Re: Launched window not activating

FROM : Ken Tozier
DATE : Tue Apr 12 07:35:47 2005

I just had a thought. The parameter block the ICA registration stuff 
requires calls for a C function as a callback so, I've been wrapping 
the method call to my "handleDeviceConnectedNotification" method inside 
a C function like this:

void DeviceNotificationHandler(ICAHeader *inData)
{
    if (inData->refcon)
        [(ICADownloader*) inData->refcon
       handleDeviceConnectedNotification: (ICARegisterEventNotificationPB*) 
inData];
}

Could the fact that the actual method call originates from inside a C 
function be causing all these problems?


On Apr 12, 2005, at 1:06 AM, Charilaos Skiadas wrote:

> Another idea then: In my case, the controller has in its init method a 
> call of the form:
>  self = [self initWithWindowNibName:@"Console"];
>
> and then at some point when the window is to appear, after the 
> application has finished launching, I have:
> [myController showWindow:self];
> And it works for me. Are you calling showWindow?
> If that doesn't work, then I would consider making a test case, as 
> minimal as possible, reproducing the problem, and file a bug report. 
> Do you have the same problems even if you do just show the window when 
> the notification comes, but strip out all other work that the app is 
> doing with the camera etc. It is necessary to determine whether this 
> has anything to do with this other camera framework you are using, or 
> if it is a pure cocoa problem.
> On Apr 11, 2005, at 11:32 PM, Ken Tozier wrote:
>

>>
>> On Apr 11, 2005, at 10:13 PM, Charilaos Skiadas wrote:
>>

>>> Ken,
>>>
>>> Where from are the cameraNotifications posted?

>>
>> They come from the ICA (image capture) interface (not my app) so I 
>> don't really know what's happening under the hood.
>>

>>> The method handling them will be running in that same thread that 
>>> they were posted on, regardless of in which thread you registered 
>>> for the notification, so the downloader methods dealing with the 
>>> notifications might actually not be running in the main thread.

>>
>> I just did a test in the callback handler checking to see if I was 
>> multithreaded but it doesn't appear that the ICA stuff is forking a 
>> new thread for messages it delivers. I was still single threaded 
>> inside the callback.
>>

>>> In that case, your downloader should be using 
>>> performSelectorOnMainThread: for the creation of the window and 
>>> bringing it to front, to make sure these operations take place in 
>>> the main thread.

>>
>> OK I tried performSelectorOnMainThread and got basically the same 
>> result. The window appears in unactivated form and sending it a 
>> "makeKeyAndOrderFront" from within performSelectorOnMainThread 
>> doesn't do anything. You can click on it and move it around the 
>> screen but it never comes to the front.
>>

>>> In any case it's a good idea to give it a try this way, and ensure 
>>> that all the UI stuff happens in the main thread.
>>> This might talk a bit more about the issue:
>>> http://cocoa.mamasam.com/MACOSXDEV/2004/02/2/85391.php

>>
>> Thanks for the link.
>>
>> Ken
>>
>>

>>>
>>> HTH
>>> On Apr 11, 2005, at 8:51 PM, Ken Tozier wrote:
>>>

>>>> Sorry to keep beating this issue, but there is something 
>>>> fundamentally wrong somewhere in the following six steps and I'm 
>>>> just not experienced enough with Cocoa GUI stuff to see it. To me, 
>>>> the algorithm looks fine, but there is some subtle thing that Cocoa 
>>>> doesn't like.
>>>>
>>>> The problem is that the window generated in step 6.A and displayed 
>>>> in 6.B is never frontmost and can't even be forced to front by 
>>>> clicking on it. The only way to bring it to front is to put the 
>>>> window load code inside a thread (which I'm told is bad for GUI 
>>>> stuff) Even when it's placed in a thread, it doesn't become 
>>>> frontmost without manually clicking on it.
>>>>
>>>> Anyone see the error?
>>>>
>>>> Thanks
>>>>
>>>> Ken
>>>>
>>>> Sequence of events:
>>>> --------------------------------
>>>> 1. Application opens "main" nib
>>>>
>>>> 2. "AppController" instance inside "main" nib initializes it's 
>>>> "downloader" instance
>>>>
>>>>     - (id) init
>>>>     {
>>>>         self = [super init];
>>>>         if (self)
>>>>         {
>>>>             downloader        = [[ICADownloader alloc] init];
>>>>         }
>>>>         
>>>>         return self;
>>>>     }
>>>>
>>>> 3. Downloader instance registers for camera connect events in it's 
>>>> "init" method
>>>>
>>>>
>>>>     - (id) init
>>>>     {
>>>>         self    = [super init];
>>>>         if (self)
>>>>         {
>>>>             [self registerForCameraConnectNotifications];
>>>>         }
>>>>         
>>>>         return self;
>>>>     }
>>>>
>>>>
>>>> 4. Time passes
>>>>
>>>> 5. User plugs in a camera
>>>>
>>>> 6. Downloader receives camera connect notification and performs 
>>>> following actions:
>>>>
>>>>     A. Creates a new window by loading the "DownloadWindow" nib file 
>>>> using NSWindowController with an owner of "self".
>>>>     B. Displays the window.
>>>>     C. Downloads photos to a specified directory.
>>>>     D. Closes window.
>>>>
>>>> 7. Done/Waits for another camera connect event.
>>>>
>>>>
>>>> Hierarchically, the location of the window create code is
>>>>
>>>> App
>>>> {
>>>>    Main Nib
>>>>    {
>>>>      AppController
>>>>      {
>>>>          downloader
>>>>          {
>>>>            handleCameraConnect <- (callback method)
>>>>            {
>>>>                NSWindowController    *wind
>>>>            }
>>>>          }
>>>>      }
>>>>    }
>>>> }
>>>>
>>>> _______________________________________________
>>>> Do not post admin requests to the list. They will be ignored.
>>>> Cocoa-dev mailing list      (<email_removed>)
>>>> Help/Unsubscribe/Update your Subscription:
>>>> http://lists.apple.com/mailman/options/cocoa-dev/
>>>> <email_removed>
>>>>
>>>> This email sent to <email_removed>
>>>>
>>>>

>>> Haris
>>>

>>  _______________________________________________
>> Do not post admin requests to the list. They will be ignored.
>> Cocoa-dev mailing list      (<email_removed>)
>> Help/Unsubscribe/Update your Subscription:
>> http://lists.apple.com/mailman/options/cocoa-dev/
>> <email_removed>
>>
>> This email sent to <email_removed>

> Haris
>