add x-touch color calibration customisation

examples/x-touch.lua

@@ -1,7 +1,7 @@
 local dt = require "darktable"
 local du = require "lib/dtutils"
 
-du.check_min_api_version("9.1.0", "x-touch") 
+du.check_min_api_version("9.1.0", "x-touch")
 
 function knob(action, element, effect, size)
   k = tonumber(action:sub(-1))
@@ -11,16 +11,30 @@ function knob(action, element, effect, size)
     which = "lib/masks/properties/" .. s[k]
 
   elseif dt.gui.action("iop/colorzones", "focus") ~= 0 then
+    which = "iop/colorzones/graph"
     local e = { "red", "orange", "yellow", "green", "aqua", "blue", "purple", "magenta" }
     element = e[k]
-    which = "iop/colorzones/graph"
 
   elseif dt.gui.action("iop/toneequal", "focus") ~= 0 then
     which ="iop/toneequal/simple/"..(k-9).." EV"
 
-  elseif k == 4 and dt.gui.action("iop/colorbalancergb", "focus") ~= 0 then
+  elseif dt.gui.action("iop/colorbalancergb", "focus") ~= 0 and k == 4 then
     which = "iop/colorbalancergb/contrast"
 
+  elseif dt.gui.action("iop/channelmixerrgb", "focus") ~= 0 and k >= 5 then
+    if k == 5 then
+      which = "iop/channelmixerrgb/page"
+      element = "CAT"
+      if     effect == "up"   then effect = "next"
+      elseif effect == "down" then effect = "previous"
+      else                         effect = "activate"
+      end
+    else
+      which = "iop/focus/sliders"
+      local e = { "1st", "2nd", "3rd" }
+      element = e[k - 5]
+    end
+
   else
     local s = { "iop/exposure/exposure",
                 "iop/filmicrgb/white relative exposure",
@@ -32,6 +46,7 @@ function knob(action, element, effect, size)
                 "iop/crop/bottom" }
     which = s[k]
   end
+
   return dt.gui.action(which, element, effect, size)
 end