allow token.tile to be a function

docs/changelog.txt

@@ -44,6 +44,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 ## API
 
 ## Lua
+- ``widgets.Label``: token ``tile`` properties can now be functions that return a value
 
 ## Removed
 

docs/dev/Lua API.rst

@@ -4704,8 +4704,8 @@ containing newlines, or a table with the following possible fields:
 
 * ``token.tile = pen``
 
-  Specifies a pen or texture index to paint as one tile before the main part of
-  the token.
+  Specifies a pen or texture index (or a function that returns a pen or texture
+  index) to paint as one tile before the main part of the token.
 
 * ``token.width = ...``
 

library/lua/gui/widgets.lua

@@ -1124,8 +1124,8 @@ function render_text(obj,dc,x0,y0,pen,dpen,disabled,hpen,hovered)
             if token.tile then
                 x = x + 1
                 if dc then
-                    local tile_pen = tonumber(token.tile) and
-                            to_pen{tile=token.tile} or token.tile
+                    local tile = getval(token.tile)
+                    local tile_pen = tonumber(tile) and to_pen{tile=tile} or tile
                     dc:char(nil, tile_pen)
                     if token.width then
                         dc:advance(token.width-1)