glib: Documentation fixes for viewer preferences
Clarify documentation about returned values
of recently added viewer preferences.
https://gitlab.freedesktop.org/poppler/poppler/issues/290
diff --git a/glib/poppler-document.cc b/glib/poppler-document.cc
index 7181de7..6b424aa 100644
--- a/glib/poppler-document.cc
+++ b/glib/poppler-document.cc
@@ -1659,6 +1659,8 @@
* @document: A #PopplerDocument
*
* Returns the duplex mode value suggested for printing by author of the document.
+ * Value POPPLER_PRINT_DUPLEX_NONE means that the document does not specify this
+ * preference.
*
* Returns: a #PopplerPrintDuplex that should be used when document is printed
*
@@ -1703,6 +1705,9 @@
* @document: A #PopplerDocument
*
* Returns the suggested number of copies to be printed.
+ * This preference should be applied only if returned value
+ * is greater than 1 since value 1 usually means that
+ * the document does not specify it.
*
* Returns: Number of copies
*
@@ -1735,6 +1740,8 @@
*
* Returns the suggested page ranges to print in the form of array
* of #PopplerPageRanges and number of ranges.
+ * NULL pointer means that the document does not specify page ranges
+ * for printing.
*
* Returns: (array length=n_ranges) (transfer full): an array
* of #PopplerPageRanges or NULL. Free the array when
