Can't use painter->fillRect with custom color

Niagarer

Hey,
I want to paint a rectangle in the drawBackground function of a QGraphicsView.
But I want to use a custom color.
So I tried:

    QColor *myColor = new QColor(71, 71, 71, 255);
    painter->fillRect(rect.intersected(sceneRect), myColor);

Then I get this error in the second line:

error: invalid conversion from 'const QColor*' to 'QRgb {aka unsigned int}' [-fpermissive]

i really don't understand that, when I try:

    QColor myColor = new QColor(71, 71, 71, 255); // no pointer!
    painter->fillRect(rect.intersected(sceneRect), myColor);

I get this error in the first line:

error: invalid conversion from 'QColor*' to 'QRgb {aka unsigned int}' [-fpermissive]
     QColor myColor = new QColor(71, 71, 71, 255);

I have no Idea what this means, I even do not use any QRgb here so I don't know what is wrong with this code
What should I write instead and what does the error mean?
Thanks for answers

Niagarer

Found it!
just had to use

    painter->fillRect(rect.intersected(sceneRect), myColor->rgb());

But I still don't know why it says

invalid conversion

in the first line, when I do not use myColor->rgb()
There was nothing wrong with the first line...

tomma

QPainter::fillRect expects QBrush or QColor and you are trying to call it with QColor pointer.

QColor *myColor = new QColor(71, 71, 71, 255);
painter->fillRect(rect.intersected(sceneRect), myColor);

QColor myColor = new QColor(71, 71, 71, 255);

These both try to create QColor using QColor* value and QColor(QRgb) seems to be closest constructor for this conversion.

painter->fillRect(rect.intersected(sceneRect), myColor->rgb());

And you create QColor using QRgb.

SGaist

Hi,

You are creating a memory leak here. There's not need to create your QColour object on the heap. Just use the stack.

const QColor myColor(71, 71, 71, 255);
painter->fillRect(rect.intersected(sceneRect), myColor);

Or even shorter:

painter->fillRect(rect.intersected(sceneRect), QColor(71, 71, 71, 255));

Niagarer

@SGaist
Ok, thanks!
Will I also be able to keep this method when I add the possibility in the program to change this color at runtime?

SGaist

Yes, just make your myColor variable a class member and update it as you want it.