GUI Programming II: Components

1. 23 GUI Programming II: Components

2. Previously • Hello World as GUI • Layout Design • Criteria In GUI • Human Interface Concepts • Requirements • Use Cases • Design GUI • Java Foundation Classes Add record View record Edit record Save record Delete record Database User actor actor

3. Overview • Hierarchy • Overview Swing Components • Swing Components

4. Hierarchy java.lang Object java.awt Component Abstract Window Toolkit (AWT) Container javax.swing JComponent JCheckBox JMenuBar JTextField JLabel JComboBox JTextArea JTable JPanel JButton

5. Swing Components • Position  Layout Managers • Look  how the control is displayed on the screen • Feel - base functionality • Do you click on them. e.g. button (JButton) • Do you type on them, e.g. text field (JTextField) ... • Functionality Events • What happen when the corresponding action has been executed by the user, e.g. clicking on the "Save" button save the data

6. Overview Swing Components • JPanel • JScrollBar • JSlider • JSplitPane • JButton • JCheckBox • JComboBox • JRadioButton • JPopupMenu Divider between panels can be drag left and right

7. Swing Components • JTree • JLabel • Fix text on the display • JDialog • JTabel SubSuperClasses • JMenuBar • JMenu • JMenuItem • JTextField • JTabbedPane • JTextArea bin doc readme.txt javadoc src Application title Data was saved. Tab 2 Tab 3 Tab 1 Panel

8. Swing Components importjavax.swing.JFrame; importjavax.swing.JLabel; public class HelloWorldGUIextendsJFrame { public static void main(String[] args) { newHelloWorldGUI(); } // main() HelloWorldGUI() { super("Hello World"); // the title JLabeljlbHelloWorld = newJLabel(" Hello World!"); add(jlbHelloWorld); // add label to the GUI setSize(150, 80); // size of the window setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setVisible(true); // show the GUI } // Constructor () } // end class HelloWorldGUI

9. Swing Components • Extend JFrame to get the general look of a GUI • JLabel corresponds to fix text to add to the GUI public class HelloWorldGUIextendsJFrame { ... HelloWorldGUI() { super("Hello World"); // the title JLabeljlbHelloWorld = newJLabel(" Hello World!"); add(jlbHelloWorld); // add label to the GUI setSize(150, 80); // size of the window setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setVisible(true); // show the GUI } // Constructor () } // end class HelloWorldGUI height Hello World width

10. Swing Components • Creating and Showing Simple Dialogs • It is a accomplished by using the class JDialog • Different ones depending of the message to display • Default title and icon JOptionPane.showMessageDialog(frame, "Data was saved.", "Message"); • Custom title, warning icon JOptionPane.showMessageDialog(frame, “Data was saved.", "Warning!", JOptionPane.WARNING_MESSAGE); • Custom title, error icon JOptionPane.showMessageDialog(frame, "Data wasn’t saved.", “Error!", JOptionPane.ERROR_MESSAGE); Data was saved. Warning! Data was saved. Error! Data wasn’t saved.

11. Swing Components • Yes/No dialog with default icon, custom title int iAnswer = JOptionPane.showConfirmDialog(frame, "Would you like to save the data?", "Question!", JOptionPane.YES_NO_OPTION); Valid return values • JOptionPane.YES_OPTION: user has selected 'YES' • JOptionPane.NO_OPTION: user has selected 'NO' • JOptionPane.CLOSED_OPTION: user closed the dialog window explicitly, rather than by choosing a button inside the option pane Question! Would you like to save the data?

12. Swing Components • JMenuBar and JMenuItem //Create the menu bar JMenuBarmenuBar = new JMenuBar(); //Build the first menu JMenu menu = newJMenu("1st Menu"); menuBar.add(menu); // add menu to menu bar // Add menu items JMenuItemmenuItem = newJMenuItem("1st Option"); menuItem.addItemListener(this); // register the listener menu.add(menuItem);// add item to a container menuItem = newJMenuItem("2nd Option"); menuItem.addItemListener(this); // register the listener menu.add(menuItem); // add item to a container ... jFrame.setJMenuBar(menuBar); // set menu bar • JMenuBar • add(JMenu) • JMenu • add(JMenuItem) • add(JMenu) • JMenuItem • addItemListener(ItemListener) • JFrame • setJMenuBar(JMenuBar)

13. Swing Components • JTextField • JButton JTextFieldjText = newJTextField(15); ... add(jText); // add to a container ... jText.getText(); // get text on the text fields JButtonjButton = newJButton("OK"); jButton.setActionCommand ("OK"); // assign an action identifier jButton.addActionListerner(this); // register the listener add(jButton); // add to a container ...

14. Swing Components • JTable // Header String[] astrColumnNames = {"First name", "Last name", "Num", "Road", "Alive"}; Object[][] aoRows = { {"Debby", "Smith", new Integer(5), "Parliament", new Boolean(false)}, {"John", "Rainbow", new Integer(3), "GreatAv.", new Boolean(true)}, {"Jason","Wood", new Integer(2), "Lower line", new Boolean(false)}, {"Jane", "White", new Integer(13),"High Street", new Boolean(true)} }; // Build table using these roes and column names JTable table = newJTable(aoRows, astrColumnNames);

15. References A Brief Introduction to the Swing Package http://download.oracle.com/javase/tutorial/ui/overview/index.html Using Swing Components http://download.oracle.com/javase/tutorial/uiswing/components/index.html Java API http://download.oracle.com/javase/6/docs/api/ Course Resources Website http://workspace.nottingham.ac.uk/display/G54ICP/Resources Java look and feel Graphics Repository http://java.sun.com/developer/techDocs/hi/repository/