diff --git a/src/types/auralist.lua b/src/types/auralist.lua
index e385588..67ac884 100644
--- a/src/types/auralist.lua
+++ b/src/types/auralist.lua
@@ -18,6 +18,7 @@ local omi = select(2, ...)
 local types = omi.GetModule("types")
 local AuraTrigger = types.AuraTrigger
 
+--- AuraList keeps track of all the auras attached to a unitframe
 local AuraList = types.CreateClass("AuraList")
 types.AuraList = AuraList
 
@@ -38,6 +39,8 @@ local statusLists = {
     }
 }
 
+-- helper function that goes over several aura slots for a unit. Runs a
+-- callback function with UnitAuraInfo table as argument
 local function ForEachAuraSlots(unit, fn, continuationToken, ...)
     local GetAuraDataBySlot = C_UnitAuras.GetAuraDataBySlot
     local n = select('#', ...)
@@ -48,6 +51,7 @@ local function ForEachAuraSlots(unit, fn, continuationToken, ...)
     return continuationToken
 end
 
+-- Helper function that goes over all aura slots for a given filter
 local function ForEachAuraFiltered(unit, filter, fn)
     local UnitAuraSlots = UnitAuraSlots
     local continuationToken = nil
@@ -63,6 +67,9 @@ local function ForEachAura(unit, fn)
     ForEachAuraFiltered(unit, "HARMFUL", fn)
 end
 
+--- Initialize AuraList
+-- unitframe
+--      The unitframe this list belongs to
 function AuraList:Init(unitframe)
     self.unitframe = unitframe
     self.unit = unitframe.unit
@@ -70,30 +77,30 @@ function AuraList:Init(unitframe)
     self.statusCount = {}
     self.auras = {} -- map AuraInstanceID to UnitAuraInfo table
 
-    
+
     self.triggers = {}
     self.triggersBySpell = {}
 end
 
-
+--- Add an AuraTrigger to this AuraList
+-- trigger
+--      an AuraTrigger object
 function AuraList:AddTrigger(trigger)
     table.insert(self.triggers, trigger)
-    if trigger:IsInstanceOf(AuraTrigger) then
-        local spellId = trigger.spellId
-        if self.triggersBySpell[spellId] == nil then
-            self.triggersBySpell[spellId] = {}
-        end
-        table.insert(self.triggersBySpell[spellId], trigger)
+    local spellId = trigger.spellId
+    if self.triggersBySpell[spellId] == nil then
+        self.triggersBySpell[spellId] = {}
     end
+    table.insert(self.triggersBySpell[spellId], trigger)
 end
 
--- Scan all the auras of the owning unit and build the aura list from scratch
--- This should only ever happen when the unit is first assigned to the frame
+--- Reset the AuraList and do a full aura scan on the unit
+-- This also resets all the triggers that are attached to this AuraList
 function AuraList:Reset()
     self.auras = {}
 
     self.statusCount = {}
-    
+
     for _, trigger in ipairs(self.triggers) do
         trigger:Reset()
     end
@@ -103,6 +110,9 @@ function AuraList:Reset()
     end)
 end
 
+--- Add an aura to the AuraList
+-- aura
+--      A UnitAuraInfo table for a newly added aura
 function AuraList:AddAura(aura)
     local statusChanged = false
     self.auras[aura.auraInstanceID] = aura
@@ -117,7 +127,7 @@ function AuraList:AddAura(aura)
             count[status] = count[status] + 1
         end
     end
-    
+
     for _, trigger in ipairs(self.triggersBySpell[aura.spellId] or {}) do
         trigger:AddAura(aura)
     end
@@ -126,7 +136,9 @@ function AuraList:AddAura(aura)
     return statusChanged
 end
 
--- Returns a table with every status that applies to the given aura
+--- Return a sequence table with all status names that match the given aura
+-- aura
+--      A UnitAuraInfo table
 function AuraList:GetStatusForAura(aura)
     local status = {}
     if aura.dispelName and aura.isHarmful then
@@ -140,6 +152,9 @@ function AuraList:GetStatusForAura(aura)
     return status
 end
 
+--- Add an aura to the AuraList
+-- aura
+--      A UnitAuraInfo table for a newly added aura
 function AuraList:UpdateAura(aura)
     for _, trigger in ipairs(self.triggersBySpell[aura.spellId] or {}) do
         trigger:UpdateAura(self.auras[aura.auraInstanceId], aura)
@@ -147,6 +162,9 @@ function AuraList:UpdateAura(aura)
     self.auras[aura.auraInstanceID] = aura
 end
 
+--- Remove an aura from the AuraList
+-- iid
+--      The instance id for a removed aura
 function AuraList:RemoveAura(iid)
     local aura = self.auras[iid]
     if aura == nil then
@@ -167,13 +185,16 @@ function AuraList:RemoveAura(iid)
             count[status] = count[status] - 1
         end
     end
-    
+
     for _, trigger in ipairs(self.triggersBySpell[aura.spellId] or {}) do
         trigger:RemoveAura(aura)
     end
     return statusChanged
 end
 
+--- Update an aura in the AuraList
+-- info
+--      The new UnitAuraInfo structure
 function AuraList:Update(info)
     local GetAuraDataByAuraInstanceID = C_UnitAuras.GetAuraDataByAuraInstanceID
     local statusChanged = false
@@ -190,7 +211,7 @@ function AuraList:Update(info)
             self:UpdateAura(aura)
         end
     end
-    
+
     for _, iid in ipairs(info.removedAuraInstanceIDs or {}) do
         if self:RemoveAura(iid) then
             statusChanged = true
diff --git a/src/types/indicator.lua b/src/types/indicator.lua
index 107299f..223843f 100644
--- a/src/types/indicator.lua
+++ b/src/types/indicator.lua
@@ -18,13 +18,35 @@ local omi = select(2, ...)
 local types = omi.GetModule("types")
 local AuraTrigger = types.AuraTrigger
 
+--- Indicator is a type for any kind of visual indicator. This type has no
+-- function and should not be created. All functional indicators derive from
+-- this type.
 local Indicator = types.CreateClass("Indicator")
 types.Indicator = Indicator
 
--- TODO: make different indicators, such as texture, text, border
--- TODO: spellid feels out of place but I wanna quickly get something for now.
--- Should rethink this when Trigger is its own class
-function Indicator:Init(unitframe, auralist, size, point, x, y, color, spellId)
+--- Show the indicator and supply it with data
+function Indicator:Show(data)
+end
+
+--- Update the indicator with new data
+function Indicator:Update(data)
+end
+
+--- Hide the indicator
+function Indicator:Hide()
+end
+
+--- SquareIndicator is an indicator that displays a colored square texture
+local SquareIndicator = types.CreateClass("SquareIndicator", Indicator)
+types.SquareIndicator = SquareIndicator
+
+--- Initialize a new SquareIndicator
+-- unitframe    Unitframe it is attached to
+-- size         Size of the indicator square
+-- point        Attachment point to the unitframe's overlay frame
+-- x, y         x and y offset for the attachment point
+-- color        Color of the square
+function SquareIndicator:Init(unitframe, size, point, x, y, color)
     local frame = unitframe.overlays
 
     local texture = frame:CreateTexture(nil, "ARTWORK")
@@ -36,26 +58,21 @@ function Indicator:Init(unitframe, auralist, size, point, x, y, color, spellId)
     self:SetColor(color)
     texture:SetVertexColor(unpack(color))
     texture:SetDrawLayer("ARTWORK")
-
-    local fn = function(activate)
-        if activate then
-            self:Show()
-        else
-            self:Hide()
-        end
-    end
-    local trigger = AuraTrigger:new(fn, spellId, true)
-    auralist:AddTrigger(trigger)
 end
 
-function Indicator:SetColor(color)
+--- Set the color of the Square Indicator
+-- color: a sequence table with 3 color channels {r, g, b}
+function SquareIndicator:SetColor(color)
     self.texture:SetVertexColor(unpack(color))
 end
 
-function Indicator:Show()
+--- Show the square indicator.
+-- data: ignored for now
+function SquareIndicator:Show(data)
     self.texture:Show()
 end
 
-function Indicator:Hide()
+--- Hide the square indicator.
+function SquareIndicator:Hide()
     self.texture:Hide()
 end
diff --git a/src/types/trigger.lua b/src/types/trigger.lua
index 72c39df..3aebfd4 100644
--- a/src/types/trigger.lua
+++ b/src/types/trigger.lua
@@ -17,47 +17,52 @@
 local omi = select(2, ...)
 local types = omi.GetModule("types")
 
+---
+-- Trigger objects provide a link between indicators and some data source. They
+-- can pass data from the data source into the trigger. This is just a
+-- supertype for all indicators and should not be constructed on its own. It
+-- has no functionality other than providing default implementations that do
+-- nothing.
 types.Trigger = types.CreateClass("Trigger")
 local Trigger = types.Trigger
 
 
--- Constructor for Trigger.
--- fn:
---      The callback function that gets called every time this trigger changes
---      states between active and inactive. Function takes one boolean argument.
-function Trigger:Init(fn)
-    self.fn = fn
+-- Initialize a new Trigger object
+-- indicator:
+--      The indicator that gets activated by this trigger.
+function Trigger:Init(indicator)
+    self.indicator = indicator
 end
 
--- Returns whether the trigger is active
+-- Returns whether or not the trigger is active
 function Trigger:IsActive()
     return false
 end
 
--- Reset the trigger to the default state. Does run the untrigger callback if
--- the trigger is active when Reset is called.
+-- Reset the trigger to the default state. Deactivates the indicator if it is
+-- active when Reset is called.
 function Trigger:Reset()
 end
 
 
+---
+-- AuraTrigger is a trigger that can be attached to AuraList as datasource
 types.AuraTrigger = types.CreateClass("AuraTrigger", Trigger)
 local AuraTrigger = types.AuraTrigger
 
--- Constructor for AuraTrigger
--- fn:
---      The callback function that gets called every time this trigger changes
---      states between active and inactive. Function takes one boolean argument.
---
--- requiredCount = 1:
---      The minimum number of conditions that must be met before the trigger
---      activates. What exactly this means depends on the trigger, examples are
---      # of matching auras, # of stacks. 
---
--- invert = false:
---      If the trigger is inverted it will activate when count < requiredCount.
---      If the trigger is not inverted it will activate when count >= requiredCount.
-function AuraTrigger:Init(fn, spellId, own, requiredCount, invert)
-    Trigger.Init(self, fn)
+--- Initialize a new AuraTrigger object
+-- indicator
+--      Indicator that gets controlled by this trigger.
+-- spellId
+--      Spell id to trigger on
+-- own
+--      Only trigger on auras by the player
+-- requiredCount=1
+--      Number of aura applications to activate trigger
+-- invert=false
+--      Whether to invert trigger activation
+function AuraTrigger:Init(indicator, spellId, own, requiredCount, invert)
+    Trigger.Init(self, indicator)
     self.spellId = spellId
     self.requiredCount = requiredCount or 1
     self.own = own
@@ -65,18 +70,19 @@ function AuraTrigger:Init(fn, spellId, own, requiredCount, invert)
     self.invert = invert or false
 end
 
--- Reset the trigger to the default state. Does run the untrigger callback if
--- the trigger is active when it is called
+--- See Trigger:Reset
 function AuraTrigger:Reset()
     local before = self:IsActive()
     self.count = 0
     local after = self:IsActive()
-    if before ~= after then
-        self.fn(after)
+    if not before and after then
+        self.indicator:Show()
+    elseif before and not after then
+        self.indicator:Hide()
     end
 end
 
--- Return true if the aura matches the trigger
+--- Return true if the aura matches the trigger
 -- aura:
 --      Must be a valid UnitAuraInfo structure.
 function AuraTrigger:IsMatching(aura)
@@ -86,10 +92,10 @@ function AuraTrigger:IsMatching(aura)
     if self.own and aura.sourceUnit ~= "player" then
         return false
     end
-    return true 
+    return true
 end
 
--- Inform the trigger about an added aura
+--- Inform the trigger about an added aura
 -- aura:
 --      Must be a valid UnitAuraInfo
 function AuraTrigger:AddAura(aura)
@@ -98,13 +104,17 @@ function AuraTrigger:AddAura(aura)
     end
     self.count = self.count + 1
 
-    -- Be mindful, this works only if count always changes by 1. 
+    -- Be mindful, this works only if count always changes by 1.
     if self.count == self.requiredCount then
-        self.fn(not self.invert)
+        if self.invert then
+            self.indicator:Hide()
+        else
+            self.indicator:Show()
+        end
     end
 end
 
--- Inform the trigger about an updated aura
+--- Inform the trigger about an updated aura
 -- before:
 --      Must be a valid UnitAuraInfo for the aura before the update
 -- after:
@@ -113,20 +123,25 @@ function AuraTrigger:UpdateAura(before, after)
     --
 end
 
--- Inform the trigger about an aura that got removed
+--- Inform the trigger about an aura that got removed
+-- aura:
 --      Must be a valid UnitAuraInfo for the aura before it got removed
 function AuraTrigger:RemoveAura(aura)
     if not self:IsMatching(aura) then
         return
     end
-    self.count = self.count - 1 
-    -- Be mindful, this works only if count always changes by 1. 
+    self.count = self.count - 1
+    -- Be mindful, this works only if count always changes by 1.
     if self.count == self.requiredCount - 1 then
-        self.fn(self.invert)
+        if self.invert then
+            self.indicator:Show()
+        else
+            self.indicator:Hide()
+        end
     end
 end
 
--- Returns true if the trigger is active, false otherwise
+--- Returns true if the trigger is active, false otherwise
 function AuraTrigger:IsActive()
     if self.invert then
         return self.count < self.requiredCount
diff --git a/src/types/unitframe.lua b/src/types/unitframe.lua
index 01ff008..659992d 100644
--- a/src/types/unitframe.lua
+++ b/src/types/unitframe.lua
@@ -18,7 +18,8 @@ local omif = select(2, ...)
 local types = omif.GetModule("types")
 local StatusBar = types.StatusBar
 local AuraList = types.AuraList
-local Indicator = types.Indicator
+local SquareIndicator = types.SquareIndicator
+local AuraTrigger = types.AuraTrigger
 
 types.UnitFrame = types.CreateClass("UnitFrame")
 local UnitFrame = types.UnitFrame
@@ -59,11 +60,29 @@ function UnitFrame:Init(unit, width, height, hideInRaid)
     overlays:Show()
     self.overlays = overlays
     self:CreateName()
-    self.indicators = {
-        Indicator:new(self, self.auras, 14, "TOPLEFT", 2, -2, colors.white, 383648),
-        Indicator:new(self, self.auras, 14, "TOPLEFT", 2, -2, colors.white, 974),
-        Indicator:new(self, self.auras, 14, "BOTTOMLEFT", 2, 2, colors.cyan, 61295)
-    }
+
+    self.auras:AddTrigger(
+        AuraTrigger:new(
+            SquareIndicator:new(self, 14, "TOPLEFT", 2, -2, colors.white),
+            383648, -- Second Earthshield on self
+            true
+        )
+    )
+    self.auras:AddTrigger(
+        AuraTrigger:new(
+            SquareIndicator:new(self, 14, "TOPLEFT", 2, -2, colors.white),
+            974, -- Earthshield
+            true
+        )
+    )
+    self.auras:AddTrigger(
+        AuraTrigger:new(
+            SquareIndicator:new(self, 14, "BOTTOMLEFT", 2, 2, colors.cyan),
+            61295, -- Riptide
+            true
+        )
+    )
+
     self:RegisterEvents()
     self:Enable()
 end
@@ -143,7 +162,7 @@ function UnitFrame:PrepareWheelBinds()
         self:SetBindingClick(false, "ALT-MOUSEWHEELUP", "BUTTONNAME", "alt-wheel-up")
         self:SetBindingClick(false, "ALT-MOUSEWHEELDOWN", "BUTTONNAME", "alt-wheel-down")
     ]]):gsub("BUTTONNAME", "OmicronSecureFrame" .. self.unit)
-   
+
     local removeBindScript = [[
         self:ClearBindings()
     ]]
@@ -297,7 +316,7 @@ function UnitFrame:UNIT_HEALTH()
         self:UpdateAll(true)
         return
     end
-    self:UpdateHealth() 
+    self:UpdateHealth()
     self:UpdateHealthColor()
 end
 
@@ -306,7 +325,7 @@ function UnitFrame:UNIT_MAXHEALTH()
         self:UpdateAll(true)
         return
     end
-    self:UpdateHealth() 
+    self:UpdateHealth()
     self:UpdateHealthColor()
 end