libs: skip library loading if already existing

libs/libcast.lua

@@ -25,6 +25,9 @@ setfenv(1, pfUI:GetEnvironment())
 --    spell can be set to "INTERRUPT" to force remove an action.
 --
 
+-- return instantly when another libcast is already active
+if pfUI.api.libcast then return end
+
 local libcast = CreateFrame("Frame", "pfEnemyCast")
 local player = UnitName("player")
 

libs/librange.lua

@@ -8,6 +8,9 @@ setfenv(1, pfUI:GetEnvironment())
 --    Returns `1` if the unit is within a 40y range
 --
 
+-- return instantly when another librange is already active
+if pfUI.api.librange then return end
+
 local librange = CreateFrame("Frame", "pfRangecheck", UIParent)
 
 -- table of 40y spells per class
@@ -183,5 +186,5 @@ function librange:UnitInSpellRange(unit)
   end
 end
 
--- add libdebuff to pfUI API
+-- add librange to pfUI API
 pfUI.api.librange = librange

libs/libspell.lua

@@ -1,6 +1,9 @@
 -- load pfUI environment
 setfenv(1, pfUI:GetEnvironment())
 
+-- return instantly when another libspell is already active
+if pfUI.api.libspell then return end
+
 local scanner = libtipscan:GetScanner("libspell")
 local libspell = {}
 

libs/libtipscan.lua

@@ -25,6 +25,9 @@ setfenv(1, pfUI:GetEnvironment())
 --  <scanner>:List()
 --    prints a list of all available scanner methods
 
+-- return instantly when another libtipscan is already active
+if pfUI.api.libtipscan then return end
+
 local libtipscan = {}
 local baseName = "pfUIScan"
 local methods = {