illogical-impulse/dots/.config/quickshell/ii/modules/waffle/bar/BarButton.qml

import QtQuick
import QtQuick.Controls
import QtQuick.Layouts
import qs.modules.common
import qs.modules.common.functions
import qs.modules.waffle.looks

Button {
    id: root

    Layout.fillHeight: true
    topInset: 4
    bottomInset: 4
    
    property color borderColor: ColorUtils.transparentize(Looks.colors.bg1Border, (root.hovered && !root.down) ? Looks.fluentContentTransparency : 1)
    Behavior on borderColor {
        animation: Looks.transition.color.createObject(this)
    }
    onBorderColorChanged: {
        borderCanvas.requestPaint();
    }

    background: Rectangle {
        id: background
        color: {
            if (root.down) {
                return Looks.colors.bg1Active
            } else if (root.hovered) {
                return Looks.colors.bg1Hover
            } else {
                return ColorUtils.transparentize(Looks.colors.bg1)
            }
        }
        radius: Looks.radius.medium
        Behavior on color {
            animation: Looks.transition.color.createObject(this)
        }
        
        // Top 1px border with color 
        Canvas {
            id: borderCanvas
            anchors.fill: parent
            onPaint: {
                var ctx = getContext("2d");
                ctx.clearRect(0, 0, width, height);

                var borderColor = root.borderColor;

                var r = background.radius;
                var fadeLength = Math.max(1, r);
                var fadeLengthPercent = fadeLength / width;

                // Compute normalized stops
                var leftFadeStop = fadeLengthPercent;
                var rightFadeStop = 1 - fadeLengthPercent;

                var grad = ctx.createLinearGradient(0, 0, width, 0);
                grad.addColorStop(0, Qt.rgba(borderColor.r, borderColor.g, borderColor.b, 0));
                grad.addColorStop(leftFadeStop, borderColor);
                grad.addColorStop(rightFadeStop, borderColor);
                grad.addColorStop(1, Qt.rgba(borderColor.r, borderColor.g, borderColor.b, 0));

                ctx.strokeStyle = grad;
                ctx.lineWidth = 1;

                ctx.beginPath();
                ctx.moveTo(r, 0.5);
                ctx.lineTo(width - r, 0.5);
                // Top-right curve
                ctx.arcTo(width, 0.5, width, r + 0.5, r);
                // Top-left curve
                ctx.moveTo(width - r, 0.5);
                ctx.arcTo(0, 0.5, 0, r + 0.5, r);
                ctx.stroke();
            }
        }
    }
}