BusEventName: "outlineloaded" | "attachmentsloaded" | "namedaction" | "pagemode" | "fileattachmentannotation" | "pagerendered" | "pagecancelled" | "scalechange" | "pagesinit" | "pagesloaded" | "documentchanged" | "rotationchanging" | "updateviewarea" | "undostorechanged" | "annotationeditstarted" | "show-custom-layout" | "hide-custom-layout" | "unselectannotation" | "annotation-bounds-change" | "pagechange" | "mousemodechange" | "request-answer" | "textlayerready" | "viewersizechanged" | "articlebeadnavigate" | "error" | "open" | "pagelabels" | "documentload"
内部 EventBus イベント名。