FOP-3207: Add warning when different pdf languages are used

3 files changed, 20 insertions, 0 deletions

diff --git a/fop-core/src/main/java/org/apache/fop/pdf/PDFFactory.java b/fop-core/src/main/java/org/apache/fop/pdf/PDFFactory.java
index 40370f705..12a6c3e09 100644
--- a/fop-core/src/main/java/org/apache/fop/pdf/PDFFactory.java
+++ b/fop-core/src/main/java/org/apache/fop/pdf/PDFFactory.java
@@ -1707,4 +1707,8 @@ public class PDFFactory {
     public void setEventBroadcaster(EventBroadcaster eventBroadcaster) {
         this.eventBroadcaster = eventBroadcaster;
     }
+
+    public EventBroadcaster getEventBroadcaster() {
+        return eventBroadcaster;
+    }
 }
diff --git a/fop-core/src/main/java/org/apache/fop/pdf/PDFRoot.java b/fop-core/src/main/java/org/apache/fop/pdf/PDFRoot.java
index b230ad879..7b6038467 100644
--- a/fop-core/src/main/java/org/apache/fop/pdf/PDFRoot.java
+++ b/fop-core/src/main/java/org/apache/fop/pdf/PDFRoot.java
@@ -23,6 +23,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Locale;
 
+import org.apache.fop.render.pdf.PDFEventProducer;
 import org.apache.fop.util.LanguageTags;
 
 /**
@@ -287,6 +288,11 @@ public class PDFRoot extends PDFDictionary {
     }
 
     private void setLanguage(String lang) {
+        Object oldLang = get("Lang");
+        if (oldLang != null && !"x-unknown".equals(oldLang) && !lang.equals(oldLang)) {
+            PDFEventProducer eventProducer = PDFEventProducer.Provider.get(document.getFactory().getEventBroadcaster());
+            eventProducer.languageChanged(this, oldLang, lang);
+        }
         put("Lang", lang);
     }
 
diff --git a/fop-core/src/main/java/org/apache/fop/render/pdf/PDFEventProducer.java b/fop-core/src/main/java/org/apache/fop/render/pdf/PDFEventProducer.java
index 24d0eb0cf..b78b472c5 100644
--- a/fop-core/src/main/java/org/apache/fop/render/pdf/PDFEventProducer.java
+++ b/fop-core/src/main/java/org/apache/fop/render/pdf/PDFEventProducer.java
@@ -90,4 +90,14 @@ public interface PDFEventProducer extends EventProducer {
      * @event.severity ERROR
      */
     void unpairedSurrogate(Object source);
+
+    /**
+     * The language was changed between pages
+     *
+     * @param source the event source
+     * @param oldLang current language
+     * @param newLang new language
+     * @event.severity WARN
+     */
+    void languageChanged(Object source, Object oldLang, String newLang);
 }