Get the window location of a custum QWidget

[A Former User]

Hi,

I just need to know how I can get the window location of a custum QWidget.
I have this own widget :

class ColorPicker : public QWidget {
	Q_OBJECT
public:
	QHBoxLayout* layout;
	ColorGradient* mainView;
};

ColorPicker::ColorPicker(QWidget *parent) : QWidget(parent) {
	this->layout = new QHBoxLayout;
	setLayout(this->layout);

	this->mainView = new ColorGradient;
	this->layout->addWidget(this->mainView);
}

class ColorGradient : public QWidget {
public:
	ColorGradient(QWidget *parent = 0);

I have for my widget ColorPicker* colorpicker->pos().y() == 130
and for colorpicker->mainView->pos().y() == 9

I don't understand why mainView->pos() is in local space. Is it possible tu have the global position ?

Best regards,
Robin

[mrjj]

Hi
When a widget is a child of a other widget, its x,y are relative to parent.
You can use
http://doc.qt.io/qt-5.5/qwidget.html#mapToGlobal
To convert the child x,y to global x,y

Can I ask why you need this?

[A Former User]

Thanks A lots!

I need this to repaint a HUD into a texture. But I didn't need to update the entire HUD. So I use the function grab on interest widget and I repose them at the correcte location.

It could seen experimental. And it'is ^^

[mrjj]

yes sounds slightly experimental :)
there is also
http://doc.qt.io/qt-5.5/qwidget.html#render
but seems u need the real widget in new pos.

[A Former User]

Is it possible to render a widget into a FBO ?
I think Qt make his render on CPU.

[mrjj]

@Robinsondesbois
Im not good with opengl but it think its possible
http://stackoverflow.com/questions/7178186/how-to-draw-qglframebufferobject-onto-the-painter-from-within-qgraphicsitempai