public renderY()

in src/TornadoChartScrolling.ts [85:140]
46 lines of code
12 McCabe index (conditional complexity)

    public renderY(data: TornadoChartDataView, onScroll: () => {}): void {
        this.isYScrollBarVisible = this.isScrollable
            && this.getPrefferedHeight() > this.viewport.height
            && this.viewport.height > 0
            && this.viewport.width > 0;

        this.brushGraphicsContextY = this.createOrRemoveScrollbar(this.isYScrollBarVisible, this.brushGraphicsContextY, "y brush");
        if (!this.isYScrollBarVisible) {
            onScroll.call(this, jQuery.extend(true, {}, data), 0, 1);
            return;
        }

        let scrollSpaceLength: number = this.viewport.height;
        let extentData: any = this.getExtentData(this.getPrefferedHeight(), scrollSpaceLength);
        let getEvent = () => require("d3-selection").event;

        let onRender = (selection: any = getEvent() && getEvent().selection, wheelDelta: number = 0) => {
            let position = selection || extentData.value;

            if (wheelDelta !== 0) {
                // Handle mouse wheel manually by moving the scrollbar half of its size
                let halfScrollsize: number = (position[1] - position[0]) / 2;
                position[0] += (wheelDelta > 0) ? halfScrollsize : -halfScrollsize;
                position[1] += (wheelDelta > 0) ? halfScrollsize : -halfScrollsize;

                if (position[0] < 0) {
                    let offset: number = -position[0];
                    position[0] += offset;
                    position[1] += offset;
                }
                if (position[1] > scrollSpaceLength) {
                    let offset: number = position[1] - scrollSpaceLength;
                    position[0] -= offset;
                    position[1] -= offset;
                }
                // Update the scroll bar accordingly and redraw
                this.scrollYBrush.move(this.brushGraphicsContextY, position);
                this.brushGraphicsContextY.select(".selection").attr("y", position[0]);
            }

            let scrollPosition: number[] = extentData.toScrollPosition(position, scrollSpaceLength);
            onScroll.call(this, jQuery.extend(true, {}, data), scrollPosition[0], scrollPosition[1]);
        };

        this.scrollYBrush.extent([[0, 0], [TornadoChart.ScrollBarWidth, this.viewport.height]]);

        this.renderScrollbar(
            this.scrollYBrush,
            this.brushGraphicsContextY,
            this.viewport.width,
            extentData.value[1],
            onRender
        );

        onRender();
    }