src/vs/base/browser/ui/centered/centeredViewLayout.ts/CenteredViewLayout/activate
class CenteredViewLayout:	activate(active: boolean): void {
		if (active === this.isActive()) {
			return;
		}

		if (active) {
			this.container.removeChild(this.view.element);
			this.splitView = new SplitView(this.container, {
				inverseAltBehavior: true,
				orientation: Orientation.HORIZONTAL,
				styles: this.style
			});
			this.splitView.orthogonalStartSash = this.boundarySashes.top;
			this.splitView.orthogonalEndSash = this.boundarySashes.bottom;

			this.splitViewDisposables.add(this.splitView.onDidSashChange(() => {
				if (this.splitView) {
					this.state.leftMarginRatio = this.splitView.getViewSize(0) / this.width;
					this.state.rightMarginRatio = this.splitView.getViewSize(2) / this.width;
				}
			}));
			this.splitViewDisposables.add(this.splitView.onDidSashReset(() => {
				this.state.leftMarginRatio = GOLDEN_RATIO.leftMarginRatio;
				this.state.rightMarginRatio = GOLDEN_RATIO.rightMarginRatio;
				this.resizeMargins();
			}));

			this.splitView.layout(this.width);
			this.splitView.addView(toSplitViewView(this.view, () => this.height), 0);
			const backgroundColor = this.style ? this.style.background : undefined;
			this.emptyViews = [createEmptyView(backgroundColor), createEmptyView(backgroundColor)];
			this.splitView.addView(this.emptyViews[0], this.state.leftMarginRatio * this.width, 0);
			this.splitView.addView(this.emptyViews[1], this.state.rightMarginRatio * this.width, 2);
		} else {
			if (this.splitView) {
				this.container.removeChild(this.splitView.el);
			}
			this.splitViewDisposables.clear();
			if (this.splitView) {
				this.splitView.dispose();
			}
			this.splitView = undefined;
			this.emptyViews = undefined;
			this.container.appendChild(this.view.element);
			this.view.layout(this.width, this.height, 0, 0);
		}
	}