Add several methods for working with form XObjects (fixes #436)

Make some more methods in QPDFPageObjectHelper work with form
XObjects, provide forEach methods to walk through nested form
XObjects, possibly recursively. This should make it easier to work
with form XObjects from user code.

1 files changed, 14 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 32291715..78aa88b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2021-01-01  Jay Berkenbilt  <ejb@ql.org>
+
+	* Add methods to QPDFPageObjectHelper: forEachXObject,
+	forEachImage, forEachFormXObject to call a function on each
+	XObject (or image or form XObject) in a page or form XObject,
+	possibly recursing into nested form XObjects.
+
+	* Add method QPDFPageObjectHelper::getFormXObjects to return a map
+	of keys to form XObjects (non-recursively) from a page or form
+	XObject.
+
+	* Add method QPDFObjectHandle::isImage to test whether an object
+	is an image.
+
 2020-12-31  Jay Berkenbilt  <ejb@ql.org>
 
 	* QPDFPageObjectHelper::removeUnreferencedResources can now be