Object-Oriented Software Engineering. PersonGui (Mark 1) Case Study

Transcription

1 Object-Oriented Software Engineering PersonGui (Mark 1) Case Study

2 Contents The PersonGui (Mark1) The The Person Gui (Mark1) ToolBar PersonGui Constructor Adding Buttons Making Buttons Handling Events 2

3 The Person Gui (Mark1): Use Cases user Define Age Define Height Display Attributes 3

4 The Person Gui (Mark1): Class Diagram 1 JPanel <<interface>> ActionListener 1 JToolBar 1 Person private Double height private Double age void setage (String) void setheight (String) String getage () String getheight () String Attributes_Description () PersonGui JFrame 1 1 JTextArea JTextField PersonGui class has caused the JPanel (which it extends) to be linked to a JToolBar 4

5 public void setage (String stringage) { age = new Double(stringAge); Person private Double height private Double age void setage (String) void setheight (String) String getage () String getheight () String Attributes_Description () public void setheight (String stringheight) { height = new Double(stringHeight); public String getage () { return age.tostring(); public String getheight () { return height.tostring(); public String Attributes_Discription () { return "This Person has height " + getheight() + " and has age " + getage() + "\n"; 5

6 JFrame The Person Gui (Mark1) JTextArea JToolBar JTextField 6

7 PersonGui Constructor: JToolBar (Full code available from course web site) public PersonGui() { super(new BorderLayout()); JToolBar toolbar = new JToolBar("Still draggable"); addbuttons(toolbar); toolbar.setfloatable(false); toolbar.setrollover(true); textarea = new JTextArea(5, 30); textarea.seteditable(false); JScrollPane scrollpane = new JScrollPane(textArea); setpreferredsize(new Dimension(750, 430)); add(toolbar, BorderLayout.PAGE_START); add(scrollpane, BorderLayout.CENTER); 7

8 PersonGui Constructor super(new BorderLayout()); Causes the enclosed code to act on the super-class that extends PersonGui. In general for a class extension can invoke methods of parent (super) class via super.method(x,y,z) 8

9 Here's what happens if we don't call super. public PersonGui() { //super(new BorderLayout()); new BorderLayout(); //Create the toolbar.... BorderLayout now attached to toolbar, not JPanel 9

10 PersonGui Constructor Internal method call JToolBar toolbar = new JToolBar("Still draggable"); addbuttons(toolbar); toolbar.setfloatable(false); toolbar.setrollover(true); If the rollover state is true then border of the toolbar buttons will be drawn only when the mouse pointer hovers over them. 10

11 toolbar.setfloatable(true); 11

12 toolbar.setrollover(true); 12

13 addbuttons method protected void addbuttons(jtoolbar toolbar) { JButton button = null; // add first button button = makenavigationbutton(print_attributes, "Prints a String containing agestring and heightstring", "Print Attributes"); toolbar.add(button); Internal method call // add second button button = makenavigationbutton(age, "Sets the value of agestring", "Define Age"); toolbar.add(button); toolbar.addseparator(); textfield.setcolumns(10); textfield.addactionlistener(this); textfield.setactioncommand(text_entered); toolbar.add(textfield); causes actions on text field to be notified to 'this' (i.e PersonGui class) 13

14 makenavigationbutton method protected JButton makenavigationbutton(string actioncommand, String tooltiptext, String alttext) { //Create and initialize the button. JButton button = new JButton(); button.setactioncommand(actioncommand); button.settooltiptext(tooltiptext); button.addactionlistener(this); button.settext(alttext); return button; causes actions on button to be notified to 'this' 14

15 button.setactioncommand(age); button press causes an ActionEvent object to be created, with an action command string set to AGE button.settooltiptext("sets the value of agestring"); when mouse hovers over button this text will appear 15

16 button.addactionlistener(this); creates an ActionListener that is attached to the PersonGui class 16

17 Handling Events: Implementing interface public void actionperformed(actionevent e) { String cmd = e.getactioncommand(); String description = null; if (PRINT_ATTRIBUTES.equals(cmd)) { //first button clicked String text = dude.attributes_discription(); description = text + newline else if (AGE.equals(cmd)) { // second button clicked agestring = textfield.gettext(); dude.setage(agestring); description = "The age of the person in: " + agestring + newline; textfield.settext(""); else if (HEIGHT.equals(cmd)) { // third button clicked... else if (TEXT_ENTERED.equals(cmd)) { // text field... displayresult(description); 17

18 actionperformed(actionevent e) button:jbutton PersonGui addactionlistener(this) left_mouse_click <<create>> e:action Event notify(e ) String cmd = e.getactioncommand(); 18

19 actionperformed(actionevent e) else if (AGE.equals(cmd)) { // second button clicked agestring = textfield.gettext(); dude.setage(agestring); description = "The age of the person in: " + agestring + newline; textfield.settext(""); :PersonGui textfield: dude:person gettext() agestring setage(agestring); settext("") 19

20 else if (HEIGHT.equals(cmd)) { // third button clicked heightstring = textfield.gettext(); dude.setheight(heightstring); description = "The height of the person is: " + heightstring + newline; textfield.settext(""); PersonGui textfield: gettext() dude:person heightstring setheight(heightstring); settext("") 20

21 if (PRINT_ATTRIBUTES.equals(cmd)) { //first button clicked String text = dude.attributes_discription(); description = text + newline; PersonGui dude:person Attributes_Discription( ) text 21

22 displayresult method protected void displayresult(string actiondescription) { textarea.append(actiondescription + newline); textarea.setcaretposition(textarea.getdocument().getlength()); Adds text after caret current position Makes sure next append will occur at the end of document. 22