Method buildPath

src/chart/tree/TreeView.ts:94–130

(ctx: CanvasRenderingContext2D, shape: TreeEdgeShape)

    }

    buildPath(ctx: CanvasRenderingContext2D, shape: TreeEdgeShape) {
        const childPoints = shape.childPoints;
        const childLen = childPoints.length;
        const parentPoint = shape.parentPoint;
        const firstChildPos = childPoints[0];
        const lastChildPos = childPoints[childLen - 1];

        if (childLen === 1) {
            ctx.moveTo(parentPoint[0], parentPoint[1]);
            ctx.lineTo(firstChildPos[0], firstChildPos[1]);
            return;
        }

        const orient = shape.orient;
        const forkDim = (orient === 'TB' || orient === 'BT') ? 0 : 1;
        const otherDim = 1 - forkDim;
        const forkPosition = parsePercent(shape.forkPosition, 1);
        const tmpPoint = [];
        tmpPoint[forkDim] = parentPoint[forkDim];
        tmpPoint[otherDim] = parentPoint[otherDim] + (lastChildPos[otherDim] - parentPoint[otherDim]) * forkPosition;

        ctx.moveTo(parentPoint[0], parentPoint[1]);
        ctx.lineTo(tmpPoint[0], tmpPoint[1]);
        ctx.moveTo(firstChildPos[0], firstChildPos[1]);
        tmpPoint[forkDim] = firstChildPos[forkDim];
        ctx.lineTo(tmpPoint[0], tmpPoint[1]);
        tmpPoint[forkDim] = lastChildPos[forkDim];
        ctx.lineTo(tmpPoint[0], tmpPoint[1]);
        ctx.lineTo(lastChildPos[0], lastChildPos[1]);

        for (let i = 1; i < childLen - 1; i++) {
            const point = childPoints[i];
            ctx.moveTo(point[0], point[1]);
            tmpPoint[forkDim] = point[forkDim];
            ctx.lineTo(tmpPoint[0], tmpPoint[1]);
        }
    }
}

class TreeView extends ChartView {