d3#mouse TypeScript Examples

The following examples show how to use d3#mouse. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example #1
Source File: MouseEventsRect.tsx    From covid19-trend-map with Apache License 2.0 4 votes vote down vote up 
MouseEventsRect: React.FC<Props> = ({
    data,
    svgContainerData,
    scales,

    onHover,
}) => {
    const containerG = React.useRef<SVGGElement>();

    const itemOnHover = React.useRef<Covid19CasesByTimeFeature>();

    const init = () => {
        const { g, dimension } = svgContainerData;

        const { height, width } = dimension;

        containerG.current = select(g).append('g').node();

        const container = select(containerG.current);

        container
            .append('line')
            .attr('class', VerticalRefLineClassName)
            .attr('x1', 0)
            .attr('y1', 0)
            .attr('x2', 0)
            .attr('y2', height)
            .style('opacity', 0)
            .attr('stroke-width', 0.5)
            .attr('stroke', 'rgba(255,255,255,.75)')
            .style('fill', 'none');

        container
            .append('rect')
            // .attr("class", ClassNames.BackgroundRect)
            .attr('width', width)
            .attr('height', height)
            .attr('fill', 'rgba(0,0,0,0)')
            .on('mouseleave', () => {
                setItemOnHover(null);
            })
            .on('mousemove', function () {
                const mousePosX = mouse(this)[0];
                setItemOnHover(getItemByMousePos(mousePosX));
            });
    };

    const setItemOnHover = (item?: Covid19CasesByTimeFeature) => {
        itemOnHover.current = item;
        updateVerticalRefLinePos();
        onHover(item);
    };

    const updateVerticalRefLinePos = (): void => {
        const { x } = scales;

        const item = itemOnHover.current;

        const vRefLine = select(containerG.current).select(
            `.${VerticalRefLineClassName}`
        );

        const xPos = item ? x(item.attributes.dt) + x.bandwidth() / 2 : 0;

        const opacity = item ? 1 : 0;

        vRefLine.attr('x1', xPos).attr('x2', xPos).style('opacity', opacity);
    };

    const getItemByMousePos = (
        mousePosX: number
    ): Covid19CasesByTimeFeature => {
        let itemIndex = -1;
        const { x } = scales;

        for (let i = 0, len = data.length; i < len; i++) {
            const currItem = data[i];
            const currItemPos = x(currItem.attributes.dt);

            const nextItemIndex = data[i + 1] ? i + 1 : i;
            const nextItem = data[nextItemIndex];
            const nextItemPos = x(nextItem.attributes.dt);

            if (mousePosX >= currItemPos && mousePosX <= nextItemPos) {
                const distToCurrItem = Math.abs(mousePosX - currItemPos);
                const distToNextItem = Math.abs(mousePosX - nextItemPos);

                itemIndex = distToCurrItem < distToNextItem ? i : nextItemIndex;

                break;
            }
        }

        return data[itemIndex];
    };

    useEffect(() => {
        if (svgContainerData && data.length) {
            init();
        }
    }, [svgContainerData, data]);

    useEffect(() => {
        if (svgContainerData && scales) {
            const { dimension } = svgContainerData;
            const { width } = dimension;

            select(containerG.current).select('rect').attr('width', width);
        }
    }, [scales]);

    return null;
}