BUG: fix FilterWatcher to avoid calling the start/end callback several times

Code/Common/otbFilterWatcherBase.cxx

@@ -25,20 +25,27 @@ namespace otb
 
 FilterWatcherBase
 ::FilterWatcherBase()
+: m_Comment("Not watching an object"),
+  m_Process(0),
+  m_StartTag(0),
+  m_EndTag(0),
+  m_ProgressTag(0),
+  m_Started(false),
+  m_Ended(false)
 {
-  // Initialize state
-  m_Comment = "Not watching an object";
-  m_Process = 0;
 }
 
 FilterWatcherBase
 ::FilterWatcherBase(itk::ProcessObject* process,
                     const char *comment)
+: m_Comment(comment),
+  m_Process(process),
+  m_StartTag(0),
+  m_EndTag(0),
+  m_ProgressTag(0),
+  m_Started(false),
+  m_Ended(false)
 {
-  // Initialize state
-  m_Process = process;
-  m_Comment = comment;
-
   // Create a series of commands
   m_StartFilterCommand = CommandType::New();
   m_EndFilterCommand = CommandType::New();

Code/Common/otbFilterWatcherBase.h

@@ -94,13 +94,21 @@ protected:
   /** Callback method to show the StartEvent */
   virtual void StartFilterCallback()
   {
-    this->StartFilter();
+    if (!m_Started)
+      {
+      this->StartFilter();
+      m_Started = true;
+      }
   }
 
   /** Callback method to show the EndEvent */
   virtual void EndFilterCallback()
   {
-    this->EndFilter();
+    if (!m_Ended)
+      {
+      this->EndFilter();
+      m_Ended = true;
+      }
   }
 
   /** Callback method to show the ProgressEvent */
@@ -142,6 +150,14 @@ protected:
   /** Progress observer */
   unsigned long m_ProgressTag;
 
+  /** Some filters (for ex. persistents) invoke the StartEvent several times
+   *  Work around this by remembering if it was called or not */
+  bool m_Started;
+
+  /** Some filters (for ex. persistents) invoke the EndEvent several times
+   *  Work around this by remembering if it was called or not */
+  bool m_Ended;
+
 private:
 
 };