Help creating scroll frame

[Animor]

Hello,

After spending lots of hours, I'm still stuck with creating a scrolling message frame. I've solved several issues, but I still got two majors ones:

1. When the scrolling frame is loaded and some messages are added to it, I get "0" for GetNumLinesDisplayed(). I need a correct value in order to set correctly the slider SetMinMaxValues(). If I print the GetNumLinesDisplayed() on some events, I then get correct value. What should I do in order to get the correct value when constructing the scrolling message frame? Note that GetNumMessages() does return the correct value.

2. I can't make the frame hide when hitting "escape". I've tried to use tinsert(UISpecialFrames, "historyFrame"), but it juse hide my frame and I can't get to show it.

I will appreciate any help, I'm really stuck here.
This is my code (can be copied and run as standalone code):

local historyFrame 	= CreateFrame("Frame", "historyFrame", UIParent)
	historyFrame.width 	= 500
	historyFrame.height	= 250
	historyFrame:SetFrameStrata("FULLSCREEN_DIALOG")	
	
	historyFrame:SetSize(historyFrame.width, historyFrame.height)	
	historyFrame:SetPoint("CENTER", UIParent, "CENTER", 0, 0)
	historyFrame:SetBackdrop({
		bgFile 		= "Interface\\DialogFrame\\UI-DialogBox-Background",
		edgeFile	= "Interface\\DialogFrame\\UI-DialogBox-Border",
		tile 		= true,
		tileSize 	= 32,
		edgeSize 	= 32,
		insets 		= { left = 8, right = 8, top = 8, bottom = 8 }
	}) 
				  
	historyFrame:SetBackdropColor(0, 0, 0, 1)
	historyFrame:EnableMouse(true)
	historyFrame:EnableMouseWheel(true)	
	
	-- Make movable/resizable	
	historyFrame:SetMovable(true)
	historyFrame:SetResizable(enable)
	frame:SetMinResize(100, 100)
	historyFrame:RegisterForDrag("LeftButton")
	historyFrame:SetScript("OnDragStart", frame.StartMoving)
	historyFrame:SetScript("OnDragStop", frame.StopMovingOrSizing)
	historyFrame:SetScript("OnLoad", function(self) print(self:GetName()) end)
	--tinsert(UISpecialFrames, historyFrame)
	
	-- Close button
	local closebutton = CreateFrame("Button", nil, historyFrame, "UIPanelButtonTemplate")
	closebutton:SetScript("OnClick", function(self) HideParentPanel(self) end)
	closebutton:SetPoint("BOTTOM", 0, 10)
	closebutton:SetHeight(25)
	closebutton:SetWidth(70)
	closebutton:SetText(CLOSE)
	
	-- ScrollingMessageFrame
	local historyScrollingMessage = CreateFrame("ScrollingMessageFrame", historyScrollingMessage, historyFrame)
	historyScrollingMessage:SetPoint("CENTER", 15, 20)	
	historyScrollingMessage:SetSize(historyFrame.width, historyFrame.height - 50)
	historyScrollingMessage:SetFontObject(GameFontNormal)
	historyScrollingMessage:SetTextColor(1, 1, 1, 1) -- default color	
	historyScrollingMessage:SetJustifyH("LEFT")
	historyScrollingMessage:SetHyperlinksEnabled(true)
	historyScrollingMessage:SetFading(false)
	historyScrollingMessage:SetMaxLines(300)
			
	historyScrollingMessage:Clear()
	historyScrollingMessage:AddMessage("1 Here is a message!")	
	historyScrollingMessage:AddMessage("2 Here is a message!")
	historyScrollingMessage:AddMessage("3 Here is a message!")
	historyScrollingMessage:AddMessage("4 Here is a message!")
	historyScrollingMessage:AddMessage("5 Here is a message!")
	historyScrollingMessage:AddMessage("6 Here is a message!")
	historyScrollingMessage:AddMessage("7 Here is a message!")
	historyScrollingMessage:AddMessage("8 Here is a message!")
	historyScrollingMessage:AddMessage("9 Here is a message!")
	historyScrollingMessage:AddMessage("10 Here is a message!")
	historyScrollingMessage:AddMessage("11 Here is a message!")
	historyScrollingMessage:AddMessage("12 Here is a message!")
	historyScrollingMessage:AddMessage("13 Here is a message!")
	historyScrollingMessage:AddMessage("14 Here is a message!")	
	historyScrollingMessage:AddMessage("15 Here is a message!")
	historyScrollingMessage:AddMessage("16 Here is a message!")
	historyScrollingMessage:AddMessage("17 Here is a message!")
	historyScrollingMessage:AddMessage("18 Here is a message!")
	historyScrollingMessage:AddMessage("19 Here is a message!")
	historyScrollingMessage:AddMessage("20 Here is a message!")	
	historyScrollingMessage:AddMessage("21 Here is a message!")
	historyScrollingMessage:AddMessage("22 Here is a message!")
	historyScrollingMessage:AddMessage("23 Here is a message!")
	historyScrollingMessage:AddMessage("24 Here is a message!")
	historyScrollingMessage:AddMessage("25 Here is a message!")	
	--historyScrollingMessage:ScrollToBottom()
	--historyScrollingMessage:ScrollDown()	
	print (historyScrollingMessage:GetNumMessages(), historyScrollingMessage:GetNumLinesDisplayed())
	-------------------------------------------------------------------------------
	-- Scroll bar
	-------------------------------------------------------------------------------
	local ScrollBar = CreateFrame("Slider", "ScrollBar", historyFrame, "UIPanelScrollBarTemplate")
	
	ScrollBar:ClearAllPoints()	
	ScrollBar:SetPoint("RIGHT", historyFrame, "RIGHT", -10, 10)	
	ScrollBar:SetSize(30, historyFrame.height - 90)	
	ScrollBar:SetMinMaxValues(0, 9)
	ScrollBar:SetValueStep(1)	
	ScrollBar.scrollStep = 1 
	ScrollBar:SetScript("OnValueChanged", function(self, value)		
		historyScrollingMessage:SetScrollOffset(select(2, ScrollBar:GetMinMaxValues()) - value)
	 end)
		
	ScrollBar:SetValue(select(2, ScrollBar:GetMinMaxValues()))
	
	historyFrame:SetScript("OnMouseWheel", function(self, delta)
		
		print (historyScrollingMessage:GetNumMessages(), historyScrollingMessage:GetNumLinesDisplayed())
		
		local cur_val = ScrollBar:GetValue()
		local min_val, max_val = ScrollBar:GetMinMaxValues()

		if delta < 0 and cur_val < max_val then
			cur_val = math.min(max_val, cur_val + 1)
			ScrollBar:SetValue(cur_val)			
		elseif delta > 0 and cur_val > min_val then
			cur_val = math.max(min_val, cur_val - 1)
			ScrollBar:SetValue(cur_val)		
		end	
	 end)