[Qt-interest] QGraphicsScene problem

[Patric]

Hi Sean,
I done it with auto connections. Now my GUI thread moves the items.

I 'v done it because I started to encounter random crashes.

Regards,
Patric

----- Original Message ----- 
From: "Sean Harmer" <sean.harmer at maps-technology.com>
To: <qt-interest at trolltech.com>
Sent: Saturday, August 29, 2009 11:51 AM
Subject: Re: [Qt-interest] QGraphicsScene problem


> Hi,
>
> On Saturday 29 Aug 2009 09:40:14 Patric wrote:
>> I don't have any timers.
>> But I have found that when the item's moveBy() functions is called, the
>> warning is given.
> What thread does your scene and items have affinity with? Main or worker?
>
> Personally I would just get your worker thread to emit signals that tell 
> the
> items where to move to rather than having the worker thread move the items
> directly which is what it sounds like you are doing form the limited
> information.
>
> This keeps your game logic code in the worker thread but keeps the GUI 
> stuff
> in the main thread where it has to live.
>
> Can you post some example code that reproduces the problem?
>
> Have you tried doing this without using threads?
>
> Sean
>
>>
>> The scene is in the main thread, the worker thread possesses a pointer to
>> the scene. And the worker thread is trying to move the item's in the 
>> scene
>> around. ----- Original Message -----
>>   From: Scott Aron Bloom
>>   To: qt-interest at trolltech.com
>>   Sent: Saturday, August 29, 2009 11:21 AM
>>   Subject: Re: [Qt-interest] QGraphicsScene problem
>>
>>
>>   The timer is owned/constructed in one theread, and is being
>> started/stoped by the worker thread.
>>
>>
>>
>>   Try calling moveToThread to move the timers into the worker thread.
>>
>>
>>
>>   Scott
>>
>>
>>
>>   From: qt-interest-bounces at trolltech.com
>> [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Patric Sent:
>> Saturday, August 29, 2009 1:11 AM
>>   To: qt-interest at trolltech.com
>>   Subject: [Qt-interest] QGraphicsScene problem
>>
>>
>>
>>   Hello guys,
>>
>>   I have QGraphicsScene here with items on it.
>>
>>
>>
>>   I have manual control (i.e. keyboard events) and also auto control
>> (through a thread which makes all the calculations where these 
>> QPixmapItems
>> should interact).
>>
>>
>>
>>   When I control them, everything is OK.
>>
>>   But when I start the auto control, i.e. my thread which simulates the
>> actions, I'm observing a very strange behaviour. It's a game actually, 
>> it's
>> turn based.
>>
>>   So somethimes the objects on the board are just not moving on their
>> turns.
>>
>>
>>
>>   I have implemented this simulation engine with the technique used in 
>> the
>> Mandelbrot example.
>>
>>
>>
>>   In my MainWindow class I have instance of the engine thread, and when
>> some button in the GUI is pressed MainWindow calls a method in the thread
>> (directly), which wakes the thread.
>>
>>   And I'm getting this shit :
>>
>>
>>
>>   QObject::killTimer: timers cannot be stopped from another thread
>>
>>   QObject::startTimer: timers cannot be started from another thread
>>
>>   QObject::killTimer: timers cannot be stopped from another thread
>>
>>   QObject::startTimer: timers cannot be started from another thread
>>
>>   QObject::killTimer: timers cannot be stopped from another thread
>>
>>   QObject::startTimer: timers cannot be started from another thread
>>
>>
>>
>>   Any ideas why ?
>>
>>
>>
>>   Regards,
>>
>>   Patric
>>
>>
>>
>>   p.s.:in the end of the thread's run method there is sleep call also.
>>
>>
>>
>> ---------------------------------------------------------------------------
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>>
>>
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