[webkit-help] How to raise asynchronous events from C++ to JavaScript

[Tim Mahoney]

If JS calls "addEventListener", then eventually EventTarget::addEventListener will be called.
I believe what you want to do is call EventTarget::dispatchEvent on the node in question. 
This should call any callbacks associated with the type of event you pass to it.

I sent this reply before, but the title was incorrect. Hopefully this shows up nicely.

On Jan 19, 2013, at 12:00 PM, webkit-help-request at lists.webkit.org wrote:

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> Today's Topics:
> 
>   1. How to raise asynchronous events from C++ to	JavaScript
>      (Programming Newbie)
>   2. Retrieve downloaded images (OC)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Fri, 18 Jan 2013 20:24:25 +0000 (GMT)
> From: Programming Newbie <newbie.programming at yahoo.com>
> To: webkit-help <webkit-help at lists.webkit.org>
> Subject: [webkit-help] How to raise asynchronous events from C++ to
> 	JavaScript
> Message-ID:
> 	<1358540665.61012.YahooMailNeo at web171506.mail.ir2.yahoo.com>
> Content-Type: text/plain; charset="utf-8"
> 
> Hi,
> 
> 
> 
> I have managed to expose C++ APIs to JS using JavaScriptCore and I am able to issue callbacks from JavaScript to C++.
> 
> Now, I wanted to raise certain events in C++ and hoping them to be received in JavaScript.
> 
> So, if in JS, someone has added code:
> 
> myElement.addEventListener("myEvent", myEventHandler(), ...)
> 
> Then, I should somehow be able to raise myEvent from C++ and want it to be passed to JavaScript(caught in JS), so that myEventHandler() gets called.
> 
> Firstly, I thought of creating callbacks for all event handler functions and calling correct event handler them from C++ whenever an event needs to be raised.
> But, if I do like it, then I need to know beforehand which event handlers are associated with which events and I can't register and deregister events on the fly.
> 
> Also, there might be more than one handler associated with some events.
> 
> JavaScript code is not mine, I have to work with already written scripts and not allowed to modify them. So, I have to find out some way to do it through c++ only.
> 
> Can anyone please expain to me, how I can do this.
> 
> Thanks,
> newbie.
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> ------------------------------
> 
> Message: 2
> Date: Fri, 18 Jan 2013 23:03:24 +0100
> From: OC <oc.spam.3454 at laposte.net>
> To: webkit-help at lists.webkit.org
> Subject: [webkit-help] Retrieve downloaded images
> Message-ID: <50F9C6AC.1000006 at laposte.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Hello,
> 
> Is it possible to retrieve the images of a web page than has just been 
> downloaded? How?
> 
> For example, with QtWebKit and Python, I run:
> 
> from PyQt4.QtGui import QApplication, QImage
> from PyQt4.QtWebKit import QWebView
>  app = QApplication([])
> view = QWebView()
> view.load(QUrl("http://www.google.com"))
> view.show()
> 
> In this operation, the image "www.google.com/images/srpr/logo1w.png" was 
> downloaded and displayed. Where is it accessible now? How can it be 
> retrieved with webkit (or QtWebKit)?
> 
> Thank you,
> 
> O.C.
> 
> 
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> End of webkit-help Digest, Vol 43, Issue 9
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