1. Generic (JComponent) services
2. Atomic Swing components
3. Containers
4. Drawing primitives
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Component Services
All (?) Swing-components, except top-level containers,
inherit from JComponent, Container and Component
Main services
Customizing Component Appearance
• get/set foreground/background colour
• get/set font
• get/set border
• specify/get opaqueness
Setting Component State
• setting tooltips
• (in)activate component
• control visibility
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Component Services
Handling Events
• (de)registration of event listeners
• check if pixel is part of component
• check to which component pixel belongs
Painting Components
• repaint() : request to repaint the components
• revalidate() : request to lay out again component
• paintComponent() : overridden method for custom drawing
Containment Hierarchy
• add/remove components from container
• get contained components in container
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Component Services
Laying Out Components
• get/set preferred, maximum and minimum sizes
• get set alignment mode
• get/set layoutmanager
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Examples :
Setting Tooltips
JComponent :
void setToolTipText(String)
class ToolTip extends JFrame {
JButton change = new JButton("Switch");
ToolTip(String title) {
super(title);
Container cp=getContentPane();
cp.setLayout(new FlowLayout());
change.setToolTipText("Press to switch");
cp.add(change);
}
public class TooltipTest {
}
public static void main(String[] args) {
ToolTip app=new ToolTip("Setting tooltips");
app.setSize(200,100);
app.setVisible(true);
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
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Examples :
Controlling Look and Feel
Format
try {
UIManager.setLookAndFeel( ……);
} catch(Exception e) { }
Look and feel options
• swing : default
or : getCrossPlatformLookAndFeelClassName()
• motif : “com.sun.java.swing.plaf.motif.MotifLookAndFeel”
• system : getSystemLookAndFeelClassName()
• before instantiating visible components
• don’t change L&F during program execution ! (possible but difficult)
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Examples :
Controlling Look and Feel
class LF extends JFrame {
JButton change = new JButton("Switch");
LF(String title) {
super(title);
Container cp=getContentPane();
cp.setLayout(new FlowLayout());
change.setToolTipText("Press to switch");
cp.add(change);
}
} public class LookAndFeelTest {
}
public static void main(String[] args) {
try {
// UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
} catch(Exception e) { }
LF app=new LF("Trying different L&F's");
app.setSize(200,100);
app.setVisible(true);
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
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Examples :
Adding Borders
How ?
• Construct a Border-object
• invoke setBorder(…) on the relevant JComponent
Types of borders
• TitledBorder
• EtchedBorder
• EmptyBorder
• BevelBorder
• LineBorder
• SoftBevelBorder
• MatteBorder
• CompoundBorder
Inherit from AbstractBorder,
Implementing the Border interface
import javax.swing.border.*;
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Examples :
Adding Borders
class BorderT extends JFrame {
private static int num=5;
private JButton[] b=new JButton[num];
public BorderT(String title) {
super(title);
for(int i=0;i<b.length;i++) {
b[i]=new JButton("Button "+i);
}
b[1].setBorder(new TitledBorder("Border Title"));
b[2].setBorder(new EtchedBorder());
b[3].setBorder(new LineBorder(Color.red));
b[4].setBorder(new BevelBorder(BevelBorder.RAISED));
getContentPane().setLayout(new FlowLayout());
for(int i=0;i<b.length;i++)
getContentPane().add(b[i]);
}
} // End of class BorderT
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Binary choices
No state
JButton
State
JToggleButton
JRadioButton
JCheckBox
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Multivalued choices
>1 alternative
• JList
• list of buttons
• JMenu
1 alternative at most
• JList (after setting seletion mode)
• JComboBox
• list of buttons added to ButtonGroup
• JMenu (JRadioButtonMenuItem, JCheckBoxMenuItem)
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Multivalued choices
JList
JComboBox (non-editable)
JMenu
JComboBox (editable)
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Multivalued choices
“continuous” value
JSlider
Fires ChangeEvents when value changes
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Multivalued choices
class SliderT extends JFrame {
private JSlider s=new JSlider(0,100,70);
private JLabel output=new JLabel("Value = 70");
public SliderT(String title) {
super(title);
Container cp=getContentPane();
s.setPaintTicks(true);
s.setMinorTickSpacing(5);
s.setMajorTickSpacing(20);
cp.setLayout(new GridLayout(2,1));
cp.add(s);
cp.add(output);
ChangeListener c=new ChangeListener() {
public void stateChanged(ChangeEvent e) {
output.setText("Value = "+s.getValue());
}
};
s.addChangeListener(c);
}
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} // End of class SliderT
Text
1 line
• JTextField
>= 1 line
• JTextArea (plain text)
• JEditorPane (styled text)
• JTextPane (styled text)
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Text
JTextArea
JTextPane
• several styles
• embedded pictures
• displays HTML
[Sun, Swing Tutorial]
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Output only ...
• JLabel
• JProgressBar
• Tool tips
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Output only ...
class ProgressT extends JFrame {
private JProgressBar pb=new JProgressBar(0,20);
private JButton start=new JButton("(Re)Start");
private JButton next=new JButton("Next");
private int count=0;
public ProgressT(String title) {
super(title);Container cp=getContentPane();
cp.setLayout(new GridLayout(3,1));
cp.add(pb);cp.add(next);cp.add(start);
pb.setStringPainted(true);
next.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
pb.setValue(++count);if(count==20) next.setEnabled(false);
}
});
start.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
count=0;pb.setValue(0);next.setEnabled(true);
}
});
}
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} // End of class ProgressT
Formatted Information
• JColorChooser
• getColor returns
color choosen
• class can create
dialog
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Formatted Information
• JColorChooser
class ColorT extends JFrame {
private JColorChooser cc=new JColorChooser();
public ColorT(String title) {
super(title);
Container cp=getContentPane();
cp.add(cc,BorderLayout.CENTER);
}
} // End of class ColorT
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Formatted Information
• JFileChooser
• JTable
• JTree
[Sun, Swing Tutorial]
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Intermediate Containers
• JPanel
• used to group components
• behavior inherited from Container
• LayoutManager
• methods to add/remove Jcomponents
• invisible by default
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Intermediate Containers
class PanelT extends JFrame {
private JPanel left=new JPanel();
private JPanel right=new JPanel();
public PanelT(String title) {
super(title);Container cp=getContentPane();
cp.setLayout(new GridLayout(1,2));
left.setLayout(new GridLayout(3,1));
right.setLayout(new GridLayout(3,1));
left.setBorder(new TitledBorder("Left Panel"));
right.setBorder(new TitledBorder("Right Panel"));
left.add(new JButton("A"));
left.add(new JSlider(0,100,75));
left.add(new JCheckBox("Check me ..."));
cp.add(left);
right.add(new JToggleButton("B"));
right.add(new JProgressBar(0,100));
right.add(new JRadioButton("Click me ..."));
cp.add(right);
}
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} // End of class PanelT
Intermediate Containers
• JScrollPane
Adds scroll bars (if needed) to any JComponent
…
JScrollPane scrollLeft=new JScrollPane(left);
cp.add(scrollLeft);
...
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Intermediate Containers
• JTabbedPane
Used to realize hierarchy and
save space
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Intermediate Containers
class TabbedPaneT extends JFrame {
private JPanel left=new JPanel();
private JPanel right=new JPanel();
public TabbedPaneT(String title) {
super(title);
Container cp=getContentPane();
JTabbedPane tp=new JTabbedPane();
left.setLayout(new GridLayout(3,1));
right.setLayout(new GridLayout(3,1));
left.add(new JButton("A"));
left.add(new JSlider(0,100,75));
left.add(new JCheckBox("Check me ..."));
right.add(new JToggleButton("B"));
right.add(new JProgressBar(0,100));
right.add(new JRadioButton("Click me ..."));
tp.addTab("Left",left);
tp.addTab("Right",right);
cp.add(tp);
}
} // End of class TabbedPaneT
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Intermediate Containers
• JSplitPane
Used to divide area in 2, allowing splitting
ratio to vary
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Intermediate Containers
class SplitPaneT extends JFrame {
private JPanel left=new JPanel();
private JPanel right=new JPanel();
public SplitPaneT(String title) {
super(title);
Container cp=getContentPane();
left.setLayout(new GridLayout(3,1));
right.setLayout(new GridLayout(3,1));
left.add(new JButton("A"));
left.add(new JSlider(0,100,75));
left.add(new JCheckBox("Check me ..."));
right.add(new JToggleButton("B"));
right.add(new JProgressBar(0,100));
right.add(new JRadioButton("Click me ..."));
JSplitPane sp=new JSplitPane(
JSplitPane.HORIZONTAL_SPLIT,left,right);
sp.setOneTouchExpandable(true);
cp.add(sp);
}
} // End of class SplitPaneT
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Intermediate Containers
• JToolBar
Graphical presentation of menu
Icon based
[Sun, Swing Tutorial]
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Top-level Containers
Can have menu bars
• JFrame
-> Base class for stand alone applications
• JApplet
-> Base class for applets
• JDialog
-> Can pop up from other Container
-> no exit when Dialog closes
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Concept
• every JComponent has a paintComponent method
responsible of drawing the component on the screen
• paintComponent is automatically called by container
object
In practice
(1) define a class extending JPanel
(2) define a drawing method with signature
public void paintComponent(Graphics g) {
super.paintComponent(g);
// drawing operations
}
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(3) make an object of this class, and add it to some container
Graphical Context
“physical” area where component can be painted
pixel (“picture element”)
(0,0)
(0,200)
(500,0)
(500,200)
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Drawing Primitives
Pen Color
Operations
• public Color getColor()
• public void setColor(Color c)
g.setColor(Color.green);
Lines
(x2,y2)
(x1,y1)
Graphics object
g.drawLine(x1,y1,x2,y2);
• public abstract void drawLine(int x1, int y1, int x2, int y2)
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Drawing Primitives
Rectangles
(x1,y1)
b
h
g.drawRect(x1,y1,b,h);
g.fillRect(x1,y1,b,h);
• public abstract void drawRect(int x1, int y1, int b, int h)
• public abstract void fillRect(int x1, int y1, int b, int h)
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Drawing Primitives
Ovals
(x1,y1)
b
h
g.drawOval(x1,y1,b,h);
g.fillOval(x1,y1,b,h);
• public abstract void drawOval(int x1, int y1, int b, int h)
• public abstract void fillOval(int x1, int y1, int b, int h)
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Drawing Primitives
Arcs
(x1,y1)
b
a
h
s
g.drawArc(x1,y1,b,h,s,a);
g.fillArc(x1,y1,b,h,s,a);
• public abstract void drawArc(int x1, int y1, int b, int h,int s, int a)
• public abstract void fillArc(int x1, int y1, int b, int h,int s, int a)
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Drawing Primitives
Polygons
(x[1],y[1])
(x[0],y[0])
(x[2],y[2])
g.drawPolyline(x,y,4);
(x[3],y[3])
g.drawPolygon(x,y,4);
g.fillPolygon(x,y,4);
• public abstract void drawPolyline(int[] x, int[] y, int n)
• public abstract void drawPolygon(int[] x, int[] y, int n)
• public abstract void fillPPolygon(int[] x, int[]y, int n)
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Example
class MyDrawing extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.red);
g.drawLine(0,0,100,100);
g.setColor(Color.blue);
g.drawOval(50,50,150,150);
}
} // End of class MyDrawing
class DrawingT extends JFrame {
private MyDrawing d=new MyDrawing();
public DrawingT(String title) {
super(title);
Container cp=getContentPane();
cp.add(d);
}
} // End of class DrawingT
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Drawing Primitives
Text
Font
• public Font getFont()
• public void setFont(Font f)
Draw
(x,y)
Message
g.drawString(“Message”,x,y);
• public abstract void drawString(String s, int x, int y)
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Specifying Fonts
Font characteristics
type
style
Options :
• Dialog
• DialogInput
• Monospaced
• Serif
• SansSerif
• Symbol
PLAIN
BOLD
ITALIC
size
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Specifying Fonts
Constructor
• public Font(String name, int style, int size)
Examples
Font f1 = new Font(“Dialog”,Font.PLAIN,10);
Font f2 = new Font(“Serif”, Font.BOLD, 14);
Font f3 = new Font(“Dialog”,Font.BOLD||Font.ITALIC, 20);
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