Cork Institute of Technology. Spring 2006 GUI/Mobile/Web (Time: 3 Hours)

Transcription

1 Cork Institute of Technology Bachelor of Science (Honours) in Software Development Stage 3 (NFQ Level 8) Spring 2006 GUI/Mobile/Web (Time: 3 Hours) Answer FOUR questions ONLY. Show all work. Marks:All questions carry equal marks. Use Java for all code. Note the APIs appendix at the end of the paper. Examiners: Mr. K. Grabe Dr. M. O Cinneide Q1 (a) The following MIDlet displays a list of breakfast items and allows the user to choose one. When the OK soft-key is pressed the text of the chosen item is displayed along with a suitable comment depending on which item was chosen: Write the following code for the MIDlet: 1. The list component with items added (5 marks) 2. The soft-key commands OK and Exit and event delegation (5 marks) 3. A method to handle Exit and OK soft-keys. (5 marks) 4. For OK soft-key display the alert. Add your own comments to be shown in the alert e.g. Buttered Toast: Good Choice, Rice Crispies: Great etc. (5 marks) What is J2ME? In your answer make reference to profiles and configurations. (5 marks) 1

2 Q2. (a) What is a MIDlet? Explain the life cycle of a MIDlet, with the use of an illustration, and explain the typical methods a MIDlet contains and what they do. Describe the constraints you have to take into account when developing an application for a mobile device in comparison to an application for a PC. (10marks) (c) Explain how various mobile devices with different command key (soft-key) set-ups can be accessed from a MIDlet program. (5 marks) Q3. (a) How would you create and set a Font in Java? With a diagram show what the following font metrics are: Height, Accent, Baseline, Leading, and Descent. (7 marks) Explain how the Color class is used to represent colour. Illustrate with a code example how you could set the current colour to green. (8 marks) (c) Write a paint( ) method for an applet that draws the following objects: an empty green circle, a solid blue rectangle with a width of 20 pixels and height of 40 pixels, an empty black polygon with 4 points, and an solid black arc that starts at 10 degrees and sweeps anticlockwise for 80 degrees (i.e finishing perpendicular to horizon). How would you erase the rectangle? 2

3 Q4. (a) A company is developing a GUI for a CD player for a PC. The GUI should allow the user to perform the following functions: select a track to play from a list play, pause, eject disk Report errors using a dialog. Display instructions/status to the user Allow the user to enter comments for the tracks Choose a GUI component for each of the functions listed above and for each one: (i) Show how to construct the component and make it visible on the screen (ii) Say what type(s) of events it generates, if any. (iii) Illustrate with code how these events can be handled (include a class for creating a listener object). (15 marks) Develop the code to be added to an application s constructor for the menus in the following program: The File New menu is a hierarchical menu, which contains items Window and Project. Add a keyboard mnemonics as shown above for the Quit and Window menu items only. Add event handler code for the Quit menu item, which allows the application to terminate when it is selected. 3

4 Q5. (a) For the JScrollpane component illustrate the following items with a diagram: Viewport Scrollable client Row Header Column Header Scroll bars Illustrate with code how to create a JTextArea component with no horizontal scrollbars and vertical scrollbars that appear only when needed. Write an application that provides a front end to a room temperature controller and has the following GUI: A slider component is set-up to vary the temperature between 10 Celsius and 30 Celsius. At program start-up the slider is set to an initial value of 20 Celsius. Tick marks should be displayed at 2 intervals and the slider should snap to these marks. When the slider setting is changed your program should display the new temperature setting on the screen. In the screen-capture example shown above the slider has been moved to the second-last tick and so is at the 28 position. Clicking on the close window icon should terminate the application. (15 marks) 4

5 Q6 (a) Define the terms Internationalisation, Localisation and Locale. List five guidelines a GUI designer should follow to insure a product can easily be localised. Illustrate two of the guidelines you ve listed with an example. In software we define Accessibility as the suite of software services and support in an application that allows people with disabilities to utilise all of the functionality of that user environment. Give five reasons why it is important to include accessibility in the design of a user interface. Explain in each of the following cases how a GUI design can cater for individuals with the following disabilities: i. Repetitive Strain Injuries (RSI) ii. Physical iii. Low Vision iv. Blindness v. Hearing Disabilities (c) List 5 guidelines for developing a user interface for a novice. (5 marks) 5

6 Appendix Taken from: Java 2 Platform, Standard Edition (J2SE) API Specification: void setforeground(color c) void Font(String name, int style, int size) Font class constants: BOLD, PLAIN, ITALIC void drawoval(int x, int y, int width, int height) void drawrect(int x, int y, int width, int height) public abstract void drawarc(int x, int y, int width, int height, int startangle, int arcangle) public Polygon( int xvalues[], int yvalues[], int numberofpoints); drawpolygon(polygon p) GridLayout(int rows, int cols, int hgap, int vgap) String Class public String tolowercase() public String touppercase() JScrollPane(Component view) Creates a JScrollPane that displays the contents of the specified component void setverticalscrollbarpolicy(int policy) void sethorizontalscrollbarpolicy(int policy) Constants for JScrollPane: HORIZONTAL_SCROLLBAR_NEVER, VERTICAL_SCROLLBAR_ALWAYS etc. public TextField(String text, int columns) Constructs a new text field public TextArea(int rows, int columns) Constructs a new empty text area JPanel Has inherited method paintcomponent(graphics g) JTextArea( string, numrows, numcolumns ) void append(string str) Appends the given text to a text area's current text. public void cut() Transfers the currently selected text to the clipboard, removing it from the JTextArea public void paste() Transfers the contents of the system clipboard into the associated JTextArea. showmessagedialog(component parentcomponent, Object message) // From JoptionPane class JMenu(String s) Constructs a new JMenu with the supplied string as its text. public void addseparator() add(jmenuitem menuitem) Appends a menu item to the end of this menu. JMenuItem(String text) Creates a menuitem with text. addactionlistener(actionlistener l) Adds an ActionListener to the button. (from JMenuItem Subclass) setmnemonic(char mnemonic) Specifies the mnemonic value (from JMenuItem Subclass) JSlider (int orientation, int min, int max, int value) Constants for JSlider: SwingConstants.HORIZONTAL, SwingConstants.VERTICAL setmajortickspacing( n ) setpaintticks( boolean ) getvalue() addchangelistener(changelistener l) void setsnaptoticks (boolean b) snaps slider to tickmarks Interface ChangeListener: voidstatechanged (ChangeEvent e) static int parseint(string s) Parses the string argument as a signed decimal integer. (from Integer Class) static double parsedouble(string s) Returns a double set to the value represented by the String(from class Double) From JOptionPane class: public static String showinputdialog(component parentcomponent, Object message) public static void showmessagedialog(component parentcomponent, Object message) public static void showmessagedialog(component parentcomponent, Object message, String title, int messagetype) Fields: JOptionPane.PLAIN_MESSAGE JOptionPane.ERROR_MESSAGE JOptionPane.INFORMATION_MESSAGE JOptionPane.WARNING_MESSAGE JOptionPane.QUESTION_MESSAGE Note: Methods other than those listed above may be required in solutions to answers. Also not every method listed is required in your solutions. 6

7 Appendix Taken from: JavaTM 2 Platform, Micro Edition (J2ME) API Specification: Class List List(String title, int listtype) int append(string stringpart, Image imagepart) int getselectedindex( ) void delete(int elementnum) static Command SELECT_COMMAND Interface Choice (also for use with List) static int EXCLUSIVE, static int IMPLICIT, static int MULTIPLE Class TextBox TextBox(String title, String text, int maxsize, int constraints) void setstring(string text) String getstring() int setmaxsize(int maxsize) int getmaxsize() Class TextField TextField(String label, String text, int maxsize, int constraints) void setstring(string text) String getstring() int setmaxsize(int maxsize) int getmaxsize() Class Alert Alert(String title) Alert(String title, String alerttext, Image alertimage, AlertType alerttype) void settimeout(int time) static int FOREVER Class Displayable public void addcommand(command cmd) void setcommandlistener(commandlistener l) void setticker(ticker ticker) Class Display void setcurrent(displayable nextdisplayable) Class Form Form(String title) Form(String title, Item[] items int append(image img) int append(string str) Interface CommandListener void commandaction(command c, Displayable d) Class Command Command(String label, int commandtype, int priority) static int BACK, static int CANCEL, static int EXIT, static int HELP, static int ITEM, static int OK, static int SCREEN, static int STOP Note: Methods other than those listed above may be required in solutions to answers. Also not every method listed is required in your solutions 7