Develop Reference

JavaScript/Jsoup - Get background-image url from "i class"

So I'm loading a webpage in my app's webview and there's an HTML i class="img profimage" and it has a background-image url and that's my target...
I want to get that target either with JavaScript or using Jsoup...
What I tried so far with Jsoup is this:
public class GetImage extends AsyncTask<String, String, String> {
protected String doInBackground(String... strings) {
Document document = null;
try {
document = Jsoup.connect(url).get();
} catch (IOException e) {
e.printStackTrace();
}
String temp = document.select("i.img.profpic").first().getElementsByAttribute("style").toString();
return temp.substring(temp.indexOf("(") + 1, temp.indexOf(")"));
}
 
protected void onPostExecute(String result) {
Log.d("ChatScreen", result);
Toast.makeText(ChatScreen.this, result, LENGTH_SHORT).show();
}
}
But I'm getting NPE...
I don't know how to get background-image url of an i class using JavaScript... I can find plenty of examples on web for how to get it for div using ids
HTML structure of page is similar to this:
<div ....>
<div ....>
<i class="img profimage" style="background-image: url("url here");"/>
</div>
</div>

Check this Answer may be this will work but I didn't try this. The JS function is written bellow in evaluateJavascript() which will read style attribute then you can use substring method to get the URL.
webview.evaluateJavascript(
"(function() { return (document.getElementsByTagName('i')[index].getAttribute('style')); })();",
new ValueCallback<String>() {
#Override
public void onReceiveValue(String html) {
Log.d("HTML", html);
// now use substring to get url.....
}
});
Hope this help you.

Referencing this answer, you could try something like below (assuming it's the only/first element with the class profimage, otherwise change the index, i.e. [n], where n is the index). Alternatively, just give the element a unique id and use document.getElementById('imgid') and remove the [0]. Wrapped it in a function in case you want to call it on a specific event.
function getUrl() {
var img = document.getElementsByClass('profimage'),
style = img[0].currentStyle || window.getComputedStyle(img[0], false),
bi = style.backgroundImage.slice(5, -2);
return bi;
}
Slicing will remove url(" before and ") after the URL itself. Note that this returns the full url.
If that doesn't work, you can try style = img.style, in lieu of the longer expression in the code above, since the background image is added with inline css in the element itself (<i ... style="background-image: url("url here");"/>). This will return the url in the inline style, in this case url here.

Detect parents' and grandparents' links in Javascript

I am making a Web Browser in C# and displaying custom context menus based on the element right clicked by the user. I am having trouble figuring out which elements should be treated as links?
if (el_tag == "a")
showLinkMenu();
else if (el_tag == "img" && parent_tag == "a")
showAdvancedMenu();
else if (el_tag == "img")
showImgMenu();
Shot1: Google chrome detected this as a link
Shot2: Structure a > div > div > div > div > img
What should I do to detect such links?

You should iterate up the list of parent tags and call it a link if any of them are an <a> with an href attribute.

I recommend implementing your own IContextMenuHandler and use the built in CefMenuCommand's and TypeFlag's to help you. With this, you can add or remove context menu items based on the element that has been right-clicked.
MenuHandler.cs
internal class MenuHandler : IContextMenuHandler
{
private const int SaveImage = 26503;
private const int OpenLinkNewTab = 26501;
public event EventHandler OnSaveImage = delegate { };
void IContextMenuHandler.OnBeforeContextMenu(IWebBrowser browserControl, IBrowser browser, IFrame frame, IContextMenuParams parameters, IMenuModel model)
{
if(parameters.TypeFlags.HasFlag(ContextMenuType.Media) && parameters.HasImageContents)
{
model.AddItem((CefMenuCommand)SaveImage, "Save image");
}
if(!string.IsNullOrEmpty(parameters.UnfilteredLinkUrl))
{
model.AddItem((CefMenuCommand)OpenLinkNewTab, "Open link in new tab");
}
}
bool IContextMenuHandler.OnContextMenuCommand(IWebBrowser browserControl, IBrowser browser, IFrame frame, IContextMenuParams parameters, CefMenuCommand commandId, CefEventFlags eventFlags)
{
return false;
}
void IContextMenuHandler.OnContextMenuDismissed(IWebBrowser browserControl, IBrowser browser, IFrame frame)
{
if ((int)commandId == SaveImage)
{
OnSaveImage?.Invoke(this, new ImageSaveEventArgs(parameters.SourceUrl)); //ImageSaveEventArgs is just a class with one property that houses the source url of the image to download.
}
}
bool IContextMenuHandler.RunContextMenu(IWebBrowser browserControl, IBrowser browser, IFrame frame, IContextMenuParams parameters, IMenuModel model, IRunContextMenuCallback callback)
{
return false;
}
}
Then wherever you create your ChromiumWebBrowser instance, you can do something like this:
ChromiumWebBrowser browser = new ChromiumWebBrowser();
MenuHandler menuHandler = new MenuHandler();
menuHandler.OnSaveImage += Handler_OnSaveImage;
browser.MenuHandler = menuHandler;
private void Handler_OnSaveImage(object sender, EventArgs e)
{
DownloadImage(((ImageSaveEventArgs)e).SourceUrl);
}
Note, this is just an example of using the built-in IContextMenuHandler to obtain what the user has right-clicked, and then handling my own event so I can implemented the required behaviour. In this case, the ability to download a file from the URL.
See MenuHandler.cs on CefSharp's GitHub page for more details and other examples.

How to enable javascript window.close() in vaadin dialog?

I have a html page which has a Close button which on click, should close the window. This html page is being loaded on a Vaadin Dialog. I understand that Vaadin takes care of closing the dialog with window.setClosable(true). But, the button in html page also should do the same. How do I enable this ?
Below is the code :
myHelp.html:
<html>
<head>
</head>
<body>
.
.
<!-- This is at the footer right corner -->
<p class="myClass" align="right"><img src="images/iconclose.gif" width="50" height="10" border="0" onClick="window.close()" title="Close"></p>
.
.
</body>
</html>
Java Code:
.
.
String link = "test/myHelp.html";
MenuItem menuItem = null;
if (link.contains("/test")) {
menuItem = menuBar.addItem("", new ExternalResource(StringUtil.append("/images/", images.get(i))), new Command() {
#Override
public void menuSelected(MenuItem selectedItem) {
final Window window = new Window(this.caption);
window.setClosable(true);
window.setWindowMode(WindowMode.NORMAL);
window.setModal(true);
window.setDraggable(true);
window.setResizable(false);
window.center();
window.addStyleName("abcdailog");
VerticalLayout layout = new VerticalLayout();
layout.setSizeFull();
layout.setSpacing(true);
layout.setMargin(true);
if (!CommonUtil.isEmpty(this.styleName)) {
window.addStyleName("abcStyle");
layout.setMargin(false);
}
if (!CommonUtil.isEmpty(link)) {
BrowserFrame browser = new BrowserFrame(null, new ExternalResource(this.link));
browser.setSizeFull();
layout.addComponent(browser);
} else {
verticalLayout.setSizeFull();
layout.addComponent(verticalLayout);
}
window.setContent(layout);
UI.getCurrent().addWindow(window);
}
}
});
.
.
.
What happens is myHtml gets loaded in the new window. As a vaadin window, everything is fine but since the html has a window.close on an image, which is suppose to work is not working. I hope the code helps in better understanding.

The simplest one would be to add a Vaadin button say at the bottom of the window. However if that's not a choice, there are a few ways of doing this, the first one which comes to mind (and possibly the next simplest one) is adding a callback JS function to close the window.
1) Custom window implementation:
import com.vaadin.shared.ui.label.ContentMode;
import com.vaadin.ui.JavaScript;
import com.vaadin.ui.Label;
import com.vaadin.ui.UI;
import com.vaadin.ui.Window;
public class MyHtmlWindow extends Window {
private static final String CLOSE_WINDOW_FUNCTION = "closeWindow";
public MyHtmlWindow() {
// some window configuration
setModal(true);
setClosable(true);
setResizable(false);
}
public void show(UI ui) {
// add some HTML content in a label including the call to the closeWindow() JS function
setContent(new Label("<html>\n" +
"<button type=\"button\" onClick=\"" + CLOSE_WINDOW_FUNCTION + "();\">Close</button>\n" +
"<script>\n", ContentMode.HTML));
// add a JS function to close the window
JavaScript.getCurrent().addFunction(CLOSE_WINDOW_FUNCTION, arguments -> this.close());
// show the window
ui.addWindow(this);
}
#Override
public void close() {
// call super so everything gets cleaned up nicely
super.close();
// remove previously added function
JavaScript.getCurrent().removeFunction(CLOSE_WINDOW_FUNCTION);
}
}
2) Usage:
public class MyVaadinUI extends UI {
#Override
protected void init(VaadinRequest request) {
new MyHtmlWindow().show(this);
}
}
3) Result:
P.S.: Suggestions for improvements are welcome

Awesomium .NET. Wpf. TitleChanged event

I have a very basic application, that shows website content within the WPF app. Everything works fine, except TitleChangedEvent. Here is the code sample (XAML):
<Window xmlns:awe="http://schemas.awesomium.com/winfx" x:Class="ShopChat.Desktop.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:webControls="clr-namespace:System.Web.UI.WebControls;assembly=System.Web"
Title="{Binding ElementName=WebControl, Path=Title}" MinHeight="480" MinWidth="640">
<Grid>
<awe:WebControl x:Name="WebControl"/>
</Grid>
And this is main window code-behind:
public MainWindow()
{
InitializeComponent();
string url = #"http://shopchat.dev";
try
{
url = ConfigurationManager.AppSettings.Get("Url");
}
catch (Exception)
{
}
WebControl.Source = new Uri(url);
WebControl.TitleChanged += WebControl_OnTitleChanged;
this.WindowTitle = "Quickchat";
}
public string WindowTitle
{
get { return (string)GetValue(WindowTitleProperty); }
set { SetValue(WindowTitleProperty, value); }
}
// Using a DependencyProperty as the backing store for WindowTitle. This enables animation, styling, binding, etc...
public static readonly DependencyProperty WindowTitleProperty =
DependencyProperty.Register("WindowTitle", typeof(string), typeof(MainWindow), new PropertyMetadata(null));
private void WebControl_OnTitleChanged(object sender, TitleChangedEventArgs e)
{
this.WindowTitle = e.Title;
}
I've also tried to bind to window title directly using Binding ElementName=WebControl. That didn't help me either.
JavaScript client code is very simple: it changes the document title on timer (setInterval).
What am I doing wrong?

try like this code
public MainWindow()
{
InitializeComponent();
DataContext = this;
MyTitle = "Title";
}
Then you just need in the XAML
Title="{Binding MyTitle}"
Then you don't need the dependency property.
Then I would like to use this INotifyPropertyChanged with a standard property.

The issue was solved. TitleChanged event seemed to be insufficient. I've incorporated the usage of global js object to get the necessary behavior.

How to catch element click by ID in Android webview?

I have the viewPager component which is containing the several webviews with HTML content from remote server.
Is it simple HTML code without possibility to change the HTMl output on the server side.
I would like to ask, how can i catch the click(tap) event on the specified element with the given ID in Android?
ViewPager
private void initViewPager() {
pager = (ViewPager) findViewById(R.id.my_pager);
adapter = new FragmentStatePagerAdapter(
getSupportFragmentManager()
) {
#Override
public int getCount() {
// This makes sure getItem doesn't use a position
// that is out of bounds of our array of URLs
Logger.d(String.valueOf(mWelcomeController.loadedPagesToDisplay.size()));
return mWelcomeController.loadedPagesToDisplay.size();
}
#Override
public android.support.v4.app.Fragment getItem(int position) {
Logger.d(mWelcomeController.loadedPagesToDisplay.toString());
return BrowserFragment.newInstance(
mWelcomeController.loadedPagesToDisplay.get(position)
);
}
};
//Let the pager know which adapter it is supposed to use
pager.setAdapter(adapter);
}
Because I cannot modify the HTML output on the server side (maybe inject some attributes into DOM on device ?) I cannot use something like that:
http://www.scriptscoop.com/t/21b53b896c9e/javascript-how-to-detect-button-click-in-webview-android.html
Detect click on HTML button through javascript in Android WebView.
I would like just something like this:
Find the given element in the HTML code
Update the HTML code (add
onclick event)
Catch this event in native code

For that you need to parse the html, a good html parser for Java (and therefor also Android) is Jsoup.
You can do something like:
// Connect to the web site
Document doc = Jsoup.connect(url).get();
Element button = doc.select("#buttonid");
button.html("new stuff here");
//parse back and put in webview
String finaloutput = doc.html();

1.
// setting
wv.addJavascriptInterface(new MyJsToAndroid(),"my");
WebSettings settings = wv.getSettings();
settings.setJavaScriptEnabled(true);
2.
// JsCallBack
class MyJsToAndroid extends Object{
#JavascriptInterface
public void myClick(String idOrClass) {
Log.d(TAG, "myClick-> " + idOrClass);
}
}
3.
// JS--
public static String addMyClickCallBackJs() {
String js = "javascript:";
js += "function myClick(event){" +
"if(event.target.className == null){my.myClick(event.target.id)}" +
"else{my.myClick(event.target.className)}}";
js += "document.addEventListener(\"click\",myClick,true);";
return js;
}
4.
#Override
public void onPageFinished(WebView wv, String url) {
//...
wv.evaluateJavascript(addMyClickCallBackJs(),null);
//...
}
So, look at the 2 log.