Textwindow.lua update for scrollbars

modules/game_textwindow/textwindow.lua

@@ -21,6 +21,18 @@ function destroy()
   end
 end
 
+function getCursorPosByNewLine(str, count)
+  local i = 0
+  for n = 1, count-1 do
+    local tPos = string.find(str, '\n', i)
+    if tPos then
+      i = tPos+1
+    end
+  end
+
+  return i - 1
+end
+
 function onGameEditText(id, itemId, maxLength, text, writter, time)
   if textWindow then return end
   textWindow = g_ui.createWidget('TextWindow', rootWidget)
@@ -32,11 +44,13 @@ function onGameEditText(id, itemId, maxLength, text, writter, time)
   local okButton = textWindow:getChildById('okButton')
   local cancelButton = textWindow:getChildById('cancelButton')
 
+  local textScroll = textWindow:getChildById('textScroll')
+
   textItem:setItemId(itemId)
   textEdit:setMaxLength(maxLength)
   textEdit:setText(text)
   textEdit:setEnabled(writeable)
-
+  
   local desc = ''
   if #writter > 0 then
     desc = tr('You read the following, written by \n%s\n', writter)
@@ -74,7 +88,38 @@ function onGameEditText(id, itemId, maxLength, text, writter, time)
     end
     destroy()
   end
-
+  
+  local _, newLineCount = string.gsub(text, '\n', '\n')
+  if(newLineCount >= 9) then
+    textScroll:setMaximum(newLineCount-9)
+  end
+    
+  local _prev, _next, _current = 0, 11, 0
+  local onValueChange = function()
+  local diff = textScroll:getValue() - _current
+  
+  if(diff > 0) then
+    textEdit:setCursorPos(getCursorPosByNewLine(text, _next+(diff-1)))
+  else
+    textEdit:setCursorPos(getCursorPosByNewLine(text, _prev+(diff+1)))
+  end
+  
+  _current = textScroll:getValue()
+  _next = _next + diff
+  _prev = _prev + diff
+  end
+  
+  textScroll.onValueChange = onValueChange
+  g_keyboard.bindKeyPress("Up", function() textScroll:setValue(textScroll:getValue()-1) end, textWindow, 400)
+  g_keyboard.bindKeyPress("Down", function() textScroll:setValue(textScroll:getValue()+1) end, textWindow, 400)
+  
+  if(not writeable) then
+    textEdit:setCursorPos(0)
+  else
+    textScroll:setValue(textScroll:getMaximum())
+    textEdit:setCursorPos(text:len())
+  end
+  
   okButton.onClick = doneFunc
   cancelButton.onClick = destroy
   --textWindow.onEnter = doneFunc -- this should be '\n'