extensions/media-preview/src/mediaPreview.ts/MediaPreview/updateState
class MediaPreview:	protected updateState() {
		if (this.previewState === PreviewState.Disposed) {
			return;
		}

		if (this.webviewEditor.active) {
			this.previewState = PreviewState.Active;
			this.binarySizeStatusBarEntry.show(this, this._binarySize);
		} else {
			this.binarySizeStatusBarEntry.hide(this);
			this.previewState = PreviewState.Visible;
		}
	}