add FRAME_THIN

docs/changelog.txt

@@ -73,6 +73,7 @@ Template for new versions:
 ## Lua
 - ``dfhack.gui.revealInDwarfmodeMap``: gained ``highlight`` parameter to control setting the tile highlight on the zoom target
 - ``dfhack.maps.getWalkableGroup``: get the walkability group of a tile
+- ``gui.FRAME_THIN``: a panel frame suitable for floating tooltips
 
 ## Removed
 

docs/dev/Lua API.rst

@@ -4583,6 +4583,10 @@ There are the following predefined frame style tables:
 
   A frame suitable for overlay widget panels.
 
+* ``FRAME_THIN``
+
+  A frame suitable for floating tooltip panels that need the DFHack signature.
+
 * ``FRAME_BOLD``
 
   A frame suitable for a non-draggable panel meant to capture the user's focus,

library/lua/gui.lua

@@ -940,6 +940,9 @@ end
 function FRAME_BOLD()
     return make_frame(textures.tp_border_bold, true)
 end
+function FRAME_THIN()
+    return make_frame(textures.tp_border_thin, false)
+end
 function FRAME_INTERIOR()
     local frame = make_frame(textures.tp_border_thin, false)
     frame.signature_pen = false