Java/Selenium Find Element by ID - Is Selenium looping over Annotations?

currently im developing a relativ small GWT-Application and I'm testing the GUI with Selenium. Everything works fine but while I was writing my tests a question popped up in my head:

On my DummyPage I do the following:

public class DummyPage {

    @FindBy(id = ID_SEARCH_BTN)     
    private WebElement btnSearch;

    @FindBy(id = ID_CANCEL_BTN_CLEAR)   
    private WebElement btnClear;
    ...

public DummyPage() {
    eventFiringDriver = DriverFactory.getInstance().getEventFiringDriver();
    PageFactory.initElements(eventFiringDriver, this);

    WebDriverWait webDriverWait = new WebDriverWait(eventFiringDriver, 20);
    wait = webDriverWait.ignoring(StaleElementReferenceException.class);
}

In my Application if the User clicks on a Button a custom dialogBox is shown. This DialogBox is build in the clickHandler of the Button so it doesn't exist on the page?! I gave the Button on my custom DialogBox an ID to locate it on my TestPage.

My Question is if I try to Find the Button on the DialogBox by:

@FindBy(id = DIALOGBOX_YES_BTN)
private WebElement dialogBoxYesBtn;

Will the Object be null, or will the WebElement be fetched when its createt? Is Selenium looping over the FindBy Annotations and tries to resolve them?

At the moment I have a test where I click the first button and then in the same method I try to find the DialogBoxButton with its ID - its working but it would be nice if I could locale all WebElements at the top of the page Object.

Thanks in advance for any Help