How do I subclass QDial to show notches values ?

[Punt]

Ok, I understand how it works.. I have an idea to determinate the position of my texts (unit cercle I guess).

But I have a problem, because for example (with a QDial 100x100) :

• if I add text in (0,50) a part of the text will be on the QDial..
• if I add text in (-10,50), a part of the text will be cut

I guess I have to extend the painting zone.. but I don't find anything...

[mrjj]

@Punt
Hi the
"Painting zone" is the size of the QDial
You cannot paint outside it using -100 for x
It clip clip as you saw.
You cannot increase this area unless its ok the QDial also becomes bigger.

[Punt]

@mrjj
Maybe I can reduce the QDial then ? Like the radius of the circle ?

Or last idea : I create a new class, in which I put an "aera" like a Widget (?), I add a QDial and I draw my "notches-text-values" (Still don't know how to call it xDD)

[mrjj]

@Punt
well maybe. i dont think so.
I think it uses all its area.
else u need to copy the paint function and alter it to allow
to paint smaller than the area.
You should look in source and see what it uses to better understand it.

[mrjj]

sorry I miss last part.

Yes also option to make a composite class where u have QDial in center ( in a layout) and
let ur class paint on top of it all.

[Punt]

@mrjj
I think I'll go for it !
It's the easiest solution I guess...

I'm done for today, I'll try it tomorrow :)
Thanks :)

[mrjj]

but since you already subclassed it, why not make it work 100% like u want?
Also need to be able to give list for the "tick words" etc.
So find the source and see the paitnevent
maybe its easy to modify for what u want.

[mrjj]

void QDial::paintEvent(QPaintEvent *)
{
QStylePainter p(this);
QStyleOptionSlider option;
initStyleOption(&option);
p.drawComplexControl(QStyle::CC_Dial, option);
}

So u can just change option.rect ( check name)
and you can control the size of the dial.

[Punt]

@mrjj said:

but since you already subclassed it, why not make it work 100% like u want?
Also need to be able to give list for the "tick words" etc.
So find the source and see the paitnevent
maybe its easy to modify for what u want.

If I create a composite class, I don't need anymore my subclass...
Well I don't know, I'll check tomorrow if it's easy (Because i'll probably have to change another thing on a QDial => but that's another thing x) )

I guess i'll update this topic tomorrow, so if someone has another idea, I take it :)

Edit for your last message : I'll check tomorrow, I go home and I can't work there :p

See you

[mrjj]

before u try composite, please try adjust paint first.
So little code.

[Punt]

@mrjj said:

void QDial::paintEvent(QPaintEvent *)
{
QStylePainter p(this);
QStyleOptionSlider option;
initStyleOption(&option);
p.drawComplexControl(QStyle::CC_Dial, option);
}

So u can just change option.rect ( check name)
and you can control the size of the dial.

I can't do "option.something" ...

[mrjj]

why not?
Look in help then?

http://doc.qt.io/qt-5/qstyleoption.html#rect-var

[Punt]

@mrjj
Now the problem is I can extend the area and write text in the right and in the bottom of the QDial (because the QDial is drawn (good english ?!) in the left-top (0,0) ). And I don't have any idea how to change that.. I searched if there is something like the position where qt draw of something like that, but didn't find it .. --'

[mrjj]

hi
Not tested myself.
option.rect should control where QDial is
and the normal rect is your widget.

So if u set option.rect before
p.drawComplex

U should be able to move it around?

[Punt]

@mrjj
Look, if I

option.rect.setX(20)

this is just moving one part of the QDial --'
Gyazo

And what do you mean about the normal rect ?

The only rect I have is option.rect no ?!

[mrjj]

@Punt
Option has rect yes, used for the drawComplexControl call.
You own widget, also has rect, simply called rect or this->rect
which is the real area since the QDial is just painted.

[Punt]

@mrjj

    rect().setRect(0,0,200,200);
    option.rect.setRect(30,30,100,100);
    p.drawText(120,120,"(120,120)");
    p.drawText(30,30,"(30,30)");
    p.drawText(200,200,"(200,200)");

=> Gyazo

I don't find anything to move ticks ...

[mrjj]

Hmm
so it dont use option.rect() for the tick drawing.
Strange.

Alternatively
new a layout
set to your widget
New a QDial
add to layout
adjust layout margins to get room for text.
Paint the text in paintEvent.
Remove the drawComplexControl etc.

[Punt]

@mrjj
In my subclass ?

[mrjj]

@Punt
Yes
In constructor
so it becomes a composite widget with a normal QDial inside.
You will also have to create some public signal to use from outside
since you cannot directly connect to the QDail.