I am trying to make listener interface between two activities Act1 and Act2
. Act1
will start Act2
. If there is some event occurred in Act2
, it will inform it to Act1
. Problem is that I am starting new activity using Intent, so how Act1 will assign itself as listener to Act2's interface?
Act1.java
public class Act1 extends ActionBarActivity implements
ActionBar.OnNavigationListener {
ActionBar actionbar;
Intent pizzaIntent;
boolean visibleFirstTime = true;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menutab);
//set actionbar here
}
@Override
public boolean onNavigationItemSelected(int arg0, long arg1)// item pos,
// itemid
{
switch (arg0) {
case 0:
if(this.visibleFirstTime == false)
{
if(pizzaIntent == null)
{
pizzaIntent = new Intent(this,Act2.class);
//how to call setChangeListener?
}
startActivity(pizzaIntent);
}
else
this.visibleFirstTime = false;
break;
case 1:
System.out.println("selected: " + arg0);
break;
case 2:
System.out.println("selected: " + arg0);
break;
case 3:
System.out.println("selected: " + arg0);
break;
default:
break;
}
return true;
}
}
Act2.java
public class Act2 extends Activity {
selectionChangeListener listener;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.pizza_slice_selection);
}
public void setChangeListener(selectionChangeListener listener)
{
this.listener = listener;
}
private interface selectionChangeListener
{
public void selectionMadeAtIndex(int index);
}
}
Note: Please don't suggest me to use fragments. I want to use activities currently.
I would suggest to create a model class. Let me give you an example:
Model class:
public class CustomModel {
public interface OnCustomStateListener {
void stateChanged();
}
private static CustomModel mInstance;
private OnCustomStateListener mListener;
private boolean mState;
private CustomModel() {}
public static CustomModel getInstance() {
if(mInstance == null) {
mInstance = new CustomModel();
}
return mInstance;
}
public void setListener(OnCustomStateListener listener) {
mListener = listener;
}
public void changeState(boolean state) {
if(mListener != null) {
mState = state;
notifyStateChange();
}
}
public boolean getState() {
return mState;
}
private void notifyStateChange() {
mListener.stateChanged();
}
}
And here's how you would use this:
// Imports
public class MainActivity extends Activity implements OnCustomStateListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
CustomModel.getInstance().setListener(this);
boolean modelState = CustomModel.getInstance().getState();
Log.d(TAG, "Current state: " + String.valueOf(modelState));
Intent intent = new Intent(this, SecondActivity.class);
startActivity(intent);
}
@Override
public void stateChanged() {
boolean modelState = CustomModel.getInstance().getState();
Log.d(TAG, "MainActivity says: Model state changed: " +
String.valueOf(modelState));
}
}
Changing the member state in second activity:
// Imports
public class SecondActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
CustomModel.getInstance().changeState(true);
}
}
LogCat output:
Current state: false
MainActivity says: Model state changed: true