Copyright 2003 Mudra Services1 SWING - JTabbedPane Helps stack pages of information into a single point of reference If information cannot be laid out

Copyright 2003 Mudra Services

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SWING - JTabbedPane

Helps stack pages of information into a single point of reference

If information cannot be laid out in one page, it can be split into multiple tabs

Not available in AWT But somewhat similar to CardLayout

A lot of text editors use it to show open files. Can work with multiple files simultaneously.


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SWING - JTabbedPane

Clicking on Name tab


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SWING - JTabbedPane

Clicking on Address tab


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SWING - JTabbedPane

Clicking on Other tab


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SWING - JTabbedPane

package tabbedexample;import java.awt.*;import javax.swing.*;

public class TabbedExample extends JFrame {

public TabbedExample() { // creation of the tabbed pane object JTabbedPane pane = new JTabbedPane();

// create the 3 panels JPanel panel1 = createPanel1(); JPanel panel2 = createPanel2(); JPanel panel3 = createPanel3();


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SWING - JTabbedPane

// add the panels to the pane pane.addTab("Name",panel1); pane.addTab("Address",panel2); pane.addTab("Other",panel3); pane.setSelectedComponent(panel1);

// create button panel JPanel buttons = new JPanel(); buttons.setLayout(new FlowLayout(FlowLayout.RIGHT,5,5)); buttons.add(new JButton("Submit"));

// add the panel to top panel getContentPane().add(pane,BorderLayout.CENTER); getContentPane().add(buttons,BorderLayout.SOUTH); }


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SWING - JTabbedPane

// create panel 1 private JPanel createPanel1() { JPanel panel = new JPanel(); panel.setLayout(new FlowLayout(FlowLayout.CENTER)); panel.setBorder(BorderFactory.createEtchedBorder()); panel.add(new JLabel("Name: ")); panel.add(new JTextField(30)); return(panel); }


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SWING - JTabbedPane

// create panel 2 private JPanel createPanel2() { JPanel panel = new JPanel(); panel.setLayout(new BorderLayout()); panel.setBorder(BorderFactory.createEtchedBorder()); panel.add("Center",new JTextArea()); return(panel); }


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SWING - JTabbedPane

// create panel 3 private JPanel createPanel3() { JPanel panel = new JPanel(); panel.setLayout(new BoxLayout(panel,BoxLayout.Y_AXIS)); panel.setBorder(BorderFactory.createEtchedBorder()); panel.add(new JCheckBox("Check if you are still in school")); panel.add(new JCheckBox("Check if you have no medical

problems")); return(panel); }


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SWING - JTabbedPane

// create main program public static void main(String[] args) { TabbedExample tabbedExample = new

TabbedExample(); tabbedExample.pack(); tabbedExample.setVisible(true); }

}


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SWING - JTabbedPane

Remove Tabs pane.removeTabAt(index)

Selecting pages pane.setSelectedIndex(index)

Adding images to tabs pane.addTab(“text”,icon,panel)

Enabling/Disabling tab pane.setEnabledAt(2,false)

Page selection changes can be detected by listening to ChangeEvents generated


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SWING - JScrollPane

Used when a panel is too big to be displayed on the screen

A typical example is a text editor where only a part of the text is displayed at a time. Scrollbars are used to scroll the text.

The developer is responsible for only populating the pane.

SWING manages all the repainting, resizing activities associated with the pane


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SWING - JScrollPane

An image being scrolled


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SWING - JScrollPane

package scrollexample;import java.awt.*;import javax.swing.*;

public class ScrollExample extends JFrame {

public ScrollExample() { // set the size of the frame setSize(600,400);

// create a JLabel component Icon image = new ImageIcon("cliff_ib.gif"); JLabel label = new JLabel(image);


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SWING - JScrollPane

// add the jlabel to the scroll pane JScrollPane pane = new JScrollPane(); pane.getViewport().add(label);

// add the scroll pane to the frame getContentPane().add("Center",pane); }

public static void main(String[] args) { ScrollExample scrollExample = new ScrollExample(); scrollExample.setVisible(true); }

}


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SWING - JScrollPane

Control scroll bars pane.setVerticalScrollBarPolicy(

ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); pane.setHorizontalScrollBarPolicy(

ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);

Control the size of scroll bars // changing the size of the scroll bars JScrollBar vBar = pane.getVerticalScrollBar(); Dimension dim = vBar.getSize(); dim.width = 5; vBar.setPreferredSize(dim);


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SWING - JScrollPane

Unit Increment Block Increment The increment size can be changed from

the default by using the Scrollable interface.

Scrollable interface Dimension getPreferredScrollableViewportSize() int getScrollableBlockIncrement() int getScrollableUnitIncrement() boolean getScrollableTracksViewportWidth() boolean getScrollableTracksViewportHeight()


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SWING - JScrollPane

class ScrollableImage extends JLabel implements Scrollable { public ScrollableImage(Icon icon) { super(icon); }

public Dimension getPreferredScrollableViewportSize() { return(new Dimension(300,300)); }

public int getScrollableBlockIncrement(Rectangle visibleRect ,int orientation,int direction) { return(20); }


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SWING - JScrollPane

public int getScrollableUnitIncrement(Rectangle visibleRect ,int orientation,int direction) { return(20); }

public boolean getScrollableTracksViewportWidth() { return(false); }

public boolean getScrollableTracksViewportHeight() { return(false); } }


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SWING - JSplitPane

View two or more pieces of information simultaneously

Resize any panel to view more or less data Orientation

left-to-right top-to-bottom

Text editors usually have split windows to create multiple copies of the same text file. This allows you to look at different parts of the

text document at the same time.


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SWING - JSplitPane

A window split into two panels

Vertical Split


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SWING - JSplitPane

package splitexample;import java.awt.*;import javax.swing.*;public class SplitExample extends JFrame { public SplitExample() {

// create a split pane JSplitPane splitpane

= new JSplitPane(JSplitPane.VERTICAL_SPLIT);

// create the panels JPanel panel1 = createPanel1(); JPanel panel2 = createPanel2();


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SWING - JSplitPane

// add to the split pane splitpane.setTopComponent(panel1); splitpane.setBottomComponent(panel2);

// add splitpane to the frame getContentPane().add(splitpane); }

public static void main(String[] args) { SplitExample splitExample = new SplitExample(); splitExample.pack(); splitExample.setVisible(true); }


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SWING - JSplitPane

// create panel 1 private JPanel createPanel1() { JPanel panel = new JPanel(); panel.setLayout(new BorderLayout()); panel.setBorder(BorderFactory.createEtchedBorder()); panel.add("Center",new JTextArea(5,30)); return(panel); }


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SWING - JSplitPane

// create panel 2 private JPanel createPanel2() { JPanel panel = new JPanel(); panel.setLayout(new BoxLayout(panel,BoxLayout.Y_AXIS)); panel.setBorder(BorderFactory.createEtchedBorder()); panel.add(new JCheckBox("Check if you are still in school")); panel.add(new JCheckBox("Check if you have no medical

problems")); return(panel); }

} // end


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SWING - JSplitPane

One split pane can be nested into another split pane for a more complex interface

Setting the divider size splitpane.setDividerSize(20)

A divider movement can be detected by using the AncestorListener Components of the split pane can implement

it


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SWING - JEditorPane

Extends from the JTextComponent class Ability to display any mime type Can easily create an HTML viewer for

online help Add internet capability to the

application


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SWING - JEditorPane

package editorpaneexample;import java.awt.*;import javax.swing.*;import javax.swing.event.*;import java.net.*;public class EditorPaneExample extends JFrame implements HyperlinkListener { private JEditorPane editorpane;

public EditorPaneExample() { try { setSize(600,600);


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SWING - JEditorPane

// create an editor pane pointing to a URL URL url = new URL("file:///D:/OLDui/index.html"); editorpane = new JEditorPane(url); editorpane.setEditable(false); editorpane.addHyperlinkListener(this);

// wrap the editor pane in a scroll pane JScrollPane scrollpane = new JScrollPane(); scrollpane.getViewport().add(editorpane,BorderLayout.CENTER);

// add the pane to the frame getContentPane().add(scrollpane,BorderLayout.CENTER); } catch (Exception exp) { System.out.println(exp.getMessage()); } }


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SWING - JEditorPane

public void hyperlinkUpdate(HyperlinkEvent event) { if (event.getEventType() ==

HyperlinkEvent.EventType.ACTIVATED) { // User clicked on a URL try { editorpane.setPage(event.getURL()); } catch (Exception exp) { System.out.println("Error :: " + exp.getMessage()); } } }


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SWING - JEditorPane

public static void main(String[] args) { EditorPaneExample editorPaneExample = new

EditorPaneExample(); editorPaneExample.setVisible(true); }

}

Swing handles RTF other than HTML Custom formats can be handled by

setting up custom editor kits


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SWING - Action

Synchronizing the action listeners for toolbars buttons, menu items and popup menu items is a nightmare

Synchronizing enabling/disabling is a problem

Actions are the solution to avoid synchronization and foster code reuse

An action object can be added to a toolbar, menu or a popup menu

Action object can be disabled/enabled


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SWING - Action

Action class should extend from AbstractAction

public class XAction extends AbstractAction {public XAction(String name,ImageIcon image) {

super(name,image);}

public void actionPerformed(ActionEvent event) {// Handle action event for X here

}}


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SWING - Action

Shows the disabled actions


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SWING - Action

package actionexample;import java.awt.*;import javax.swing.*;import java.awt.event.*;public class ActionExample extends JFrame { private JPopupMenu popup = new JPopupMenu();

// Handle right clicks public class MouseHandler extends MouseAdapter { public void mouseReleased(MouseEvent e) { if (e.isPopupTrigger()) { popup.show(e.getComponent(),e.getX(),e.getY()); } } }


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SWING - Action

// Action class for 'New' class NewAction extends AbstractAction { NewAction(String name,ImageIcon icon) { super(name,icon);

}

public void actionPerformed(ActionEvent e) { // handle new action } }


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SWING - Action

// Action class for 'Save' class SaveAction extends AbstractAction { SaveAction(String name,ImageIcon icon) { super(name,icon);

}

public void actionPerformed(ActionEvent e) { // handle save action } }


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SWING - Action

// Action class for 'SaveAll' class SaveAllAction extends AbstractAction { SaveAllAction(String name,ImageIcon icon) { super(name,icon);

}

public void actionPerformed(ActionEvent e) { // handle saveAll action } }


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SWING - Action

public ActionExample() { setSize(300,300); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Action newAction = new NewAction("Open",new ImageIcon("open.gif"));

Action saveAction = new SaveAction("Save",new ImageIcon("save.gif"));

Action saveallAction = new SaveAllAction("Save All",new ImageIcon("saveall.gif"));

// create a menu bar and file menu JMenuBar menubar = new JMenuBar(); JMenu fileMenu = new JMenu("File");


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SWING - Action

fileMenu.add(newAction); fileMenu.add(saveAction); fileMenu.add(saveallAction); menubar.add(fileMenu); setJMenuBar(menubar);

// create a tool bar JToolBar tool = new JToolBar(); tool.add(newAction); tool.add(saveAction); tool.add(saveallAction);

getContentPane().add("North",tool);

Add actions toMenu bar

Add actions toTool bar


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SWING - Action

// add to popup menu popup.add(newAction); popup.add(saveAction); popup.add(saveallAction);

// disable saveall action and save action saveAction.setEnabled(false); saveallAction.setEnabled(false);

getContentPane().add("Center",new JPanel()); getContentPane().addMouseListener(new MouseHandler()); }

Add actions toPopup menu item


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SWING - Action

public static void main(String[] args) {

ActionExample actionExample = new ActionExample();

// pack and show actionExample.setVisible(true); }

}


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SWING - JDialog

Secondary application window Almost like a JFrame

But supports modal operation. Extends from the Dialog class in AWT


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SWING - JDialog

A JDialog window


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SWING - JDialog

package dialogexample;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class DialogExample extends JFrame implements ActionListener { public DialogExample() { // exit the frame on close this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

// create a JButton and add it to the content pane JButton jbutton = new JButton("Open Dialog"); jbutton.addActionListener(this); getContentPane().add(jbutton); }


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SWING - JDialog

public void actionPerformed(ActionEvent e) { // when the button is clicked, control comes here TestDialog dialog = new TestDialog(this,"Test Dialog",true);

dialog.pack(); dialog.setVisible(true); }

public static void main(String[] args) { DialogExample dialogExample = new DialogExample();

dialogExample.pack(); dialogExample.setVisible(true); }}


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SWING - JDialog

package dialogexample;import java.awt.*;import javax.swing.*;public class TestDialog extends JDialog {

public TestDialog(Frame frame, String title, boolean modal) { super(frame, title, modal);

// dispose the dialog on close

this.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);

// create a button panel JPanel buttons = new JPanel();


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SWING - JDialog

buttons.setLayout(new FlowLayout(FlowLayout.RIGHT,5,5)); buttons.add(new JButton("Close"));

// add the buttons JPanel areaPanel = new JPanel(); JTextArea area = new JTextArea(5,40); areaPanel.add(area); areaPanel.setBorder(BorderFactory.createCompoundBorder( BorderFactory.createEtchedBorder(), BorderFactory.createEmptyBorder(5,5,5,5))); getContentPane().add("Center",areaPanel); getContentPane().add("South",buttons); }}


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SWING - JOptionPane

Simplifies the task of displaying quick information to the user

Messages can be in the form of Error Message Information message Warning message Question message Plain message

Can show confirm dialog


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SWING - JOptionPane

JOptionPane option = new JOptionPane();

option.showMessageDialog(this,"This is an Error" ,"Error",JOptionPane.ERROR_MESSAGE);


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SWING - JOptionPane


option.showMessageDialog(this,"This is an Warning"

,"Warning",JOptionPane.WARNING_MESSAGE);


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SWING - JOptionPane


int uoption = option.showConfirmDialog(this,"Is this a Question?"

,"Question",JOptionPane.YES_NO_OPTION ,JOptionPane.QUESTION_MESSAGE,null); if (uoption == JOptionPane.YES_OPTION) { …………….}


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SWING - JColorChooser

Platform independent way of choosing color

Simplifies the user interface for color selection

Can be Used as an independent dialog for choosing

a color Embedded in a frame which contains other

panel


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SWING - JColorChooser

Color color = JColorChooser.showDialog(this,"Choose a Color",Color.blue);

// Act on the color chosen by the user


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SWING - JFileChooser

Platform independent way of providing a file selection mechanism

Allows filtering of files

JFileChooser chooser = new JFileChooser(); int value = chooser.showOpenDialog(this); if (value == JFileChooser.APPROVE_OPTION) { File file = chooser.getSelectedFile(); // handle file selection }


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SWING - JFileChooser

A file chooser


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SWING - JInternalFrame

Allows the capability to embed frames within frames

The internal frames can move within the bounds of the parent frame

Can be maximized,minimized or restored

Also called the MDI (multiple document interface)


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package internalexample;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class InternalExample extends JFrame implements ActionListener { private JDesktopPane deskPane; public InternalExample() { setSize(500,500); // create a tool bar JToolBar toolbar = new JToolBar(); JButton newButton = new JButton("Create"); newButton.addActionListener(this); toolbar.add(newButton);


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// create a desktop pane deskPane = new JDesktopPane(); getContentPane().add("Center",deskPane); getContentPane().add("North",toolbar); } public void actionPerformed(ActionEvent e) { TestInternalFrame frame = new TestInternalFrame(); frame.setVisible(true); deskPane.add(frame); }


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public static void main(String[] args) { InternalExample internalExample = new

InternalExample(); internalExample.setVisible(true); }

} // end Internal Example


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package internalexample;import java.awt.*;import javax.swing.*;

public class TestInternalFrame extends JInternalFrame { public TestInternalFrame() { super("Internal Frame");

// set the frame properties setClosable(true); setMaximizable(true); setIconifiable(true); setResizable(true);


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// set the size and add test area setSize(400,400); getContentPane().add("Center",new JTextArea()); }

} // end TestInternalFrame

Other methods moveToFront() moveToBack() setMenuBar(JMenuBar menubar) addInternalFrameListener(InternalFrameListener listener)


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SWING – Exercise 3


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SWING – Exercise

Create a UI layout as shown in the previous page. When the frame is first shown the label at the bottom should say “File not selected”. When the user clicks on button and chooses a file or directory, the label text should change to the full absolute path of the file.

When the window is closed, the application should exit.


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SWING - JList

Collection of items from which user can make one or more selection

Has the ability to provide graphics inside the list


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SWING - JList

Jlist accepts String[], Vector or ListModel

String[] items = new String[] {

"item1","item2","item3","item4" ,"item5","item6","item7","item8" ,"item9","item10" }; JList list = new JList(items); list.setVisibleRowCount(5); getContentPane().add("Center",new JScrollPane(list));


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SWING - JList

// A Custom List Model

class TestModel extends AbstractListModel {

public int getSize() { return(10); }

public Object getElementAt(int index) { return "item" + index; } }


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SWING - JList


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SWING - JList

package listexample;import java.awt.*;import javax.swing.*;

public class ListExample extends JFrame {

private String[] items =

{"Open","Save","SaveAll","Zoom","Zoomin","Zoomout"}; private String[] images =

{"open.gif","save.gif","saveall.gif","zoom.gif" ,"zoomin.gif","zoomout.gif"};


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SWING - JList

// Custom model class TestModel extends AbstractListModel { public int getSize() { return(items.length); }

public Object getElementAt(int index) { return(items[index]); } } // end TestModel


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SWING - JList

// Custom cell renderer class CustomCellRenderer extends JLabel implements ListCellRenderer { public CustomCellRenderer() { setOpaque(true); }

public Component getListCellRendererComponent(JList list ,Object value ,int index,boolean isSelected,boolean cellHasFocus) { this.setText(value.toString()); this.setIcon(new ImageIcon(images[index])); if (isSelected) { this.setBackground(Color.blue); this.setForeground(Color.white); }


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SWING - JList

else { this.setBackground(Color.white); this.setForeground(Color.black); } return this; }

} // end CustomCellRenderer

public ListExample() { setSize(200,200); JList list = new JList(new TestModel()); list.setCellRenderer(new CustomCellRenderer()); getContentPane().add("Center",new JScrollPane(list)); }


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SWING - JList

public static void main(String[] args) { ListExample listExample = new ListExample(); listExample.setVisible(true); }}


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SWING - JList

Listening to list activity addListSelectionListener ListSelectionEvent

Any component can be rendered inside the list box. JButton JTextField JCheckBox etc


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SWING - JTable

Simple two dimensional display Supports custom data models Supports custom cell rendering

Render any component inside the cell Support custom header rendering Highly flexible component

Can be customized by the programmer Class is called JTable


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SWING - JTable

A JTable which shows information about people


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SWING - JTable

package simpletable;import java.awt.*;import javax.swing.*;public class SimpleTableExample extends JFrame { public SimpleTableExample() { setSize(600,300);

// create the columns and the values String[] columns = {"Name","Telephone","City","Company"}; String values[][] = { {"Mr. X","703-4228989","Herndon","Bell Atlantic"}, {"Mr. Z","301-6748989","Rockville","Artesia Tech"}, {"Mr. W","703-4258999","Herndon","Intersect Soft"}, {"Mr. A","703-7864456","Herndon","Intelsat"} };


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SWING - JTable

JTable table = new JTable(values,columns); JScrollPane pane = new JScrollPane(table);

// add the table to the frame getContentPane().add(pane); }

public static void main(String[] args) { SimpleTableExample simpleTableExample = new SimpleTableExample(); simpleTableExample.setVisible(true); }

} // end program


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SWING - JTable

JTable uses the DefaultDataModel class as the model by default

A custom data model can be created for the table by extending AbstractTableModel


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SWING - JTable

Using a custom table model


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SWING - JTable

package simpletable;import java.awt.*;import javax.swing.*;import javax.swing.table.*;public class SimpleTableExample extends JFrame { public SimpleTableExample() { // set the size of the frame setSize(600,300); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JTable table = new JTable(new SimpleTableModel()); table.setShowHorizontalLines(false); JScrollPane pane = new JScrollPane(table); pane.getViewport().setBackground(Color.white);

Set the tableBackground to white


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SWING - JTable

// add the table to the frame

getContentPane().add(pane); }

public static void main(String[] args) { SimpleTableExample simpleTableExample

= new SimpleTableExample(); simpleTableExample.setVisible(true); }

}


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SWING - JTable

package simpletable;import javax.swing.table.*;class SimpleTableModel extends AbstractTableModel {

// create the columns and the values private String[] columns =

{"Name","Telephone","City","Company"}; private String values[][] = { {"Mr. X","703-4228989","Herndon","Bell Atlantic"}, {"Mr. Z","301-6748989","Rockville","Artesia Tech"}, {"Mr. W","703-4258999","Herndon","Intersect Software"}, {"Mr. A","703-7864456","Herndon","Intelsat"} };


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SWING - JTable

// Return object at (row,col) public Object getValueAt(int row,int col) { return(values[row][col]); }

// Set object at (row,col) public void setValueAt(Object value,int row,int col) { // do nothing }

// Return the column count public int getColumnCount() { return(columns.length); }


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SWING - JTable

// Return the row count

public int getRowCount() { return(values.length); }

// Return the column name at col public String getColumnName(int col) { return(columns[col]); }

} // end model


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SWING - JTable

A JTable in which the second column is right justified with yellow background


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SWING - JTable

package simpletable;import java.awt.*;import javax.swing.*;import javax.swing.table.*;

public class TelephoneRenderer extends JLabel implements TableCellRenderer {

public TelephoneRenderer() { setOpaque(true); }


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SWING - JTable

public Component getTableCellRendererComponent(JTable table,Object value,boolean isSelected,boolean hasFocus,int row,int column) {

this.setHorizontalAlignment(JLabel.RIGHT); this.setText((String)value); this.setBackground(Color.yellow); return(this); }

} // end renderer

Return the label


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SWING - JTable

Associating a cell renderer to a column

TableColumn column = table.getColumn("Telephone");column.setCellRenderer(new TelephoneRenderer());

Table header rendering can be achieved by

column.setHeaderRenderer(<renderer>)


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SWING - JTable

Table selection events can be observed by implementing the ListSelectionListener interface.

ListSelectionEvent is generated whenever the selections change.

table.getSelectionModel().addListSelectionListener(this);


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SWING - JTable

public void valueChanged(ListSelectionEvent event) {

if (event.getSource() == table.getSelectionModel() && !event.getValueIsAdjusting()) { int row = table.getSelectedRow(); if (row >= 0) { SimpleTableModel model = (SimpleTableModel)table.getModel(); String name = (String)model.getValueAt(row,0);

JOptionPane pane = new JOptionPane(); pane.showMessageDialog(this,"Selected : " + name); } } }


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SWING - JTree

Presents hierarchical information Entirely made up of nodes. Every node has a parent except for the

root node. Supports

custom models custom rendering

Class is called JTree


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SWING - JTree

Uses the default tree model to create the tree


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SWING - JTree

package treeexample;import java.awt.*;import javax.swing.*;import javax.swing.tree.*;public class TreeExample extends JFrame { private JTree jtree;

public TreeExample() { // set the size setSize(400,400);

// root node DefaultMutableTreeNode filenode

= new DefaultMutableTreeNode("TreeExample.java");


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SWING - JTree

// immediate children DefaultMutableTreeNode importnode

= new DefaultMutableTreeNode("Imports"); DefaultMutableTreeNode datanode

= new DefaultMutableTreeNode("Variables"); DefaultMutableTreeNode methodnode

= new DefaultMutableTreeNode("Methods"); filenode.add(importnode); filenode.add(datanode); filenode.add(methodnode);

// import children DefaultMutableTreeNode awt

= new DefaultMutableTreeNode("java.awt.*");


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SWING - JTree

DefaultMutableTreeNode swing = new DefaultMutableTreeNode("javax.swing.*");

DefaultMutableTreeNode swingtree = new DefaultMutableTreeNode("javax.swing.tree.*");

importnode.add(awt); importnode.add(swing); importnode.add(swingtree);

// data children DefaultMutableTreeNode variable

= new DefaultMutableTreeNode("JTree jtree"); datanode.add(variable);


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SWING - JTree

// method children DefaultMutableTreeNode method1

= new DefaultMutableTreeNode("JTree()"); DefaultMutableTreeNode method2

= new DefaultMutableTreeNode("main()"); methodnode.add(method1); methodnode.add(method2);

// create the tree from the default model DefaultTreeModel model = new DefaultTreeModel(filenode); jtree = new JTree(model);

getContentPane().add("Center",new JScrollPane(jtree));

}


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SWING - JTree

public static void main(String args[]) { TreeExample treeexample = new TreeExample(); treeexample.setVisible(true); }

}// end program


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SWING - JTree

Custom data models can be used with the JTree

Extends from DefaultTreeModel Object getChild(Object parent,int index) int getChildCount(Object parent) boolean isLeaf(Object node)

Each DefaultMutableTreeNode contains a user object which can store any object in the node


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SWING - JTree

package customtreeexample;public class JavaFile { private String name; private String[] imports; private String[] variables; private String[] methods;

public JavaFile() { name = "CustomTreeExample.java"; imports

= new String[] {"java.awt.*","javax.swing.*","javax.swing.tree.*"};

variables = new String[] {"JTree jtree"}; methods = new String[] {"CustomTreeExample()","main()"}; }

Hardcoded values


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SWING - JTree

public String getName() { return name; }

public String[] getSubTypes() { return(new String[] {"Imports","Data","Methods"}); }

public String[] getImports() { return(imports); }

public String[] getVariables() { return(variables); }


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SWING - JTree

public String[] getMethods() { return(methods); }

} // end JavaFile


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SWING - JTree

package customtreeexample;import javax.swing.tree.*;public class SimpleTreeModel extends DefaultTreeModel { private JavaFile file; private DefaultMutableTreeNode root; private String rootName;

public SimpleTreeModel(DefaultMutableTreeNode node,JavaFile file) {

super(node); this.file = file; this.rootName = file.getName(); this.root = node; }


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SWING - JTree

// get the child at the specified index public Object getChild(Object parent,int index) { DefaultMutableTreeNode parentNode

= (DefaultMutableTreeNode)parent; String userObject = (String)parentNode.getUserObject(); if (userObject.equals(rootName)) { String[] types = file.getSubTypes(); DefaultMutableTreeNode node

= new DefaultMutableTreeNode(types[index]); return(node); }


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SWING - JTree

else if (userObject.equals("Imports")) { String[] imports = file.getImports(); DefaultMutableTreeNode node

= new DefaultMutableTreeNode(imports[index]); return(node); } else if (userObject.equals("Data")) { String[] variables = file.getVariables(); DefaultMutableTreeNode node

= new DefaultMutableTreeNode(variables[index]); return(node); }


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SWING - JTree

else if (userObject.equals("Methods")) { String[] methods = file.getMethods(); DefaultMutableTreeNode node

= new DefaultMutableTreeNode(methods[index]);

return(node); }

return(null);

} // end getChild()


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SWING - JTree

// get the child count for the parent public int getChildCount(Object parent) { DefaultMutableTreeNode parentNode

= (DefaultMutableTreeNode)parent; String userObject = (String)parentNode.getUserObject(); if (userObject.equals(rootName)) { return(file.getSubTypes().length); } else if (userObject.equals("Imports")) { return(file.getImports().length); }


109

SWING - JTree

else if (userObject.equals("Data")) { return(file.getVariables().length); } else if (userObject.equals("Methods")) { return(file.getMethods().length); }

return(0);

} // end getChildCount()


110

SWING - JTree

// return TRUE if the node is a leaf public boolean isLeaf(Object node) { DefaultMutableTreeNode parentNode = (DefaultMutableTreeNode)node; String userObject = (String)parentNode.getUserObject(); if (userObject.equals(rootName) || userObject.equals("Imports") || userObject.equals("Data") || userObject.equals("Methods")) { return(false); } return(true); }

} // end SimpleTreeModel


111

SWING - JTree

Custom Rendering Useful for changing icons, fonts etc Implement TreeCellRenderer class Component

getTreeCellRendererComponent(…) must be implemented

Nodes can contain any Component (TextField, Checkbox etc)

Listening to tree selections Implement TreeSelectionListener


112

SWING - JTree

Listening for Tree expansions Implement TreeExpansionListener

Hiding root node tree.setRootVisible(false);

Other methods tree.expandPath(path) tree.collapsePath(path) tree.setSelectionPath(path) tree.clearSelection()


113



114


Add a JTable to the center panel which shows the name of the file/directory and the size as columns. Whenever a file or directory is chosen it should update the table.

What mechanism would you use to make the size column right justified?


115

SWING – Look And Feel

Supports different look and feel Metal Motif Windows Mac

MVC pattern Can create corporate look and feel Change the look And Feel

UIManager.setLookAndFeel(“<class name>”);


116

SWING – Look And Feel

Add this code to the tree example

UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.

WindowsLookAndFeel");


117

SWING - Multithreading

Threads can improve performance by allowing simultaneous execution of two or more related tasks

Event Dispatching thread Event Dispatching thread and data collection

threads can be separate but needs synchronization

For performance Once a Swing component is displayed on the screen

they cannot be changed from any thread other than the event dispatching thread

Inherently Multi-thread unsafe


118


invokeLater Queues the GUI request. The event

dispatching thread will pick it up and execute it at some later time

invokeAndWait Queues and waits till the task is performed.

DO NOT CALL THIS FROM THE EVENT DISPATCHING THREAD


119


class RunnableClass implements Runnable {public void run() {

// do gui work here}

}

// will queue the request for the event dispatching thread// to executeSwingUtilities.invokeLater(new RunnableClass());


120

SWING Exercise 5

Change the code for exercise 4 so that the output is in windows look and feel


121

SWING – Popular IDEs

Integrated Development Environments Borland JBuilder (most popular)

http://www.borland.com/jbuilder/index.html WebGain Visual Café

http://www.webgain.com/products/visual_cafe/ IBM VisualAge For Java

http://www-3.ibm.com/software/ad/vajava/ Sun[tm] ONE Studio 4

http://wwws.sun.com/software/sundev/jde/index.html


122

What’s Next Threads

Go from single threaded applications to multithreaded applications

Networking Go from one user applications to muti user

applications Distributed Objects

Go from objects in single JVM to objects in multiple JVMs (maybe in different machines)

Documents

Copyright 2003 Mudra Services1 SWING - JTabbedPane Helps stack pages of information into a single point of reference If information cannot be laid out