How to read a color of a pixel on a Widget?

Is there any way to read a color of a pixel on a widget? i.e. read the color of a pixel right under my mouse pointer. I've been searching in various places and I'm slowly starting to think that QT doesn't support such functionality, but I might just be looking at the wrong place. Please give some advice to a newbie!!! :)

you can use QPixmap::grabWidget(), convert it to QImage and then use QImage::pixel().

I just solved it using a similar technique, but thanks for the reply!!! :D

Code:

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QPixmap pixmap(this->size());
	this->render(&pixmap);
	QImage img(pixmap.toImage());
	QRgb pix = img.pixel(10,10);
	std::cout << "Red : " << qRed(pix) << std::endl;
	std::cout << "Green : " << qGreen(pix) << std::endl;
	std::cout << "Blue : " << qBlue(pix) << std::endl;

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It should be faster if you open the painter directly on the QImage object instead of the pixmap.

If you are using the mouse - do it through QMouseEvent with QEvent::MouseMove. So you will get theright coordinates and then call QImage through QPainter. That is faster.

Quote:

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Originally Posted by Tanuki-no Torigava

So you will get theright coordinates and then call QImage through QPainter. That is faster.

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Only if you cache the image, because rendering the image every time you move the mouse is damn slow!