evaluateJavaScript function can be used for loading maps in qt widgets?

[Anisha Kaul]

I tried the c++ code from this example: http://wiki.forum.nokia.com/index.ph..._With_QWebView

It compiled but didn't load the map or the marker. I am NOT trying to load the map on some website. In fact I am trying to load it in a Qt widget.

This code connect(this,SIGNAL(reloadMap()), this,SLOT(loadCoordinates())); from that example never got called.

Then when I tried to call the function loadCoordinates myself at the end of the constructor, nothing happened, no maps no markers.

Is this problem related to evaluateJavaScript function?

I am missing some point here, I think. I need help.

[divanov]

Are you sure that Google Maps API key is still valid?
P.S. This is why error handling, which is completely missing in the wiki article, is so important.

[Anisha Kaul]

Thanks for responding, now I followed this page: http://code.google.com/apis/maps/signup.html
This page at the end asks me to enter the name of the website! But I am not developing this on any website, so how should I get the key?

I tried some random website name and got a random key, but that too doesn't work.

Please help.

[divanov]

Try to debug the wiki example.

[Anisha Kaul]

but I don't know what is wrong where so what should I start debugging?
The problem may be related to the api key also.

[divanov]

When you start debugging you always know that something is wrong and don't know what exactly. Finding exact reason of defect is a content of a debugging process.

[Anisha Kaul]

void QGoogleMapView::geoCode(const QString& address)
{
	cout << "\ngeocode\n";
	clearCoordinates();
    
	QString requestStr
(tr ("http://maps.google.com/maps/api/staticmap?center=Brooklyn+Bridge,New+York,NY&zoom=14&size=512x512&maptype=roadmap"
"&markers=color:blue%7Clabel:S%7C40.702147,-74.015794&markers=color:green%7Clabel:G%7C40.711614,-74.012318"
"&markers=color:red%7Ccolor:red%7Clabel:C%7C40.718217,-73.998284&sensor=false"));

	QNetworkReply *h = manager->get (QNetworkRequest (requestStr));
	
	if (h == 0)
	{
		cout << "NO ERROR";
	}
	else
	{
		cout << dec << "ERROR" << h << hex;
	}
}

This results in ERROR 0x6de9e0
There is no specified error with this code.

Any helps?

[divanov]

This was really funny. You've made my day!

P. S. pointers are not error codes.
Additional reading:
http://en.wikipedia.org/wiki/Pointer_%28computing%29
http://doc.qt.nokia.com/latest/qnetworkreply.html#error

[Anisha Kaul]

I realized my fault soon after posting that,

QString hh = 
"http://maps.google.com/maps/api/staticmap?center=Brooklyn+Bridge,New+York,NY&zoom=14&size=512x512&maptype=roadmap"
"&markers=color:blue%7Clabel:S%7C40.702147,-74.015794&markers=color:green%7Clabel:G%7C40.711614,-74.012318"
"&markers=color:red%7Ccolor:red%7Clabel:C%7C40.718217,-73.998284&sensor=false";


	QNetworkReply *h = manager->get (QNetworkRequest (QUrl (hh)));
	
	if (h->error() == 0)
	{
		cout << "NO ERROR";
	}
	else
	{
		cout << hex << "ERROR: " << h << dec;
	}

there are no errors in this part, and that's more frightening, cz. map is still not loading.

[divanov]

This is also wrong as network errors are asynchronous by their nature. You should check for error in slot connected to finished signal.

[Anisha Kaul]

Also, a question: how to know which version of Google's API am I using? I have heard that version 3 api doesn't need key.

[Anisha Kaul]

I checked the replyFinished slot:

QString     replyStr (reply->readAll());

QStringList coordinateStrList = replyStr.split(",");

cout << coordinateStrList.size();

[/code]
and the coordinateStrList is showing 4 and value is: "200,1,1.3520830,103.8198360"
still noting is getting displayed!!

What can be the cause?

[Anisha Kaul]

Also, I haven't mentioned the Google API Key, since I don't have a webpage or a
phone, I am doing this on my computer on a qt widget. Is that the reason the javascript code is not doing anything?

[Anisha Kaul]

I have identified the problem this time. There is a flaw in the way I am passing the Javascript code to the evaluatejavascript func. of QWebView.

Using Google maps's API, when I click a pushButton attached to the slot holding the below code

this->page()->mainFrame()->evaluateJavaScript (QString ("Open(%1,2)").arg ( point.x ()).arg (point.y ()) );

the map pertaining to the location in question gets displayed.

Now if I want to add a marker to a particular coordinate, I do:

this->page()->mainFrame()->evaluateJavaScript (QString ("addMarker (%1, %2)").arg (point.x ()).arg (point.y ()) );

This code doesn't execute. Any ideas?

Besides this, what is the way to add a user defined function to evaluateJavaScript for evaluation?

[Anisha Kaul]

Finally found the answer!

Any Javascript function which has to be called from function evaluateJavaScript is supposed to defined in an html file read by the C++ source as shown below:

Now instead of creating a new add marker function, I have added its code in the Open function defined below:

var map;

function initialize()
{
      if (GBrowserIsCompatible()) 
      {
            map = new GMap2(document.getElementById("map"));
            map.setCenter( new GLatLng(0,0),1 );
      }
    }

function Open (x,y)
{
    map.setCenter (new GLatLng(x,y), 13);

    var point = new GLatLng (x,y);
    map.addOverlay (new GMarker(point));
}