Get field value from PopupScreen back to MainScreen in Blackberry - blackberry

Question

Now i have a MyScreen which extends from MainScreen containing a button. When the button clicked, it will show the PopupScreen containing list of RadioButtonFields, OK and Cancel buttons. My question is how to get RadioButtonField value from PopupScreen back to MyScreen.
Please help me in this case.
Thanks
Below is my code
MyScreen.java
public class MyScreen extends MainScreen{
private int currentValue = 0;
public MyScreen() {
LabelField lblField = new LabelField();
lblField.setText("Current Value = " + currentValue);
ButtonField btnPopup = new ButtonField("Show Popup");
btnPopup.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().pushScreen(new MyPopupScreen());
}
});
add(lblField);
add(btnPopup);
}
}
MyPopupScreen
public class MyPopupScreen extends PopupScreen implements FieldChangeListener {
private int currentValue = -1;
public MyPopupScreen() {
super(new VerticalFieldManager(VerticalFieldManager.VERTICAL_SCROLL|VerticalFieldManager.VERTICAL_SCROLLBAR), Field.FOCUSABLE
);
add(new LabelField("Select Chart Type"));
RadioButtonGroup radioGroup = new RadioButtonGroup();
for (int i = 0; i < 10; i++) {
RadioButtonField radio = new RadioButtonField("Option no. " + i, radioGroup, false);
radio.setChangeListener(this);
add(radio);
}
ButtonField cancelBtn = new ButtonField("Close");
ButtonField okBtn = new ButtonField("OK");
add(okBtn);
add(cancelBtn);
cancelBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().popScreen();
}
});
okBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
//How to get radio value or index value to pass back to MyScreen
}
});
}
public void fieldChanged(Field field, int context) {
if (field instanceof RadioButtonField) {
RadioButtonField radio = (RadioButtonField) field;
currentValue = radio.getIndex();
}
}
}

Answer 1

As Vijay, suggested this is one way that we could achieve this using inner class. The other approach could be, using design observer design patterns.
Try understanding the below code, and use what ever is efficient for you.
MyScreen.java
public class MyScreen extends MainScreen implements MyListener {
MyScreen screen = null;
public MyScreen() {
screen = this;
LabelField lblField = new LabelField();
lblField.setText("Current Value = " + currentValue);
ButtonField btnPopup = new ButtonField("Show Popup");
btnPopup.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().pushScreen(new MyPopupScreen(screen));
}
});
add(lblField);
add(btnPopup);
}
public void valueChanged(int selectedIdx) {
Dialog.alert(selectedIdx );
}
}
MyListener.java
public interface MyListener {
public void valueChanged(int selectedIdx);
}
MyPopupScreen.java
public class MyPopupScreen extends PopupScreen implements FieldChangeListener {
MyScreen deligate = null;
public MyPopupScreen(final MyScreen deligate) {
super(new VerticalFieldManager(VerticalFieldManager.VERTICAL_SCROLL|VerticalFieldManager.VERTICAL_SCROLLBAR), Field.FOCUSABLE);
this.deligate = deligate;
add(new LabelField("Select Type"));
ButtonField closeBtn = new ButtonField("Close");
ButtonField okBtn = new ButtonField("OK");
add(okBtn);
add(closeBtn);
closeBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
}
});
okBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
deligate.valueChanged(radioGroup.getSelectedIndex());
UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
}
});
}
}

Answer 2

public class MyScreen extends MainScreen{
private int currentValue = 0;
String result; // Declare the result
public MyScreen() {
LabelField lblField = new LabelField();
lblField.setText("Current Value = " + currentValue);
ButtonField btnPopup = new ButtonField("Show Popup");
btnPopup.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().pushScreen(new MyPopupScreen());
}
});
ButtonField btnGetResult = new ButtonField("result"); //Add new Button
btnGetResult.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
Dialog.inform(result);
}
});
add(lblField);
add(btnPopup);
add(btnGetResult);// Add button to get the selected index
}
public class MyPopupScreen extends PopupScreen implements FieldChangeListener {
private int currentValue = -1;
RadioButtonField radio;
public MyPopupScreen() {
super(new VerticalFieldManager(VerticalFieldManager.VERTICAL_SCROLL|VerticalFieldManager.VERTICAL_SCROLLBAR), Field.FOCUSABLE
);
add(new LabelField("Select Chart Type"));
final RadioButtonGroup radioGroup = new RadioButtonGroup();
for (int i = 0; i < 10; i++) {
radio = new RadioButtonField("Option no. " + i, radioGroup, false);
radio.setChangeListener(this);
add(radio);
}
ButtonField cancelBtn = new ButtonField("Close");
ButtonField okBtn = new ButtonField("OK");
add(okBtn);
add(cancelBtn);
cancelBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().popScreen(MyPopupScreen.this);
}
});
okBtn.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
result = radioGroup.getSelectedIndex()+"";
UiApplication.getUiApplication().popScreen(MyPopupScreen.this);
}
});
}
public void fieldChanged(Field field, int context) {
if (field instanceof RadioButtonField) {
RadioButtonField radio = (RadioButtonField) field;
currentValue = radio.getIndex();
}
}
}
}