Bug 61203 - XSSFDrawing.getAnchorFromParent handles CTOneCellAnchor incorrectly, ignores CTAbsoluteAnchor

This is likely incomplete, but closer to where things should be.  It is backward compatible with previous uses of XSSFClientAnchor.

This fixes a bug in XSSFGraphicFrame that was hiding the parent class anchor property (which is a protected field set directly from XSSFDrawing).  This is a peril of using direct property access - the hiding wasn't obvious because there was no setter being overridden.

XSSFGraphicFrame now notices when it relates to a chart, and setts the frame property of the XSSFChart.  That was not being set on parse previously, only when creating charts from scratch.  That didn't seem right.

XSSFClientAnchor now calculates size and position correctly based on initial inputs from the different types of anchors.  It DOES NOT update those initial inputs, however.  It does properly adjust if the size or initial position are absolute and the corresponding row/column values are requested.

Added new class EMUUtils to centralize the measurement constants and conversions since there are so many units in play in the OOXML spec and POI APIs:

* EMUs (English Metric Units)
* Inches
* Centimeters
* Points
* Pixels
* Twips (1/20th of a point)

I'm sure there are more conversions that could be done there, I just started with what I needed.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1799643 13f79535-47bb-0310-9956-ffa450edef68

5 files changed, 327 insertions, 53 deletions

diff --git a/src/java/org/apache/poi/ss/usermodel/ClientAnchor.java b/src/java/org/apache/poi/ss/usermodel/ClientAnchor.java
index 702970c69e..d11edc56ae 100644
--- a/src/java/org/apache/poi/ss/usermodel/ClientAnchor.java
+++ b/src/java/org/apache/poi/ss/usermodel/ClientAnchor.java
@@ -20,10 +20,17 @@ import org.apache.poi.util.Internal;
 import org.apache.poi.util.Removal;
 
 /**
- * A client anchor is attached to an excel worksheet.  It anchors against a
- * top-left and bottom-right cell.
- *
- * @author Yegor Kozlov
+ * A client anchor is attached to an excel worksheet.  It anchors against 
+ * absolute coordinates, a top-left cell and fixed height and width, or
+ * a top-left and bottom-right cell, depending on the {@link AnchorType}:
+ * <ol>
+ * <li> {@link AnchorType#DONT_MOVE_AND_RESIZE} == absolute top-left coordinates and width/height, no cell references
+ * <li> {@link AnchorType#MOVE_DONT_RESIZE} == fixed top-left cell reference, absolute width/height
+ * <li> {@link AnchorType#MOVE_AND_RESIZE} == fixed top-left and bottom-right cell references, dynamic width/height
+ * </ol>
+ * Note this class only reports the current values for possibly calculated positions and sizes.
+ * If the sheet row/column sizes or positions shift, this needs updating via external calculations.
+ * 
  */
 public interface ClientAnchor {
     
@@ -91,8 +98,9 @@ public interface ClientAnchor {
          * <p>
          * Specifies that the current drawing shall not move with its
          * row and column, but should be resized. This option is not normally
-         * used, but is included for completeness.
+         * used, but is included for completeness. 
          * </p>
+         * Note: Excel has no setting for this combination, nor does the ECMA standard.
          */
         DONT_MOVE_DO_RESIZE(1),
         
@@ -145,9 +153,10 @@ public interface ClientAnchor {
     }
     
     /**
-     * Returns the column (0 based) of the first cell.
+     * Returns the column (0 based) of the first cell, or -1 if there is no top-left anchor cell.
+     * This is the case for absolute positioning (AnchorType{@link #DONT_MOVE_AND_RESIZE}).
      *
-     * @return 0-based column of the first cell.
+     * @return 0-based column of the first cell or -1 if none.
      */
     public short getCol1();
 
@@ -159,9 +168,11 @@ public interface ClientAnchor {
     public void setCol1(int col1);
 
     /**
-     * Returns the column (0 based) of the second cell.
+     * Returns the column (0 based) of the second cell, or -1 if there is no bottom-right anchor cell.
+     * This is the case for absolute positioning ({@link AnchorType#DONT_MOVE_AND_RESIZE})
+     * and absolute sizing ({@link AnchorType#MOVE_DONT_RESIZE}.
      *
-     * @return 0-based column of the second cell.
+     * @return 0-based column of the second cell or -1 if none.
      */
     public short getCol2();
 
@@ -173,9 +184,10 @@ public interface ClientAnchor {
     public void setCol2(int col2);
 
     /**
-     * Returns the row (0 based) of the first cell.
+     * Returns the row (0 based) of the first cell, or -1 if there is no bottom-right anchor cell.
+     * This is the case for absolute positioning ({@link AnchorType#DONT_MOVE_AND_RESIZE}).
      *
-     * @return 0-based row of the first cell.
+     * @return 0-based row of the first cell or -1 if none.
      */
     public int getRow1();
 
@@ -187,9 +199,11 @@ public interface ClientAnchor {
     public void setRow1(int row1);
 
     /**
-     * Returns the row (0 based) of the second cell.
+     * Returns the row (0 based) of the second cell, or -1 if there is no bottom-right anchor cell.
+     * This is the case for absolute positioning ({@link AnchorType#DONT_MOVE_AND_RESIZE})
+     * and absolute sizing ({@link AnchorType#MOVE_DONT_RESIZE}.
      *
-     * @return 0-based row of the second cell.
+     * @return 0-based row of the second cell or -1 if none.
      */
     public int getRow2();
 
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFClientAnchor.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFClientAnchor.java
index 0f2c1a186d..0fa3f96ff0 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFClientAnchor.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFClientAnchor.java
@@ -18,50 +18,73 @@
 package org.apache.poi.xssf.usermodel;
 
 import org.apache.poi.ss.usermodel.ClientAnchor;
+import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.util.Internal;
 import org.apache.poi.util.Removal;
+import org.apache.poi.xssf.util.EMUUtils;
+import org.openxmlformats.schemas.drawingml.x2006.main.CTPoint2D;
+import org.openxmlformats.schemas.drawingml.x2006.main.CTPositiveSize2D;
 import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTMarker;
 
 /**
- * A client anchor is attached to an excel worksheet.  It anchors against
- * top-left and bottom-right cells.
+ * A client anchor is attached to an excel worksheet.  It anchors against:
+ * <ol>
+ * <li>A fixed position and fixed size
+ * <li>A position relative to a cell (top-left) and a fixed size
+ * <li>A position relative to a cell (top-left) and sized relative to another cell (bottom right)
+ * </ol>
  *
- * @author Yegor Kozlov
+ * which method is used is determined by the {@link AnchorType}.  
  */
-public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
-    private AnchorType DEFAULT_ANCHOR_TYPE = AnchorType.MOVE_AND_RESIZE;
+public class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
+    
+    /**
+     * placeholder for zeros when needed for dynamic position calculations
+     */
+    private static final CTMarker EMPTY_MARKER = CTMarker.Factory.newInstance();
+    
     private AnchorType anchorType;
 
     /**
-     * Starting anchor point
+     * Starting anchor point (top-left cell + relative offset)
+     * if left null recalculate as needed from point
      */
     private CTMarker cell1;
 
     /**
-     * Ending anchor point
+     * Ending anchor point (bottom-right cell + relative offset)
+     * if left null, re-calculate as needed from size and cell1
      */
     private CTMarker cell2;
 
     /**
+     * if present, fixed size of the object to use instead of cell2, which is inferred instead
+     */
+    private CTPositiveSize2D size;
+    
+    /**
+     * if present, fixed top-left position to use instead of cell1, which is inferred instead
+     */
+    private CTPoint2D position;
+    
+    /**
+     * sheet to base dynamic calculations on, if needed.  Required if size and/or position or set.
+     * Not needed if cell1/2 are set explicitly (dynamic sizing and position relative to cells).
+     */
+    private XSSFSheet sheet;
+    
+    /**
      * Creates a new client anchor and defaults all the anchor positions to 0.
+     * Sets the type to {@link AnchorType#MOVE_AND_RESIZE} relative to cell range A1:A1.
      */
     public XSSFClientAnchor() {
-        anchorType = DEFAULT_ANCHOR_TYPE;
-        cell1 = CTMarker.Factory.newInstance();
-        cell1.setCol(0);
-        cell1.setColOff(0);
-        cell1.setRow(0);
-        cell1.setRowOff(0);
-        cell2 = CTMarker.Factory.newInstance();
-        cell2.setCol(0);
-        cell2.setColOff(0);
-        cell2.setRow(0);
-        cell2.setRowOff(0);
+        this(0,0,0,0,0,0,0,0);
     }
 
     /**
      * Creates a new client anchor and sets the top-left and bottom-right
-     * coordinates of the anchor.
+     * coordinates of the anchor by cell references and offsets.
+     * Sets the type to {@link AnchorType#MOVE_AND_RESIZE}.
      *
      * @param dx1  the x coordinate within the first cell.
      * @param dy1  the y coordinate within the first cell.
@@ -73,11 +96,13 @@ public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
      * @param row2 the row (0 based) of the second cell.
      */
     public XSSFClientAnchor(int dx1, int dy1, int dx2, int dy2, int col1, int row1, int col2, int row2) {
-        this();
+        anchorType = AnchorType.MOVE_AND_RESIZE;
+        cell1 = CTMarker.Factory.newInstance();
         cell1.setCol(col1);
         cell1.setColOff(dx1);
         cell1.setRow(row1);
         cell1.setRowOff(dy1);
+        cell2 = CTMarker.Factory.newInstance();
         cell2.setCol(col2);
         cell2.setColOff(dx2);
         cell2.setRow(row2);
@@ -85,77 +110,203 @@ public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
     }
 
     /**
-     * Create XSSFClientAnchor from existing xml beans
-     *
+     * Create XSSFClientAnchor from existing xml beans, sized and positioned relative to a pair of cells.
+     * Sets the type to {@link AnchorType#MOVE_AND_RESIZE}.
      * @param cell1 starting anchor point
      * @param cell2 ending anchor point
      */
     protected XSSFClientAnchor(CTMarker cell1, CTMarker cell2) {
-        anchorType = DEFAULT_ANCHOR_TYPE;
+        anchorType = AnchorType.MOVE_AND_RESIZE;
         this.cell1 = cell1;
         this.cell2 = cell2;
     }
 
+    /**
+     * Create XSSFClientAnchor from existing xml beans, sized and positioned relative to a pair of cells.
+     * Sets the type to {@link AnchorType#MOVE_DONT_RESIZE}.
+     *
+     * @param sheet needed to calculate ending point based on column/row sizes
+     * @param cell1 starting anchor point
+     * @param size object size, to calculate ending anchor point
+     */
+    protected XSSFClientAnchor(XSSFSheet sheet, CTMarker cell1, CTPositiveSize2D size) {
+        anchorType = AnchorType.MOVE_DONT_RESIZE;
+        this.sheet = sheet;
+        this.size = size;
+        this.cell1 = cell1;
+//        this.cell2 = calcCell(sheet, cell1, size.getCx(), size.getCy());
+    }
+    
+    /**
+     * Create XSSFClientAnchor from existing xml beans, sized and positioned relative to a pair of cells.
+     * Sets the type to {@link AnchorType#DONT_MOVE_AND_RESIZE}.
+     *
+     * @param sheet needed to calculate starting and ending points based on column/row sizes
+     * @param position starting absolute position
+     * @param size object size, to calculate ending position
+     */
+    protected XSSFClientAnchor(XSSFSheet sheet, CTPoint2D position, CTPositiveSize2D size) {
+        anchorType = AnchorType.DONT_MOVE_AND_RESIZE;
+        this.sheet = sheet;
+        this.position = position;
+        this.size = size;
+        // zeros for row/col/offsets
+//        this.cell1 = calcCell(sheet, EMPTY_MARKER, position.getCx(), position.getCy());
+//        this.cell2 = calcCell(sheet, cell1, size.getCx(), size.getCy());
+    }
+    
+    /**
+     *
+     * @param sheet
+     * @param cell starting point and offsets (may be zeros)
+     * @param size dimensions to calculate relative to starting point
+     */
+    private CTMarker calcCell(CTMarker cell, long w, long h) {
+        CTMarker c2 = CTMarker.Factory.newInstance();
+        
+        int r = cell.getRow();
+        int c = cell.getCol();
+        
+        int cw = EMUUtils.EMUsFromColumnWidth(sheet.getColumnWidth(c));
+        
+        // start with width - offset, then keep adding column widths until the next one puts us over w
+        long wPos = cw - cell.getColOff();
+        
+        while (wPos < w) {
+            c++;
+            cw = EMUUtils.EMUsFromColumnWidth(sheet.getColumnWidth(c));
+            wPos += cw;
+        }
+        // now wPos >= w, so end column = c, now figure offset
+        c2.setCol(c);
+        c2.setColOff(cw - (wPos - w));
+        
+        int rh = EMUUtils.EMUsFromPoints(getRowHeight(sheet, r));
+        // start with height - offset, then keep adding row heights until the next one puts us over h
+        long hPos = rh - cell.getRowOff();
+        
+        while (hPos < h) {
+            r++;
+            rh = EMUUtils.EMUsFromPoints(getRowHeight(sheet, r));
+            hPos += rh;
+        }
+        // now hPos >= h, so end row = r, now figure offset
+        c2.setRow(r);
+        c2.setRowOff(rh - (hPos - h));
+        
+        return c2;
+    }
+    
+    /**
+     * @param sheet
+     * @param row
+     * @return height in twips (1/20th of point) for row or default
+     */
+    private static float getRowHeight(XSSFSheet sheet, int row) {
+        XSSFRow r = sheet.getRow(row);
+        return r == null ? sheet.getDefaultRowHeightInPoints() : r.getHeightInPoints();
+    }
+    
+    private CTMarker getCell1() {
+        return cell1 != null ? cell1 : calcCell(EMPTY_MARKER, position.getX(), position.getY());
+    }
+    
+    private CTMarker getCell2() {
+        return cell2 != null ? cell2 : calcCell(getCell1(), size.getCx(), size.getCy());
+    }
+    
     public short getCol1() {
-        return (short)cell1.getCol();
+        return (short)getCell1().getCol();
     }
 
+    /**
+     * @throws NullPointerException if cell1 is null (fixed position)
+     * @see org.apache.poi.ss.usermodel.ClientAnchor#setCol1(int)
+     */
     public void setCol1(int col1) {
         cell1.setCol(col1);
     }
 
     public short getCol2() {
-        return (short)cell2.getCol();
+        return (short) getCell2().getCol();
     }
 
+    /**
+     * @throws NullPointerException if cell2 is null (fixed size)
+     * @see org.apache.poi.ss.usermodel.ClientAnchor#setCol2(int)
+     */
     public void setCol2(int col2) {
         cell2.setCol(col2);
     }
 
     public int getRow1() {
-        return cell1.getRow();
+        return getCell1().getRow();
     }
 
+    /**
+     * @throws NullPointerException if cell1 is null (fixed position)
+     * @see org.apache.poi.ss.usermodel.ClientAnchor#setRow1(int)
+     */
     public void setRow1(int row1) {
         cell1.setRow(row1);
     }
 
     public int getRow2() {
-        return cell2.getRow();
+        return getCell2().getRow();
     }
 
+    /**
+     * @throws NullPointerException if cell2 is null (fixed size)
+     * @see org.apache.poi.ss.usermodel.ClientAnchor#setRow2(int)
+     */
     public void setRow2(int row2) {
         cell2.setRow(row2);
     }
 
     public int getDx1() {
-        return (int)cell1.getColOff();
+        return (int) getCell1().getColOff();
     }
 
+    /**
+     * @throws NullPointerException if cell1 is null (fixed position)
+     * @see org.apache.poi.ss.usermodel.ChildAnchor#setDx1(int)
+     */
     public void setDx1(int dx1) {
         cell1.setColOff(dx1);
     }
 
     public int getDy1() {
-        return (int)cell1.getRowOff();
+        return (int) getCell1().getRowOff();
     }
 
+    /**
+     * @throws NullPointerException if cell1 is null (fixed position)
+     * @see org.apache.poi.ss.usermodel.ChildAnchor#setDy1(int)
+     */
     public void setDy1(int dy1) {
         cell1.setRowOff(dy1);
     }
 
     public int getDy2() {
-        return (int)cell2.getRowOff();
+        return (int) getCell2().getRowOff();
     }
 
+    /**
+     * @throws NullPointerException if cell2 is null (fixed size)
+     * @see org.apache.poi.ss.usermodel.ChildAnchor#setDy2(int)
+     */
     public void setDy2(int dy2) {
         cell2.setRowOff(dy2);
     }
 
     public int getDx2() {
-        return (int)cell2.getColOff();
+        return (int) getCell2().getColOff();
     }
 
+    /**
+     * @throws NullPointerException if cell2 is null (fixed size)
+     * @see org.apache.poi.ss.usermodel.ChildAnchor#setDx2(int)
+     */
     public void setDx2(int dx2) {
         cell2.setColOff(dx2);
     }
@@ -184,7 +335,7 @@ public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
 
     @Override
     public String toString(){
-        return "from : " + cell1 + "; to: " + cell2;
+        return "from : " + getCell1() + "; to: " + getCell2();
     }
 
     /**
@@ -194,7 +345,7 @@ public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
      */
     @Internal
     public CTMarker getFrom(){
-        return cell1;
+        return getCell1();
     }
 
     protected void setFrom(CTMarker from){
@@ -208,13 +359,47 @@ public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
      */
     @Internal
     public CTMarker getTo(){
-        return cell2;
+        return getCell2();
     }
 
     protected void setTo(CTMarker to){
         cell2 = to;
     }
 
+    /**
+     * @return absolute top-left position, or null if position is determined from the "from" cell
+     * @since POI 3.17 beta 1
+     */
+    public CTPoint2D getPosition() {
+        return position;
+    }
+    
+    /**
+     * Sets the top-left absolute position of the object.  To use this, "from" must be set to null.
+     * @param position
+     * @since POI 3.17 beta 1
+     */
+    public void setPosition(CTPoint2D position) {
+        this.position = position;
+    }
+
+    /**
+     *
+     * @return size or null, if size is determined from the to and from cells
+     * @since POI 3.17 beta 1
+     */
+    public CTPositiveSize2D getSize() {
+        return size;
+    }
+    
+    /**
+     * Sets the size of the object.  To use this, "to" must be set to null.
+     * @param size
+     * @since POI 3.17 beta 1
+     */
+    public void setSize(CTPositiveSize2D size) {
+        this.size = size;
+    }
 
     /**
      * Sets the anchor type
@@ -250,7 +435,9 @@ public final class XSSFClientAnchor extends XSSFAnchor implements ClientAnchor {
     }
 
     public boolean isSet(){
-        return !(cell1.getCol() == 0 && cell2.getCol() == 0 &&
-                 cell1.getRow() == 0 && cell2.getRow() == 0);
+        CTMarker c1 = getCell1();
+        CTMarker c2 = getCell2();
+        return !(c1.getCol() == 0 && c2.getCol() == 0 &&
+                 c1.getRow() == 0 && c2.getRow() == 0);
     }
 }
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java
index 42518fa9f5..7078f3c09d 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDrawing.java
@@ -58,6 +58,7 @@ import org.openxmlformats.schemas.drawingml.x2006.main.CTNonVisualDrawingProps;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTPoint2D;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTPositiveSize2D;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTTransform2D;
+import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTAbsoluteAnchor;
 import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTConnector;
 import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTDrawing;
 import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTGraphicalObjectFrame;
@@ -676,7 +677,10 @@ public final class XSSFDrawing extends POIXMLDocumentPart implements Drawing<XSS
                 anchor = new XSSFClientAnchor(ct.getFrom(), ct.getTo());
             } else if (parentXbean instanceof CTOneCellAnchor) {
                 CTOneCellAnchor ct = (CTOneCellAnchor)parentXbean;
-                anchor = new XSSFClientAnchor(ct.getFrom(), CTMarker.Factory.newInstance());
+                anchor = new XSSFClientAnchor(getSheet(), ct.getFrom(), ct.getExt());
+            } else if (parentXbean instanceof CTAbsoluteAnchor) {
+                CTAbsoluteAnchor ct = (CTAbsoluteAnchor) parentXbean;
+                anchor = new XSSFClientAnchor(getSheet(), ct.getPos(), ct.getExt());
             }
         }
         return anchor;
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java
index 4cee01628d..fff0005518 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFGraphicFrame.java
@@ -21,6 +21,7 @@ package org.apache.poi.xssf.usermodel;
 
 import javax.xml.namespace.QName;
 
+import org.apache.poi.POIXMLDocumentPart;
 import org.apache.poi.util.Internal;
 import org.apache.xmlbeans.XmlCursor;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTGraphicalObjectData;
@@ -32,6 +33,8 @@ import org.openxmlformats.schemas.drawingml.x2006.main.CTTransform2D;
 import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTGraphicalObjectFrame;
 import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTGraphicalObjectFrameNonVisual;
 import org.openxmlformats.schemas.officeDocument.x2006.relationships.STRelationshipId;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
 
 /**
  * Represents DrawingML GraphicalObjectFrame.
@@ -43,7 +46,6 @@ public final class XSSFGraphicFrame extends XSSFShape {
 	private static CTGraphicalObjectFrame prototype = null;
 
 	private CTGraphicalObjectFrame graphicFrame;
-	private XSSFClientAnchor anchor;
 
 	/**
 	 * Construct a new XSSFGraphicFrame object.
@@ -54,6 +56,23 @@ public final class XSSFGraphicFrame extends XSSFShape {
 	protected XSSFGraphicFrame(XSSFDrawing drawing, CTGraphicalObjectFrame ctGraphicFrame) {
 		this.drawing = drawing; // protected field on XSSFShape
 		this.graphicFrame = ctGraphicFrame;
+		// TODO: there may be a better way to delegate this
+		CTGraphicalObjectData graphicData = graphicFrame.getGraphic().getGraphicData();
+        if (graphicData != null) {
+            NodeList nodes = graphicData.getDomNode().getChildNodes();
+            for (int i = 0; i < nodes.getLength(); i++) {
+                final Node node = nodes.item(i);
+                // if the frame references a chart, associate the chart with this instance
+                if (node.getNodeName().equals("c:chart")) {
+                    // this better succeed or the document is invalid
+                    POIXMLDocumentPart relation = drawing.getRelationById(node.getAttributes().getNamedItem("r:id").getNodeValue());
+                    // Do XWPF charts need similar treatment?
+                    if (relation instanceof XSSFChart) {
+                        ((XSSFChart) relation).setGraphicFrame(this);
+                    }
+                }
+            }
+        }
 	}
 
 	@Internal
@@ -126,10 +145,10 @@ public final class XSSFGraphicFrame extends XSSFShape {
 
 	/**
 	 * Returns the frame anchor.
-	 * @return the anchor this frame is attached to
+	 * @return the XSSFClientAnchor anchor this frame is attached to
 	 */
 	public XSSFClientAnchor getAnchor() {
-		return anchor;
+		return (XSSFClientAnchor) anchor;
 	}
 
 	/**
diff --git a/src/ooxml/java/org/apache/poi/xssf/util/EMUUtils.java b/src/ooxml/java/org/apache/poi/xssf/util/EMUUtils.java
new file mode 100644
index 0000000000..d5b82a696a
--- /dev/null
+++ b/src/ooxml/java/org/apache/poi/xssf/util/EMUUtils.java
@@ -0,0 +1,50 @@
+package org.apache.poi.xssf.util;
+
+import org.apache.poi.xssf.usermodel.XSSFShape;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+/**
+ * Conversion methods for OOXML EMU values - "English Metric Units" or more accurately
+ * "Evil Measurement Units".
+ * <p/>
+ * These are defined briefly in <a href="https://en.wikipedia.org/wiki/Office_Open_XML_file_formats#DrawingML">Wikipedia</a>
+ * as a "rational" way to use an integer value to represent something that could be in 
+ * inches, centimeters, points, or pixels.
+ * So now we get to convert between all those.
+ */
+public class EMUUtils {
+    public static final int EMUS_PER_INCH = 914400;
+    public static final int EMUS_PER_POINT = 12700;
+    public static final int EMUS_PER_CENTIMETER = 360000;
+    
+    // TODO: these could move here or something to standardize definitions
+    public static final int EMU_PER_PIXEL = XSSFShape.EMU_PER_PIXEL;
+    public static final int EMU_PER_POINT = XSSFShape.EMU_PER_POINT;
+    public static final int PIXEL_DPI = XSSFShape.PIXEL_DPI;
+    public static final int POINT_DPI = XSSFShape.POINT_DPI;
+    public static final int EMU_PER_CHARACTER = (int) (EMU_PER_PIXEL * XSSFWorkbook.DEFAULT_CHARACTER_WIDTH);
+    
+    /**
+     * @param columnWidth as (fractional # of characters) * 256
+     * @return EMUs
+     */
+    public static final int EMUsFromColumnWidth(int columnWidth) {
+        return (int) (columnWidth /256d * EMUUtils.EMU_PER_CHARACTER);
+    }
+    
+    /**
+     * @param twips (1/20th of a point) typically a row height
+     * @return EMUs
+     */
+    public static final int EMUsFromTwips(short twips) {
+        return (int) (twips / 20d * EMU_PER_POINT);
+    }
+    
+    /**
+     * @param points (fractional)
+     * @return EMUs
+     */
+    public static final int EMUsFromPoints(float points) {
+        return (int) (points * EMU_PER_POINT);
+    }
+}