Curs 6. GUI Swing. POO - curs 6

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Rosamund Morris
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1 Curs 6 GUI Swing 1

2 JFC si Swing JFC = Java TM Foundation Classes, un grup de clase care permit construirea interfetelor grafice (GUI). Caracteristici: The Swing Components Pluggable Look and Feel Support Se pot alege diferite looks and feels. Separare a datelor in modele... Pachete: javax.swing javax.swing.event... 2

3 Componente Swing si Componente AWT Componentele AWT au fost furnizate de platformele JDK 1.0 si 1.1 Componentele Swing sunt implementate fara a se folosi cod nativ. Deoarece componentele Swing nu sunt restrictionate la caracteristicile de baza existente pe fiecare platforma pot avea o functionalitate mai complexa decat componentele AWT. Avantaje ale componentelor Swing: Butoanele si etichetele pot avea nu numai text dar si imagini. Se pot adauga sau schimba usor margini in jurul componentelor Swing. Se poate schimba usor comportamentul si forma componentelor Swing prin apelarea unor metode sau prin constructia uor clase derivate. Ccomponentele Swing pot sa nu fie rectangulare. 3

4 Setarea Look and Feel Setting the Java Look&Feel public static void main(string[] args) { try { UIManager.setLookAndFeel( UIManager.getCrossPlatformLookAndFeelClassName()); catch (Exception e) { new SwingApplication(); //Create and show the GUI. Setting the Windows Look & Feel UIManager.setLookAndFeel( "com.sun.java.swing.plaf.windows.windowslookandfeel ) Setting the native Look&Feel for whatever platform UIManager.setLookAndFeel( UIManager.getSystemLookAndFeelClassName()); 4

5 Exemplu 5

6 Containeri Swing Top-level Cel putin unul pentru fiecare aplicatie care foloseste GUI. JFrame, JDialog, ori JApplet. JFrame object -> main window, JDialog object -> secondary window, JApplet object -> an applet's display area within a browser window. Furnizeaza suport pentru componentele Swing sa se afiseze si pentru tratarea evenimentelor. 6

7 Ierarhia containerilor Top-level container Intermediate container (panel): JPanel, JScrollPane, JTabbedPane) Atomic components Diagrama ierarhiei pentru exemplu (SwingApplication). 7

8 Exemplu - implementare import javax.swing.*; import java.awt.*; import java.awt.event.*; public class SwingApplication {... public static void main(string[] args) {... JFrame frame = new JFrame("SwingApplication"); //...create the components to go into the frame... //...stick them in a container named contents... frame.getcontentpane().add(contents, BorderLayout.CENTER); //Finish setting up the frame, and show it. frame.addwindowlistener(...); frame.pack(); frame.setvisible(true); 8

9 Crearea Butoanelor si etichetelor JButton button = new JButton("I'm a Swing button!"); button.addactionlistener(...create an action listener...);...//where instance variables are declared: private static String labelprefix = "Number of button clicks: "; private int numclicks = 0;...//in GUI initialization code: final JLabel label = new JLabel(labelPrefix + "0 ");...//in the event handler for button clicks: label.settext(labelprefix + numclicks); 9

10 Adaugarea componentelor in containeri JPanel pane = new JPanel(); pane.setborder( BorderFactory.createEmptyBorder( 30, 30, 10, 30)); pane.setlayout(new GridLayout(0, 1)); pane.add(button); pane.add(label); 10

11 Adaugarea marginilor pane.setborder( BorderFactory.createEmptyBorder( 30, //top 30, //left 10, //bottom 30) //right ); 11

12 Layout Management Layout management este procesul de determinare a marimii si pozitiei componentelor. Implicit fiecare container are un layout manager -- un obiect care realizeaza layout management pentru componentele din container. Trebuie sa se tina seama de layout manager atunci cand se adauga (add) o componenta intr-un container. 12

13 Setarea pentru Layout Manager JPanel pane = new JPanel(); pane.setlayout(new BorderLayout()); Caracteristicile unei componente Dimensiuni setminimumsize, setpreferredsize, setmaximumsize) sau se pot defini subclase care pot suprascrie metodele-- getminimumsize, getpreferredsize, getmaximumsize. Aliniamente setalignmentx setalignmenty getalignmentx getalignmenty Spatiu intre componente Trei factori:: Layout manager Componente invisibile Margini 13

BorderLayout BorderLayout implicit pentru <content pane. > Container contentpane = getcontentpane(); //contentpane.setlayout(new BorderLayout()); //unnecessary contentpane.

14 BorderLayout BorderLayout implicit pentru <content pane. > Container contentpane = getcontentpane(); //contentpane.setlayout(new BorderLayout()); //unnecessary contentpane.add(new JButton("Button 1 (NORTH)"), BorderLayout.NORTH); contentpane.add(new JButton("2 (CENTER)"), BorderLayout.CENTER); contentpane.add(new JButton("Button 3 (WEST)"), BorderLayout.WEST); contentpane.add(new JButton("Long-Named Button 4 (SOUTH)"), BorderLayout.SOUTH); contentpane.add(new JButton("Button 5 (EAST)"), BorderLayout.EAST); 14

15 FlowLayout FlowLayout implicit pentru JPanel. Container contentpane = getcontentpane(); contentpane.setlayout(new FlowLayout()); contentpane.add(new JButton("Button 1")); contentpane.add(new JButton("2")); contentpane.add(new JButton("Button 3")); contentpane.add(new JButton("Long-Named Button 4")); contentpane.add(new JButton("Button 5")); 15

GridLayout. Container contentpane = getcontentpane(); contentpane.setlayout(new GridLayout(0,2)); contentpane.add(new JButton("Button 1")); contentpane.

16 GridLayout. Container contentpane = getcontentpane(); contentpane.setlayout(new GridLayout(0,2)); contentpane.add(new JButton("Button 1")); contentpane.add(new JButton("2")); contentpane.add(new JButton("Button 3")); contentpane.add(new JButton("Long-Named Button 4")); contentpane.add(new JButton("Button 5")); 16

17 Event Handling Act that results in the event Listener type User clicks a button, presses Return while typing in a text field, or chooses a menu item User closes a frame (main window) User presses a mouse button while the cursor is over a component User moves the mouse over a component Component becomes visible Component gets the keyboard focus Table or list selection changes ActionListener WindowListener MouseListener MouseMotionListener ComponentListener FocusListener ListSelectionListener 17

18 Fiecare eveniment este reprezentat de un obiect care furnizeaza informatie despre eveniment si sursa acestuia. Sursele sunt in general componente. Fiecare sursa de evenimente poate avea inregistrati mai multi listeners. Un singur listener poate fi inregistrat pentru mai multe surse. 18

19 Implementarea unui Event Handler Exemplu : ActionListener public class MyClass implements ActionListener { public void actionperformed(actionevent e) {...//code that reacts to the action... Inregistrare: somecomponent.addactionlistener( instanceofmyclass) 19

20 Informatii despre eveniment EventObject. Object getsource() Returneaza obiectul sursa al evenimentului. Exemplu: MouseEvent furnizeaza informatii despre pozitia mouse-ului, numar de clickuri, etc. 20

21 Exemplu (ActionEvent) Object Δ java.util.eventobject Δ java.awt.awtevent Δ java.awt.event.actionevent ActionEvent +getactioncommand():string +setactioncommand(string) +getsource():object 21

22 Evenimente low-level si semantice Evenimente Low-level: window-system occurrences, low-level input, Semantice toate celelalte. Exemple: mouse, key, component, container, focus, and window events. action events, item events, list selection events. Recomandare!!!! Tratati evenimentele semantice daca e posibil nu ecele low-level! 22

23 Ascultatori suportati de toate componentele Swing Component listener Schimbari de marime, pozitie si vizibilitate Focus listener Key listener Mouse listener Mouse motion listener 23

24 Tratarea evenimentelor pentru SwingApplication button.addactionlistener(new ActionListener() { public void actionperformed(actionevent e) { numclicks++; label.settext(labelprefix + numclicks); );... frame.addwindowlistener(new WindowAdapter() { public void windowclosing(windowevent e) { System.exit(0); ); 24

25 Main Windows public static void main(string s[]) { JFrame frame = new JFrame("FrameDemo"); frame.addwindowlistener(new WindowAdapter() { public void windowclosing(windowevent e) {System.exit(0); ); //...create a blank label, set its preferred size... frame.getcontentpane().add( emptylabel,borderlayout.center); frame.pack(); frame.setvisible(true); 25

26 Window Listener public class WindowEventDemo... implements WindowListener {...//where initialization occurs: //Create but don't show window. window = new JFrame("Window Event Window"); window.addwindowlistener(this); window.getcontentpane().add( new JLabel("The frame listens to this window " + "for window events."), BorderLayout.CENTER); window.pack(); public void windowclosing(windowevent e) { window.setvisible(false); displaymessage("window closing", e); public void windowclosed(windowevent e) { displaymessage("window closed", e); 26

27 public void windowopened(windowevent e) { displaymessage("window opened", e); public void windowiconified(windowevent e) { displaymessage("window iconified", e); public void windowdeiconified(windowevent e) { displaymessage("window deiconified", e); public void windowactivated(windowevent e) { displaymessage("window activated", e); public void windowdeactivated(windowevent e) { displaymessage("window deactivated", e); void displaymessage(string prefix, WindowEvent e) { display.append(prefix + ": " + e.getwindow() + newline);... 27

28 Adaptori class WindowAdapter implements WindowListener{ public void windowclosing(windowevent e) { public void windowclosed(windowevent e) { public void windowopened(windowevent e) { public void windowiconified(windowevent e) { public void windowdeiconified(windowevent e) { public void windowactivated(windowevent e) { public void windowdeactivated(windowevent e) { Ex: frame.addwindowlistener(new WindowAdapter() { public void windowclosing(windowevent e) { System.exit(0); ); 28

29 SwingApplication-(1) import javax.swing.*; import java.awt.*; import java.awt.event.*; public class SwingApplication { private static String labelprefix = "Number of button clicks:"; private int numclicks = 0; private String s=""; public Component createcomponents() { final JLabel label = new JLabel(labelPrefix + "0 "); final JTextField text = new JTextField("cliks", 20); JButton button = new JButton("I'm a Swing button!"); button.setmnemonic('i'); 29

30 SwingApplication-(2) button.addactionlistener(new ActionListener() { public void actionperformed(actionevent e) { numclicks++; s=new String(text.getText()); label.settext(labelprefix + numclicks+ s ); ); label.setlabelfor(button); JPanel pane = new JPanel(); pane.setborder( BorderFactory.createEmptyBorder(20, 20, 50, 40) ); pane.setlayout(new GridLayout(3, 1)); pane.add(button); pane.add(label); pane.add(text); return pane; 30

31 SwingApplication-(3) public static void main(string[] args) { try { UIManager.setLookAndFeel( UIManager.getCrossPlatformLookAndFeelClassName()); catch (Exception e) { JFrame frame = new JFrame("SwingApplication"); SwingApplication app = new SwingApplication(); Component contents = app.createcomponents(); frame.getcontentpane().add(contents, BorderLayout.CENTER); frame.addwindowlistener(new WindowAdapter() { public void windowclosing(windowevent e) { System.exit(0); ); frame.pack(); frame.setvisible(true); 31

32 Clasa AbstractButton Subclase: JButton, JMenuItem, JToggleButton JToggleButton Implementare a unui buton cu 2 stari. Subclase:» JCheckBox, JRadioButton 32

33 Constructori: JButton(Icon icon) JButton(String text) Clasa JButton JButton(String text, Icon icon) class ImageIcon implements Icon { Constructori: ImageIcon(Image image) ImageIcon(Image image, String description) ImageIcon(String filename) ImageIcon(String filename, String description) 33

34 Class JTextField JTextField (Extinde JTextComponent) Constructori: JTextField(int columns). JTextField(String text) JTextField(String text, int columns) Metode: public String gettext() public String getselectedtext() public void settext(string t) public void seteditable(boolean b) 34

35 Clasa JTextArea JTextArea. (Extinde JTextComponent) Constructori: : JTextArea(int rows, int columns) JTextArea(String text) JTextArea(String text, int rows, int columns) Metode: void append(string str) void insert(string str, int pos) void setcolumns(int columns) void setrows(int rows) 35

36 Exemplu import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.lang.*; public class Actions extends JPanel implements ActionListener { int power=0; JTextField field, fieldrez; ImageIcon buttonimage; JButton button; JRadioButton radiobutton; ButtonGroup grp; JCheckBox checkbox; JLabel label1; JLabel label2; JLabel label3; 36

37 public Actions() { setlayout (new GridLayout(5,1,10,10)); setbackground (Color.lightGray); JPanel subpanel = new JPanel(); label1 = new JLabel("Number:"); subpanel.add(label1); // Creates a text field where the number is read field = new JTextField(10); field.addactionlistener (this); label1.setlabelfor(field); subpanel.add(field); add(subpanel); subpanel = new JPanel(); subpanel.setlayout(new GridLayout(3,2)); label2 = new JLabel("Power:"); 37

38 // Creates three radio buttons that specifies the exponent grp = new ButtonGroup(); radiobutton = new JRadioButton("One"); radiobutton.addactionlistener(this); radiobutton.setactioncommand("one Activated"); grp.add(radiobutton); subpanel.add(new JLabel("")); subpanel.add(radiobutton); subpanel.add(label2); radiobutton = new JRadioButton("Two"); radiobutton.addactionlistener(this); radiobutton.setactioncommand("two Activated"); grp.add(radiobutton); subpanel.add(radiobutton); radiobutton = new JRadioButton("Three"); radiobutton.addactionlistener(this); radiobutton.setactioncommand("three Activated"); grp.add(radiobutton); subpanel.add(new JLabel("")); subpanel.add(radiobutton); add(subpanel); 38

39 // Creates a checkbox that specifies if the square root is computed subpanel=new JPanel(); checkbox=new JCheckBox("Square Root"); checkbox.addactionlistener(this); subpanel.add(checkbox); add(subpanel); subpanel=new JPanel(); // Creates a button with an icon buttonimage = new ImageIcon("c:/temp/qs_cons.gif"); button = new JButton("Compute"); button.seticon(buttonimage); button.addactionlistener(this); button.setactioncommand("button Activated"); subpanel.add(button); add(subpanel); subpanel=new JPanel(); label3 =new JLabel("Result"); subpanel.add(label3); fieldrez = new JTextField(15); fieldrez.seteditable(false); subpanel.add(fieldrez); add(subpanel); 39

40 public void actionperformed(actionevent e) { if (e.getactioncommand().equals("one Activated")) power=1; if (e.getactioncommand().equals("two Activated")) power=2; if (e.getactioncommand().equals("three Activated")) power=3; if (e.getactioncommand().equals("button Activated")) { double rez; try{ rez=integer.parseint(field.gettext()); rez=math.pow(rez,power); if (checkbox.isselected()) rez=math.sqrt(rez); fieldrez.settext((new Double(rez)).toString()); catch(numberformatexception ee){ JOptionPane.showMessageDialog( field,"give an integer number!","error", JOptionPane.ERROR_MESSAGE ) ; field.requestfocus(); 40

41 public Dimension getpreferredsize() { return new Dimension(200, 400); public static void main(string s[]) { JFrame frame = new JFrame("Computer"); Actions panel = new Actions(); frame.setforeground(color.blue); frame.setbackground(color.lightgray); frame.setlocation(100,100); frame.addwindowlistener(new WindowCloser()); frame.getcontentpane().add(panel,"center"); frame.pack(); frame.setvisible(true); class WindowCloser extends WindowAdapter { public void windowclosing(windowevent e) { System.exit(0); 41

42 Liste O componenta JList afiseaza un grup de elemente din care utilizatorul poate alege. Listele sunt incluse in general in scroll pane. Separare dintre date si afisare: Model / View Datele continute intr-o lista sunt pastrate intr-un ListModel 42

43 Interfata ListModel ListModel void addlistdatalistener(listdatalistener l) Object getelementat(int index) int getsize(). void removelistdatalistener(listdatalistener l) Clasa DefaultListModel Se pot creare propriile clase de tip ListModel prin extinderea clasei AbstractListModel 43

44 Setarea elementelor unei liste Method JList(ListModel) JList(Object[]) JList(Vector) void setmodel(listmodel) ListModel getmodel() void setlistdata(object[]) void setlistdata(vector) Purpose Create a list with the initial list items specified. The second and third constructors implicitly create an immutable ListModel. Set or get the model that contains the contents of the list. Set the items in the list. These methods implicitly create an immutable ListModel 44

45 Tipuri de selectii Exemple Mod SINGLE_SELECTION Descriere La un moment dat doar un element este selectat. SINGLE_INTERVAL_ SELECTION La un moment dat pot fi selectate mai multe elemente consecutive. MULTIPLE_INTERVAL_ SELECTION (implicit) Orice combinatie de selectii. Deselectarea se face explicit. 45

46 Method void addlistselectionlistener( ListSelectionListener) Selectarea in liste void setselectedindex(int) void setselectedindices(int[]) void setselectedvalue(object, boolean) void setselectedinterval(int, int) int getselectedindex() int getminselectionindex() int getmaxselectionindex() int[] getselectedindices() Object getselectedvalue() Object[] getselectedvalues() void setselectionmode(int) int getselectionmode() void clearselection() boolean isselectionempty() boolean isselectedindex(int) Purpose Register to receive notification of selection changes. Set the current selection as indicated. Use setselectionmode to set what ranges of selections are acceptable. The boolean argument specifies whether the list should attempt to scroll itself so that the selected item is visible. Get information about the current selection as indicated. Set or get the selection mode. Acceptable values are: SINGLE_SELECTION, SINGLE_INTERVAL_SELECTION, or MULTIPLE_INTERVAL_SELECTION (the default), which are defined in ListSelectionModel. Set or get whether any items are selected. Determine whether the specified index is selected. 46

47 Exemplu import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class ListDemoSimple extends JFrame implements ListSelectionListener { private JList list; private DefaultListModel listmodel; private static final String addstring = "Add"; private static final String deletestring ="Delete"; 47

48 private JButton addbutton; private JButton deletebutton; private JTextField namefield; private JTextArea log; static private String newline = "\n"; ListDemoSimple(String s){ super(s); // the constructor of JFrame public Dimension getpreferredsize() { return new Dimension(600, 400); 48

49 public JPanel init() { //Create and populate the list model. listmodel = new DefaultListModel(); listmodel.addelement("whistler, Canada"); listmodel.addelement("jackson Hole, Wyoming"); listmodel.addelement("squaw Valley, California"); listmodel.addelement("telluride, Colorado"); listmodel.addelement("taos, New Mexico"); listmodel.addelement("snowbird, Utah"); listmodel.addelement("chamonix, France"); listmodel.addelement("banff, Canada"); listmodel.addlistdatalistener( new MyListDataListener()); 49

50 //Create the list and put it in a scroll pane. list = new JList(listModel); list.setselectionmode( ListSelectionModel.SINGLE_INTERVAL_SELECTION); list.setselectedindex(0); list.addlistselectionlistener(this); JScrollPane listscrollpane = new JScrollPane(list); //Create the list modifying buttons. addbutton = new JButton(addString); addbutton.setactioncommand(addstring); addbutton.addactionlistener( new AddButtonListener()); deletebutton = new JButton(deleteString); deletebutton.setactioncommand(deletestring); deletebutton.addactionlistener( new DeleteButtonListener()); 50

51 //Create the text field for entering new names. namefield = new JTextField(15); namefield.addactionlistener( new AddButtonListener()); String name = listmodel.getelementat( list.getselectedindex()).tostring(); namefield.settext(name); //Create a control panel (uses the default FlowLayout). JPanel buttonpane = new JPanel(); buttonpane.add(namefield); buttonpane.add(addbutton); buttonpane.add(deletebutton); 51

52 //Create the log for reporting list data events. log = new JTextArea(5, 2); JScrollPane logscrollpane = new JScrollPane(log); //Create a split pane for the log and the list. JSplitPane splitpane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, listscrollpane, logscrollpane); JPanel panel=new JPanel(); panel.setlayout(new BorderLayout()); panel.add(buttonpane, BorderLayout.NORTH); panel.add(splitpane, BorderLayout.CENTER); return panel; 52

53 class MyListDataListener implements ListDataListener { public void contentschanged(listdataevent e) { log.append("contentschanged: " + e.getindex0() + ", " + e.getindex1() + newline); public void intervaladded(listdataevent e) { log.append("intervaladded: " + e.getindex0() + ", " + e.getindex1() + newline); public void intervalremoved(listdataevent e) { log.append("intervalremoved: " + e.getindex0() + ", " + e.getindex1() + newline); 53

54 class DeleteButtonListener implements ActionListener { public void actionperformed(actionevent e) { ListSelectionModel lsm = list.getselectionmodel(); int firstselected = lsm.getminselectionindex(); int lastselected = lsm.getmaxselectionindex(); listmodel.removerange(firstselected, lastselected); int size = listmodel.size(); if (size == 0) { //List is empty: disable delete. deletebutton.setenabled(false); else { //Adjust the selection. if (firstselected == listmodel.getsize()) { //Removed item in last position. firstselected--; list.setselectedindex(firstselected); 54

55 class AddButtonListener implements ActionListener { public void actionperformed(actionevent e) { if (namefield.gettext().equals("")) { //User didn't type in a name... Toolkit.getDefaultToolkit().beep(); return; int index = list.getselectedindex(); int size = listmodel.getsize(); //If no selection or if item in last position is selected, //add the new one to end of list, and select new one. if (index == -1 (index+1 == size)) { listmodel.addelement(namefield.gettext()); list.setselectedindex(size); //Otherwise insert the new one after // the current selection, and select new one. else { listmodel.insertelementat(namefield.gettext(), index+1); list.setselectedindex(index+1); 55

56 //Listener method for list selection changes. public void valuechanged(listselectionevent e) { if (e.getvalueisadjusting() == false) { if (list.getselectedindex() == -1) { //No selection: disable delete button. deletebutton.setenabled(false); namefield.settext(""); else if (list.getselectedindices().length > 1) { //Multiple selection: disable add button. deletebutton.setenabled(true); addbutton.setenabled(false); else { //Single selection: permit all operations. deletebutton.setenabled(true); addbutton.setenabled(true); namefield.settext( list.getselectedvalue().tostring()); 56

57 public static void main(string args[]){ ListDemoSimple frame= new ListDemoSimple("Lista"); frame.setforeground(color.blue); frame.setbackground(color.lightgray); frame.setlocation(100,100); frame.addwindowlistener(new WindowAdapter() { public void windowclosing(windowevent e) {System.exit(0); ); JPanel panel=frame.init(); frame.getcontentpane().add(panel,"center"); frame.setsize(panel.getpreferredsize()); frame.pack(); frame.setvisible(true); 57

58 JScrollPanel - Decorator Constructori JScrollPane() Creaza un JScrollPane vid (fara viewport); bare de scroll orizontale si verticale apar cand este necesar. JScrollPane(Component view) Creaza a JScrollPane care afiseaza continutul componentei; bare de scroll orizontale si verticale apar daca componenta este mai mare. 58

59 Meniuri Clase: JMenuBar, JMenu, JMenuItem Exemplu private JMenuItem additem; private JMenuItem deleteitem; additem = new JMenuItem(addString); additem.addactionlistener(new AddButtonListener()); deleteitem = new JMenuItem(deleteString); deleteitem.addactionlistener(new DeleteButtonListener()); private JMenuBar menub = new JMenuBar(); private JMenu menu1 = new JMenu("menu1"); private JMenu menu2 = new JMenu("menu2"); menu1.add(additem); menu2.add(deleteitem); menub.add(menu1); menub.add(menu2); frame.setjmenubar(menub); 59

Introduction to the JAVA UI classes Advanced HCI IAT351

Introduction to the JAVA UI classes Advanced HCI IAT351 Week 3 Lecture 1 17.09.2012 Lyn Bartram lyn@sfu.ca About JFC and Swing JFC Java TM Foundation Classes Encompass a group of features for constructing