How to set the font-size of text inside a Button?

[fancellu]

I ask as the default font size seems tiny on my 4k screen, and I can't adjust it as I can for a simple Text

e.g.

import { Button, VerticalBox } from "std-widgets.slint";

export component AppWindow inherits Window {
    in-out property<int> counter: 42;
    callback request-increase-value();
    VerticalBox {
           
        Text {
            text: "Counter: \{root.counter}";
            font-size: 50px;
        }
        Button {
            text: "Increase value!!!";
            
            clicked => {
                root.request-increase-value();
            }
        }
    }
}

Trust me, it is much smaller on my 4k screen.

[bjorn]

You may want to try setting default-font-size: https://slint.dev/releases/1.3.2/docs/slint/src/language/concepts/fonts

[ogoffart]

I think the Qt style don't respect the default window style.

In practice, you can't change the font size of a native button because the font size should be the one which is good for buttons. If you want non-native style, you need to re-implement your components.

If the font is too small for native component, this can mean that the detection of the scale factor is wrong. What is your platform? Is it wayland or x11? Do you have a scale factor set? Can you also try with the winit backend?

[sealor]

Thank you for your reply.
I'm using Linux (EndeavourOS) with xfce4 (X11). I didn't set a scale factor. I only used the code which I wrote previously.

When using the winit backend the font size is higher by default but the default-font-size attribute is still not recognized by the button text.

SLINT_BACKEND=winit cargo run

[tronical]

Even with the winit backend this is still rendered using the Qt style. We could make it respect default-font-size if we use get_font() like we do for draw_text() and pass the QFont to QStyleOption.

@sealor If you set the widget style to say "Fluent", then it default-font-size should work.

@ogoffart would you say that it's a bug that the QStyle based style doesn't respect default-font-* or would you say that it's by design?

[ogoffart]

Yes, this is probably a bug that the qt style don't respect the style.
But even then, you don't want to encourage people to set it.
Because

1. That's not the way to do it so a deskop app looks good on a 4k monitor. Normally, it should use the proper scale factor such that the font text looks the same as every apps. And it would look terribly wrong when deployed on a non-4k monitor.
2. that doesn't work in the live preview when previewing components separately.

[tronical]

Related issue to track support for default-font-* with the Qt style: #1022

[sealor]

Even with the winit backend this is still rendered using the Qt style. We could make it respect default-font-size if we use get_font() like we do for draw_text() and pass the QFont to QStyleOption.

@sealor If you set the widget style to say "Fluent", then it default-font-size should work.

@ogoffart would you say that it's a bug that the QStyle based style doesn't respect default-font-* or would you say that it's by design?

I tried the following:

SLINT_STYLE=fluent cargo run

Result: