Method render

src/chart/tree/TreeView.ts:154–233

(
        seriesModel: TreeSeriesModel,
        ecModel: GlobalModel,
        api: ExtensionAPI
    )

    }

    render(
        seriesModel: TreeSeriesModel,
        ecModel: GlobalModel,
        api: ExtensionAPI
    ) {
        const data = seriesModel.getData();

        const layoutInfo = seriesModel.layoutInfo;

        const group = this._mainGroup;

        const layout = seriesModel.get('layout');

        if (layout === 'radial') {
            group.x = layoutInfo.x + layoutInfo.width / 2;
            group.y = layoutInfo.y + layoutInfo.height / 2;
        }
        else {
            group.x = layoutInfo.x;
            group.y = layoutInfo.y;
        }

        this._updateViewCoordSys(seriesModel, api);

        updateRoamControllerSimply(
            seriesModel,
            api,
            this._controller,
            createIsInSelfByPointerCheckerEl(this.group),
            null,
        );

        const oldData = this._data;

        data.diff(oldData)
            .add(function (newIdx) {
                if (symbolNeedsDraw(data, newIdx)) {
                    // Create node and edge
                    updateNode(data, newIdx, null, group, seriesModel);
                }
            })
            .update(function (newIdx, oldIdx) {
                const symbolEl = oldData.getItemGraphicEl(oldIdx) as TreeSymbol;
                if (!symbolNeedsDraw(data, newIdx)) {
                    symbolEl && removeNode(oldData, oldIdx, symbolEl, group, seriesModel);
                    return;
                }
                // Update node and edge
                updateNode(data, newIdx, symbolEl, group, seriesModel);
            })
            .remove(function (oldIdx) {
                const symbolEl = oldData.getItemGraphicEl(oldIdx) as TreeSymbol;
                // When remove a collapsed node of subtree, since the collapsed
                // node haven't been initialized with a symbol element,
                // you can't found it's symbol element through index.
                // so if we want to remove the symbol element we should insure
                // that the symbol element is not null.
                if (symbolEl) {