Add a way to open prepared layouts

[Atria1234]

It would be nice if layouts like island outlines could be stored in AD and loaded without the need to search for them on the internet.

Add library dialog of prepared layouts. Or the screenshot could be generated by loading the layout in the background and exporting the layout to png in memory to show it. Also custom screenshots (like shots from the game) would be good to give better idea what the layout is.

Layouts should not be embedded in the program binary, they should be stored as files next to the binary, so people can add more if they want.

[Atria1234]

Requirements:

• Layout preset library is available in AD
• It must be possible to load layout preset as new layout
• It must be possible to add objects from layout preset to current layout
• Layout preset location must be configurable
• Layout presets should be in a hierarchical list
• User must be able to easily create new layout preset
• Layout preset must be able to contain metadata describing it
• Layout preset must be able to contain arbitrary images and should be available in the library
• Layout preset preview should be available without need to manually add it as image to layout preset (generated by exporting the layout to image in memory)
• Default layout presets should be available as separate download (same as other presets)
• It should be possible to update default layout presets if new version is available

Proposed structure of layout preset:

• Zip file containing
  • exactly one AD file (possibly with specific name)
  • up to one metadata JSON file (also something with specific name like metadata.json)
    • Name (multi langual)
    • Description (multi langual)
    • Author
    • Author contact
  • any .png or other supported images
• AD layout
  • easy and fast but no way to add extra images or metadata

Questions:

• What should we do with user made layout presets during update?