Steps 1 & 2 are unnecessary.
You can just call your C++ function from the Objective-C++ code.
And by setting up you signal / slot registration correctly, you can even
let Qt handle the threading issues,
What you describe is more akin to Java to Qt C++ call, with
Objective-C++ it really is simple.
Harri
On 15/05/2015 14:17, Edward Sutton wrote:
Harri,
Thank you.
I think I need to figure out how to:
1 - Pass in a function pointer to the Objective-C code.
2 - The Objective-C callback block calls the function pointer back
into the C++ code
3 - C++ code raises a Qt signal
4 - Qt client app receives signal
And figure out any threading issues.
-Ed
On May 15, 2015, at 1:48 AM, Harri Pasanen <ha...@mpaja.com
<mailto:ha...@mpaja.com>> wrote:
Actually it is trivial.
Just rename your Objective-C .m to .mm to make it Objective-C++
Then you can just mix Qt code in the same source.
So your successBlock could read:
successBlock:^(NDHTMLtoPDF *htmlToPDF) {
QString *result = QString::fromNSString([NSString
stringWithFormat:@"HTMLtoPDF did succeed (%@ / %@)", htmlToPDF,
htmlToPDF.PDFpath]);
qDebug() << result;
}
Only thing you may need to be aware of is threading, the success block
could be called from different thread you Qt code is running.
Hope this helps,
Harri
On 14/05/2015 23:53, Edward Sutton wrote:
Can anyone share an example on how to implement the asynchronous
return of a result from an Objective-C callback block to Qt?
For example, see the “successBlock:” below which gets called back
asynchronously.
self.PDFCreator = [NDHTMLtoPDF createPDFWithHTML:(NSString*)html
baseURL:(NSURL*)baseUrl
pathForPDF:[@"~/Documents/hello-world.pdf"
stringByExpandingTildeInPath]
pageSize:kPaperSizeA4
margins:UIEdgeInsetsMake(10, 5, 10, 5)
successBlock:^(NDHTMLtoPDF *htmlToPDF) {
NSString *result = [NSString stringWithFormat:@"HTMLtoPDF
did succeed (%@ / %@)", htmlToPDF, htmlToPDF.PDFpath];
NSLog(@"%@",result);
self.resultLabel.text = result;
}
errorBlock:^(NDHTMLtoPDF *htmlToPDF) {
NSString *result = [NSString stringWithFormat:@"HTMLtoPDF
did fail (%@)", htmlToPDF];
NSLog(@"%@",result);
self.resultLabel.text = result;
}];
Background:
————————
I need to implement native iOS code to replace the missing QPrinter
functionality I used to convert HTML to a PDF report on Android, OS
X, Linux, and Windows.
Unfortunately the Qt html-to-pdf functionality is implemented in
QPrinter. This functionality is gone from Qt iOS since iOS has no
printer device support, even though I am not accessing a printer
device from iOS.
I found this project which seems to work:
https://github.com/iclems/iOS-htmltopdf
Objective-C interfacing to C++ is challenging.
Thanks in advance for any tips,
-Ed
This email and any files transmitted with it from The Charles
Machine Works, Inc. are confidential and intended solely for the use
of the individual or entity to which they are addressed. If you have
received this email in error please notify the sender. Our company
accepts no liability for the contents of this email, or for the
consequences of any actions taken on the basis of the information
provided, unless that information is subsequently confirmed in
writing. Please note that any views or opinions presented in this
email are solely those of the author and do not necessarily
represent those of the company. Finally, the recipient should check
this email and any attachments for the presence of viruses. The
company accepts no liability for any damage caused by any virus
transmitted by this email.
_______________________________________________
Interest mailing list
Interest@qt-project.org <mailto:Interest@qt-project.org>
http://lists.qt-project.org/mailman/listinfo/interest
_______________________________________________
Interest mailing list
Interest@qt-project.org <mailto:Interest@qt-project.org>
http://lists.qt-project.org/mailman/listinfo/interest
This email and any files transmitted with it from The Charles Machine
Works, Inc. are confidential and intended solely for the use of the
individual or entity to which they are addressed. If you have received
this email in error please notify the sender. Our company accepts no
liability for the contents of this email, or for the consequences of
any actions taken on the basis of the information provided, unless
that information is subsequently confirmed in writing. Please note
that any views or opinions presented in this email are solely those of
the author and do not necessarily represent those of the company.
Finally, the recipient should check this email and any attachments for
the presence of viruses. The company accepts no liability for any
damage caused by any virus transmitted by this email.
_______________________________________________
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
_______________________________________________
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
