Scratch pad map panel #3288

Sometimes it is useful to have a custom arrangement of tiles, possibly from multiple tilesets, somewhere quickly accessible. A dedicated "scratch pad" panel that displays a map but only lets you pick tiles from it like from a tileset would be very helpful for this.

The panel itself should work a lot like the Tilesets panel:

• Display one map at a time, similar to how the Tilesets panel displays one tileset at a time
• Allow multiple maps to be added to the panel, so users can switch between them with tabs
• Allow zooming
• Have buttons at the bottom to add a map to the panel, to remove a map from the panel, and to Edit a map, which would just open that map in the Map Editor.
• Allow selecting a single or multiple tiles via click, shift+click, ctrl+click, and click+drag
• If there are no maps, it should display some text like "Add maps to this panel to quickly access their tiles." and an "Add Map" button

Behaviour

Selecting a tile in the scratch pad should behave just like selecting a tile in the Map Editor, including bringing up the tileset of the selected tile(s) in the Tilesets panel, or selecting no tile if the cell is empty.

If a map has multiple layers, the top-most non-empty tile should be selected, if there is one. This would allow users to layer multiple tiles for clarity, but be unambiguous about which tile they'll pick.

• Optional: if the user right-clicks on the panel with tile(s) selected, the context menu could include options for selecting tiles from any layer that has tiles in the selected cells, similar to how Alt + right click works for stacked objects.
• Optional: There could also be an option to copy the entire stack of tiles. This is perhaps treading on Tile Stamp territory, but I think it would be useful.

The maps can inherit their tile grid display settings from the Map Editor. Using the same settings as the Tilesets Panel is also acceptable, if that's easier to implement.

The maps in the scratch pad should automatically update either immediately upon changes, or when the map file is saved, whichever is more convenient.

Optional: Let users drag a map document tab to the scratch pad panel to add that map to it.

Use scenarios

• Quick-access palette for commonly used tiles from multiple tilesets
• A quick way to select a particular tileset if you have a lot of tilesets, you can have a representative tile from each tileset in the scratch pad map and click it to go to that tileset, instead of scrolling through the tabs or a list. Tiles are often more compact that tileset titles, and can be zoomed.
• A custom arrangement of a tileset that's more flexible than the Rearrange Tiles feature, since you can leave empty spaces to group together related tiles, without introducing empty space into the tileset itself.
• As an always-visible reference for style/density from an earlier maps, or just a quick way to open a particular map in the editor.
• A map with some text objects on it could be used to label groups of tiles, display a to-do list or reminders, etc. The text objects would not be selectable.
• Isometric/hexagonal display of tilesets, instead of the orthogonal display in the Tilesets panel, which would solve #3228

Objects

The feature as described above would treat Objects as entirely cosmetic and ignore them when selecting tiles.

It could also be cool to have both the default Tile selection mode, and an Object selection mode, toggleable via buttons at the bottom of the panel. In Object mode, you'd be able to select objects and these objects would be automatically copied. However, this would probably encourage blind copypasting instead of using Templates, so it might not be a good addition. Perhaps a separate visual Template Browser panel would be better.