[Qt-interest] QPainterPath::contains() alternative behaviour

[Jonathan Kew]

On 4 Apr 2009, at 23:58, Ioannis Nousias wrote:

> Jonathan Kew wrote:
>> On 4 Apr 2009, at 17:47, Ioannis Nousias wrote:
>>
>>
>>> yes, I've tried that, but contains() didn't trigger at all. Just  
>>> to  make sure I'm not doing something wrong, here is what I did:
>>>
>>> QPainterPathStroker stroker;
>>> QPainterPath stroke = stroker.createStroke(path);
>>>
>>> bool contains = stroke.contains
>>> (
>>> QRectF(event->pos(),event->pos())
>>> .adjusted(-0.5,-0.5,0.5,0.5)
>>> );
>>>
>>>
>>
>> Perhaps you need to set the width of the QPainterPathStroker? The   
>> documentation doesn't seem to mention a default....perhaps it's  
>> too  narrow to hit.
>>
>> JK
>>
>>
>
> My understanding is that paths have no width. It's the Pen that you  
> use that defines the width and other such properties. Am I right?

Yes, I believe so.

But when you use QPainterPathStroker, it has no idea what pen you  
might be intending to use (or have already used) for drawing the path;  
all you're giving it in createStroke() is the actual path, no pen  
information.

However, it does have a setWidth() method of its own (and similarly  
for other characteristics: dashes, mitre limit, etc). That's what I  
think you may need to set, to match the characteristics of the pen  
you're planning to use. Otherwise, how can it create a new path that  
corresponds to the outline of what that pen would draw?

So I'm suggesting you try

   stroker.setWidth(<the width of your pen>);

before calling stroker.createStroke(path).

JK