am 07322102: revise code sample for callback interface

a {@link android.support.v4.app.DialogFragment}:</p>

<pre>

public class FireMissilesDialog extends DialogFragment {

public class FireMissilesDialogFragment extends DialogFragment {

    @Override

    public Dialog onCreateDialog(Bundle savedInstanceState) {

        // Use the Builder class for convenient dialog construction

           })

           .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {

               public void onClick(DialogInterface dialog, int id) {

                   NoticeDialog.this.getDialog().cancel();

                   LoginDialogFragment.this.getDialog().cancel();

               }

           });      

    return builder.create();

<p>When the user touches one of the dialog's action buttons or selects an item from its list,

your {@link android.support.v4.app.DialogFragment} might perform the necessary

action itself, but often you'll want to deliver the event to the activity or fragment that

opened the dialog. To do this, define an interface with a method for each type of click event,

then implement that interface in the host component that will

opened the dialog. To do this, define an interface with a method for each type of click event.

Then implement that interface in the host component that will

receive the action events from the dialog.</p>

<p>For example, here's a {@link android.support.v4.app.DialogFragment} that defines an

interface through which it delivers the events back to the host activity:</p>

<pre>

public class NoticeDialog extends DialogFragment {

public class NoticeDialogFragment extends DialogFragment {

    /* The activity that creates an instance of this dialog fragment must

     * implement this interface in order to receive event callbacks.

    }

    // Use this instance of the interface to deliver action events

    static NoticeDialogListener mListener;

    /* Call this to instantiate a new NoticeDialog.

     * @param activity  The activity hosting the dialog, which must implement the

     *                  NoticeDialogListener to receive event callbacks.

     * @returns A new instance of NoticeDialog.

     * @throws  ClassCastException if the host activity does not

     *          implement NoticeDialogListener

     */

    public static NoticeDialog newInstance(Activity activity) {

    NoticeDialogListener mListener;

    // Override the Fragment.onAttach() method to instantiate the NoticeDialogListener

    @Override

    public void onAttach(Activity activity) {

        super.onAttach(activity);

        // Verify that the host activity implements the callback interface

        try {

            // Instantiate the NoticeDialogListener so we can send events with it

            // Instantiate the NoticeDialogListener so we can send events to the host

            mListener = (NoticeDialogListener) activity;

        } catch (ClassCastException e) {

            // The activity doesn't implement the interface, throw exception

            throw new ClassCastException(activity.toString()

                    + " must implement NoticeDialogListener");

        }

        NoticeDialog frag = new NoticeDialog();

        return frag;

    }

    ...

}

</pre>

<p>The activity hosting the dialog creates and shows an instance of the dialog

by calling {@code NoticeDialog.newInstance()} and receives the dialog's

<p>The activity hosting the dialog creates an instance of the dialog

with the dialog fragment's constructor and receives the dialog's

events through an implementation of the {@code NoticeDialogListener} interface:</p>

<pre>

public class MainActivity extends FragmentActivity

                          implements NoticeDialog.NoticeDialogListener{

                          implements NoticeDialogFragment.NoticeDialogListener{

    ...

    public void showNoticeDialog() {

        // Create an instance of the dialog fragment and show it

        DialogFragment dialog = NoticeDialog.newInstance(this);

        dialog.show(getSupportFragmentManager(), "NoticeDialog");

        DialogFragment dialog = new NoticeDialogFragment();

        dialog.show(getSupportFragmentManager(), "NoticeDialogFragment");

    }

    // The dialog fragment receives a reference to this Activity through the

    // Fragment.onAttach() callback, which it uses to call the following methods

    // defined by the NoticeDialogFragment.NoticeDialogListener interface

    @Override

    public void onDialogPositiveClick(DialogFragment dialog) {

        // User touched the dialog's positive button

</pre>

<p>Because the host activity implements the {@code NoticeDialogListener}&mdash;which is

enforced by the {@code newInstance()} method shown above—the dialog fragment can use the

enforced by the {@link android.support.v4.app.Fragment#onAttach onAttach()}

callback method shown above—the dialog fragment can use the

interface callback methods to deliver click events to the activity:</p>

<pre>

public class NoticeDialog extends DialogFragment {

public class NoticeDialogFragment extends DialogFragment {

    ...

    @Override

               .setPositiveButton(R.string.fire, new DialogInterface.OnClickListener() {

                   public void onClick(DialogInterface dialog, int id) {

                       // Send the positive button event back to the host activity

                       mListener.onDialogPositiveClick(NoticeDialog.this);

                       mListener.onDialogPositiveClick(NoticeDialogFragment.this);

                   }

               })

               .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {

                   public void onClick(DialogInterface dialog, int id) {

                       // Send the negative button event back to the host activity

                       mListener.onDialogPositiveClick(NoticeDialog.this);

                       mListener.onDialogPositiveClick(NoticeDialogFragment.this);

                   }

               });

        return builder.create();

<h2 id="ShowingADialog">Showing a Dialog</h2>

<p>When you want to show your dialog, create an instance of your {@link

<pre>

public void confirmFireMissiles() {

    DialogFragment newFragment = FireMissilesDialog.newInstance(this);

    DialogFragment newFragment = new FireMissilesDialogFragment();

    newFragment.show(getSupportFragmentManager(), "missiles");

}

</pre>

dialog or an embeddable fragment (using a layout named <code>purchase_items.xml</code>):</p>

<pre>

public class CustomLayoutDialog extends DialogFragment {

public class CustomDialogFragment extends DialogFragment {

    /** The system calls this to get the DialogFragment's layout, regardless

        of whether it's being displayed as a dialog or an embedded fragment. */

    @Override

<pre>

public void showDialog() {

    FragmentManager fragmentManager = getSupportFragmentManager();

    CustomLayoutDialog newFragment = new CustomLayoutDialog();

    CustomDialogFragment newFragment = new CustomDialogFragment();

    if (mIsLargeLayout) {

        // The device is using a large layout, so show the fragment as a dialog