Add a status bar for incoming heals

This shows a prediction of incoming direct heals.

src/types/statusbar.lua

@@ -90,3 +90,17 @@ function StatusBar:SetColor(r, g, b)
         self.bg:SetVertexColor(0.2 * r, 0.2 * g, 0.2 * b)
     end
 end
+
+function StatusBar:SetAlpha(alpha)
+    self.bar:SetAlpha(alpha)
+end
+
+function StatusBar:GetColor()
+    local r, g, b = self.bar:GetStatusBarColor()
+    return r, g, b
+end
+
+function StatusBar:AttachTo(statusBar, point, relativePoint)
+    self.bar:ClearAllPoints()
+    self.bar:SetPoint(point, statusBar.bar:GetStatusBarTexture(), relativePoint)
+end

src/types/unitframe.lua

@@ -97,14 +97,18 @@ function UnitFrame:Init(unit, config)
 
     self.hp = StatusBar:new(self, width, height, 0, true, texture, texture)
 
-    self.power = StatusBar:new(self, width, 6, 2, false, texture, texture)
+    self.power = StatusBar:new(self, width, 6, 3, false, texture, texture)
     self.power:Hide()
 
-    self.absorb = StatusBar:new(self, width, height, 1, true, texture_top)
+    self.incomingHeals = StatusBar:new(self, width, height, 1, true, texture)
+    self.incomingHeals:AttachTo(self.hp, "TOPLEFT", "TOPRIGHT")
+    self.incomingHeals:Hide()
+
+    self.absorb = StatusBar:new(self, width, height, 2, true, texture_top)
     self.absorb:SetColor(unpack(colors.absorb))
     self.absorb:SetFillStyle(Enum.StatusBarFillStyle.Reverse)
 
-    self.shield = StatusBar:new(self, width, height, 1, true, texture_bot)
+    self.shield = StatusBar:new(self, width, height, 2, true, texture_bot)
     self.shield:SetColor(unpack(colors.shield))
     self.shield:SetRange(0, 1)
     self.shield:SetValue(0.6)
@@ -444,6 +448,7 @@ function UnitFrame:RegisterEvents()
     secure:RegisterUnitEvent("UNIT_NAME_UPDATE", unit)
     secure:RegisterUnitEvent("UNIT_ABSORB_AMOUNT_CHANGED", unit)
     secure:RegisterUnitEvent("UNIT_HEAL_ABSORB_AMOUNT_CHANGED", unit)
+    secure:RegisterUnitEvent("UNIT_HEAL_PREDICTION", unit)
 end
 
 -- returns whether or not the unit guid has changed since the last call to this
@@ -504,6 +509,7 @@ function UnitFrame:UNIT_HEALTH()
     end
     self:UpdateHealth()
     self:UpdateHealthColor()
+    self:UpdateIncomingHeals()
 end
 
 function UnitFrame:UNIT_MAXHEALTH()
@@ -513,6 +519,15 @@ function UnitFrame:UNIT_MAXHEALTH()
     end
     self:UpdateHealth()
     self:UpdateHealthColor()
+    self:UpdateIncomingHeals()
+end
+
+function UnitFrame:UNIT_HEAL_PREDICTION()
+    if self:HasUnitChanged() then
+        self:UpdateAll(true)
+        return
+    end
+    self:UpdateIncomingHeals()
 end
 
 function UnitFrame:UNIT_TARGET()
@@ -603,6 +618,7 @@ function UnitFrame:UpdateAll(unitChanged)
     end
     self:UpdateHealth()
     self:UpdateHealthColor()
+    self:UpdateIncomingHeals()
     self:UpdateAbsorb()
     self:UpdateShield()
     self:UpdateRange()
@@ -700,3 +716,21 @@ function UnitFrame:UpdateName()
     end
     self.name:SetText(utf8_truncate((UnitName(self.unit)), 5))
 end
+
+function UnitFrame:UpdateIncomingHeals()
+    local incoming = UnitGetIncomingHeals(self.unit) or 0
+    local health = UnitHealth(self.unit)
+    local maxHealth = UnitHealthMax(self.unit)
+    incoming = math.min(incoming, maxHealth - health)
+
+    if incoming <= 0 then
+        self.incomingHeals:Hide()
+    else
+        local r, g, b = self.hp:GetColor()
+        self.incomingHeals:SetColor(r, g, b)
+        self.incomingHeals:SetAlpha(0.4)
+        self.incomingHeals:SetRange(0, maxHealth)
+        self.incomingHeals:SetValue(incoming)
+        self.incomingHeals:Show()
+    end
+end