Add a new function `svg-embed'

* doc/lispref/display.texi (SVG Images): Document `svg-embed'.

* lisp/svg.el (svg-embed): New function.
(svg--image-data): Ditto.

1 files changed, 23 insertions, 0 deletions

diff --git a/lisp/svg.el b/lisp/svg.el
index c4f3270ea8a..c33b0923c26 100644
--- a/lisp/svg.el
+++ b/lisp/svg.el
@@ -137,6 +137,18 @@ POINTS is a list of x/y pairs."
 			    ", "))
       ,@(svg--arguments svg args)))))
 
+(defun svg-embed (svg image image-type datap &rest args)
+  "Insert IMAGE into the SVG structure.
+IMAGE should be a file name if DATAP is nil, and a binary string
+otherwise.  IMAGE-TYPE should be a MIME image type, like
+\"image/jpeg\" or the like."
+  (svg--append
+   svg
+   (dom-node
+    'image
+    `((xlink:href . ,(svg--image-data image image-type datap))
+      ,@(svg--arguments svg args)))))
+
 (defun svg--append (svg node)
   (let ((old (and (dom-attr node 'id)
 		  (dom-by-id svg
@@ -147,6 +159,17 @@ POINTS is a list of x/y pairs."
       (dom-append-child svg node)))
   (svg-possibly-update-image svg))
 
+(defun svg--image-data (image image-type datap)
+  (with-temp-buffer
+    (set-buffer-multibyte nil)
+    (if datap
+        (insert image)
+      (insert-file-contents image))
+    (base64-encode-region (point-min) (point-max) t)
+    (goto-char (point-min))
+    (insert "data:" image-type ";base64,")
+    (buffer-string)))
+
 (defun svg--arguments (svg args)
   (let ((stroke-width (or (plist-get args :stroke-width)
 			  (dom-attr svg 'stroke-width)))