Method onLayoutChange

platform/java/example/ViewerCore.java:621–621

(int width, int height, int em)

		public void onChapterCountChange(int chapters);
		public void onLayoutChange(int width, int height, int em);
		public void onLinearizedChange(boolean linearized);
		public void onMetadataChange(String title, String author, String format, String encryption);
		public void onOutlineChange(OutlineItem[] outline);