src/vs/workbench/browser/layout.ts/Layout/centerEditorLayout
class Layout:	centerEditorLayout(active: boolean, skipLayout?: boolean): void {
		this.stateModel.setRuntimeValue(LayoutStateKeys.EDITOR_CENTERED, active);

		const activeEditor = this.editorService.activeEditor;

		let isEditorComplex = false;
		if (activeEditor instanceof DiffEditorInput) {
			isEditorComplex = this.configurationService.getValue('diffEditor.renderSideBySide');
		} else if (activeEditor?.hasCapability(EditorInputCapabilities.MultipleEditors)) {
			isEditorComplex = true;
		}

		const isCenteredLayoutAutoResizing = this.configurationService.getValue('workbench.editor.centeredLayoutAutoResize');
		if (
			isCenteredLayoutAutoResizing &&
			(this.editorGroupService.groups.length > 1 || isEditorComplex)
		) {
			active = false; // disable centered layout for complex editors or when there is more than one group
		}

		if (this.editorGroupService.isLayoutCentered() !== active) {
			this.editorGroupService.centerLayout(active);

			if (!skipLayout) {
				this.layout();
			}
		}

		this._onDidChangeCenteredLayout.fire(this.stateModel.getRuntimeValue(LayoutStateKeys.EDITOR_CENTERED));
	}