Creating the data model

At this point in the application, it's time to build a simple data model that the user interface will back onto. Each claim will be represented by a ClaimItem object, and will contain any number of Attachment objects, each of which will reference the File that was attached, and have a marker to help decide how the attachment should be previewed. All these classes will need to be Parcelable, because they need to be saved in the CaptureClaimActivity. The CaptureClaimActivity will also use them as input and output parameters, and any time an object needs to be passed as a parameter to or from an Activity, it needs to be Parcelable.

You'll also be creating a Category enum that links the Android IDs to an internal model that can be stored without having to worry about the Android IDs changing their values as the application evolves.

Creating the Attachment class

The Attachment class represents files that have been attached to a ClaimItem by the user. These should always be...