src/vs/base/browser/ui/splitview/paneview.ts/PaneView/flipOrientation
class PaneView:	flipOrientation(height: number, width: number): void {
		this.orientation = this.orientation === Orientation.VERTICAL ? Orientation.HORIZONTAL : Orientation.VERTICAL;
		const paneSizes = this.paneItems.map(pane => this.getPaneSize(pane.pane));

		this.splitview.dispose();
		clearNode(this.element);

		this.splitview = this._register(new SplitView(this.element, { orientation: this.orientation }));

		const newOrthogonalSize = this.orientation === Orientation.VERTICAL ? width : height;
		const newSize = this.orientation === Orientation.HORIZONTAL ? width : height;

		this.paneItems.forEach((pane, index) => {
			pane.pane.orthogonalSize = newOrthogonalSize;
			pane.pane.orientation = this.orientation;

			const viewSize = this.size === 0 ? 0 : (newSize * paneSizes[index]) / this.size;
			this.splitview.addView(pane.pane, viewSize, index);
		});

		this.size = newSize;
		this.orthogonalSize = newOrthogonalSize;

		this.splitview.layout(this.size);
	}