Annotations

From OpenAlchemy.org

Annotations are pervasive in OpenAlchemy. By this we mean, a user can annotate any page/content in Alchemy by tapping the "Annotate" button in the bottom bar. In other words, an application has to explicitly turn off annotations else, annotations are always active.

Now, what constitutes an annotation? An explanatory note or comment in freehand (i.e. handwriting) on the current context (i.e. page/screen) is what makes up an annotation. So, there are two parts to an annotation viz. the current page/screen and the handwritten note. The current page/screen is stored as an image and forms the background for the handwritten note which is stored in the Amida Paper format.

In order to be able to view an annotation at the context it was created, there is a notion of an annotate key. The application together with the annotation key is a means to communicate to OpenAlchemy the current context of an annotation. As such, OpenAlchemy has opened up a channel for every application to communicate the context through

  ac_control_win(AC_CMD_SET_ANNOTATE_KEY, "annotn key", display, main_window);

To cite an example, consider the Browser. When a user visits a website, its URL becomes the annotation key. As such, if the user had made an annotation when she/he last visited the website, it would become visible because the context (application+annotation key) is the same. To cite another example, consider the Photo Album. Every image's id (maybe its filename) becomes the annotation key. So, if a user had made an annotation on a photograph/image, when she/he views it again, the context becomes clear and the annotation on it can be retrieved.