diff --git a/src/xdisp.c b/src/xdisp.c
index b14b7daf2b..d5fa3a1cfe 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -25210,6 +25210,10 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
 				   + (WINDOW_HAS_FRINGES_OUTSIDE_MARGINS (it->w)
 				      ? WINDOW_RIGHT_FRINGE_WIDTH (it->w)
 				      : 0)));
+          if (EQ (prop, Qleft_edge))
+            return OK_ALIGN_TO (WINDOW_LEFT_PIXEL_EDGE (it->w));
+          if (EQ (prop, Qright_edge))
+            return OK_ALIGN_TO (WINDOW_RIGHT_PIXEL_EDGE (it->w));
 	}
       else
 	{
@@ -25223,6 +25227,13 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
 	    return OK_PIXELS (WINDOW_RIGHT_MARGIN_WIDTH (it->w));
 	  if (EQ (prop, Qscroll_bar))
 	    return OK_PIXELS (WINDOW_SCROLL_BAR_AREA_WIDTH (it->w));
+	  if (EQ (prop, Qleft))
+            return OK_PIXELS (window_box_left_offset (it->w, TEXT_AREA));
+          if (EQ (prop, Qright))
+	    return OK_PIXELS (window_box_right_offset (it->w, TEXT_AREA));
+	  if (EQ (prop, Qcenter))
+	    return OK_PIXELS (window_box_left_offset (it->w, TEXT_AREA)
+				+ window_box_width (it->w, TEXT_AREA) / 2);
 	}
 
       prop = buffer_local_value (prop, it->w->contents);
@@ -32207,6 +32218,8 @@ They are still logged to the *Messages* buffer.  */);
   DEFSYM (Qspace, "space");
   DEFSYM (Qmargin, "margin");
   DEFSYM (Qpointer, "pointer");
+  DEFSYM (Qleft_edge, "left-edge");
+  DEFSYM (Qright_edge, "right-edge");
   DEFSYM (Qleft_margin, "left-margin");
   DEFSYM (Qright_margin, "right-margin");
   DEFSYM (Qcenter, "center");