ENH: Add a PassiveObserver flag to vtkCommand. Passive observers do not...

ENH: Add a PassiveObserver flag to vtkCommand.  Passive observers do not change the system state, and always get events, even if another command has focus.  Change vtkObject to process passive observers first.
ENH: Change vtkInteractorEventRecorder to have PassiveObserver commands.
ENH: Change InteractorStyleTreeMapHover to use the vtkInteractorEventRecorder.

Common/vtkCommand.cxx

@@ -97,7 +97,7 @@ static const char *vtkCommandEventStrings[] = {
 };
 
 //----------------------------------------------------------------
-vtkCommand::vtkCommand():AbortFlag(0)
+vtkCommand::vtkCommand():AbortFlag(0),PassiveObserver(0)
 {
 #ifdef VTK_DEBUG_LEAKS
   vtkDebugLeaks::ConstructClass("vtkCommand or subclass");

Common/vtkCommand.h

@@ -92,6 +92,20 @@ public:
   void AbortFlagOff() 
     { this->SetAbortFlag(0); }
   
+  // Description:
+  // Set/Get the passive observer flag. If this is set to true, this
+  // indicates that this command does not change the state of the
+  // system in any way. Passive observers are processed first, and
+  // are not called even when another command has focus.
+  void SetPassiveObserver(int f)  
+    { this->PassiveObserver = f; }
+  int GetPassiveObserver() 
+    { return this->PassiveObserver; }
+  void PassiveObserverOn() 
+    { this->SetPassiveObserver(1); }
+  void PassiveObserverOff() 
+    { this->SetPassiveObserver(0); }
+  
 //BTX
   // Description:
   // All the currently defined events are listed here.  Developers can
@@ -179,6 +193,8 @@ public:
 
 protected:
   int AbortFlag;
+  int PassiveObserver;
+
   vtkCommand();
   virtual ~vtkCommand() {}
 

Common/vtkObject.cxx

@@ -21,7 +21,7 @@
 
 #include <vtkstd/map>
 
-vtkCxxRevisionMacro(vtkObject, "1.100");
+vtkCxxRevisionMacro(vtkObject, "1.101");
 
 // Initialize static member that controls warning display
 static int vtkObjectGlobalWarningDisplay = 1;
@@ -490,7 +490,13 @@ int vtkSubjectHelper::InvokeEvent(unsigned long event, void *callData,
     elem = elem->Next;
     }
 
-  // Loop once or twice, giving preference to focus holders, if any.
+  // Loop two or three times, giving preference to passive observers 
+  // and focus holders, if any.
+  //
+  // 0. Passive observer loop
+  //   Loop over all observers and execute those that are passive observers.
+  //   These observers should not affect the state of the system in any way,
+  //   and should not be allowed to abort the event.
   //
   // 1. Focus loop
   //   If there is a focus holder, loop over all observers and execute
@@ -502,12 +508,41 @@ int vtkSubjectHelper::InvokeEvent(unsigned long event, void *callData,
   //   remaining observers. This loop will always get executed when there
   //   is no focus holder.
 
+  // 0. Passive observer loop
+  //
+  elem = this->Start;
+  vtkObserver *next;
+  while (elem)
+    {
+    // store the next pointer because elem could disappear due to Command
+    next = elem->Next;
+    VisitedMapType::iterator vIter = visited.find(elem->Tag);
+    if ((vIter != visited.end()) && (vIter->second == false) &&
+        elem->Command->GetPassiveObserver() &&
+        (elem->Event == event || elem->Event == vtkCommand::AnyEvent))
+      {
+      vIter->second = true;;
+      vtkCommand* command = elem->Command;
+      command->Register(command);
+      elem->Command->Execute(self,event,callData);
+      command->UnRegister();
+      }
+    if (this->ListModified)
+      {
+      elem = this->Start;
+      this->ListModified = 0;
+      }
+    else
+      {
+      elem = next;
+      }
+    }
+
   // 1. Focus loop
   //
   if (this->Focus1 || this->Focus2)
     {
     elem = this->Start;
-    vtkObserver *next;
     while (elem)
       {
       // store the next pointer because elem could disappear due to Command
@@ -550,13 +585,13 @@ int vtkSubjectHelper::InvokeEvent(unsigned long event, void *callData,
   if (!focusHandled)
     {
     elem = this->Start;
-    vtkObserver *next;
     while (elem)
       {
       // store the next pointer because elem could disappear due to Command
       next = elem->Next;
       VisitedMapType::iterator vIter = visited.find(elem->Tag);
       if ((vIter != visited.end()) && (vIter->second == false) &&
+          !elem->Command->GetPassiveObserver() &&
           (elem->Event == event || elem->Event == vtkCommand::AnyEvent))
         {
         vIter->second = true;;

Infovis/vtkInteractorStyleTreeMapHover.cxx

@@ -39,7 +39,7 @@
 #include "vtkWorldPointPicker.h"
 #include "vtkVariant.h"
 
-vtkCxxRevisionMacro(vtkInteractorStyleTreeMapHover, "1.11");
+vtkCxxRevisionMacro(vtkInteractorStyleTreeMapHover, "1.12");
 vtkStandardNewMacro(vtkInteractorStyleTreeMapHover);
 
 //----------------------------------------------------------------------------
@@ -331,6 +331,23 @@ void vtkInteractorStyleTreeMapHover::OnLeftButtonUp()
   int y = this->Interactor->GetEventPosition()[1];
   this->FindPokedRenderer(x, y);
   
+#if 0
+  vtkRenderer* r = this->CurrentRenderer;
+  if (r == NULL)
+    {
+    return;
+    }
+
+  if (!r->HasViewProp(this->Balloon))
+    {
+    r->AddActor(this->Balloon);
+    this->Balloon->SetRenderer(r);
+    }
+
+  double loc[2] = {x, y};
+  this->Balloon->EndWidgetInteraction(loc);
+#endif
+  
   this->CurrentSelectedId = GetTreeMapIdAtPos(x,y);
 
   // Get the pedigree id of this object and

Rendering/vtkInteractorEventRecorder.cxx

@@ -19,7 +19,7 @@
 
 #include <vtksys/ios/sstream>
 
-vtkCxxRevisionMacro(vtkInteractorEventRecorder, "1.12");
+vtkCxxRevisionMacro(vtkInteractorEventRecorder, "1.13");
 vtkStandardNewMacro(vtkInteractorEventRecorder);
 
 float vtkInteractorEventRecorder::StreamVersion = 1.0;
@@ -30,10 +30,11 @@ vtkInteractorEventRecorder::vtkInteractorEventRecorder()
   //take over the processing of delete and keypress events from the superclass
   this->KeyPressCallbackCommand->SetCallback(
     vtkInteractorEventRecorder::ProcessCharEvent);
+  this->EventCallbackCommand->SetPassiveObserver(1); // get events first
 
-  this->Priority = VTK_LARGE_FLOAT; //get events first
   this->EventCallbackCommand->SetCallback(
     vtkInteractorEventRecorder::ProcessEvents);
+  this->EventCallbackCommand->SetPassiveObserver(1); // get events first
 
   this->FileName = NULL;