Difference between revisions of "Teams Winter 2011/team1/BlackBerry/Add Elements to Main Screen"
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− | === 3. Add Elements | + | === 3. Add Elements on Main (First) Screen === |
3.1. Open <code>MyScreen.java</code> class.<br/> | 3.1. Open <code>MyScreen.java</code> class.<br/> | ||
3.2. Create class <code>Student</code> with the following fields: | 3.2. Create class <code>Student</code> with the following fields: | ||
− | < | + | <source lang="java"> |
private String firstName; | private String firstName; | ||
private String lastName; | private String lastName; | ||
private String email; | private String email; | ||
− | </ | + | </source> |
− | 3.3. Add | + | |
− | 3. | + | 3.3. Add three argument constructor: |
− | < | + | <source lang="java"> |
− | + | public Student(String firstName, String lastName, String email) { | |
− | + | this.firstName = firstName; | |
− | 3. | + | this.lastName = lastName; |
− | < | + | this.email = email; |
− | + | } | |
− | Background | + | </source> |
− | + | ||
− | + | 3.4. Add getter method for e-mail and override the <code>toString()</code> from the Object class(it will be used to implement <code>Comparator</code> interface): | |
− | + | <source lang="java"> | |
− | + | public String getEmail() { | |
− | 3. | + | return email; |
− | < | + | } |
− | + | ||
− | + | public String toString() { | |
− | </ | + | return firstName + " " + lastName; |
− | 3. | + | } |
− | < | + | </source> |
− | + | ||
− | + | 3.5. Add class that will hold all Student objects and make necessary manipulations: | |
− | + | <source lang="java"> | |
− | + | public class StudentList extends SortedReadableList implements KeywordProvider { | |
− | + | ||
− | </ | + | public StudentList(Vector students) { |
+ | super(new StudentListComparator()); | ||
+ | loadFrom(students.elements()); | ||
+ | } | ||
+ | |||
+ | /** | ||
+ | * Adds a new element to the list. | ||
+ | * @param element The element to be added. | ||
+ | */ | ||
+ | void addElement(Object element) { | ||
+ | doAdd(element); | ||
+ | } | ||
+ | |||
+ | /** | ||
+ | * A Comparator class used for sorting our Student objects by name. | ||
+ | */ | ||
+ | final static class StudentListComparator implements Comparator { | ||
+ | /** | ||
+ | * Compares two students by comparing their names in alphabetical order. | ||
+ | * @see net.rim.device.api.util.Comparator#compare(Object, Object) | ||
+ | */ | ||
+ | public int compare(Object o1, Object o2) { | ||
+ | if (o1 == null || o2 == null) { | ||
+ | throw new IllegalArgumentException("Cannot compare null students"); | ||
+ | } | ||
+ | return o1.toString().compareTo(o2.toString()); | ||
+ | } | ||
+ | } | ||
+ | |||
+ | public String[] getKeywords(Object element) { | ||
+ | if(element instanceof Student ) | ||
+ | { | ||
+ | return StringUtilities.stringToWords(element.toString()); | ||
+ | } | ||
+ | return null; | ||
+ | } | ||
+ | } | ||
+ | </source> | ||
+ | |||
+ | 3.6. The following elements are added to the <code>MyScreen()</code> constructor:<br/> | ||
+ | <source lang="java"> | ||
+ | // A reference to the UiApplication instance for use in this class | ||
+ | _app = app; | ||
+ | // Obtain a reference to the UiApplication's KeywordFilterField | ||
+ | _keywordFilterField = _app.getKeywordFilterField(); | ||
+ | </source> | ||
+ | |||
+ | 3.7. Other elements are added inside the <code>ViewStudentApp</code> class. Add necessary private fields: | ||
+ | <source lang="java"> | ||
+ | private KeywordFilterField _keywordFilterField; | ||
+ | private StudentList _studentList; | ||
+ | private Vector _students; | ||
+ | </source> | ||
+ | |||
+ | 3.8. Add search field and students list: | ||
+ | <source lang="java"> | ||
+ | MyScreen _mainScreen = new MyScreen(this); | ||
+ | |||
+ | _students = getFromList(); | ||
+ | _studentList = new StudentList(_students); | ||
+ | |||
+ | // Add our list to a KeywordFilterField object. | ||
+ | _keywordFilterField = new KeywordFilterField(); | ||
+ | _keywordFilterField.setSourceList(_studentList, _studentList); | ||
+ | |||
+ | |||
+ | _mainScreen.setTitle(_keywordFilterField.getKeywordField()); | ||
+ | _mainScreen.add(_keywordFilterField); | ||
+ | </source> | ||
+ | |||
+ | 3.9. Add background to the ''keywordFilterField'': | ||
+ | <source lang="java"> | ||
+ | // Attempt to load a bitmap background | ||
+ | try | ||
+ | { | ||
+ | Background bitmapBackground = BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("background.png"), | ||
+ | Background.POSITION_X_CENTER, Background.POSITION_Y_CENTER, Background.REPEAT_BOTH); | ||
+ | _keywordFilterField.setBackground(bitmapBackground); | ||
+ | |||
+ | } | ||
+ | catch (final IllegalArgumentException e) | ||
+ | { | ||
+ | UiApplication.getUiApplication().invokeLater(new Runnable() { | ||
+ | public void run() { | ||
+ | Dialog.alert(e.toString()); | ||
+ | } | ||
+ | }); | ||
+ | } | ||
+ | </source> | ||
+ | |||
+ | 3.10. Add inner class for custom search field: | ||
+ | <source lang="java"> | ||
+ | final static class CustomKeywordField extends BasicEditField { | ||
+ | // Constructor | ||
+ | CustomKeywordField() { | ||
+ | // Custom style. | ||
+ | super(USE_ALL_WIDTH|NON_FOCUSABLE|NO_LEARNING|NO_NEWLINE); | ||
+ | setLabel("Search: "); | ||
+ | } | ||
+ | |||
+ | /** | ||
+ | * Intercepts ESCAPE key. | ||
+ | * @see net.rim.device.api.ui.component.TextField#keyChar(char,int,int) | ||
+ | */ | ||
+ | protected boolean keyChar(char ch, int status, int time) { | ||
+ | switch(ch) { | ||
+ | case Characters.ESCAPE: | ||
+ | // Clear keyword. | ||
+ | if(super.getTextLength() > 0) | ||
+ | { | ||
+ | setText(""); | ||
+ | return true; | ||
+ | } | ||
+ | } | ||
+ | return super.keyChar(ch, status, time); | ||
+ | } | ||
+ | |||
+ | /** | ||
+ | * Overriding super to add custom painting to our class. | ||
+ | * @see net.rim.device.api.ui.Field#paint(Graphics) | ||
+ | */ | ||
+ | protected void paint(Graphics graphics) | ||
+ | { | ||
+ | super.paint(graphics); | ||
+ | // Draw caret. | ||
+ | getFocusRect(new XYRect()); | ||
+ | drawFocus(graphics, true); | ||
+ | } | ||
+ | } | ||
+ | </source> | ||
+ | |||
+ | 3.11. Add the method that creates lists of students: | ||
+ | <source lang="java"> | ||
+ | private Vector getFromList() { | ||
+ | Vector students = new Vector(); | ||
+ | |||
+ | students.addElement(new Student("Anastasia", "Semionova", "asemionova1@learn.senecac.on.ca")); | ||
+ | students.addElement(new Student("Minoo", "Ziaei", "minoo.ziaei@senecac.on.ca")); | ||
+ | students.addElement(new Student("Ladan", "Zadeh", "lzahiroleslamzadeh@learn.senecac.on.ca")); | ||
+ | students.addElement(new Student("Sergiu", "Ecob", "secob@learn.senecac.on.ca")); | ||
+ | |||
+ | return students; | ||
+ | } | ||
+ | |||
+ | /** | ||
+ | * Adds a new element and updates the student list. | ||
+ | * @param str The string to be added to the element list. | ||
+ | */ | ||
+ | void addElementToList(Student student) { | ||
+ | _studentList.addElement(student); | ||
+ | _keywordFilterField.updateList(); | ||
+ | } | ||
+ | </source> | ||
+ | |||
+ | 3.12. Add the method to access the <code>KeywordFilterField</code> object: | ||
+ | <source lang="java"> | ||
+ | KeywordFilterField getKeywordFilterField() { | ||
+ | return _keywordFilterField; | ||
+ | } | ||
+ | </source> | ||
+ | |||
+ | 3.13. Run the application:<br/> | ||
+ | [[Image: BB_mainscreen.png | 300px]]<br/> | ||
+ | 3.14. Type the desired student name in the search field:<br/> | ||
+ | [[Image: BB_search.png | 300px]] |
Latest revision as of 12:35, 9 April 2011
3. Add Elements on Main (First) Screen
3.1. Open MyScreen.java
class.
3.2. Create class Student
with the following fields:
private String firstName;
private String lastName;
private String email;
3.3. Add three argument constructor:
public Student(String firstName, String lastName, String email) {
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
}
3.4. Add getter method for e-mail and override the toString()
from the Object class(it will be used to implement Comparator
interface):
public String getEmail() {
return email;
}
public String toString() {
return firstName + " " + lastName;
}
3.5. Add class that will hold all Student objects and make necessary manipulations:
public class StudentList extends SortedReadableList implements KeywordProvider {
public StudentList(Vector students) {
super(new StudentListComparator());
loadFrom(students.elements());
}
/**
* Adds a new element to the list.
* @param element The element to be added.
*/
void addElement(Object element) {
doAdd(element);
}
/**
* A Comparator class used for sorting our Student objects by name.
*/
final static class StudentListComparator implements Comparator {
/**
* Compares two students by comparing their names in alphabetical order.
* @see net.rim.device.api.util.Comparator#compare(Object, Object)
*/
public int compare(Object o1, Object o2) {
if (o1 == null || o2 == null) {
throw new IllegalArgumentException("Cannot compare null students");
}
return o1.toString().compareTo(o2.toString());
}
}
public String[] getKeywords(Object element) {
if(element instanceof Student )
{
return StringUtilities.stringToWords(element.toString());
}
return null;
}
}
3.6. The following elements are added to the MyScreen()
constructor:
// A reference to the UiApplication instance for use in this class
_app = app;
// Obtain a reference to the UiApplication's KeywordFilterField
_keywordFilterField = _app.getKeywordFilterField();
3.7. Other elements are added inside the ViewStudentApp
class. Add necessary private fields:
private KeywordFilterField _keywordFilterField;
private StudentList _studentList;
private Vector _students;
3.8. Add search field and students list:
MyScreen _mainScreen = new MyScreen(this);
_students = getFromList();
_studentList = new StudentList(_students);
// Add our list to a KeywordFilterField object.
_keywordFilterField = new KeywordFilterField();
_keywordFilterField.setSourceList(_studentList, _studentList);
_mainScreen.setTitle(_keywordFilterField.getKeywordField());
_mainScreen.add(_keywordFilterField);
3.9. Add background to the keywordFilterField:
// Attempt to load a bitmap background
try
{
Background bitmapBackground = BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("background.png"),
Background.POSITION_X_CENTER, Background.POSITION_Y_CENTER, Background.REPEAT_BOTH);
_keywordFilterField.setBackground(bitmapBackground);
}
catch (final IllegalArgumentException e)
{
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
Dialog.alert(e.toString());
}
});
}
3.10. Add inner class for custom search field:
final static class CustomKeywordField extends BasicEditField {
// Constructor
CustomKeywordField() {
// Custom style.
super(USE_ALL_WIDTH|NON_FOCUSABLE|NO_LEARNING|NO_NEWLINE);
setLabel("Search: ");
}
/**
* Intercepts ESCAPE key.
* @see net.rim.device.api.ui.component.TextField#keyChar(char,int,int)
*/
protected boolean keyChar(char ch, int status, int time) {
switch(ch) {
case Characters.ESCAPE:
// Clear keyword.
if(super.getTextLength() > 0)
{
setText("");
return true;
}
}
return super.keyChar(ch, status, time);
}
/**
* Overriding super to add custom painting to our class.
* @see net.rim.device.api.ui.Field#paint(Graphics)
*/
protected void paint(Graphics graphics)
{
super.paint(graphics);
// Draw caret.
getFocusRect(new XYRect());
drawFocus(graphics, true);
}
}
3.11. Add the method that creates lists of students:
private Vector getFromList() {
Vector students = new Vector();
students.addElement(new Student("Anastasia", "Semionova", "asemionova1@learn.senecac.on.ca"));
students.addElement(new Student("Minoo", "Ziaei", "minoo.ziaei@senecac.on.ca"));
students.addElement(new Student("Ladan", "Zadeh", "lzahiroleslamzadeh@learn.senecac.on.ca"));
students.addElement(new Student("Sergiu", "Ecob", "secob@learn.senecac.on.ca"));
return students;
}
/**
* Adds a new element and updates the student list.
* @param str The string to be added to the element list.
*/
void addElementToList(Student student) {
_studentList.addElement(student);
_keywordFilterField.updateList();
}
3.12. Add the method to access the KeywordFilterField
object:
KeywordFilterField getKeywordFilterField() {
return _keywordFilterField;
}
3.13. Run the application:
3.14. Type the desired student name in the search field: