function getLegendStyle()

in src/component/legend/LegendView.ts [594:676]
68 lines of code
18 McCabe index (conditional complexity)

function getLegendStyle(
    iconType: string,
    legendItemModel: LegendModel['_data'][number],
    lineVisualStyle: PathStyleProps,
    itemVisualStyle: PathStyleProps,
    drawType: 'fill' | 'stroke',
    isSelected: boolean,
    api: ExtensionAPI
) {
    /**
     * Use series style if is inherit;
     * elsewise, use legend style
     */
    function handleCommonProps(style: PathStyleProps, visualStyle: PathStyleProps) {
        // If lineStyle.width is 'auto', it is set to be 2 if series has border
        if ((style.lineWidth as any) === 'auto') {
            style.lineWidth = (visualStyle.lineWidth > 0) ? 2 : 0;
        }

        each(style, (propVal, propName) => {
            style[propName] === 'inherit' && ((style as any)[propName] = visualStyle[propName]);
        });
    }

    // itemStyle
    const itemStyleModel = legendItemModel.getModel('itemStyle') as Model<LegendItemStyleOption>;
    const itemStyle = itemStyleModel.getItemStyle();
    const iconBrushType = iconType.lastIndexOf('empty', 0) === 0 ? 'fill' : 'stroke';
    const decalStyle = itemStyleModel.getShallow('decal');
    itemStyle.decal = (!decalStyle || decalStyle === 'inherit')
                    ? itemVisualStyle.decal
                    : createOrUpdatePatternFromDecal(decalStyle, api);

    if (itemStyle.fill === 'inherit') {
        /**
         * Series with visualDrawType as 'stroke' should have
         * series stroke as legend fill
         */
        itemStyle.fill = itemVisualStyle[drawType];
    }
    if (itemStyle.stroke === 'inherit') {
        /**
         * icon type with "emptyXXX" should use fill color
         * in visual style
         */
        itemStyle.stroke = itemVisualStyle[iconBrushType];
    }
    if ((itemStyle.opacity as any) === 'inherit') {
        /**
         * Use lineStyle.opacity if drawType is stroke
         */
        itemStyle.opacity = (drawType === 'fill' ? itemVisualStyle : lineVisualStyle).opacity;
    }
    handleCommonProps(itemStyle, itemVisualStyle);

    // lineStyle
    const legendLineModel = legendItemModel.getModel('lineStyle') as Model<LegendLineStyleOption>;
    const lineStyle: LineStyleProps = legendLineModel.getLineStyle();
    handleCommonProps(lineStyle, lineVisualStyle);

    // Fix auto color to real color
    (itemStyle.fill === 'auto') && (itemStyle.fill = itemVisualStyle.fill);
    (itemStyle.stroke === 'auto') && (itemStyle.stroke = itemVisualStyle.fill);
    (lineStyle.stroke === 'auto') && (lineStyle.stroke = itemVisualStyle.fill);

    if (!isSelected) {
        const borderWidth = legendItemModel.get('inactiveBorderWidth');
        /**
         * Since stroke is set to be inactiveBorderColor, it may occur that
         * there is no border in series but border in legend, so we need to
         * use border only when series has border if is set to be auto
         */
        const visualHasBorder = itemStyle[iconBrushType];
        itemStyle.lineWidth = borderWidth === 'auto'
            ? (itemVisualStyle.lineWidth > 0 && visualHasBorder ? 2 : 0)
            : itemStyle.lineWidth;
        itemStyle.fill = legendItemModel.get('inactiveColor');
        itemStyle.stroke = legendItemModel.get('inactiveBorderColor');
        lineStyle.stroke = legendLineModel.get('inactiveColor');
        lineStyle.lineWidth = legendLineModel.get('inactiveWidth');
    }
    return { itemStyle, lineStyle };
}