SuperMap employs logical groups to organize marker, line, and region symbol libraries.
To facilitate a better understanding of the management of the symbols, here we explain how symbols are organized with logical groups by referring to how files are organized in Windows Explorer with folders. In the following description, we call a logical symbol group as a symbol group.
Windows Explorer uses folders to classify and organize files. Essentially, files are physically stored in the disk and the folder is only a physical concept for organizing and managing files, which facilitates the managing, searching, and usage of files. For example:
- “C:” indicates the root disk, which contains a set of files and folders, with each of which containing a set of files and folder. A folder can contain not only files but also folders.
- We can locate a file through the path of the file. Absolute file path is like C:\SuperMap\Data\City\Changchun.udb, indicating the full path of the Changchun.udb file.
About the logical grouping management of symbols, following concepts are covered.
- Root Group: The root directory for symbol management in the symbol library. It is equivalent to the root directory of a disk, like “C:”.
- Symbol Group: The child directory of the Root group in the symbol library. It is equivalent to the folder on a disk. A folder has its name, and similarly, a symbol group has a name.
- Symbol: It is equivalent to the file.
- Similar to the organization of Windows Explorer, the root group can contain multiple symbols and symbol groups. And each symbol group can have multiple symbols or symbol groups. Symbols are classified and stored in the symbol library.
- The path of a symbol is the symbol group where the symbol is placed. The path is absolute path, which is in the format of “Root Group\Symbol Group A\Symbol Group C”, indicating the contents in the Symbol Group C.
- In Windows Explorer, you can create a new folder in any directory and place new files in the new folder, or move a file in a folder to another folder. For the symbol library, it is similar. You are allowed to create a new symbol group in a symbol group and add symbols for the new symbols for the new symbol group. Also, you can move a symbol from a symbol group to another symbol group.
- Similar to file management, symbols with identical names cannot exist in the same symbol group.
- The symbol in the symbol library is uniquely identified by the symbol ID.