## Saving Annotations

#### Overview

Whyteboard saves .wtbd files as a renamed zip file. This contains any images that were loaded into the program, and a "save.data" file.

#### Zip Files

The file format .wtbd is essentially a renamed zip file. This contains any images that were saved inside the program, allowing a file saved on one computer to be opened, and edited on another. Versions prior to 0.39.3 did not do this.

The zip also contains a "save.data" file - this contains various information about the program state. This includes:

- Currently selected tool
- Current colour
- Current thickness
- Currently selected tab
- Last used font/size/style (if any)
- All sheets' names (preserving renamed sheets)
- Version of the Whyteboard the save was created with

This allows a user to carry on from where they were last editing their file.

When you load in .wtbd file, it may take a while to load as all the thumbnails need to be refreshed, which can take a few seconds; depending mainly on how many sheets are contained in the saved file.

#### Zip Performance Implications

There are a few issues with the zip file implementation, it will take longer to read and write larger .wtbd files containing many images/sheets/shapes.