Trouble with knowsPageRank:

• Konni Scheller Trouble with knowsPageRank: Dec 14 2006, 12:51
  Hi,
  
  I've a lot of data sets to print. But I don't know how tall the rect
  for a data set is until it is printed. This is because a field in the
  data set can have free text, which could be very long[1], and
  therefore I don't know how tall is the line until it is
  calculated.
  
  So I really don't know the size of the NSView to print until I go
  thru all of the data sets.
  
  The function *knowsPageRange:* now is the problem. It looks strange
  to me that I've to do the same calculations twice: one time for
  *knowsPageRange* and one time the same again for *drawRect:*
  
  Is there a simple way to avoid the double calculations? It looks very
  inefficient to me.
  
  Regards,
  Konni
  
  [1] I solved this by linking a new subview to the printed view. This
  NSTextView holds the free text and I get the size of this
  NSTextView from the corrosponding layoutManager. Better solutions are
  welcome.
• Matt Neuburg Re: Trouble with knowsPageRank: Dec 14 2006, 19:40
  On Thu, 14 Dec 2006 12:51:59 +0100, Konni Scheller <konni...>
  said:
  

  > Hi,
  >
  > I've a lot of data sets to print. But I don't know how tall the rect
  > for a data set is until it is printed. This is because a field in the
  > data set can have free text, which could be very long[1], and
  > therefore I don't know how tall is the line until it is
  > calculated.
  >
  > So I really don't know the size of the NSView to print until I go
  > thru all of the data sets.
  >
  > The function *knowsPageRange:* now is the problem. It looks strange
  > to me that I've to do the same calculations twice: one time for
  > *knowsPageRange* and one time the same again for *drawRect:*
  >
  > Is there a simple way to avoid the double calculations? It looks very
  > inefficient to me.
  

  
  One solution is not to use knowsPageRange for this. Just use the
  adjustPageHeightNew: mechanism. This is a wonderful device because the call
  is automatically passed along to all subviews of your main printing view. So
  if every block of material that is to be printed is itself a subview, then
  any subview can say where to split itself (or can prevent itself from being
  split). If every block of material knows how to draw itself and how to split
  itself (or prevent itself from being split), then printing just happens, and
  it just happens once; in fact, your main printing view's drawRect can be
  empty.
  
  m.
  
  --
  matt neuburg, phd = <matt...>, <http://www.tidbits.com/matt/>
  A fool + a tool + an autorelease pool = cool!
  AppleScript: the Definitive Guide - Second Edition!
  <http://www.amazon.com/gp/product/0596102119>