Function buildVisualMapping

src/chart/treemap/treemapVisual.ts:172–225

(
    node: TreemapLayoutNode,
    nodeModel: NodeModel,
    nodeLayout: TreemapItemLayout,
    nodeItemStyleModel: NodeItemStyleModel,
    visuals: TreemapVisual,
    viewChildren: TreemapLayoutNode[]
)

}

function buildVisualMapping(
    node: TreemapLayoutNode,
    nodeModel: NodeModel,
    nodeLayout: TreemapItemLayout,
    nodeItemStyleModel: NodeItemStyleModel,
    visuals: TreemapVisual,
    viewChildren: TreemapLayoutNode[]
) {
    if (!viewChildren || !viewChildren.length) {
        return;
    }

    const rangeVisual = getRangeVisual(nodeModel, 'color')
        || (
            visuals.color != null
            && visuals.color !== 'none'
            && (
                getRangeVisual(nodeModel, 'colorAlpha')
                || getRangeVisual(nodeModel, 'colorSaturation')
            )
        );

    if (!rangeVisual) {
        return;
    }

    const visualMin = nodeModel.get('visualMin');
    const visualMax = nodeModel.get('visualMax');
    const dataExtent = nodeLayout.dataExtent.slice() as [number, number];
    visualMin != null && visualMin < dataExtent[0] && (dataExtent[0] = visualMin);
    visualMax != null && visualMax > dataExtent[1] && (dataExtent[1] = visualMax);

    const colorMappingBy = nodeModel.get('colorMappingBy');
    const opt: VisualMappingOption = {
        type: rangeVisual.name,
        dataExtent: dataExtent,
        visual: rangeVisual.range
    };
    if (opt.type === 'color'
        && (colorMappingBy === 'index' || colorMappingBy === 'id')
    ) {
        opt.mappingMethod = 'category';
        opt.loop = true;
        // categories is ordinal, so do not set opt.categories.
    }
    else {
        opt.mappingMethod = 'linear';
    }

    const mapping = new VisualMapping(opt);
    inner(mapping).drColorMappingBy = colorMappingBy;

    return mapping;
}

// Notice: If we don't have the attribute 'colorRange', but only use
// attribute 'color' to represent both concepts of 'colorRange' and 'color',