[Interest] Qt/iOS subclassing and/or delegating

[maitai]

Finally got it working... with a bad hack

I cloned QIOSViewController.h and .mm from qt sources (and added qt's 
iOS headers in my include path, I already had core-private and 
gui-private in my pro files) and modified it to do what I want. I also 
had to add a lockedOrientation property to it for some mysterious 
reason...

At least it's doing what I need (i.e. ignore device rotation when I 
decide to). Of course it's a really bad hack and I'm still hoping 
someone can point me to a better solution.

Thanks
Philippe.


Le 29-05-2015 11:24, maitai a écrit :
> I had a look at QT sources... Basically what I want to do is override
> QIOSViewController:shouldAutorotate.
> 
> I tried
> @interface MyIOSViewController : QIOSViewController
> @end
> @implementation MyIOSViewController
> - (BOOL) shouldAutorotate {
>      NSLog(@"Inside shouldAutorotate");
>      return NO;
> }
> 
> It compiles and does not crash (I import QIOSViewController.h), but 
> that
> all it does...
> 
> 
> Le 29-05-2015 10:23, Harri Pasanen a écrit :
>> Compared to C++, Objective-C is very dynamic language and you can do
>> many things at runtime.
>> 
>> So you can add methods to existing classes using categories:
>> https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/CustomizingExistingClasses/CustomizingExistingClasses.html
>> 
>> Or resort to something quite funky to replace existing methods:
>> https://github.com/rentzsch/jrswizzle
>> 
>> As to your original question, rotation handling is surprisingly tricky
>> even in pure Objective-C if you want to conditionally rotate.   For
>> instance iOS 8.3 broke some of my code handling that which had worked
>> fine since iOS 6, pure Objective-C.
>> 
>> I don't know how Qt hooks into it.
>> 
>> Harri
>> 
>> On 29/05/2015 09:41, Robert Iakobashvili wrote:
>>> On Fri, May 29, 2015 at 8:38 AM, maitai <maitai at virtual-winds.org>
>>> wrote:
>>>> Thanks Ben for your reply
>>>> 
>>>> After much digging I made some progress but I am still looking for a
>>>> way to
>>>> temporary lock screen auto rotation.
>>>> 
>>>> I have created my own app delegate to catch openUrl(), and
>>>> surprisingly it
>>>> works. I register my app delegate from main.cpp by calling something
>>>> like
>>>> this:
>>>> 
>>>> void QtAppDelegateInitialize ()
>>>> 
>>>> {
>>>> 
>>>>      QtAppDelegate *appDelegate = (QtAppDelegate *)[[UIApplication
>>>> sharedApplication] delegate];
>>>> 
>>>>      [[UIApplication sharedApplication] setDelegate:[QtAppDelegate
>>>> sharedQtAppDelegate]];
>>>> 
>>>>      NSLog(@"Created a new appdelegate");
>>>> 
>>>> }
>>>> 
>>>> 
>>>> 
>>>> I then found this very interesting post:
>>>> https://forum.qt.io/topic/48745/how-to-get-didfinishlaunchingwithoptions-called-in-ios-delegate/7
>>>> which links to this bug report: QTBUG-38184.
>>>> 
>>>> First question: I am now wondering how my delegate can possibly work
>>>> since
>>>> it seems I can have only one delegate... so what happened to
>>>> QIOSApplicationDelegate?
>>>> 
>>>> I then tried various things to add yet another delegate this time
>>>> based on
>>>> UINavigationControllerDelegate, but although after much sweat it
>>>> seems to
>>>> load, the various methods I am trying to override are never called
>>>> when I
>>>> rotate the device.
>>>> 
>>>> Could it be that I should instead modify/interface
>>>> QIOSApplicationDelegate
>>>> itself and not try to create my own delegates?
>>>> 
>>>> A bit confused at this point, I admit ;)
>>>> 
>>>> Thanks for any tip
>>>> 
>>>> Philippe Lelong
>>>> 
>>>> 
>>>> 
>>>> Le 27-05-2015 20:24, Ben Lau a écrit :
>>>> 
>>>> 
>>>> 
>>>> On 28 May 2015 at 02:07, maitai <maitai at virtual-winds.org> wrote:
>>>>> Hello all,
>>>>> 
>>>>> I've started to port on iOS and need to override some methods, like
>>>>> we
>>>>> do easily through Java on Qt/Android. I succeeded to implement an
>>>>> appDelegate in objective-C that works for some events like openURL
>>>>> and
>>>>> such, but for instance I also need to lock automatic screen 
>>>>> rotation
>>>>> in
>>>>> some circumstances (but not always).
>>>> 
>>>> Objective-C has a feature to replace the original method of a class.
>>>> So you
>>>> may just override the method you needed (In case it don't break Qt)
>>>> Customizing Existing Classes
>>>> 
>>>> Example Code:
>>>> quickios/appdelegate.mm at 0b067e17dc13b8533ca3f7dd574d7e81ea17a015 
>>>> ·
>>>> benlau/quickios
>>>> 
>>>> I have tested to override openURL and didFinishLaunchingWithOptions
>>>> of
>>>> AppDelegate with Qt 5.4.1. This method works.
>>>> 
>>>>> I read that I should somehow override "bool
>>>>> UINavigationController::shouldRotate()"
>>>> 
>>>> Never tried. But should be worth to try? I am also be interested 
>>>> with
>>>> your
>>>> result.
>>>> 
>>>>> Should I reimp (subclass?) UINavigationController and how? Or is
>>>>> there a
>>>>> way to create a new delegate or even better to extend my current
>>>>> appDelegate?
>>>>> 
>>>>> 
>>>>> I'm new to Objective-C as you can guess... Any clue would be really
>>>>> appreciated :)
>>>>> 
>>>>> Thanks
>>>>> Philippe Lelong
>>> Dear Philippe,
>>> 
>>> Please see the reply Tor Arne inside
>>> 
>>> https://bugreports.qt.io/browse/QTBUG-42123
>>> 
>>> That could be an answer - Let it be.
>>> 
>>> Sincerely,
>>> Robert
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