我有一个带有图像和一些文字的网页，图像具有视差效果。当我在滚动视图内的Web视图中加载网页时，视差效果不起作用。滚动视图还具有回收视图和Web视图。如何实现网页中的视差效果以及整页的无缝滚动？
This video have the page i have developed with web view inside scroll view
This video is the demo screen with only web view, just to test the parallax in the web page
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/parent_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white">
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/news_detail_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<WebView
android:id="@+id/web_view"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<RelativeLayout
android:id="@+id/related"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="gone">
<View
android:id="@+id/view"
android:layout_width="match_parent"
android:layout_height="@dimen/list_item_divider_height"
android:background="#dedede"
android:visibility="visible" />
<TextView
android:id="@+id/related_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/view"
android:layout_margin="@dimen/main_margin"
android:text="@string/related_news"
android:textColor="@android:color/black"
android:textSize="@dimen/list_item_title"
android:textStyle="bold"
android:visibility="visible" />
<android.support.v7.widget.RecyclerView
android:id="@+id/related_article"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/related_title"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:visibility="visible" />
</RelativeLayout>
<RelativeLayout
android:id="@+id/recommendation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="gone">
<View
android:id="@+id/recommendation_seperator"
android:layout_width="match_parent"
android:layout_height="@dimen/list_item_divider_height"
android:background="#dedede"
android:visibility="visible" />
<TextView
android:id="@+id/recommendation_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/main_margin"
android:text="Sponsored Stories"
android:textColor="@android:color/black"
android:textSize="@dimen/list_item_title"
android:textStyle="bold" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_margin="@dimen/main_margin"
android:orientation="horizontal">
<TextView
android:id="@+id/drawer_title_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_gravity="center"
android:text="Recommended by "
android:textColor="@color/black_semi_trans"
android:textSize="12dp"
android:textStyle="bold" />
<ImageView
android:layout_width="24dp"
android:layout_height="24dp"
android:src="@drawable/ic_recommendation" />
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/recommendation_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/recommendation_title" />
</RelativeLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
<ProgressBar
android:id="@+id/progress_bar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true" />
</RelativeLayout>
public class NewsDetailFragment extends Fragment implements ViewModel.ResponseListener<News>, RecyclerViewEvents.Listener<Object>,
View.OnKeyListener, RecommendationsListener {
private List<NewsItem> relatedList = new ArrayList<>();
private RelatedArticleListAdapter relatedAdapter;
private String url;
private ClickEvents.ListItemListener listItemListener;
private WebView webView;
private ProgressBar progressBar;
private boolean isWebViewPaused;
private List<OBRecommendation> outbrainList = new ArrayList();
private OutbrainAdapter outbrainAdapter;
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
listItemListener = (ClickEvents.ListItemListener) activity;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
url = getArguments().getString(Constants.BundleKeys.URL);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate((Network.isConnected(getActivity())) ? R.layout.fragment_news_detail : R.layout.fragment_news_detail_offline, container, false);
progressBar = (ProgressBar) view.findViewById(R.id.progress_bar);
webView = (WebView) view.findViewById(R.id.web_view);
webView.setHorizontalScrollBarEnabled(false);
webView.getSettings().setAppCacheEnabled(false);
webView.setScrollBarStyle(WebView.SCROLLBARS_INSIDE_INSET);
webView.setVerticalScrollBarEnabled(false);
webView.setOnKeyListener(this);
webView.getSettings().setJavaScriptEnabled(true);
int fontSize = PreferenceManager.getsInstance(getActivity()).getSharedPrefs().getInt(PreferenceManager.PreferenceKeys.SETTINGS_CURRENT_FONT_SIZE, -1);
switch (fontSize) {
case 0: //LARGE
webView.getSettings().setTextZoom(160);
break;
case 1: // MEDIUM
webView.getSettings().setTextZoom(130);
break;
case 2: //NORMAL
webView.getSettings().setTextZoom(100);
break;
case 3: //SMALL
webView.getSettings().setTextZoom(70);
break;
default:
webView.getSettings().setTextZoom(100);
}
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (Network.isConnected(getActivity())) {
RecyclerView relatedRecyclerView = (RecyclerView) getView().findViewById(R.id.related_article);
RecyclerView recommendationRecyclerView = (RecyclerView) getView().findViewById(R.id.recommendation_view);
RelativeLayout recommendationLayout = (RelativeLayout) getView().findViewById(R.id.recommendation);
RelativeLayout relatedLayout = (RelativeLayout) getView().findViewById(R.id.related);
webView.setWebViewClient(new WebClient(progressBar, recommendationLayout, relatedLayout));
relatedRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false));
relatedRecyclerView.setAdapter(relatedAdapter = new RelatedArticleListAdapter(getActivity(), relatedList, this));
OBRequest request = new OBRequest(url, getResources().getString(R.string.outbrain_widget));
Outbrain.fetchRecommendations(request, this);
GridLayoutManager layoutManager = new GridLayoutManager(getActivity(), 2);
recommendationRecyclerView.setLayoutManager(layoutManager);
outbrainAdapter = new OutbrainAdapter(getActivity(), outbrainList, this);
recommendationRecyclerView.setAdapter(outbrainAdapter);
webView.loadUrl(url);
String keywords = getArguments().getString(Constants.BundleKeys.KEYWORDS);
if (keywords != null) {
String newsId = getArguments().getString(Constants.BundleKeys.NEWS_ID);
String url = ConfigManager.getsInstance().getURL(Constants.CustomApiType.RELATED_NEWS);
StringBuilder builder = new StringBuilder(url).append("&").append(APIService.QueryKeys.EXCLUDE_ID)
.append("=").append(newsId)
.append("&").append(APIService.QueryKeys.ALL_FIELDS).append("=")
.append(keywords);
NewsViewModel newsViewModel = new NewsViewModel(getActivity(), this, builder.toString());
newsViewModel.downloadRelatedNews();
}
} else {
webView.setWebViewClient(new WebClient(progressBar));
downloadCachedHTML(url);
}
}
private void downloadCachedHTML(String url) {
boolean isBookMarkNews = getArguments().getBoolean(Constants.BundleKeys.IS_BOOKMARK, false);
HTMLClient client = HTMLClientFactory.create(getActivity(), isBookMarkNews ? CacheInfo.BOOKMARK_NEWS : CacheInfo.NEWS_DETAIL);
HTMLAPIService apiService = client.getAPIService(HTMLAPIService.class);
Call<String> call = apiService.downloadHtml(url);
call.enqueue(new Callback<String>() {
@Override
public void onResponse(Call<String> call, retrofit2.Response<String> response) {
if (getActivity() == null)
return;
progressBar.setVisibility(View.GONE);
if (response.body() != null) {
webView.loadDataWithBaseURL("", response.body(), "text/html", "utf-8", null);
}
}
@Override
public void onFailure(Call<String> call, Throwable t) {
progressBar.setVisibility(View.GONE);
}
});
}
@Override
public void onItemClick(Object item, View v, int position) {
if (item instanceof NewsItem) {
News news = new News();
news.newsList = relatedList;
listItemListener.onNewsListItemClick(news, position, "", false);
}
if (item instanceof OBRecommendation)
listItemListener.onRecommendationItemClick(((OBRecommendation) item).getUrl());
}
@Override
public void onResponse(News response) {
relatedList.clear();
relatedList.addAll(response.newsList);
relatedAdapter.notifyDataSetChanged();
}
@Override
public void onNextResponse(News response) {
}
@Override
public void onNextError() {
}
@Override
public void onError() {
relatedList.clear();
}
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (getActivity() == null)
return;
if (webView == null)
return;
if (isVisibleToUser)
webView.onResume();
else webView.onPause();
}
@Override
public void onPause() {
super.onPause();
webView.onPause();
isWebViewPaused = true;
}
@Override
public void onResume() {
super.onResume();
if (isWebViewPaused) {
webView.onResume();
isWebViewPaused = false;
}
}
@Override
public void onOutbrainRecommendationsSuccess(OBRecommendationsResponse recommendations) {
outbrainList.clear();
outbrainList.addAll(recommendations.getAll());
outbrainAdapter.notifyDataSetChanged();
}
@Override
public void onOutbrainRecommendationsFailure(Exception ex) {
outbrainList.clear();
}
private class WebClient extends WebViewClient {
private final ProgressBar progressBar;
private RelativeLayout recommendation;
private RelativeLayout related;
public WebClient(ProgressBar progressBar, RelativeLayout recommendation, RelativeLayout related) {
this.progressBar = progressBar;
this.recommendation = recommendation;
this.related = related;
}
public WebClient(ProgressBar progressBar) {
this.progressBar = progressBar;
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
progressBar.setVisibility(View.VISIBLE);
if (Network.isConnected(getActivity())) {
recommendation.setVisibility(View.GONE);
related.setVisibility(View.GONE);
}
}
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
progressBar.setVisibility(View.GONE);
if (Network.isConnected(getActivity())) {
related.setVisibility(relatedList.isEmpty() ? View.GONE : View.VISIBLE);
recommendation.setVisibility(outbrainList.isEmpty() ? View.GONE : View.VISIBLE);
}
}
@SuppressWarnings("deprecation")
@Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
if (!Network.isConnected(getActivity())) {
WebResourceResponse response = getResponse(url);
return response == null ? super.shouldInterceptRequest(view, url) : response;
}
return super.shouldInterceptRequest(view, url);
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
if (!Network.isConnected(getActivity())) {
String url = request.getUrl().toString();
WebResourceResponse response = getResponse(url);
return response == null ? super.shouldInterceptRequest(view, request) : response;
}
return super.shouldInterceptRequest(view, request);
}
@Nullable
private WebResourceResponse getResponse(String url) {
if (url.endsWith(".png") || url.endsWith(".jpg")) {
boolean isBookMarkNews = getArguments().getBoolean(Constants.BundleKeys.IS_BOOKMARK, false);
HTMLClient client = HTMLClientFactory.create(getActivity(), isBookMarkNews ? CacheInfo.BOOKMARK_NEWS : CacheInfo.NEWS_DETAIL);
File cachedFile = new File(client.getImageDir() + File.separator + HTMLInterceptor.getFileName(url));
if (cachedFile.exists()) {
try {
return new WebResourceResponse(
"image/*", "utf-8", new FileInputStream(cachedFile));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
return null;
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
if (Network.isConnected(progressBar.getContext()))
return false;
else return true;
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return super.shouldOverrideUrlLoading(view, url);
}
}
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
WebView webView = (WebView) v;
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
if (webView.canGoBack()) {
webView.goBack();
return true;
}
break;
}
}
return false;
}
@Override
public void onDestroyView() {
super.onDestroyView();
webView.destroy();
}
}