 ].isSelected() )
Font.BOLD
BOLD;
style += Font.
BOLD
;
Determine new font style
// check for italic selection
if ( styleItems[ 1 ].isSelected() )
style += Font.ITALIC
Font.ITALIC;
ITALIC;
displayLabel.setFont(
new Font( displayLabel.getFont().getName(), style, 72 ) );
Paulo André Castro
POO
ITA – Stefanini
42
7
206
207
repaint();
208
}
209
210
} // end class StyleHandler
211
212 } // end class MenuTest
Paulo André Castro
Exercício
•
ITA – Stefanini
POO
• Context-sensitive popup menus
– JPopupMenu
– Menu generated depending on which component is accessed
Paulo André Castro
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
POO
ITA – Stefanini
getContentPane().setBackground( Color.WHITE );
// declare a MouseListener for the window that displays
// a JPopupMenu when the popup trigger event occurs
addMouseListener(
// handle mouse press event
public void mousePressed( MouseEvent event )
{
checkForTriggerEvent( event );
}
// handle mouse release event
public void mouseReleased( MouseEvent event )
{
checkForTriggerEvent( event );
}
Paulo André Castro
POO
Determine whether popuptrigger event occurred
when user presses or
releases mouse button
ITA – Stefanini
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
47
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
ITA – Stefanini
POO
44
// Fig. 4.10: PopupTest.java
// Demonstrating JPopupMenus
import java.awt.*;
public class PopupTest extends JFrame {
private JRadioButtonMenuItem items[];
private final Color colorValues[] =
Color.BLUE,
Color.YELLOW,
{ Color.BLUE
, Color.YELLOW
, Color.RED };
private JPopupMenu popupMenu;
// set up GUI
public PopupTest()
{
super(
super( "Using JPopupMenus" );
ItemHandler handler = new ItemHandler();
String colors[] = { "Blue",
"Blue", "Yellow",
"Yellow", "Red" };
// set up popup menu and its items
ButtonGroup colorGroup = new ButtonGroup();
popupMenu = new JPopupMenu();
items = new JRadioButtonMenuItem[ 3 ];
Paulo André Castro
45
// construct each menu item and add to popup menu; also
// enable event handling for each menu item
for ( int count = 0; count < items.length; count++ ) {
items[ count ] = new JRadioButtonMenuItem( colors[ count ] );
popupMenu.add( items[ count ] );
colorGroup.add( items[ count ] );
Create JRadioButtonMenuItem
items[ count ].addActionListener( handler );
objects to add to JPopupMenu
}
new MouseAdapter() {
Paulo André Castro
43
4.8 JPopupMenu
Introduza um novo item no Menu File. O item deve ser “Text”, a tecla
mnemônica deve ser ‘T’. Ao ser acionado, o item abre uma caixa de
diálogo que pede ao usuário um novo texto, o qual será utilizado para
modificar o texto apresentado ao centro da janela. Mantendo a cor,
estilo e fonte do texto.
Instantiate JPopupMenu object
ITA – Stefanini
POO
46
// determine whether event should trigger popup menu
private void checkForTriggerEvent( MouseEvent event )
{
if ( event.isPopupTrigger() )
popupMenu.show(
event.getComponent(), event.getX(), event.getY() );
}
Show JPopupMenu if
popup-trigger occurred
} // end anonymous inner clas
); // end call to addMouseListener
setSize( 300,
300, 200 );
setVisible( true );
} // end constructor PopupTest
{
PopupTest application = new PopupTest();
}
Paulo André Castro
POO
ITA – Stefanini
48
8
// private inner class to handle menu item events
private class ItemHandler implements ActionListener {
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
} // end private inner class ItemHandler
} // end class PopupTest
Paulo André Castro
POO
ITA – Stefanini
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
– Windows
– Motif
– Java
UIManager.LookAndFeelInfo looks
•
•
•
// recupera os LookAndFeel instalados
looks=UIManager.getInstalledLookAndFeels();
//muda o LookAndFeel
•
UIManager.setLookAndFeel(look[i]);
Paulo André Castro
POO
ITA – Stefanini
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
// set up button for NORTH panel
button = new JButton( "JButton" );
northPanel.add( button );
// set up combo box for NORTH panel
comboBox = new JComboBox( strings );
northPanel.add( comboBox );
// create array for radio buttons
radio = new JRadioButton[ strings.length ];
// set up panel for SOUTH of BorderLayout
JPanel southPanel = new JPanel();
southPanel.setLayout( new GridLayout( 1, radio.length ) );
// set up radio buttons for SOUTH panel
group = new ButtonGroup();
ItemHandler handler = new ItemHandler();
POO
ITA – Stefanini
53
POO
ITA – Stefanini
50
// Fig. 4.11: LookAndFeelDemo.java
// Changing the look and feel.
import java.awt.*;
public class LookAndFeelDemo extends JFrame {
private final String strings[] = { "Metal",
"Metal", "Motif",
"Motif", "Windows" };
private UIManager.LookAndFeelInfo looks[];
private JRadioButton radio[];
private ButtonGroup group;
Hold installed look-and-feel
private JButton button;
private JLabel label;
private JComboBox comboBox;
information
// set up GUI
public LookAndFeelDemo()
{
super(
super
( "Look and Feel Demo" );
// set up panel for NORTH of BorderLayout
JPanel northPanel = new JPanel();
northPanel.setLayout( new GridLayout( 3, 1, 0, 5 ) );
Paulo André Castro
51
// set up label for NORTH panel
label = new JLabel( "This is a Metal looklook-andand-feel",
feel",
SwingConstants.CENTER );
northPanel.add( label );
Paulo André Castro
Paulo André Castro
49
• É possível mudar a aparência de sua aplicação
Swing em tempo de execução
•
• Altere o código do exemplo anterior para incluir
as opções Green, Black e White, no pop-up Menu
e que ao serem selecionadas alterem a cor de
fundo da janela para a cor correspondente
Determine which
JRadioButtonMenuItem was selected,
then set window background color
4.9 Pluggable Look-and-Feel
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Exercício
Invoked when user selects
// process menu item selections
JRadioButtonMenuItem
{
// determine which menu item was selected
for ( int i = 0; i < items.length; i++ )
if ( event.getSource() == items[ i ] ) {
getContentPane().setBackground( colorValues[ i ] );
return;
return
;
}
}
POO
ITA – Stefanini
52
ITA – Stefanini
54
for ( int count = 0; count < radio.length; count++ ) {
radio[ count ] = new JRadioButton( strings[ count ] );
radio[ count ].addItemListener( handler );
group.add( radio[ count ] );
southPanel.add( radio[ count ] );
}
// attach NORTH and SOUTH panels to content pane
container.add( northPanel, BorderLayout.NORTH );
container.add( southPanel, BorderLayout.SOUTH );
// get installed looklook-andand-feel information
looks = UIManager.getInstalledLookAndFeels();
setSize( 300,
300, 200 );
setVisible( true );
radio[ 0 ].setSelected( true );
} // end constructor LookAndFeelDemo
// use UIManager to change looklook-andand-feel of GUI
private void changeTheLookAndFeel( int value )
{
Paulo André Castro
POO
9
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
// change look and feel
try {
UIManager.setLookAndFeel( looks[ value ].getClassName() );
SwingUtilities.updateComponentTreeUI( this );
}
// process problems changing look and feel
catch ( Exception exception ) {
exception.printStackTrace();
}
Change look-and-feel
}
101
if ( radio[ count ].isSelected() ) {
102
label.setText( "This is a " +
103
strings[ count ] + " looklook-andand-feel" );
104
comboBox.setSelectedIndex( count );
105
changeTheLookAndFeel( count );
106
}
107
}
108
109
} // end private inner class ItemHandler
110
111 } // end class LookAndFeelDemo
{
LookAndFeelDemo application = new LookAndFeelDemo();
}
// private inner class to handle radio button events
private class ItemHandler implements ItemListener {
// process user's looklook-andand-feel selection
public void itemStateChanged( ItemEvent event )
{
for ( int count = 0; count < radio.length; count++ )
Paulo André Castro
POO
ITA – Stefanini
Paulo André Castro
55
ITA – Stefanini
POO
56
4.10 JDesktopPane and JInternalFrame
Internal Frames
Minimize
Maximize Close
• Multiple document interface
– Main (parent) window
– Child windows
– Switch freely among documents
Minimized internal frames
Paulo André Castro
POO
ITA – Stefanini
Paulo André Castro
57
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Paulo André Castro
POO
ITA – Stefanini
59
Position the mouse over any corner of
a child window to resize the window (if
resizing is allowed).
POO
ITA – Stefanini
58
// Fig. 4.12: DesktopTest.java
// Demonstrating JDesktopPane.
import java.awt.*;
public class DesktopTest extends JFrame {
private JDesktopPane theDesktop;
Manages JInternalFrame child
windows displayed in JDesktopPane
// set up GUI
public DesktopTest()
{
super(
super
( "Using a JDesktopPane" );
// create menu bar, menu and menu item
JMenuBar bar = new JMenuBar();
JMenu addMenu = new JMenu( "Add" );
JMenuItem newFrame = new JMenuItem( "Internal Frame" );
addMenu.add( newFrame );
bar.add( addMenu );
setJMenuBar( bar );
// set up desktop
theDesktop = new JDesktopPane();
getContentPane().add( theDesktop );
Paulo André Castro
POO
ITA – Stefanini
60
10
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
// set up listener for newFrame menu item
newFrame.addActionListener(
Handle event when user
selects JMenuItem
// display new internal window
public void actionPerformed( ActionEvent event ) {
Invoked when user
selects JMenuItem
// create internal frame
JInternalFrame frame = new JInternalFrame(
Frame",
"Internal Frame"
, true,
true, true,
true, true,
true, true );
// attach panel to internal frame content pane
Container container = frame.getContentPane();
MyJPanel panel = new MyJPanel();
container.add( panel, BorderLayout.CENTER );
Create JInternalFrame
JPanels can be added
to JInternalFrames
// set size internal frame to size of its contents
frame.pack();
Use preferred
size for window
// attach internal frame to desktop and show it
theDesktop.add( frame );
frame.setVisible( true );
}
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
setSize( 600,
600, 460 );
setVisible( true );
{
DesktopTest application = new DesktopTest();
}
} // end class DesktopTest
// class to display an ImageIcon on a panel
class MyJPanel extends JPanel {
private ImageIcon imageIcon;
"yellowflowers.png",
private String[] images = { "yellowflowers.png"
, "purpleflowers.png",
"purpleflowers.png",
"redflowers.png",
"redflowers2.png",
"redflowers.png"
, "redflowers2.png"
, "lavenderflowers.png" };
// load image
public MyJPanel()
{
Paulo André Castro
POO
ITA – Stefanini
Paulo André Castro
61
80
int randomNumber = ( int ) ( Math.random() * 5 );
81
imageIcon = new ImageIcon( images[ randomNumber ] );
82
}
83
84
// display imageIcon on panel
85
86
{
87
// call superclass paintComponent method
88
super.paintComponent( g );
89
90
// display icon
91
imageIcon.paintIcon( this,
this, g, 0, 0 );
92
}
93
// return image dimensions
94
95
96
{
97
return new Dimension( imageIcon.getIconWidth(),
98
imageIcon.getIconHeight() );
99
}
100
101 } // end class MyJPanel
Paulo André Castro
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
POO
ITA – Stefanini
Create a
JTabbedPane
the first panel
// set up panel2 and add it to JTabbedPane
JLabel label2 = new JLabel( "panel two",
two", SwingConstants.CENTER );
JPanel panel2 = new JPanel();
Add the
panel2.setBackground( Color.YELLOW );
panel2.add( label2 );
Two",
null,
tabbedPane.addTab( "Tab Two"
, null
, panel2, "Second Panel" );
second panel
ITA – Stefanini
Paulo André Castro
63
{
POO
ITA – Stefanini
64
– One layer visible at a time
– Access each layer via a tab
– JTabbedPane
// set up pane11 and add it to JTabbedPane
JLabel label1 = new JLabel( "panel one",
one", SwingConstants.CENTER );
Add
panel1.add( label1 );
tabbedPane.addTab( "Tab One",
One", null,
null, panel1, "First Panel" );
Paulo André Castro
62
• Arranges GUI components into layers
// set up GUI
public JTabbedPaneDemo()
{
super(
super
( "JTabbedPane Demo " );
// create JTabbedPane
JTabbedPane tabbedPane = new JTabbedPane();
ITA – Stefanini
4.11 JTabbedPane
// Fig. 4.13: JTabbedPaneDemo.java
// Demonstrating JTabbedPane.
import java.awt.*;
public class JTabbedPaneDemo extends JFrame
POO
65
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
POO
// set up panel3 and add it to JTabbedPane
JLabel label3 = new JLabel( "panel three" );
panel3.setLayout( new BorderLayout() );
panel3.add( new JButton( "North" ), BorderLayout.NORTH );
panel3.add( new JButton( "West" ), BorderLayout.WEST );
panel3.add( new JButton( "East" ), BorderLayout.EAST );
panel3.add( new JButton( "South" ), BorderLayout.SOUTH );
panel3.add( label3, BorderLayout.CENTER );
Three",
null,
tabbedPane.addTab( "Tab Three"
, null
, panel3, "Third Panel" );
// add JTabbedPane to container
getContentPane().add( tabbedPane );
Add the third panel
setSize( 250,
250, 200 );
setVisible( true );
{
JTabbedPaneDemo tabbedPaneDemo = new JTabbedPaneDemo();
tabbedPaneDemo.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}
} // end class CardDeck
Paulo André Castro
POO
ITA – Stefanini
66
11
4.12 Layout Managers: BoxLayout e
GridBagLayout
BoxLayout Layout Manager
• Dois Novos Layout Managers
• BoxLayout
– BoxLayout:
– Arranges GUI components
• Permite que os componentes GUI sejam arranjados da esquerda
para direita ou de cima para baixo em um container. A classe
Box declara um container com BoxLayout como Layout padrão e
provê métodos estáticos para criar Box com BoxLayout vertical
ou horizontal
• Horizontally along x-axis
• Vertically along y-axis
– GridBagLayout:
• Similar a GridLayout, porém cada componente pode variar de
tamnho e os componentes podem ser adicionados em qualquer
ordem.
Paulo André Castro
ITA – Stefanini
POO
Paulo André Castro
67
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Paulo André Castro
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
ITA – Stefanini
POO
// create strut and add buttons to Box vertical1 Add
for ( int count = 0; count < SIZE;
SIZE; count++ ) {
vertical1.add( Box.createVerticalStrut( 25 ) );
vertical1.add( new JButton( "Button " + count ) );
}
three JButtons to vertical Box
Strut guarantees space
between components
// create horizontal glue and add buttons to Box horizontal2
Add three JButtons to
SIZE; count++ ) {
horizontal Box
horizontal2.add( Box.createHorizontalGlue() );
horizontal2.add( new JButton( "Button " + count ) );
Glue
guarantees expandable
}
space between components
// create rigid area and add buttons to Box vertical2
SIZE; count++ ) {
Add three
to vertical
12,
8 ) ) );
vertical2.add( Box.createRigidArea( new Dimension(
12, JButtons
vertical2.add( new JButton( "Button " + count ) );
}
Rigid area guarantees
Box
fixed component size
// create vertical glue and add buttons to panel
JPanel panel = new JPanel();
panel.setLayout( new BoxLayout( panel, BoxLayout.Y_AXIS
BoxLayout.Y_AXIS ) );
SIZE; count++ ) {
panel.add( Box.createGlue() );
panel.add( new JButton( "Button " + count ) );
}
Paulo André Castro
POO
ITA – Stefanini
71
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
68
// Fig. 4.15: BoxLayoutDemo.java
// Demonstrating BoxLayout.
import java.awt.*;
public class BoxLayoutDemo extends JFrame {
// set up GUI
public BoxLayoutDemo()
{
super(
super
( "Demostrating BoxLayout" );
// create Box containers with BoxLayout
Box horizontal1 = Box.createHorizontalBox();
Box vertical1 = Box.createVerticalBox();
Box horizontal2 = Box.createHorizontalBox();
Box vertical2 = Box.createVerticalBox();
Create Boxes
final int SIZE = 3; // number of buttons on each Box
Add three JButtons to
horizontal Box
// add buttons to Box horizontal1
SIZE; count++ )
horizontal1.add( new JButton( "Button " + count ) );
Paulo André Castro
69
ITA – Stefanini
POO
ITA – Stefanini
POO
// create a JTabbedPane
JTabbedPane tabs = new JTabbedPane(
JTabbedPane.TOP
TOP,
JTabbedPane.
TOP
, JTabbedPane.SCROLL_TAB_LAYOUT
JTabbedPane.SCROLL_TAB_LAYOUT );
70
Create a JTabbedPane
to hold the Boxes
// place each container on tabbed pane
tabs.addTab( "Horizontal Box",
Box", horizontal1 );
tabs.addTab( "Vertical Box with Struts",
Struts", vertical1 );
tabs.addTab( "Horizontal Box with Glue",
Glue", horizontal2 );
Areas",
tabs.addTab( "Vertical Box with Rigid Areas"
, vertical2 );
Glue",
tabs.addTab( "Vertical Box with Glue"
, panel );
getContentPane().add( tabs );
// place tabbed pane on content pane
setSize( 400,
400, 220 );
setVisible( true );
{
BoxLayoutDemo application = new BoxLayoutDemo();
}
} // end class BoxLayoutDemo
Paulo André Castro
POO
ITA – Stefanini
72
12
Fig. 4.16
GridBagLayout Layout Manager
Designing a GUI that will use
GridBagLayout
• GridBagLayout
– Flexible GridBagLayout
• Components can vary in size
• Components can occupy multiple rows and columns
• Components can be added in any order
Column
0
– Uses GridBagConstraints
Fig. 4.17
GridBagConstraints
field
fill
1
ITA – Stefanini
POO
2
Paulo André Castro
73
POO
ITA – Stefanini
74
POO
ITA – Stefanini
76
Description
gridx
Resize the component in specified direction (NONE, HORIZONTAL,
VERTICAL, BOTH) when the display area is larger than the
component.
The column in which the component will be placed.
gridy
The row in which the component will be placed.
gridwidth
The number of columns the component occupies.
gridheight
The number of rows the component occupies.
weightx
The portion of extra space to allocate horizontally. The grid slot can
become wider when extra space is available.
weighty
The portion of extra space to allocate vertically. The grid slot can
become taller when extra space is available.
GridBagLayout with the
weights set to zero
ITA – Stefanini
POO
public class GridBagDemo extends JFrame {
private Container container;
private GridBagLayout layout;
private GridBagConstraints constraints;
// set up GUI
public GridBagDemo()
{
super(
super
( "GridBagLayout" );
container = getContentPane();
layout = new GridBagLayout();
container.setLayout( layout );
Set GridBagLayout
as layout manager
// instantiate gridbag constraints
constraints = new GridBagConstraints();
// create GUI components
JTextArea textArea1 = new JTextArea( "TextArea1",
"TextArea1", 5, 10 );
"TextArea2",
, 2, 2 );
JTextArea textArea2 = new JTextArea( "TextArea2"
POO
Used to determine
component location
and size in grid
ITA – Stefanini
Paulo André Castro
75
// Fig. 4.19: GridBagDemo.java
// Demonstrating GridBagLayout.
import java.awt.*;
Paulo André Castro
3
GridBagConstraints fields
Paulo André Castro
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
2
Row
• Specifies how component is placed in GridBagLayout
Paulo André Castro
1
0
77
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
String names[] = { "Iron"
"Iron",
, "Steel",
"Steel", "Brass" };
JComboBox comboBox = new JComboBox( names );
JTextField textField = new JTextField(
JButton button1 = new JButton( "Button
"TextField" );
1" );
2" );
3" );
If user resizes Container,
first JTextArea is filled
entire allocated area in grid
First JTextArea spans
// weightx and weighty for textArea1 are both 0: the default
one row and three columns
// anchor for all components is CENTER: the default
constraints.fill = GridBagConstraints.BOTH;
GridBagConstraints.BOTH;
If user resizes Container, first
addComponent( textArea1, 0, 0, 1, 3 );
JButton fills horizontally in grid
// weightx and weighty for button1 are both 0: the default
constraints.fill = GridBagConstraints.HORIZONTAL;
GridBagConstraints.HORIZONTAL;
First
addComponent( button1, 0, 1, 2, 1 );
JButton spans two
rows and one column
// weightx and weighty for comboBox are both 0: the default
// fill is HORIZONTAL
addComponent( comboBox, 2, 1, 2, 1 );
// button2
constraints.weightx = 1000;
1000; // can grow wider
// can grow taller
constraints.weighty = 1;
constraints.fill = GridBagConstraints.BOTH
;
Paulo André Castro
POO
If user resizes Container,
second JButton fills extra space
ITA – Stefanini
78
13
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
// fill is BOTH for button3
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
// weightx and weighty for textField are both 0, fill is BOTH
addComponent( textField, 3, 0, 2, 1 );
// weightx and weighty for textArea2 are both 0, fill is BOTH
addComponent( textArea2, 3, 2, 1, 1 );
setSize( 300,
300, 150 );
setVisible( true );
} // end constructor GridBagDemo
// set constraints and add component
layout.setConstraints( component, constraints );
container.add( component );
}
{
GridBagDemo application = new GridBagDemo();
}
} // end class GridBagDemo
// method to set constraints on
private void addComponent( Component component,
int row, int column, int width, int height )
{
// set gridx and gridy
constraints.gridx = column;
constraints.gridy = row;
Paulo André Castro
ITA – Stefanini
POO
• Constants RELATIVE and REMAINDER
– Usados em substituição a gridx e gridy
– RELATIVE
• Especifica proximidade necessária ao último componente adicionado
constraints.gridwidth = GridBagConstraints.RELATIVE;
• layout.setConstraints( component, constraints );
• Container.add(component);
– REMAINDER
• Especifica que o componente deve ser o último da linha ou coluna
• constraints.gridwidth = GridBagConstraints.REMAINDER;
Paulo André Castro
ITA – Stefanini
POO
String fonts[] = { "Serif",
"Serif", "Monospaced" };
JList list = new JList( fonts );
String names[] = { "zero",
"zero", "one",
"one", "two",
"two", "three",
"three", "four" };
JButton buttons[] = new JButton[ names.length ];
for ( int count = 0; count < buttons.length; count++ )
buttons[ count ] = new JButton( names[ count ] );
// buttons[0] -- weightx and weighty are 1: fill is BOTH
constraints.gridwidth = 1;
addComponent( buttons[ 0 ] );
GridBagConstraints.RELATIVE;
Paulo André Castro
POO
last
row
Place button[0] as first
component in second row
Place button[1] right
next to button[0]
ITA – Stefanini
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
83
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
ITA – Stefanini
POO
80
// Fig. 4.20: GridBagDemo2.java
// Demonstrating GridBagLayout constants.
import java.awt.*;
public class GridBagDemo2 extends JFrame {
private GridBagLayout layout;
private GridBagConstraints constraints;
private Container container;
// set up GUI
public GridBagDemo2()
{
super(
super
( "GridBagLayout" );
container = getContentPane();
layout = new GridBagLayout();
container.setLayout( layout );
Set GridBagLayout
as layout manager
// instantiate gridbag constraints
constraints = new GridBagConstraints();
Used to determine
component location
and size in grid
// create GUI components
String metals[] = { "Copper",
"Copper", "Aluminum",
"Aluminum", "Silver" };
JComboBox comboBox = new JComboBox( metals );
Paulo André Castro
81
JTextField textField = new JTextField( "TextField" );
// define GUI component constraints for textField Specify textField as
(only) component in first
constraints.fill = GridBagConstraints.BOTH
;
GridBagConstraints.REMAINDER;
constraints.gridwidth = GridBagConstraints.REMAINDER
;
addComponent( textField );
Paulo André Castro
79
GridBagConstraints Constants RELATIVE
and REMAINDER
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
// set gridwidth and gridheight
constraints.gridwidth = width;
constraints.gridheight = height;
ITA – Stefanini
POO
constraints.gridwidth = GridBagConstraints.REMAINDER;
// comboBox -- weightx is 1: fill is BOTH
;
addComponent( comboBox );
// buttons[3] -- weightx is 1: fill is BOTH
;
82
Place button[2] right
next to button[1]
Specify comboBox as last
(only) component in third row
Specify buttons[3] as last
(only) component in fourth row
GridBagConstraints.RELATIVE;
Place
button[4] as first
component in fifth row
// list -- weightx and weighty are 1: fill is BOTH
constraints.gridwidth = GridBagConstraints.REMAINDER;
addComponent( list );
Specify list as last
component in fifth row
setSize( 300,
300, 200 );
setVisible( true );
}
// end constructor
Paulo André Castro
POO
ITA – Stefanini
84
14
81
82
83
84
85
86
87
88
89
90
91
92
93
94
// add a Component to the container
private void addComponent( Component component )
{
layout.setConstraints( component, constraints );
container.add( component );
// add component
}
{
GridBagDemo2 application = new GridBagDemo2();
}
}
// end class GridBagDemo2
Paulo André Castro
POO
ITA – Stefanini
85
15

Aula 4

Transcrição

Documentos relacionados