Documentation file for class CDXVertTextScoller


(c) 4/1999 by Ioannis Karagiorgos
              EMail: karagior@pluto.fernuni-hagen.de
    
    
contributions to the CDX project and to everyone who uses and extends it!



Purpose of CDXVertTextScroller class:
-------------------------------
  The CDXVertTextScroller class is able to display vertical scrolling text.
  You supply the class with a text and output rectangle and can display the
  text in the output rectangle and scroll it up and down.
  The text is formatted into separate lines automatically, you can support
  this by inserting linefeeds (\n) in the text string.
  
  
Reference:
----------

   CDXVertTextScroller( CDXScreen * Scr , RECT * ClipRectangle , 
                        char * ScrollText , int TextJustify, 
                        int LineSpace , CDXBitmapFont * Font )
        - Scr               = pointer to the CDXScreen object
        - ClipRectabgle     = output rectangle for the scroll text
        - Scrolltext        = text, you can insert linefeeds in the text to control the way the
                              class breaks the text into lines
                              e.g. "Hello world\nThis is a scroll text\n....."
        - TextJustify [OPTIONAL } = How is the text displayed?
                                     CDX_CENTERJUSTIFY = each line is displayed centered
                                     CDX_LEFTJUSTIFY   = each line is displayed left justified
                                     CDX_RIGHTJUSTIFY  = each line is displayed right justified
        - LineSpace    [OPTIONAL] = space between the text lines, default = 3
        - Font         [OPTIONAL] = CDXBitmapFont object for the scrolltext font, default = NULL
                                    You can pass a CDXBitmapFont object, if you don't, the class
                                    will create an own font, Courier, height=12, Color=RGB(255,255,255)

        - This constructor creates a CDXVertTextScroller object


    HRESULT Draw( CDXSurface * lpDDS )
        - lpDDS     = destination surface for text output
        - HRESULT   = error code of the last blit
        
        - This function draws the text with its background color, for transparent drawing look next function
        
        
    HRESULT DrawTrans( CDXSurface * lpDDS )
        - lpDDS     = destination surface for text output
        - HRESULT   = error code of the last blit
        
        - This function draws the text transparent
        
        
    void ScrollUp( int Count )
        - Count [OPTIONAL] = number of pixels to scroll the text up, default=1
        
        - This function scrolls the scroll text Count lines up
        
        
    void ScrollDown( int Count )
        - Count [OPTIONAL] = number of pixels to scroll the text down, default=1        
        
        - This function scrolls the scroll text Count lines down
        
        
    void ResetPosition()
        - This function resets the scrolltext position.
          The scrolltext is one pixel under the bottom of the display rectangle
          If you scroll the text up it will become visible.
          
    BOOL IsTopEnd()
        - This function returns TRUE if the text runs out of the screen
          while you scroll it upwards, else FALSE.
          
    BOOL IsBottomEnd()
        - This function returns TRUE if the text runs out of the screen
          while you scroll it upwards, else FALSE.
                              