org.pentaho.reporting.engine.classic.core.layout.process
Class ParagraphLineBreakStep

java.lang.Object
  org.pentaho.reporting.engine.classic.core.layout.process.IterateStructuralProcessStep
      org.pentaho.reporting.engine.classic.core.layout.process.ParagraphLineBreakStep

public final class ParagraphLineBreakStep
extends IterateStructuralProcessStep

This static computation step performs manual linebreaks on all paragraphs. This transforms the pool-collection into the lines-collection.

For now, we follow a very simple path: A paragraph cannot be validated, if it is not yet closed. The linebreaking, be it the static one here or the dynamic one later, must be redone when the paragraph changes.

Splitting for linebreaks happens only between inline-boxes. BlockBoxes that are contained in inline-boxes (like 'inline-block' elements or 'inline-tables') are considered unbreakable according to the CSS specs. Linebreaking can be suspended in these cases.

As paragraphs itself are block elements, the linebreaks can be done iterative, using a simple stack to store the context of possibly nested paragraphs. The paragraph's pool contains the elements that should be processed, and the line-container will receive the pool's content (contained in an artificial inline element, as the linecontainer is a block-level element).

Change-tracking should take place on the paragraph's pool element instead of the paragraph itself. This way, only structural changes are taken into account.

Author:

Thomas Morgner

Constructor Summary

ParagraphLineBreakStep()

Method Summary

void	compute(LogicalPageBox root)
void	finishCanvasBox(CanvasRenderBox box)
void	finishRowBox(RenderBox box)
boolean	startCanvasBox(CanvasRenderBox box)
boolean	startRowBox(RenderBox box)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ParagraphLineBreakStep

public ParagraphLineBreakStep()

Method Detail

compute

public void compute(LogicalPageBox root)

startCanvasBox

public boolean startCanvasBox(CanvasRenderBox box)

finishCanvasBox

public void finishCanvasBox(CanvasRenderBox box)

startRowBox

public boolean startRowBox(RenderBox box)

finishRowBox

public void finishRowBox(RenderBox box)