Function border

pub fn border(
    child: impl UiNode,
    widths: impl IntoVar<SideOffsets>,
    sides: impl IntoVar<BorderSides>,
) -> impl UiNode

P Border widths, color and style.

This property coordinates with any other border in the widget to fit inside or outside the other borders, it also works with the corner_radius property drawing round corners if configured.

This property disables inline layout for the widget.

Examples

A border of width 1.dip(), solid color BLUE in all border sides and corner radius 4.dip().

Wgt! {
    border = 1, colors::BLUE;
    corner_radius = 4;
}

A border that sets each border line to a different width top: 1, right: 2, bottom: 3, left: 4, each corner radius to a different size top_left: 1x1, top_right: 2x2, bottom_right: 3x3, bottom_left: 4x4 and each border line to a different style and color.

Wgt! {
    border = {
        widths: (1, 2, 3, 4),
        sides: BorderSides::new(
            BorderSide::solid(colors::RED),
            BorderSide::dashed(colors::GREEN),
            BorderSide::dotted(colors::BLUE),
            BorderSide::double(colors::YELLOW),
        ),
    };
    corner_radius = (1, 2, 3, 4);
}

Multiple Borders

The border fits in with other borders in the widget, in this example we declare a new border property by copying the signature of this one:

/// Another border property.
#[property(BORDER, default(0, BorderStyle::Hidden))]
pub fn my_border(
    child: impl UiNode,
    widths: impl IntoVar<SideOffsets>,
    sides: impl IntoVar<BorderSides>
) -> impl UiNode {
    zng_wgt::border(child, widths, sides)
}

Now we can set two borders in the same widget:

Wgt! {
    border = 4, colors::RED;
    my_border = 4, colors::GREEN;
    corner_radius = 8;
}

This will render a RED border around a GREEN one, the inner border will fit perfectly inside the outer one, the corner_radius defines the outer radius, the inner radius is computed automatically to fit.

Note that because both borders have the same NestGroup::BORDER the position they are declared in the widget matters:

Wgt! {
    my_border = 4, colors::GREEN;
    border = 4, colors::RED;
    corner_radius = 8;
}

Now the GREEN border is around the RED.

You can adjust the nest group to cause a border to always be outside or inside:

/// Border that is always around the other borders.
#[property(BORDER-1, default(0, BorderStyle::Hidden))]
pub fn outside_border(child: impl UiNode, widths: impl IntoVar<SideOffsets>, sides: impl IntoVar<BorderSides>) -> impl UiNode {
    zng_wgt::border(child, widths, sides)
}
 
/// Border that is always inside the other borders.
#[property(BORDER+1, default(0, BorderStyle::Hidden))]
pub fn inside_border(child: impl UiNode, widths: impl IntoVar<SideOffsets>, sides: impl IntoVar<BorderSides>) -> impl UiNode {
    zng_wgt::border(child, widths, sides)
}