src/vs/workbench/contrib/notebook/browser/contrib/find/notebookFindReplaceWidget.ts/SimpleFindReplaceWidget/_updateButtons
class SimpleFindReplaceWidget:	private _updateButtons(): void {
		this._findInput.setEnabled(this._isVisible);
		this._replaceInput.setEnabled(this._isVisible && this._isReplaceVisible);
		const findInputIsNonEmpty = (this._state.searchString.length > 0);
		this._replaceBtn.setEnabled(this._isVisible && this._isReplaceVisible && findInputIsNonEmpty);
		this._replaceAllBtn.setEnabled(this._isVisible && this._isReplaceVisible && findInputIsNonEmpty);

		this._domNode.classList.toggle('replaceToggled', this._isReplaceVisible);
		this._toggleReplaceBtn.setExpanded(this._isReplaceVisible);

		this.foundMatch = this._state.matchesCount > 0;
		this.updateButtons(this.foundMatch);
	}