addon/Quests/Frames/TranslationFrame.lua

function CzechQuestsAddon:CreateTranslationFrame()
    local frame = {};

    -- Main Translation Frame
    frame = CreateFrame("Frame", "CzechQuestTranslationFrame", nil, BackdropTemplateMixin and "BackdropTemplate")
    frame:SetWidth(300)
    frame:SetBackdrop({ edgeFile = "Interface/Tooltips/UI-Tooltip-Border", edgeSize = 8 })
    frame:Hide()

    -- Background Parchment texture
    frame.texture = frame:CreateTexture(nil, "BACKGROUND", nil, -1);
    frame.texture:SetAllPoints(true);
    frame.texture:SetHorizTile(true)

    -- Apply correct texture for wow version
    if (WOW_PROJECT_ID == WOW_PROJECT_CLASSIC) then
        frame.texture:SetTexture("Interface/QUESTFRAME/QuestBG");
        frame.texture:SetTexCoord(0, .58, 0.005, 0.66)
    else
        frame.texture:SetTexture("Interface/QUESTFRAME/QuestBackgroundParchment");
        CzechQuestsAddon:SetTextureFromSettings(frame)
    end

    frame.primaryHeader = CzechQuestsAddon:CreateTranslationFont(
            frame,
            "CzechQuestTranslationPrimaryHeader",
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_HEADER_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_PRIMARY_HEADER_FONT_SIZE
    )
    frame.secondaryHeader = CzechQuestsAddon:CreateTranslationFont(
            frame,
            "CzechQuestTranslationSecondaryHeader",
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_HEADER_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_SECONDARY_HEADER_FONT_SIZE
    )
    frame.primaryText = CzechQuestsAddon:CreateTranslationFont(
            frame,
            "CzechQuestTranslationPrimaryText",
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_SIZE
    )
    frame.secondaryText = CzechQuestsAddon:CreateTranslationFont(
            frame,
            "CzechQuestTranslationSecondaryText",
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_SIZE
    )

    return frame;
end

function CzechQuestsAddon:CreateTranslationFont(frame, name, font, size)
    local label = frame:CreateFontString(name, "OVERLAY")
    label:SetWidth(frame:GetWidth() - 20)
    label:SetJustifyH("LEFT")
    label:SetTextColor(0, 0, 0, 1)
    label:SetFont(font, size, nil)
    return label;
end

function CzechQuestsAddon:ResetTranslationText(frame)
    frame.primaryHeader:SetText("")
    frame.secondaryHeader:SetText("")
    frame.primaryText:SetText("")
    frame.secondaryText:SetText("")
end

function CzechQuestsAddon:SetTextureFromSettings(frame)
    if (WOW_PROJECT_ID == WOW_PROJECT_CLASSIC) then
        if CzechQuestsAddon_Store.config.DARK_MODE then
            frame:SetBackdropColor(0, 0, 0, 1)
            frame.texture:SetColorTexture(0, 0, 0, 1)
            frame.primaryHeader:SetTextColor(255, 255, 255, 1)
            frame.secondaryHeader:SetTextColor(255, 255, 255, 1)
            frame.primaryText:SetTextColor(255, 255, 255, 1)
            frame.secondaryText:SetTextColor(255, 255, 255, 1)
        end
    else
        -- TODO add DARK MODE support for retail
        -- Read CVar from settings to setup same parchment as Quest frame
        if C_CVar.GetCVar("questTextContrast") == "0" then
            frame.texture:SetTexCoord(0, .01, 0, 0.4) -- Parchment (brown)
        else
            frame.texture:SetTexCoord(0, .01, .4, .8) -- Parchment (white)
        end
    end
end

function CzechQuestsAddon:UpdateTranslationFrameFontSettings()
    CzechQuestsAddon.translationFrame.primaryHeader:SetFont(
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_HEADER_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_PRIMARY_HEADER_FONT_SIZE,
            nil
    )
    CzechQuestsAddon.translationFrame.secondaryHeader:SetFont(
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_HEADER_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_SECONDARY_HEADER_FONT_SIZE,
            nil
    )
    CzechQuestsAddon.translationFrame.primaryText:SetFont(
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_SIZE,
            nil
    )
    CzechQuestsAddon.translationFrame.secondaryText:SetFont(
            CzechQuestsAddon.fontPath .. CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_FAMILY,
            CzechQuestsAddon_Store.config.TRANSLATION_FRAME_TEXT_FONT_SIZE,
            nil
    )
end