In your MyView::paintEvent write QPainter painter(viewport()); instead of QPainter painter(this);.

@AdrianCruz
hi
Super :)
just as a note
To avoid getting possible NULLs in the list, i would suggest doing

QGraphicsItem *item = qgraphicsitem_cast<QGraphicsItem*>(text); if (item) list.push_back(item);

Hi,

You shouldn't use the size of a widget in its own constructor. The widget being not yet visible, the value won't make sense.

@raven-worx

I tried the following but didn't work out..

QGraphicsPixmapItem* item = new QGraphicsPixmapItem(QPixmap::fromImage(qImage, Qt::AutoColor)); m_ViewerScene->addItem(item); QGraphicsRectItem* rect = new QGraphicsRectItem(m_BoundingBox); m_ViewerScene->addItem(rect); rect->setParentItem(item); m_ViewerScene->update(); //add the resized QGraphicsPixmapItem to the pixmap item->setPixmap( item->pixmap().scaled(QSize(128, 32),Qt::IgnoreAspectRatio, Qt::SmoothTransformation)); qInfo()<<"Rect resize props:::"<<item->childItems()[0]->boundingRect(); m_BoundingBox = item->childItems()[0]->boundingRect();

later I'm drawing box, on the image in an other viewer, with m_BoundingBox.

The grey area within the blue rectangle will be resized to 128 * 32, and then the red rectangle would be added on the resized image. How to get the co-ordinates of red rect on the resized image?

Hi @wthung, I don't think this forum supports file uploads.

Can you create a simple example that demonstrates the memory leak? Just post the code here, no need to upload an attachment.

@JEllery Glad you got it fixed. Sorry I disappeared mid helping you. I get really busy with work sometimes and don't have time to be on the forums here.

Hi
I just keep a pointer to the "white lines" and adjust if i move yellow.

class ColorItem : public QGraphicsItem { .. ConnectorLine* line = nullptr; .. protected: QVariant itemChange(GraphicsItemChange change, const QVariant& value) override { if (change == ItemPositionChange && scene()) { if (line) { line->adjust(); } } return QGraphicsItem::itemChange(change, value); } private: QColor color; };

line->Adjust() alters its endpoints. You could just adjust it directly here.

You're welcome !

Since you have it working now, please mark the thread as solved using the "Topic Tools" button so that other forum users may know a solution has been found :)

What do you think about this?

int length = this->boundingRect().width(); length = (int)(((double)length * (double)value) / 100.0); QPixmap pix(this->boundingRect().width() - length, this->boundingRect().height()); pix.fill(Qt::transparent); QPainter p; p.begin(&pix); p.fillRect(pix.rect(), QColor(0, 0, 0, 120)); p.end(); gauge->setPixmap(pix); gauge->setPos(pos().x()+length, pos().y());

It works fine and the effect is the same as on example pixtures above.

:D
I haven't had much time to test if the bug exists in Qt5. I'll check it out and update the topic accordingly. If the bug is still there, of course, I will submit the fix.

Thanks for your time.

Its not moving the pointer that is making it work. It is the QRect that I created to test. If I comment out
the rect it all goes back to not moving and only being created at 0,0

@Wieland Wow you are just killing it today for me aren't you? Haha. I'll judge which is best for me a give it a roll.

Thanks a bunch (again)!

EDIT:

I ended up going for the event filter route and it works beautifully. Other than the exact syntax the approach also feels pretty intuitive which I like.

I had the same problem with items moving rightward as I stretched the window/viewport beyond the scene rect. This fixed it:

view->setAlignment( Qt::AlignLeft | Qt::AlignTop );

@Joel-Bodenmann
That's the manual way i talked about uptop but thanks anyways :)
It reassures me that i'm not "re-inventing" the wheel by applying this method .

Yep , fixed !!

Biggest achievement of ma layf.

Topic->setAsSolvedPolicy(Qt::AlwaysTrue);

I'd recommend reading this article which explains everything fairly well: Coordinate System

As the article explains, each graphics item maintains it's own coordinate system. The methods you are referring to are used to translate coordinates between those items, between the items and the scene and so on.
I hope that reading that article will help, otherwise feel free to ask if clarification is needed.

I had misconfigured ensureVisible's margins , and the view's size and the scene's rect .
Now it works fine :)

ok will do

@LoPiTaL
you could still combine both styles in one CSS. You just need to adapt your selectors.
E.g. you could set an property to your widgets and only apply certain styles to them.

@cfdev said:

I would like to know if Qtquick can doing the same thing as QGraphicsScene ?

Yes.

Hi
you could maybe use
http://doc.qt.io/qt-5/qgraphicsitem.html#sceneBoundingRect
and see if they are next to each other?

I implemented some kind of clipping done in the MainWindow's paintEvent(). This leads to a satisfying number of items. But the question: Is this the right place to remove and / or create scene items?

@VRonin
Hi
Oh yeah, I didn't think about a .gif ! That will spare me the complication of trying to find a way to make the scene recurrent. Thank you !

hi
As far as I know there is no build in raster to vector conversion.
Also many images are not really good for it.

Im wonder if QGraphicsScene is scaling images with best quality.
http://stackoverflow.com/questions/22652491/qt-resize-image-with-best-quality

@Joel-Bodenmann

There is a quite simple, if ugly solution:

Copy the code of "fitInView" from Qt sources into your class. Give it a new name (e.g. fitInViewTightly) Strip away the modifiers that cause your headache

@Lays147

If only you want changed background color for QGraphicsScene, then:

scene()->setBackgroundBrush(palette().window());

After further investigation, it appears that this is because I am using OpenGL - the 'fullUpdate' flag in updateScene is always set in this case - qgraphicsView has "accelerateScrolling = !isGlWidget" [in setupViewport, line 2759] and "fullUpdate = !d->accelerateScrolling" [in updateScene, line 2675]

@alogim
Yes, you can, but then you'll need at some point to update the scene's viewport (the QSceneView) manually and this might have some undesirable effects when you move/resize your widget(s).

Hi,

Please don't post the same question multiple times. If you have additional informations to add to your thread, you can edit the post. rather than deleting it and write a new one.

(One?) Solution is to call QGraphicsView( QRectF ) with QRectF obtained from QGraphicsScene::sceneRect() immediately after assigning a new scene rectangle.

Hi,

Might be a silly question but are you sure that the new image is valid and not null ?

@Jakob Hm, it seems I didn't refresh - you already did mark as solved - my apologies