ShaguTweaks-ClassicAPI/mods/castbar-move.lua

-- Movable Cast Bar
--
-- Hold Ctrl+Shift+Alt to show a marker over the player's cast bar and drag
-- it anywhere; right-click the marker to put it back. The position is saved
-- per character. The Swing Timer, Wand Timer and the Improved Castbar icon
-- are anchored to the cast bar, so they follow it.

local _G = ShaguTweaks.GetGlobalEnv()
local T = ShaguTweaks.T

local module = ShaguTweaks:register({
  title = T["Movable Cast Bar"],
  description = T["Hold <Ctrl>, <Shift> and <Alt> to move the cast bar; right-click to reset."],
  expansions = { ["vanilla"] = true },
  category = T["Action Bar"],
  enabled = true,
})

local POSITION_KEY = "CastBarPosition"

-- One table for state: Lua 5.0 allows only 32 upvalues per function.
local S = { preview = false }

local function ModifiersDown()
  local API = ShaguTweaks.API or {}
  local shift = API.IsShiftKeyDown or IsShiftKeyDown
  local ctrl = API.IsControlKeyDown or IsControlKeyDown
  local alt = API.IsAltKeyDown or IsAltKeyDown
  return shift() and ctrl() and alt() and true or false
end

local function SavedPosition()
  local pos = ShaguTweaks_config and ShaguTweaks_config[POSITION_KEY]
  if pos and pos[1] and pos[2] then return pos end
end

-- Put the bar at the saved spot. Goes through the original SetPoint because
-- the wrapper below ignores everybody else while a saved spot exists.
local function Apply()
  local pos = SavedPosition()
  if not pos then return end
  CastingBarFrame:ClearAllPoints()
  S.orig(CastingBarFrame, "BOTTOMLEFT", UIParent, "BOTTOMLEFT", pos[1], pos[2])
end

-- Back to the stock spot; Reduced Actionbar re-anchors it on the next layout pass.
local function Reset()
  if ShaguTweaks_config then ShaguTweaks_config[POSITION_KEY] = nil end
  CastingBarFrame:ClearAllPoints()
  S.orig(CastingBarFrame, "BOTTOM", UIParent, "BOTTOM", 0, 60)
  if _G.UIParent_ManageFramePositions then _G.UIParent_ManageFramePositions() end
end

local function SetPreview(on)
  if S.preview == on then return end
  S.preview = on
  if on then
    S.mover:Show()
  else
    CastingBarFrame:StopMovingOrSizing()
    S.mover:Hide()
  end
end

local function CreateMover()
  local m = CreateFrame("Frame", "ShaguTweaksCastBarMover", UIParent)
  m:SetFrameStrata("DIALOG")
  m:SetAllPoints(CastingBarFrame)
  m:EnableMouse(true)
  m:Hide()

  m.bg = m:CreateTexture(nil, "BACKGROUND")
  m.bg:SetTexture("Interface\\Buttons\\WHITE8X8")
  m.bg:SetAllPoints(m)
  m.bg:SetVertexColor(1, .7, 0, .6)

  m.text = m:CreateFontString(nil, "OVERLAY")
  m.text:SetFont("Fonts\\FRIZQT__.TTF", 11, "OUTLINE")
  m.text:SetPoint("CENTER", m, "CENTER", 0, 0)
  m.text:SetText(T["Cast Bar"])

  m:SetScript("OnMouseDown", function()
    if arg1 == "LeftButton" then CastingBarFrame:StartMoving() end
  end)
  m:SetScript("OnMouseUp", function()
    CastingBarFrame:StopMovingOrSizing()
    ShaguTweaks_config = ShaguTweaks_config or {}
    if arg1 == "RightButton" then
      Reset()
    else
      ShaguTweaks_config[POSITION_KEY] = { CastingBarFrame:GetLeft(), CastingBarFrame:GetBottom() }
      Apply()
    end
  end)

  S.mover = m
end

module.enable = function(self)
  if not CastingBarFrame then return end

  if not S.mover then
    S.orig = CastingBarFrame.SetPoint
    CreateMover()

    CastingBarFrame:SetMovable(true)
    CastingBarFrame:SetClampedToScreen(true)

    S.events = CreateFrame("Frame")
    S.events:SetScript("OnEvent", function()
      if event == "MODIFIER_STATE_CHANGED" then
        SetPreview(ModifiersDown())
      else
        Apply()
      end
    end)
  end

  -- Reduced Actionbar and others re-anchor the bar on every layout pass.
  -- While a saved spot exists their SetPoint calls are ignored.
  CastingBarFrame.SetPoint = function(frame, a, b, c, d, e)
    if SavedPosition() then return end
    return S.orig(frame, a, b, c, d, e)
  end

  S.events:RegisterEvent("PLAYER_ENTERING_WORLD")
  S.events:RegisterEvent("MODIFIER_STATE_CHANGED")
  Apply()
end

module.disable = function(self)
  if not S.mover then return end
  SetPreview(false)
  S.events:UnregisterAllEvents()
  CastingBarFrame.SetPoint = nil
end