i m writing one application in which i have created custom list field for displaying listview.
my CustomListField contains one image and text in a row. i m gettiing field change listener on click of listfield row but i want to put fieldchange listener on image too..
can anyone tell me how can i do that.
here is my code.
public class CustomListField extends ListField implements ListFieldCallback {
private Vector _listData;
private int _MAX_ROW_HEIGHT = 60;
public CustomListField(Vector data) {
_listData = data;
setSize(_listData.size());
setSearchable(true);
setCallback(this);
setRowHeight(_MAX_ROW_HEIGHT);
}
protected void drawFocus(Graphics graphics, boolean on) {
XYRect rect = new XYRect();
graphics.setGlobalAlpha(150);
graphics.setColor(Color.BLUE);
getFocusRect(rect);
drawHighlightRegion(graphics, HIGHLIGHT_FOCUS, true, rect.x, rect.y, rect.width, rect.height);
}
public int moveFocus(int amount, int status, int time) {
this.invalidate(this.getSelectedIndex());
return super.moveFocus(amount, status, time);
}
public void onFocus(int direction) {
super.onFocus(direction);
}
protected void onUnFocus() {
this.invalidate(this.getSelectedIndex());
}
public void refresh() {
this.getManager().invalidate();
}
public void drawListRow(ListField listField, Graphics graphics, int index, int y, int w) {
listField.setBackground(BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("listing_bg.png")));
ListRander listRander = (ListRander) _listData.elementAt(index);
graphics.setGlobalAlpha(255);
graphics.setFont(Font.getDefault().getFontFamily().getFont(Font.PLAIN, 24));
final int margin = 5;
final Bitmap thumb = listRander.getListThumb();
final String listHeading = listRander.getListTitle();
final Bitmap nevBar = listRander.getNavBar();
// list border
graphics.setColor(Color.GRAY);
graphics.drawRect(0, y, w, _MAX_ROW_HEIGHT);
// thumbnail border & thumbnail image
graphics.setColor(Color.BLACK);
// graphics.drawRoundRect(margin-2, y+margin-2,thumb.getWidth()+2, thumb.getHeight()+2, 5, 5);
graphics.drawBitmap(margin, y + margin, thumb.getWidth(), thumb.getHeight(), thumb, 0, 0);
// drawing texts
// graphics.setFont(Font.BOLD);
graphics.drawText(listHeading, margin + thumb.getWidth(), y + margin);
graphics.setColor(Color.GRAY);
// graphics.setFont(Font.smallFont); // graphics.drawText(listDesc, 2*margin+thumb.getWidth(), y+ margin+20); // //
// graphics.drawText(listDesc2, 2*margin+thumb.getWidth(), y+ margin+32);
// draw navigation button
final int navBarPosY = y + (_MAX_ROW_HEIGHT / 2 - nevBar.getHeight() / 2);
final int navBarPosX = Graphics.getScreenWidth() - nevBar.getWidth() + margin;
graphics.drawBitmap(navBarPosX, navBarPosY, nevBar.getWidth(), nevBar.getHeight(), nevBar, 0, 0);
}
public Object get(ListField listField, int index) {
String rowString = (String) _listData.elementAt(index);
return rowString;
}
public int indexOfList(ListField listField, String prefix, int start) {
for (Enumeration e = _listData.elements(); e.hasMoreElements();) {
String rowString = (String) e.nextElement();
if (rowString.startsWith(prefix)) {
return _listData.indexOf(rowString);
}
}
return 0;
}
public int getPreferredWidth(ListField listField) {
return 3 * listField.getRowHeight();
}
/*
protected boolean trackwheelClick(int status, int time) {
invalidate(getSelectedIndex());
Dialog.alert(" U have selected :" + getSelectedIndex());
return super.trackwheelClick(status, time);
}
*/
}
i want to put click listner on star image of listfield row
and following is output of abbove code.
I did something very similar to this on a past project:
Background
As Arhimed said in his answer, and as you can read about on the BlackBerry forums here, you can't have full-fledged Field objects within the ListField. The content of ListField rows is just drawn directly in drawListRow() as text, and Bitmaps, etc. The contents aren't Field instances, and therefore, are not focusable.
So, what I did was to replace ListField with a subclass of Manager. Originally, I used a VerticalFieldManager, but I ran into problems with that. I've also been seeing a lot of issues on stack overflow, where people subclass VerticalFieldManager, customize just one small behaviour, and everything starts breaking. It seems to me that VerticalFieldManager works well if you accept its normal behaviour, and if you need something more, just extend Manager directly. Performing layout for vertically stacked rows is pretty easy.
I then made each row its own Manager, and implemented custom layout in sublayout() to place the row's Fields where I wanted them. I could then also make the row focusable, and then a bitmap/button on the row separately focusable (like your star). Clicking the row invokes one action, and clicking the star invokes another one.
I will note, however, that in my app, performance was not an issue, because I only had 10-20 rows. Also, I did have to modify my code to match your example, so consider this code only lightly tested. However, I did build it into an app, so it should perform fine as long as my assumptions, and your description were valid.
Implementation
First, it wasn't clear to me what your ListRander is (you didn't show that code). However, in my code, I need a data class to contain details about one row. It looked like that's how you used ListRander, so that's what I used:
public class ListRander {
private String _title;
private Bitmap _thumb;
public ListRander(String title, Bitmap thumb) {
_title = title;
_thumb = thumb;
}
public String getTitle() {
return _title;
}
public Bitmap getThumb() {
return _thumb;
}
}
Then, I replaced your CustomListField class with my own:
public class CustomListField extends Manager implements FocusChangeListener {
private int _MAX_ROW_HEIGHT = 60;
private boolean _searchable = false;
private Vector _listData;
private FieldChangeListener _fieldListener;
public CustomListField(Vector data) {
super(FOCUSABLE | VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
setSearchable(true);
setEditable(false);
setListData(data);
}
public void setChangeListener(FieldChangeListener listener) {
// we need to save this listener, because we set it to listen to all new rows
_fieldListener = listener;
int numFields = getFieldCount();
for (int f = 0; f < numFields; f++) {
getField(f).setChangeListener(listener);
}
super.setChangeListener(listener);
}
public int getRowHeight() {
return _MAX_ROW_HEIGHT;
}
public void setSearchable(boolean searchable) {
_searchable = searchable;
}
public int getSelectedIndex() {
return getFieldWithFocusIndex(); // TODO??
}
public Object get(int index) {
return _listData.elementAt(index);
}
public int indexOfList(String prefix, int start) {
if (start >= _listData.size() || !_searchable) {
return -1;
} else {
int result = getSelectedIndex(); // the default result if we find no matches
for (Enumeration e = _listData.elements(); e.hasMoreElements(); ) {
String rowString = (String) e.nextElement();
if (rowString.startsWith(prefix)) {
return _listData.indexOf(rowString);
}
}
return result;
}
}
protected boolean navigationClick(int status, int time) {
CustomListRow focus = (CustomListRow) getFieldWithFocus();
if (focus != null) {
// see if the row wants to process this click
if (!focus.navigationClick(status, time)) {
// let our FieldChangeListener know that this row has been clicked
fieldChangeNotify(getFieldWithFocusIndex());
}
return true;
} else {
return false;
}
}
protected void sublayout(int width, int height) {
int w = Math.min(width, getPreferredWidth());
int h = Math.min(height, getPreferredHeight());
int rowHeight = getRowHeight();
int numRows = getFieldCount();
setExtent(w, h);
setVirtualExtent(w, rowHeight * numRows);
for (int i = 0; i < numRows; i++) {
Field f = getField(i);
setPositionChild(f, 0, rowHeight * i);
layoutChild(f, w, rowHeight);
}
}
public int getPreferredWidth() {
return Display.getWidth();
}
public int getPreferredHeight() {
return Display.getHeight();
}
public void setListData(Vector listData) {
_listData = listData;
if (listData != null) {
int listSize = listData.size();
int numRows = getFieldCount();
for (int s = 0; s < listSize; s++) {
if (s < numRows) {
// we can reuse existing CustomListRows
CustomListRow row = (CustomListRow) getField(s);
row.setData((ListRander) listData.elementAt(s));
} else {
CustomListRow row = new CustomListRow((ListRander) listData.elementAt(s));
row.setChangeListener(_fieldListener);
row.setFocusListener(this);
add(row);
}
}
if (listSize < numRows) {
// delete the excess rows
deleteRange(listSize, numRows - listSize);
}
} else {
deleteAll();
}
invalidate();
}
public void focusChanged(Field field, int eventType) {
// we handle scrolling here, when focus changes between rows
if (eventType == FOCUS_GAINED) {
if (field.getTop() < getVerticalScroll()) {
// field is off the top of the screen, so scroll up
setVerticalScroll(field.getTop());
} else if (field.getTop() >= getVerticalScroll() + getVisibleHeight()) {
// field is off the bottom of the screen, so scroll down
setVerticalScroll(field.getTop() - getVisibleHeight() + getRowHeight());
}
}
}
}
Finally, one row is represented by my CustomListRow class:
public class CustomListRow extends Manager implements FieldChangeListener {
private static final int _MAX_ROW_HEIGHT = 60;
private ListRander _data;
private BitmapField _thumb;
private LabelField _title;
private FocusableBitmapField _star;
private static final Bitmap _starImg = Bitmap.getBitmapResource("star.png");
private static final Bitmap _bgImg = Bitmap.getBitmapResource("listing_bg.png");
private SeparatorField _separator;
private int _fontColor = Color.BLACK;
private boolean _highlighted = false;
private int _width;
// subclass exists to expose focus methods (make public)
private class FocusableBitmapField extends BitmapField {
public FocusableBitmapField() {
super(_starImg, BitmapField.FOCUSABLE | BitmapField.EDITABLE);
}
public void onFocus(int direction) {
super.onFocus(direction);
}
public void onUnfocus() {
super.onUnfocus();
}
}
public CustomListRow(ListRander data) {
super(Field.FOCUSABLE | Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR);
setBackground(BackgroundFactory.createBitmapBackground(_bgImg));
_width = Display.getWidth();
long labelStyle = (DrawStyle.LEFT | DrawStyle.TOP | DrawStyle.ELLIPSIS);
_title = new LabelField("", labelStyle) { // custom anonymous class to change font color
protected void paint(Graphics g) {
int c = g.getColor();
g.setColor(_fontColor);
super.paint(g);
g.setColor(c);
}
};
_title.setFont(Font.getDefault().getFontFamily().getFont(Font.PLAIN, 24));
_thumb = new BitmapField();
_star = new FocusableBitmapField();
_star.setChangeListener(this);
_separator = new SeparatorField() { // custom anonymous class to change separator color
protected void paint(Graphics g) {
int c = g.getColor();
g.setColor(Color.GRAY);
super.paint(g);
g.setColor(c);
}
};
setData(data);
add(_thumb);
add(_title);
add(_star);
add(_separator);
}
public ListRander getData() {
return _data;
}
public void setData(ListRander value) {
if (value != _data) {
_data = value;
_title.setText(value.getTitle());
_thumb.setBitmap(value.getThumb());
}
}
private void onStarClicked() {
Dialog.alert("Star has been clicked or tapped!");
}
private void onRowClicked() {
Dialog.alert("Row has been clicked or tapped!");
}
public void fieldChanged(Field field, int context) {
if (field == _star) {
onStarClicked();
}
}
public boolean navigationClick(int status, int time) {
if (_star.isFocus()) {
onStarClicked();
return true;
} /* else {
onRowClicked();
return true;
} */
return false; // we will not consume this event
}
protected void highlight(boolean onRow) {
_fontColor = onRow ? Color.WHITE : Color.BLACK; // change font color for contrast
_highlighted = onRow;
invalidate();
}
protected void onFocus(int direction) {
// called when focus first transfers to this row, from another Field
if (direction == 1) {
// coming from top to bottom, we highlight the row first, not the star
highlight(true);
} else if (direction == -1) {
// coming from bottom to top, we highlight the star button first, not the row
_star.onFocus(direction);
highlight(false);
}
}
protected void onUnfocus() {
// remove highlighting of the row, if any
highlight(false);
super.onUnfocus();
}
protected int moveFocus(int amount, int status, int time) {
// called when this row already has focus (either on row, or star button)
if (amount > 0) {
// moving top to bottom
if (!_star.isFocus()) {
// we were on the row, now move to the star button
_star.onFocus(1);
highlight(false);
amount--; // consume one unit of movement
}
} else {
// moving from bottom to top
if (_star.isFocus()) {
// we were on the star button, now move back over to the row
_star.onUnfocus();
highlight(true);
amount++; // consume one unit of movement
}
}
return amount;
}
protected boolean touchEvent(net.rim.device.api.ui.TouchEvent event) {
// We take action when the user completes a click (a.k.a. unclick)
int eventCode = event.getEvent();
if ((eventCode == TouchEvent.UNCLICK) || (eventCode == TouchEvent.DOWN)) {
// Get the touch location, within this Manager
int x = event.getX(1);
int y = event.getY(1);
if ((x >= 0) && (y >= 0) && (x < _width) && (y < _MAX_ROW_HEIGHT)) {
int field = getFieldAtLocation(x, y);
if ((field >= 0) && (getField(field) == _star)) {
// Let event propagate to (star) button field
return super.touchEvent(event);
} else {
if (eventCode == TouchEvent.UNCLICK) {
// A completed click anywhere else in this row should popup details for this selection
fieldChangeNotify(1);
onRowClicked();
} else {
// This is just a soft touch (TouchEvent.DOWN), without full click
setFocus();
}
// Consume the event
return true;
}
}
}
// Event wasn't for us, let superclass handle in default manner
return super.touchEvent(event);
}
protected void sublayout(int width, int height) {
height = Math.min(getPreferredHeight(), height);
setExtent(_width, height);
final int margin = 5;
int thumbWidth = _thumb.getPreferredWidth();
layoutChild(_thumb, thumbWidth, _thumb.getPreferredHeight());
setPositionChild(_thumb, margin, margin);
int starWidth = _star.getPreferredWidth();
int starHeight = _star.getPreferredHeight();
layoutChild(_star, starWidth, starHeight);
setPositionChild(_star, width - starWidth - margin, (height - starHeight) / 2);
// this assumes you want margin between all fields, and edges
layoutChild(_title, width - thumbWidth - starWidth - 4 * margin, _title.getPreferredHeight());
setPositionChild(_title, margin + thumbWidth /* + margin */, margin); // TODO?
}
protected void paintBackground(Graphics g) {
super.paintBackground(g);
if (_highlighted) {
// you can't override drawFocus() for a Manager, so we'll handle that here:
int oldColor = g.getColor();
int oldAlpha = g.getGlobalAlpha();
XYRect rect = new XYRect();
g.setGlobalAlpha(150);
g.setColor(Color.BLUE);
getFocusRect(rect);
drawHighlightRegion(g, HIGHLIGHT_FOCUS, true, rect.x, rect.y, rect.width, rect.height);
g.setGlobalAlpha(oldAlpha);
g.setColor(oldColor);
}
}
public int getPreferredWidth() {
return _width;
}
public int getPreferredHeight() {
return _MAX_ROW_HEIGHT;
}
}
Usage
This is how you might use the whole list field (maybe in a Screen class):
public class ListScreen extends MainScreen implements FieldChangeListener {
public ListScreen() {
try {
Vector data = new Vector();
Bitmap icon = Bitmap.getBitmapResource("list_icon.png");
for (int i = 0; i < 15; i++) {
ListRander lr = new ListRander("Product Name " + i, icon);
data.addElement(lr);
}
CustomListField list = new CustomListField(data);
add(list);
list.setChangeListener(this);
} catch (Exception e) {
e.printStackTrace();
}
}
public void fieldChanged(Field field, int context) {
if (field instanceof CustomListRow) {
CustomListRow row = (CustomListRow) field;
Dialog.alert(row.getData().getTitle() + " was selected!");
}
}
}
In my app, it made sense for the CustomListRow itself to handle the equivalent of your star click. However, for me, it did not make sense to have the row click handled that way. So, I let you set a FieldChangeListener on the CustomListField itself, which is called back when any row is selected. See the example above in my screen class. If you want to handle the row click inside the CustomListRow class, too, that's fine. I laid out a onRowClicked() method there. Search in the code for where that's commented out, and you can reactivate, an implement that method (onRowClicked()).
Issues
My app didn't require list searching. I laid out a sample implementation of that, like ListField has. But, I didn't test it. That's your job, if you need it. I just got you started with the CustomListField implementation (see indexOfList()).
I didn't see what your "nav bar" was for. A bar is usually a full-width item, like a status bar, or toolbar. I don't see anything like that in your screenshot. A nav item might be a little arrow at the right side of each row, to bring up details. But, I didn't see that in your screenshot either. So, I ignored that code. If you need a nav bar, you obviously know what it should be, and can add that to my code above.
I couldn't tell whether or not you just added the star as part of the row's background image, or if you had a separate image for that. I added a separate star.png to represent the star. I would assume that clicking the star fills it in, or highlights it, or something. But, you didn't describe that problem, so I assume you can handle that. If you need a custom field to represent the star, that can have selected and unselected images, just post that as a new question.
You had some code that appeared like it was trying to set the row width to 3x the row height, but that didn't match your screen shot. Most lists are full-screen width anyway. So, I remove that code. My CustomListRow class implements getPreferredWidth() and requests the full screen width. Change if you like.
Unlike Android's ListView the BB's ListField is not designed to have a focusable/clickable fields inside of list items. So any attempt to workaround this will have some negative side effects.
A relatively easy/quick workaround would be to switch to VerticalFieldManager (check this other stack overflow question). But if the list is too long (more than several hundreds, I believe) you risk to "eat" too much memory.
If the app is designed for touch screens only, then you can try to stay with ListField + do some manual tracking of touch event coordinates. So when you detect a list field click (in a way you would normally do it) you can check whether the touch coordinates correspond to the star image area (at least on the X axis). I am not going to invent/provide an implementation, but just giving an idea.
I want to manually display a field.
public class Main_NewsDetail extends MainScreen {
private Custom_FontField slider;
private boolean a;
public Main_NewsDetail() {
super(USE_ALL_WIDTH);
slider = new Custom_FontField(
Bitmap.getBitmapResource("slider_thumb_normal.png"),
Bitmap.getBitmapResource("slider_progress_normal.png"),
Bitmap.getBitmapResource("slider_base_normal.png"),
Bitmap.getBitmapResource("slider_thumb_focused.png"),
Bitmap.getBitmapResource("slider_progress_focused.png"),
Bitmap.getBitmapResource("slider_base_focused.png"),
Bitmap.getBitmapResource("slider_thumb_pressed.png"),
Bitmap.getBitmapResource("slider_progress_pressed.png"),
Bitmap.getBitmapResource("slider_base_pressed.png"), 35, 10, 5,
5, FOCUSABLE);
if(a)
add(slider);
}
public class Custom_NewsDetailBottom extends Manager implements
FieldChangeListener {
Custom_NewsDetailBottom() {
super(Manager.USE_ALL_WIDTH | Manager.NO_VERTICAL_SCROLL
| Manager.NO_HORIZONTAL_SCROLL);
Background background = BackgroundFactory
.createBitmapBackground(bg);
setBackground(background);
fontbtn = new Custom_ButtonField(font, fontactive, fontactive) {
protected boolean navigationClick(int status, int time) {
a = !a; <-- here is to control field display
return true;
}
};
fontbtn.setChangeListener(this);
add(fontbtn);
}
protected void sublayout(int width, int height) {
Field field = getField(0);
layoutChild(field, font.getWidth(), font.getHeight());
setPositionChild(field, getGap(), 5);
width = Math.min(width, getPreferredWidth());
height = Math.min(height, getPreferredHeight());
setExtent(width, height);
}
public int getPreferredHeight() {
return 70;
}
public int getPreferredWidth() {
return Display.getWidth();
}
protected void paint(Graphics graphics) {
int rectHeight = getPreferredHeight();
int rectWidth = getPreferredWidth();
graphics.drawRect(0, 0, rectWidth, rectHeight);
super.paint(graphics);
}
private int getGap() {
return ((getPreferredWidth() / 4) - font.getWidth()) / 2;
}
public void fieldChanged(Field field, int context) {
if (field == sharebtn) {
} else if (field == commentbtn) {
Main.getUiApplication().pushScreen(new Main_Comments());
} else if (field == otherbtn) {
Main.getUiApplication().pushScreen(new Menu_Others());
}
}
public boolean keyDown(int keycode, int status) {
if (Keypad.key(keycode) == Keypad.KEY_ESCAPE) {
delete(slider);
return true;
}
return super.keyDown(keycode, status);
}
}
}
Above is the code that display a screen. In fontbtn, When click will change the variable true / false. However, it cannot update instant to display the field slider.
slider is something like seekbar in Android. In android, when click then can setvisibility but not blackberry RIM, so how to control it?
First of all, I would recommend not using variables with names like this if you can avoid it:
private boolean a;
Try to give it a name that's more descriptive, as that will help us understand your code better.
Next, it looks like you are testing the variable a before it ever has a chance to change, in the Main_NewsDetail constructor. So that won't work. Maybe try this in the Main_NewsDetail class:
/** separate boolean used because Field.isVisible() doesn't seem totally robust */
private boolean isSliderVisible = false;
private void setSliderVisible(boolean isVisible) {
if (isVisible != isSliderVisible) {
if (isVisible) {
add(slider);
} else {
delete(slider);
// but, we still retain the "slider" member variable, so it can be
// added again later
}
isSliderVisible = isVisible;
// I'm not actually sure that this is needed. I include it because I can't run this code right now!
invalidate();
}
}
Then, in your button click handler:
fontbtn = new Custom_ButtonField(font, fontactive, fontactive) {
protected boolean navigationClick(int status, int time) {
setSliderVisible(!isSliderVisible);
return true;
}
};
Now, this code can work because your Main_NewsDetail has only one Field in it, the slider. If there are actually multiple Field objects (which you probably will have), then you may need more complicated logic. You may want to show the slider in the same location every time. For that, you can record the index of the slider, in the list of all the Main_NewsDetails fields (for example, is the slider the 1st field, the 2nd, the 5th?). Then, instead of calling add(slider), you would do:
private void setSliderVisible(boolean isVisible) {
if (isVisible != isSliderVisible) {
if (isVisible) {
insert(slider, sliderIndex);
You might need to make Main_NewsDetail a subclass of Manager and implement the sublayout() method. That way, you can make sure that if isSliderVisible, you always lay out the slider in the same position.
Try calling Manager's invalidate-method to force a repaint for the managed area:
Marks this entire manager as requiring repainting.
Invoke this method to signal that this manager's entire region requires repainting.
How do I display a list of items where list items can be selected for further action, in a BlackBerry application?
You want to use a ListField. Here is a sample of code that makes use of the ListField.
class CustomListField extends ListField implements ListFieldCallback
{
public static int x;
public Vector rows;
private Bitmap p1;
int z = this.getRowHeight();
public LabelField label,label2,label3,label4,label5;
public CustomListFieldCode(int rowcount,int service_No,String text1,String time)
{
super(0, ListField.MULTI_SELECT);
setRowHeight(3*z);
setEmptyString("Hooray, no tasks here!", DrawStyle.HCENTER);
setCallback(this);
rows = new Vector();
for (x = 0; x < rowcount; x++)
{
TableRowManager row = new TableRowManager();
if(x%2==0)
row.setBackground(BackgroundFactory.createSolidBackground(Color.AQUA));
label = new LabelField("Service"+x);
row.add(label);
rows.addElement(row);
}
setSize(rows.size());
}
// ListFieldCallback Implementation
public void drawListRow(ListField listField, Graphics g, int index, int y,int width)
{
CustomListFieldCode list = (CustomListFieldCode) listField;
TableRowManager rowManager = (TableRowManager) list.rows.elementAt(index);
rowManager.drawRow(g, 0, y, width, list.getRowHeight());
}
private class TableRowManager extends Manager
{
public TableRowManager()
{
super(0);
}
// Causes the fields within this row manager to be layed out then
// painted.
public void drawRow(Graphics g, int x, int y, int width, int height)
{
// Arrange the cell fields within this row manager.
layout(width, height);
// Place this row manager within its enclosing list.
setPosition(x, y);
// Apply a translating/clipping transformation to the graphics
// context so that this row paints in the right area.
g.pushRegion(getExtent());
// Paint this manager's controlled fields.
subpaint(g);
g.setColor(0x00CACACA);
//g.drawLine(0, 0, getPreferredWidth(), 0);
// Restore the graphics context.
g.popContext();
}
// Arrages this manager's controlled fields from left to right within
// the enclosing table's columns.
protected void sublayout(int width, int height)
{
// write your code for arranging the elements of the row
}
// The preferred width of a row is defined by the list renderer.
public int getPreferredWidth()
{
return Graphics.getScreenWidth();
}
// The preferred height of a row is the "row height" as defined in the
// enclosing list.
public int getPreferredHeight()
{
return getRowHeight();
}
}
public Object get(ListField listField, int index)
{
// TODO Auto-generated method stub
return null;
}
public int getPreferredWidth(ListField listField)
{
// TODO Auto-generated method stub
return 0;
}
public int indexOfList(ListField listField, String prefix, int start)
{
// TODO Auto-generated method stub
return 0;
}
}
for handling the event Use the "TouchEvent" on each row.
i have written a class which implements ListFieldCallBack like,
import java.util.Vector;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ListFieldCallback;
class ListCallBack implements ListFieldCallback
{
private Vector listelements = new Vector();
public void drawListRow(ListField listField, Graphics graphics, int index, int y, int width)
{
String text = (String)listelements.elementAt(index);
graphics.drawText(text,0,y,0,width);
}
public Object get(ListField listField, int index)
{
return listelements.elementAt(index);
}
public int indexOfList(ListField listField, String prefix, int start)
{
return listelements.indexOf(prefix, start);
}
public int getPreferredWidth(ListField listField)
{
return Graphics.getScreenWidth();
}
public void insert(String toInsert, int index)
{
listelements.addElement(toInsert);
}
public void erase()
{
listelements.removeAllElements();
}
}
And in my constructor having the main class is coded as
helloWorld()
{
mylist = new ListField();
ListCallBack myCallBack = new ListCallBack();
mylist.setCallback(myCallBack);
for(int i = 0; i<array.length;i++)//array is a string array
{
list_category.insert(i);
myCallBack.insert(array[i], i);
}
this.add(list_category);
}
this works properly..
like, i am getting output like,
Aby
Eric
Allay
vine
But i want to add another string to the next of that array in the each row displayed in list.. How could i do this?
Like, for example, i want my screen output like,
Aby : Smart
Eric : 0000
Allay : 9789
vine : Like
how could i do this?
You should change the ListFieldCallback.drawListRow(ListField listField, Graphics graphics, int index, int y, int width) to draw that.
Use net.rim.device.api.ui.Graphics API to draw whatever you want.