Stuck on first attempt at Blackberry App - blackberry

Question

attempting a first Blackberry App.
It will display diary data (eventually).
I'm just trying to get things working bit by bit.
I can't get the buttons to work in the simulator ie I click them and nothing happens.
Any help appreciated.
Code is below (hopefully ok formatted - first post so apologies if not).
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.FieldChangeListener;
import net.rim.device.api.ui.component.ButtonField;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.SeparatorField;
import net.rim.device.api.ui.container.HorizontalFieldManager;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;
/**
* A class extending the MainScreen class.
*/
public class MyScreen extends MainScreen implements FieldChangeListener
{
/**
* Creates a new MyScreen object
*/
ButtonField lastWeek;
ButtonField todayWeek;
ButtonField nextWeek;
LabelField Monday;
LabelField MondayData;
LabelField Tuesday;
LabelField TuesdayData;
LabelField Wednesday;
LabelField WednesdayData;
LabelField Thursday;
LabelField ThursdayData;
LabelField Friday;
LabelField FridayData;
LabelField Satday;
LabelField SaturdayData;
LabelField Sunday;
LabelField SundayData;
public MyScreen(){
LabelField banner = new LabelField("Diary",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField title = new LabelField("Week starting...",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Monday = new LabelField("Monday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField MondayData = new LabelField("MondayData",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Tuesday = new LabelField("Tuesday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField TuesdayData = new LabelField("TuesdayData",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Wednesday = new LabelField("Wednesday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField WednesdayData = new LabelField("WednesdayData",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Thursday = new LabelField("Thursday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField ThursdayData = new LabelField("ThursdayData",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Friday = new LabelField("Friday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField FridayData = new LabelField("FridayData",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Saturday = new LabelField("Saturday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField SaturdayData = new LabelField("SaturdayData",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField Sunday = new LabelField("Sunday",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
LabelField SundayData = new LabelField("Sundaydata",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
HorizontalFieldManager hfm = new HorizontalFieldManager(Field.FIELD_HCENTER);
ButtonField lastWeek = new ButtonField("<<", ButtonField.CONSUME_CLICK);
lastWeek.setChangeListener(this);
ButtonField todayWeek = new ButtonField("Today", ButtonField.CONSUME_CLICK);
todayWeek.setChangeListener(this);
ButtonField nextWeek = new ButtonField(">>", ButtonField.CONSUME_CLICK);
nextWeek.setChangeListener(this);
hfm.add(lastWeek);hfm.add(todayWeek);hfm.add(nextWeek);
hfm.setPadding(10, 0, 10, 0);
VerticalFieldManager vfm = new VerticalFieldManager(Field.FIELD_VCENTER);
vfm.add(Monday);
vfm.add(MondayData);
vfm.add(Tuesday);
vfm.add(TuesdayData);
vfm.add(Wednesday);
vfm.add(WednesdayData);
vfm.add(Thursday);
vfm.add(ThursdayData);
vfm.add(Friday);
vfm.add(FridayData);
vfm.add(Saturday);
vfm.add(SaturdayData);
vfm.add(Sunday);
vfm.add(SundayData);
add(vfm);
add(new SeparatorField());
setTitle(title);
setBanner(banner);
setStatus(hfm);
}
public void fieldChanged(Field field, int context) {
if (field == lastWeek) {
lastTextFields();
}
else if (field == todayWeek) {
todayTextFields();
}
else if (field == nextWeek) {
nextTextFields();
}
}
private void lastTextFields() {
Monday.setText("Monday-old");
MondayData.setText("MondayData-old");
}
public void todayTextFields() {
//Monday.setText("Monday");
// MondayData.setText("MondayData");
Dialog.inform("Today pressed");
}
private void nextTextFields() {
Monday.setText("Monday-new");
MondayData.setText("MondayData-new");
}
}

Answer 1

Since you are running your application on 8520 device simulator that doesn't have touch screen, clicking on the buttons will get you nowhere. There are several options available:
Navigate to desired button by using one of the following methods:
Use the keyboard arrow keys to navigate. Press Enter to "click" on it.
Use your mouse's scroll wheel to navigate and then left click to "click".
Press F12 to turn "trackball mode" on and use your mouse navigate. Then either press Enter or right click when the desired button is selected.
Also check this Use the trackball and other Simulating BlackBerry device interaction manuals.
Alternatively, you can compile your application with JRE 6.0 or higher and pick a use a device simulator that supports touchscreen (9800 Torch, 9930 Bold and etc...).
EDIT
You are initiating local LabelFields and ButtonFields instead of the class' member variable. All class member variable remained uninitialized (e.g. equal null). You should remove the redundant local variable definitions.
Update all your LabelFields and ButtonFields in the following way:
LabelField banner = new LabelField("Diary", LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
ButtonField lastWeek = new ButtonField("<<", ButtonField.CONSUME_CLICK);