diff --git a/pdfio-content.c b/pdfio-content.c
index c3edd1e..7c591b9 100644
--- a/pdfio-content.c
+++ b/pdfio-content.c
@@ -7,10 +7,6 @@
 // information.
 //
 
-//
-// Include necessary headers...
-//
-
 #include "pdfio-private.h"
 #include "pdfio-content.h"
 #include "ttf.h"
@@ -1064,6 +1060,27 @@ pdfioContentTextEnd(pdfio_stream_t *st)	// I - Stream
 }
 
 
+//
+// 'pdfioContextTextMeasure()' - Measure a text string and return its width.
+//
+
+double					// O - Width
+pdfioContextTextMeasure(
+    pdfio_obj_t *font,			// I - Font object created by @link pdfioFileCreateFontObjFromFile@
+    const char  *s,			// I - UTF-8 string
+    double      size)			// I - Font size/height
+{
+  ttf_t		*ttf = (ttf_t *)_pdfioObjGetExtension(font);
+					// TrueType font data
+  ttf_rect_t	extents;		// Text extents
+
+
+  ttfGetExtents(ttf, size, s, &extents);
+
+  return (extents.right - extents.left);
+}
+
+
 //
 // 'pdfioContentTextMoveLine()' - Move to the next line and offset.
 //
diff --git a/pdfio-content.h b/pdfio-content.h
index f5f11ac..deb9341 100644
--- a/pdfio-content.h
+++ b/pdfio-content.h
@@ -115,6 +115,7 @@ extern bool		pdfioContentSetTextXScaling(pdfio_stream_t *st, double percent) _PD
 extern bool		pdfioContentStroke(pdfio_stream_t *st) _PDFIO_PUBLIC;
 extern bool		pdfioContentTextBegin(pdfio_stream_t *st) _PDFIO_PUBLIC;
 extern bool		pdfioContentTextEnd(pdfio_stream_t *st) _PDFIO_PUBLIC;
+extern double		pdfioContextTextMeasure(pdfio_obj_t *font, const char *s, double size) _PDFIO_PUBLIC;
 extern bool		pdfioContentTextMoveLine(pdfio_stream_t *st, double tx, double ty) _PDFIO_PUBLIC;
 extern bool		pdfioContentTextMoveTo(pdfio_stream_t *st, double tx, double ty) _PDFIO_PUBLIC;
 extern bool		pdfioContentTextNextLine(pdfio_stream_t *st) _PDFIO_PUBLIC;
diff --git a/pdfio-object.c b/pdfio-object.c
index fe10c56..baa62f3 100644
--- a/pdfio-object.c
+++ b/pdfio-object.c
@@ -7,10 +7,6 @@
 // information.
 //
 
-//
-// Include necessary headers...
-//
-
 #include "pdfio-private.h"
 
 
@@ -267,6 +263,17 @@ pdfioObjGetDict(pdfio_obj_t *obj)	// I - Object
 }
 
 
+//
+// '_pdfioObjGetExtension()' - Get the extension pointer for an object.
+//
+
+void *					// O - Extension data
+_pdfioObjGetExtension(pdfio_obj_t *obj)	// I - Object
+{
+  return (obj->data);
+}
+
+
 //
 // 'pdfioObjGetGeneration()' - Get the object's generation number.
 //
@@ -498,6 +505,21 @@ pdfioObjOpenStream(pdfio_obj_t *obj,	// I - Object
 }
 
 
+//
+// '_pdfioObjSetExtension()' - Set extension data for an object.
+//
+
+void
+_pdfioObjSetExtension(
+    pdfio_obj_t *obj,			// I - Object
+    void        *data,			// I - Data
+    void        (*datafree)(void *))	// I - Free function
+{
+  obj->data     = data;
+  obj->datafree = datafree;
+}
+
+
 //
 // 'write_obj_header()' - Write the object header...
 //
diff --git a/pdfio-private.h b/pdfio-private.h
index 67b7ba6..92b002b 100644
--- a/pdfio-private.h
+++ b/pdfio-private.h
@@ -287,6 +287,8 @@ struct _pdfio_obj_s			// Object
   size_t	stream_length;		// Length of stream, if any
   _pdfio_value_t value;			// Dictionary/number/etc. value
   pdfio_stream_t *stream;		// Open stream, if any
+  void		*data;			// Extension data, if any
+  void		(*datafree)(void *);	// Free callback for extension data
 };
 
 struct _pdfio_stream_s			// Stream
@@ -365,7 +367,9 @@ extern off_t		_pdfioFileTell(pdfio_file_t *pdf) _PDFIO_INTERNAL;
 extern bool		_pdfioFileWrite(pdfio_file_t *pdf, const void *buffer, size_t bytes) _PDFIO_INTERNAL;
 
 extern void		_pdfioObjDelete(pdfio_obj_t *obj) _PDFIO_INTERNAL;
+extern void		*_pdfioObjGetExtension(pdfio_obj_t *obj) _PDFIO_INTERNAL;
 extern bool		_pdfioObjLoad(pdfio_obj_t *obj) _PDFIO_INTERNAL;
+extern void		_pdfioObjSetExtension(pdfio_obj_t *obj, void *data, void (*datafree)(void *)) _PDFIO_INTERNAL;
 
 extern pdfio_stream_t	*_pdfioStreamCreate(pdfio_obj_t *obj, pdfio_obj_t *length_obj, pdfio_filter_t compression) _PDFIO_INTERNAL;
 extern pdfio_stream_t	*_pdfioStreamOpen(pdfio_obj_t *obj, bool decode) _PDFIO_INTERNAL;