addon/Addon/Code/Quest.lua

function CzechQuestsAddon:ShowQuestTranslation(event)
    -- Hide frame, may contain old texts
    CzechQuestsAddon.translationQuestFrame:Hide()

    -- Classic Era has QuestLogFrame
    if QuestLogFrame then
        if QuestLogFrame:IsShown() then
            local questIndex = GetQuestLogSelection()
            if questIndex > 0 then
                local questId = select(8, GetQuestLogTitle(questIndex))
                local questData = CzechQuestsAddon:GetData("quest", questId)
                if questData then
                    local suffix = CzechQuestsAddon_Store.config.DEBUG_MODE and " (" .. questId .. ")" or ""
                    local questTitle = questData.title .. suffix
                    CzechQuestsAddon:ShowTranslationQuestFrame(
                            questTitle,
                            questData.objective,
                            "Popis",
                            questData.description,
                            QuestLogFrame,
                            -14,
                            0
                    )
                    CzechQuestsAddon.translationQuestFrame:Show()
                end
            end
        end
    end

    -- Retail has QuestMapDetailsScrollFrame
    if QuestMapDetailsScrollFrame then
        if QuestMapDetailsScrollFrame:IsVisible() then
            local questId = C_QuestLog.GetSelectedQuest()
            local hasModel = QuestModelScene:IsVisible()
            local questData = CzechQuestsAddon:GetData("quest", questId)
            if questData then
                local suffix = CzechQuestsAddon_Store.config.DEBUG_MODE and " (" .. questId .. ")" or ""
                local questTitle = questData.title .. suffix
                local xOffset = hasModel and 210 or 50
                CzechQuestsAddon:ShowTranslationQuestFrame(
                        questTitle,
                        questData.objective,
                        "Popis",
                        questData.description,
                        QuestMapFrame,
                        0,
                        xOffset
                )
                CzechQuestsAddon.translationQuestFrame:Show()
            else
                CzechQuestsAddon.translationQuestFrame:Hide()
            end
        end
    end

    -- If quest is right from NPC, this work for both wow version
    if event ~= nil then
        local questId = GetQuestID()
        local hasModel = QuestModelScene and QuestModelScene:IsShown() or false
        if questId then
            local questData = CzechQuestsAddon:GetData("quest", questId)
            if questData then
                CzechQuestsAddon.translationQuestFrame:Show()
                local suffix = CzechQuestsAddon_Store.config.DEBUG_MODE and " (" .. questId .. ")" or ""
                local questTitle = questData.title .. suffix
                local xOffset = hasModel and 210 or 0
                if event == "QUEST_PROGRESS" then
                    CzechQuestsAddon:ShowTranslationQuestFrame(
                            questTitle,
                            questData.progress,
                            "",
                            "",
                            QuestFrame,
                            -20,
                            xOffset
                    )
                elseif event == "QUEST_COMPLETE" then
                    CzechQuestsAddon:ShowTranslationQuestFrame(
                            questTitle,
                            questData.completion,
                            "",
                            "",
                            QuestFrame,
                            -20,
                            xOffset
                    )
                elseif event == "QUEST_DETAIL" then
                    CzechQuestsAddon:ShowTranslationQuestFrame(
                            questTitle,
                            questData.description,
                            "Cíl úkolu",
                            questData.objective,
                            QuestFrame,
                            -20,
                            xOffset
                    )
                else
                    CzechQuestsAddon.translationQuestFrame:Hide()
                end
            else
                CzechQuestsAddon.translationQuestFrame:Hide()
            end
        end
    end
end

function CzechQuestsAddon:ShowQuestItemTranslation()
    -- Hide frame, may contain old texts
    CzechQuestsAddon.translationQuestFrame:Hide()

    -- should work for both wow version
    if ItemTextFrame:IsShown() then
        local item = {}

        -- get item name
        local itemName = ItemTextGetItem();
        local titlePage = CzechQuestsAddon:GetData("item", itemName)

        -- check if item is translated
        if titlePage ~= nil then
            item.name = titlePage.titleMale;
            local pageNum = ItemTextGetPage()
            local contentPage = CzechQuestsAddon:GetData("item", itemName .. '__' .. pageNum)

            -- check if item is translated
            if contentPage ~= nil then
                item.content = contentPage.text
                if item.name ~= nil and item.content ~= nil then
                    CzechQuestsAddon:ShowTranslationQuestFrame(
                            item.name,
                            item.content,
                            "",
                            "",
                            ItemTextFrame,
                            -20,
                            0
                    )
                end
            end
        end

        CzechQuestsAddon.translationQuestFrame:Show()
    end
end