Shielded casts trick

[zork]

I want to share sth I do to make non-interuptable castbars in different color based on the shield texture.

The Show() and Hide() functions of the shield get rewritten to recolor the castbar instead.

--shield for uninterruptable casts
    local s = self.Castbar
    s.Shield = s:CreateTexture(nil,"BACKGROUND",nil,-8)
    s.Shield:SetTexture(0,0,0,0) --make it invisible
    --now replace the Show() and Hide() functions to make them work for us
    s.Shield.Show = function(shield)
      local bar = shield:GetParent()
      bar:SetStatusBarColor(0.6,0.6,0.6,1) --we want to recolor the statusbar in case the shield pops up
      bar.bg:SetVertexColor(0.2,0.2,0.2,0.7) --in case you have a background set
    end
    s.Shield.Hide = function(shield)
      local bar = shield:GetParent()
      bar:SetStatusBarColor(1,0.8,0,1) --back to normal
      bar.bg:SetVertexColor(0.2,0.2,0,0.7) --in case you have a background set
    end

[Rainrider]

Hm, why not using castbar.interrupt like this:

if (castbar.interrupt and UnitCanAttack("player", unit)) then
    castbar:SetStatusBarColor(0.69, 0.31, 0.31)
    castbar.IconOverlay:SetVertexColor(0.69, 0.31, 0.31)
else
    castbar:SetStatusBarColor(0.55, 0.57, 0.61)
    castbar.IconOverlay:SetVertexColor(0.4, 0.4, 0.4)
end

(castbar.IconOverlay is the icon border for the spell being cast)

I do this in PostCastStart, PostCastInterruptible, PostCastNotInterruptible and PostChannelStart. Btw castbar.interrupt means the cast is not interruptible.

[Dawn]

local PostCastStart = function(Castbar, unit, spell, spellrank)
	if Castbar.interrupt and UnitCanAttack("player", unit) then
-- if cast can't be interrupted, bright pink color
		Castbar:SetStatusBarColor(0.9, 0, 1.0, 0.6) -- cast bar color
		Castbar.IconGlow:SetBackdropColor(0.9, 0, 1.0, 0.6) -- spell icon border
	else
-- normal color (this is what I use to unpack my config color, can be simplified, ofc)
		local cbR, cbG, cbB = unpack(cfg.trdcolor)
		Castbar:SetStatusBarColor(cbR, cbG, cbB, 0.6)
		Castbar.IconGlow:SetBackdropColor(unpack(cfg.brdcolor))	
	end	
end

[zork]

Haste does the check already in the castbar.lua and on conditions shows or hides the shield. Thus: No "PostCast" etc is needed. The only thing that speaks for the PostCast etc is the UnitCanAttack("player", unit) condition which is not done by haste.

So yeah maybe

--check for interruptable spellcast
  local checkShield = function(bar, unit, ...)
    if bar.interrupt and UnitCanAttack("player", unit) then
      bar:SetStatusBarColor(0.6,0.6,0.6,1)   --we want to recolor the statusbar in case the shield pops up
      bar.bg:SetVertexColor(0.2,0.2,0.2,0.7) --in case you have a background set
    else
      bar:SetStatusBarColor(1,0.8,0,1)       --back to normal
      bar.bg:SetVertexColor(0.2,0.2,0,0.7)   --in case you have a background set
    end
  end
 
  self.Castbar.PostCastStart = checkShield
  self.Castbar.PostChannelStart = checkShield

is the best choice.

[Rainrider]

You could also use PostCastStart and the like for some fancy boss-spells-that-should-be-interrupted-highlighting. This is my currently untested way of doing it if you are interested. I'll just have to figure out if I really need PostCastInterruptible and PostCastNotInterruptible as they don't get a spell name passed and the info whether a cast is interruptible is ready through UnitCastingInfo/UnitChannelInfo at UNIT_SPELLCAST_START/UNIT_SPELLCAST_CHANNEL_START. Or are there any spells that change interruptibility midcast?