How to set brush in QML code

VieiraFilho

Hey guys

I tried to find an example, but I didn't find anything.
In ScatterSeries there is a property called brush.
I want to define a color and fill pattern directly in QML code, such as ("red", Qt.SolidPattern).
If property exists, I believe there is a way to do this.
Does anyone have any example of how to set this property?

raven-worx

@VieiraFilho said in How to set brush in QML code:

If property exists, I believe there is a way to do this

not necessarily. AFAIK QBrush is not contained in the QML engine as a type so you have to use C++.
You can either pass the ScatterSeries object to an invokable C++ method (accepting a QObject* or QScatterSeries* parameter) and fill it there. Or you create an invokable C++ method which returns a QBrush from your call parameters packed in a QVariant (You must register the QBrush type with the meta type system).
I am not quite sure if the second approach really works though, but try it.

eyllanesc

@raven-worx like this https://stackoverflow.com/a/59009525/6622587

GrecKo

@eyllanesc said in How to set brush in QML code:

@raven-worx like this https://stackoverflow.com/a/59009525/6622587

:/

Definitely try the second method (a helper method returning a QBrush) before modifying your UI objects from your business code.

eyllanesc

@GrecKo I know it's not fancy, I just wanted to show an example of the first method. It would be more elegant if QML allows you to create those basic types from QML directly,

raven-worx

@GrecKo said in How to set brush in QML code:

before modifying your UI objects from your business code

i was talking about modifying the ScatterSeries object, which actually acts as a model for charts if you want so.

GrecKo

It's not only a model, it's also a representation of the data. I maintain that you should not modify that in C++.

The solution to OP's problem is the following:

Create a class like that in C++

class BrushFactory : public QObject
{
    Q_OBJECT

  public:
    Q_INVOKABLE QBrush brushFromColor(const QColor& color) // method returning a "fancy" brush
    {
      return QBrush(color, Qt::Dense4Pattern);
    }
};

Register it as a singleton type to the QML engine, and us it in QML like so:

ScatterSeries {
    // ...
    brush: BrushFactory.brushFromColor("pink")
    //  ...
}

Note that if you just want to set a simple color on the series, it already has a color property.

ndias

@GrecKo said in How to set brush in QML code:

Note that if you just want to set a simple color on the series, it already has a color property.

Thanks for this tip. I hadn't noticed that this property was defined in the parent class XYSeries