New methods used in calculating percent-based property values

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@193768 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 25 insertions, 1 deletions

diff --git a/src/org/apache/fop/fo/FObj.java b/src/org/apache/fop/fo/FObj.java
index bc4f789f6..221c25e27 100644
--- a/src/org/apache/fop/fo/FObj.java
+++ b/src/org/apache/fop/fo/FObj.java
@@ -142,7 +142,31 @@ public class FObj extends FONode {
         return(properties.get(name));
   }
 
-  
+  /**
+   * Return the width of the containing area for this FO's areas.
+   * This is used by percent-based properties to get the dimension of
+   * the containing block.
+   * If an FO has a property with a percentage value, that value
+   * is usually calculated on the basis of the corresponding dimenions
+   * of the block which contains areas generated by the FO.
+   * Implementation note: if this block has an FObj parent, this method
+   * returns the value of getContentWidth() on that FObj. Normally subclasses
+   * will override getContentWidth and not getContainingWidth().
+   */
+  public int getContainingWidth() {
+    FObj parent = getParent();
+    if (parent != null)
+	return parent.getContentWidth();
+    else return 0;  // no parent, top level box
+  }
+
+  /**
+   * Return the "content width" of the areas generated by this FO.
+   * NOTE: subclasses of FObj should implement this!
+   */
+  protected int getContentWidth() {
+    return 0;
+  }
 
   /**
    * removes property id