support showing a different tile on hover for Labels

docs/changelog.txt

@@ -64,6 +64,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 ## API
 
 ## Lua
+- ``widget.Label``: tokens can now specify a ``htile`` property to indicate the tile that should be shown when the Label is hovered over with the mouse
 
 ## Removed
 

docs/dev/Lua API.rst

@@ -4731,10 +4731,12 @@ containing newlines, or a table with the following possible fields:
   Specifies the number of character positions to advance on the line
   before rendering the token.
 
-* ``token.tile = pen``
+* ``token.tile``, ``token.htile``
 
   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.
+  index) to paint as one tile before the main part of the token. If ``htile``
+  is specified, that is used instead of ``tile`` when the Label is hovered over
+  with the mouse.
 
 * ``token.width = ...``
 
@@ -4762,10 +4764,10 @@ containing newlines, or a table with the following possible fields:
 
   Same as the attributes of the label itself, but applies only to the token.
 
-* ``token.pen``, ``token.dpen``
+* ``token.pen``, ``token.dpen``, ``token.hpen``
 
-  Specify the pen and disabled pen to be used for the token's text.
-  The field may be either the pen itself, or a callback that returns it.
+  Specify the pen, disabled pen, and hover pen to be used for the token's text.
+  The fields may be either the pen itself, or a callback that returns it.
 
 * ``token.on_activate``
 

library/lua/gui/widgets.lua

@@ -1121,10 +1121,10 @@ function render_text(obj,dc,x0,y0,pen,dpen,disabled,hpen,hovered)
                 end
             end
 
-            if token.tile then
+            if token.tile or (hovered and token.htile) then
                 x = x + 1
                 if dc then
-                    local tile = getval(token.tile)
+                    local tile = hovered and getval(token.htile or token.tile) or getval(token.tile)
                     local tile_pen = tonumber(tile) and to_pen{tile=tile} or tile
                     dc:char(nil, tile_pen)
                     if token.width then