painter->save ()

QTransform trans = painter->transform ();
double currentScale = extractScale (trans); // Write function to extract the scale portion of the transform
double newScale = originalScale / currentScale;
trans.scale (newScale, newScale); // This may need to be scaled about the origin of the object so the text
// stays with the object
// eg. scaleAbout (invScale, originPt);
painter->setTransform (trans); // Now painter has a transform that has the scale removed
// TODO: draw your text
painter->restore ();

Scaling about points can be found in Computer Graphics Principles and Practice by Foley,VanDam,Feiner, and Hughes pages 208-210.

Since transformations are orthogonal, scales are found along the diagonal. If rotations are involved, the scales are componentized,

Thanks for your reply ...

@Buckwheat

"I have found, you can use inverse scaling on the object. Take a snapshot of the transformations scale when you start. From then after, apply an inverse scale on the object using save and restore like @m-sue presented. You will most likely have to scale "about" the location to apply the inverse scale."

Can you explain this point with some codes Please

I have found, you can use inverse scaling on the object. Take a snapshot of the transformations scale when you start. From then after, apply an inverse scale on the object using save and restore like @m-sue presented. You will most likely have to scale "about" the location to apply the inverse scale.

Another idea is to map the text location at the current transformation to the screen, setup the transformation as @m-sue suggested and then draw the text at the screen location.

Both these suggestions should help you move the text around. If you do not want to move the text (ie a Title, Legend, etc) then the QGraphicsScene::drawForeground (...) and QGraphicsScene::drawBackground (...) will suffice with a cleared transformation.

painter->save();
painter->setTransform(QTransform());
//draw text
painter->restore();

-Michael.

Hi...
Thanks for your reply ...

Hope its a good solution ..

The problem in my case is that in my app there are N no of items already present in the QGraphicsScene . Also according to the requirements , I should draw the text seperately with out disturbing the items present in the scene .
So I drawn the text in drawBackground() method of my scene .... Want some help for drawing the text through painter

See http://doc.qt.io/qt-5/qgraphicsitem.html#setFlags