From 0a05a9f1295e06d158bba4bb7e86f96d4bd845a7 Mon Sep 17 00:00:00 2001
From: Vincent Hennebert <vhennebert@apache.org>
Date: Fri, 16 Oct 2009 15:53:13 +0000
Subject: [PATCH] Route message for missing alt-text property through event
 notification system

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/Temp_Accessibility@825964 13f79535-47bb-0310-9956-ffa450edef68
---
 src/java/org/apache/fop/events/EventFormatter.xml   |  1 +
 .../apache/fop/fo/FOValidationEventProducer.java    | 13 ++++++++++++-
 .../fop/fo/extensions/ExtensionElementMapping.java  |  2 +-
 .../org/apache/fop/fo/flow/AbstractGraphics.java    |  6 ++++++
 .../fop/render/pdf/PDFLogicalStructureHandler.java  |  3 ---
 5 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/java/org/apache/fop/events/EventFormatter.xml b/src/java/org/apache/fop/events/EventFormatter.xml
index 147744a0d..7561f1548 100644
--- a/src/java/org/apache/fop/events/EventFormatter.xml
+++ b/src/java/org/apache/fop/events/EventFormatter.xml
@@ -105,4 +105,5 @@ Any reference to it will be considered a reference to the first occurrence in th
   <message key="org.apache.fop.fonts.FontEventAdapter.fontSubstituted">Font "{requested}" not found. Substituting with "{effective}".</message>
   <message key="org.apache.fop.fonts.FontEventAdapter.fontLoadingErrorAtAutoDetection">Unable to load font file: {fontURL}.[ Reason: {e}]</message>
   <message key="org.apache.fop.fonts.FontEventAdapter.glyphNotAvailable">Glyph "{ch}" (0x{ch,hex}[, {ch,glyph-name}]) not available in font "{fontName}".</message>
+  <message key="org.apache.fop.fo.FOValidationEventProducer.altTextMissing">Alternate text is missing on {foElement}.{{locator}}</message>
 </catalogue>
diff --git a/src/java/org/apache/fop/fo/FOValidationEventProducer.java b/src/java/org/apache/fop/fo/FOValidationEventProducer.java
index 889bf706a..ff005b1b4 100644
--- a/src/java/org/apache/fop/fo/FOValidationEventProducer.java
+++ b/src/java/org/apache/fop/fo/FOValidationEventProducer.java
@@ -36,7 +36,9 @@ public interface FOValidationEventProducer extends EventProducer {
     /**
      * Provider class for the event producer.
      */
-    class Provider {
+    final class Provider {
+
+        private Provider() { }
 
         /**
          * Returns an event producer.
@@ -354,4 +356,13 @@ public interface FOValidationEventProducer extends EventProducer {
     void unknownFormattingObject(Object source, String elementName,
             QName offendingNode, Locator loc);
 
+    /**
+     * Alternate text is missing for a graphic element.
+     *
+     * @param source the event source
+     * @param foElement name of the element (external-graphic or instream-foreign-object)
+     * @param loc the location of the error or null
+     * @event.severity WARN
+     */
+    void altTextMissing(Object source, String foElement, Locator loc);
 }
diff --git a/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java b/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java
index ee2b3886e..f9a556167 100644
--- a/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java
+++ b/src/java/org/apache/fop/fo/extensions/ExtensionElementMapping.java
@@ -47,7 +47,7 @@ public class ExtensionElementMapping extends ElementMapping {
         propertyAttributes.add("internal-destination");
         propertyAttributes.add("disable-column-balancing");
         //These are FOP's extension properties for accessibility
-        propertyAttributes.add("alt");
+        propertyAttributes.add("alt-text");
     }
 
     /**
diff --git a/src/java/org/apache/fop/fo/flow/AbstractGraphics.java b/src/java/org/apache/fop/fo/flow/AbstractGraphics.java
index bd4152295..eeb06c1df 100644
--- a/src/java/org/apache/fop/fo/flow/AbstractGraphics.java
+++ b/src/java/org/apache/fop/fo/flow/AbstractGraphics.java
@@ -106,6 +106,12 @@ public abstract class AbstractGraphics extends FObj
         scaling = pList.get(PR_SCALING).getEnum();
         textAlign = pList.get(PR_TEXT_ALIGN).getEnum();
         width = pList.get(PR_WIDTH).getLength();
+        if (getUserAgent().isAccessibilityEnabled()) {
+            String altText = pList.get(PR_X_ALT_TEXT).getString();
+            if (altText.equals("")) {
+                getFOValidationEventProducer().altTextMissing(this, getLocalName(), getLocator());
+            }
+        }
     }
 
     /**
diff --git a/src/java/org/apache/fop/render/pdf/PDFLogicalStructureHandler.java b/src/java/org/apache/fop/render/pdf/PDFLogicalStructureHandler.java
index 2313431f0..cfa0719ea 100644
--- a/src/java/org/apache/fop/render/pdf/PDFLogicalStructureHandler.java
+++ b/src/java/org/apache/fop/render/pdf/PDFLogicalStructureHandler.java
@@ -163,9 +163,6 @@ class PDFLogicalStructureHandler {
             if (altTextNode != null) {
                 structElem.put("Alt", altTextNode.getNodeValue());
             } else {
-                // TODO route that to event notification system
-//                log.warn("fo:" + s
-//                 + " requires an alternative text attribute fox:alt-text for accessibility");
                 structElem.put("Alt", "No alternate text specified");
             }
         }
-- 
2.39.5