C++ String::isNull方法代碼示例

MediaPlayer::SupportsType MediaPlayerPrivate::supportsType(const WTF::String& type, const WTF::String& codecs, const KURL& url)
{
    bool isRTSP = url.protocolIs("rtsp");

    if (!isRTSP && (type.isNull() || type.isEmpty())) {
        LOG(Media, "MediaPlayer does not support type; type is null or empty.");
        return MediaPlayer::IsNotSupported;
    }

    // spec says we should not return "probably" if the codecs string is empty
    if (isRTSP || PlatformPlayer::mimeTypeSupported(type.ascii().data())) {
        LOG(Media, "MediaPlayer supports type %s.", isRTSP ? "rtsp" : type.ascii().data());
        return codecs.isEmpty() ? MediaPlayer::MayBeSupported : MediaPlayer::IsSupported;
    }
    LOG(Media, "MediaPlayer does not support type %s.", type.ascii().data());
    return MediaPlayer::IsNotSupported;
}

static inline std::string fromWTFString(const WTF::String& wtf_string) {
  if (wtf_string.isNull()) return std::string();
  WTF::CString cstring = wtf_string.ascii();
  return std::string(cstring.data(), cstring.length());
}

void WebHistoryItem::updateHistoryItem(WebCore::HistoryItem* item) {
    // Do not want to update during inflation.
    if (!m_active)
        return;
    WebHistoryItem* webItem = this;
    // Now we need to update the top-most WebHistoryItem based on the top-most
    // HistoryItem.
    if (m_parent) {
        webItem = m_parent.get();
        if (webItem->hasOneRef()) {
            // if the parent only has one ref, it is from this WebHistoryItem.
            // This means that the matching WebCore::HistoryItem has been freed.
            // This can happen during clear().
            LOGW("Can't updateHistoryItem as the top HistoryItem is gone");
            return;
        }
        while (webItem->parent())
            webItem = webItem->parent();
        item = webItem->historyItem();
        if (!item) {
            // If a HistoryItem only exists for page cache, it is possible that
            // the parent HistoryItem destroyed before the child HistoryItem. If
            // it happens, skip updating.
            LOGW("Can't updateHistoryItem as the top HistoryItem is gone");
            return;
        }
    }
    JNIEnv* env = JSC::Bindings::getJNIEnv();
    if (!env)
        return;

    // Don't do anything if the item has been gc'd already
    AutoJObject realItem = getRealObject(env, webItem->m_object);
    if (!realItem.get())
        return;

    const WTF::String urlString = WebFrame::convertIDNToUnicode(item->url());
    jstring urlStr = NULL;
    if (!urlString.isNull())
        urlStr = wtfStringToJstring(env, urlString);
    const WTF::String originalUrlString = WebFrame::convertIDNToUnicode(item->originalURL());
    jstring originalUrlStr = NULL;
    if (!originalUrlString.isNull())
        originalUrlStr = wtfStringToJstring(env, originalUrlString);
    const WTF::String& titleString = item->title();
    jstring titleStr = NULL;
    if (!titleString.isNull())
        titleStr = wtfStringToJstring(env, titleString);

    // Try to get the favicon from the history item. For some pages like Grand
    // Prix, there are history items with anchors. If the icon fails for the
    // item, try to get the icon using the url without the ref.
    jobject favicon = NULL;
    WTF::String url = item->urlString();
    if (item->url().hasFragmentIdentifier()) {
        int refIndex = url.reverseFind('#');
        url = url.substring(0, refIndex);
    }
    // FIXME: This method should not be used from outside WebCore and will be removed.
    // http://trac.webkit.org/changeset/81484
    WebCore::Image* icon = WebCore::iconDatabase().synchronousIconForPageURL(url, WebCore::IntSize(16, 16));

    if (icon)
        favicon = webcoreImageToJavaBitmap(env, icon);

    WTF::Vector<char> data;
    jbyteArray array = WebHistory::Flatten(env, data, item);
    env->CallVoidMethod(realItem.get(), gWebHistoryItem.mUpdate, urlStr,
            originalUrlStr, titleStr, favicon, array);
    env->DeleteLocalRef(urlStr);
    env->DeleteLocalRef(originalUrlStr);
    env->DeleteLocalRef(titleStr);
    if (favicon)
        env->DeleteLocalRef(favicon);
    env->DeleteLocalRef(array);
}