Dialog message buttons dont do what is inside the code?

Question

I have a method to delete something from a database. I want to get the user confirmation. In order to do it I implement a boolean function to get the confirmation with a dialog.

Well my problem is that doesn't matter whether I choose yes or no I always get the same false result.

(I used final boolean[]beacuse otherwise I get an error)

This is the method:

public boolean alertMessage() { //Confirmation to delete routine
    final boolean[] confirmation = {false};
    DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            switch (which) {
                case DialogInterface.BUTTON_POSITIVE:
                    // Yes button clicked
                    confirmation[0] =true;
                    break;
                case DialogInterface.BUTTON_NEGATIVE:
                    // No button clicked
                    // do nothing
                    confirmation[0]=false;
                    break;
            }
        }
    };

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage(R.string.sure_delete)
            .setPositiveButton(R.string.yes, dialogClickListener)
            .setNegativeButton(R.string.no, dialogClickListener).show();
    return confirmation[0];
}

And this is how I check it in my delete code:

//CONFIRMATION
if(!alertMessage()){
 return;
}

Update: Try this with one answer suggestion but still the same:

public boolean alertMessage() { //Confirmation to delete routine
    final boolean[] confirmation = {false};
    new AlertDialog.Builder(this)
            .setTitle(R.string.delete)
            .setMessage(R.string.sure_delete)
            .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    confirmation[0]=true;
                }
            })
            .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    confirmation[0]=false;
                }
            })
            .setIcon(android.R.drawable.ic_dialog_alert)
            .show();
    return confirmation[0];
}

I put final boolean [] becuase with just a boolean I get an error:

"Variable is accessed from within an inner class, needs to be declared final."

And once I declare it final:

"Can not assign a value to final variable"

So I have to transform it into an array. I would like it to be a boolean method and don't implement the delete inside the "yes", because I want to reuse it in other methods.

Answer 1

This is because your code doesn't stop running when you show a dialog, so your method will always return false, as it's the default value assigned to it. The best way for you to ask deletion confirmation, is to have the deletion method being called inside of the dialog's positive button.

Let's say you have a listview and you want to delete an item when its clicked. Here's how you should do it.

public class MyActivity extends AppCompatActivity {


    public ListViewCompat listView;
    private List<Object> myObjects;

    public void onCreate(Bundle savedinstance) {
        super.onCreate(savedinstance);
        setContentView(R.layout.activity_my_list);

        listView = (ListViewCompat) findViewById(R.id.my_list_view);
        //Set a listview adapter

        listView.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
                showConfirmationDialog(position);         
            }
        });
    }

    private void showConfirmationDialog(int itemPosition) {
        AlerDialog.Builder builder = new AlerDialog.Builder(this);

        builder.setTitle("Confirmation");
        builder.setMessage("Delete item?")
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            deleteItem(itemPosition);
        });
        builder.setNegativeButton("No", null);

        builder.create().show();
    }

    private void deleteItem(int itemPosition) {
        //Delete item
        myObjects.remove(itemPosition);
    }
}

Answer 2

As you want, the same dialog box for differents actions on differents elements of the same list :

public final static TAG_UPDATE = "update";
public final static TAG_DELETE = "delete";

public void alertMessage(String id, String actionTag) { //the same call for all elements of a list
final String mIdElement = idElement;
final String mActionTag = actionTag;

new AlertDialog.Builder(this)
        .setTitle(R.string.confirmation)
        .setMessage(R.string.sure_confirmation)
        .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                makeSomething(mIdElement, mActionTag);
            }
        })
        .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                //no-op
            }
        })
        .setIcon(android.R.drawable.ic_dialog_alert)
        .show();
}

public void makeSomething(String idElement, String actionTag){
    switch(actionTag) {
        case TAG_UPDATE :
            // your update code to update the id element
            break;
        case TAG_DELETE :
            // your delete code to delete the id element
            break;
    } 
}

Answer 3

Try use interfaces:

public class MainActivity extends AppCompatActivity implements DialogInterface.OnClickListener {

    private static final String TAG = MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.e(TAG, "onCreate");
        setContentView(R.layout.activity_main);

        new AlertDialog.Builder(this)
                .setTitle("Hello")
                .setMessage("World")
                .setPositiveButton(android.R.string.yes, this)
                .setNegativeButton(android.R.string.no, this)
        .show();

    }

    @Override
    public void onClick(DialogInterface dialog, int which) {
        switch(which) {
            case DialogInterface.BUTTON_POSITIVE:
                Log.d(TAG, "Ok");
                break;
            case DialogInterface.BUTTON_NEGATIVE:
                Log.d(TAG, "Cancel");
                break;
        }

    }
}