How to generate a responsive Image?

[Berrysoft]

I would like to generate a image which is reponsive to the avaliable size. For example, the layout is

VerticalBox {
    Image {
        // Need source here.
    }
    Button {
        text: "Some other functionalities";
    }
}

I would like the Image widget occupy all remaining spaces, and generate an bitmap (e.g. a plot from plotters).

My questions are the following:

• How to know the remaining spaces in a VerticalBox?
• How to response the resize event of the window?
• Or, how to response the redraw event of the Image widget?

Either the solutions below is OK, I think:

• Property changed event. Have callback emitted when a property changes #112
• Window resize event.
• Widget redraw event.

[Berrysoft]

Specifically, for plots, there's another solution: enable Image to load SVG from memory.