Return a function to cancel the callback in spr.completed

README.md

@@ -49,6 +49,8 @@ spr.completed(obj: Instance, callback: ()->())
 Registers a callback function that will be called the next time the instance stops animating. The callback is only called once.
 This is useful for tracking instance lifetime, such as destroying a part when it becomes invisible.
 
+To cancel the callback function, use the function returned from spr.completed, as given in the example below.
+
 ### `spr.stop`
 ```lua
 spr.stop(obj: Instance, property: string?)
@@ -127,6 +129,16 @@ spr.target(workspace.Part, 1, 1, {Transparency = 1})
 spr.completed(workspace.Part, function() workspace.Part:Destroy() end)
 ```
 
+```lua
+spr.target(script.Parent.TextButton, 1, 1, {BackgroundTransparency = 1})
+local cancel = spr.completed(script.Parent.TextButton, function() script.Parent.TextButton:Destroy() end)
+wait(1)
+-- if the background transparency has returned to the initial value (0) by another interaction, cancel the callback
+if script.Parent.TextButton.BackgroundTransparency == 0 then
+    cancel()
+end
+```
+
 ### `spr.stop`
 
 ```lua

spr.lua

@@ -779,6 +779,18 @@ function spr.completed(instance: Instance, callback: ()->())
 	else
 		completedCallbacks[instance] = {callback}
 	end
+
+	return function()
+		local callbackList2 = completedCallbacks[instance]
+		local index = table.find(callbackList2, callback)
+		if callbackList2 and index then
+			if #callbackList2 == 1 then
+				completedCallbacks[instance] = nil
+			else
+				table.remove(callbackList2, index)
+			end
+		end
+	end
 end
 
 return table.freeze(spr)