Update GUI when widget is selected

We need to update the gui when the widget is selected so the current bone
in the tree is the selected bone in the API.
To this reason, we use a signal on the armature beacuse the gui listens
to the current armature.
(This prevent us from having the gui listening to all the bones in its
tree).
The event is fired with the modified bone node's ID. This ID is then used
in the GUI to select the current bone.

See Issue #13629

Modules/Loadable/Armatures/MRML/Core/vtkMRMLArmatureNode.h

@@ -26,6 +26,10 @@
 
 // Armatures includes
 #include "vtkBenderArmaturesModuleMRMLCoreExport.h"
+
+// VTK includes
+#include "vtkCommand.h"
+
 class vtkMRMLBoneNode;
 
 class vtkArmatureWidget;
@@ -144,6 +148,13 @@ class VTK_BENDER_ARMATURES_MRML_CORE_EXPORT vtkMRMLArmatureNode
   void SetBoneLinkedWithParent(vtkBoneWidget* bone, bool linked);
   bool GetBoneLinkedWithParent(vtkBoneWidget* bone);*/
 
+  //BTX
+  enum MRMLArmatureNode
+    {
+    ArmatureBoneModified = vtkCommand::UserEvent + 1
+    };
+  //ETX
+
   //--------------------------------------------------------------------------
   // Bone methods
   //--------------------------------------------------------------------------

Modules/Loadable/Armatures/MRML/DisplayableManagers/vtkMRMLArmatureDisplayableManager.cxx

@@ -662,6 +662,13 @@ ::UpdateBoneNodeFromWidget(vtkMRMLBoneNode* boneNode,
   boneNode->EndModify(wasModifying);
 
   this->UpdateBoneDisplayNodeFromWidget(boneNode->GetBoneDisplayNode(), widget);
+
+  vtkMRMLArmatureNode* armatureNode = this->GetArmatureNode(boneNode);
+  if (armatureNode && boneNode->GetSelected())
+    {
+    armatureNode->InvokeEvent(
+      vtkMRMLArmatureNode::ArmatureBoneModified, boneNode->GetID());
+    }
 }
 
 //---------------------------------------------------------------------------

Modules/Loadable/Armatures/qSlicerArmaturesModuleWidget.cxx

@@ -40,6 +40,7 @@
 #include <vtkSlicerAnnotationModuleLogic.h>
 
 // MRML includes
+#include <vtkMRMLBoneDisplayNode.h>
 #include <vtkMRMLHierarchyNode.h>
 #include <vtkMRMLInteractionNode.h>
 #include <vtkMRMLSelectionNode.h>
@@ -306,12 +307,12 @@ ::updateHierarchy(vtkMRMLBoneNode* boneNode)
 
     wasBlocked = this->LinkedToParentCheckBox->blockSignals(true);
     this->LinkedToParentCheckBox->setChecked(
-      this->BoneNode->GetBoneLinkedWithParent());
+      boneNode->GetBoneLinkedWithParent());
     this->LinkedToParentCheckBox->blockSignals(false);
     }
 
-  bool enable = this->BoneNode
-    && this->BoneNode->GetWidgetState() != vtkMRMLBoneNode::Pose;
+  bool enable = boneNode
+    && boneNode->GetWidgetState() != vtkMRMLBoneNode::Pose;
 
   this->ParentBoneNodeComboBox->setEnabled(enable);
   this->LinkedToParentCheckBox->setEnabled(enable);
@@ -439,6 +440,24 @@ ::setCoordinatesToBoneNode(vtkMRMLBoneNode* boneNode)
     }
 }
 
+//-----------------------------------------------------------------------------
+void qSlicerArmaturesModuleWidgetPrivate
+::selectBoneNode(vtkObject* sender, void* callData)
+{
+  Q_Q(qSlicerArmaturesModuleWidget);
+
+  char* nodeID = reinterpret_cast<char*>(callData);
+  if (nodeID)
+    {
+    vtkMRMLBoneNode* boneNode =
+      vtkMRMLBoneNode::SafeDownCast(q->mrmlScene()->GetNodeByID(nodeID));
+    if (boneNode && boneNode->GetSelected())
+      {
+      this->BonesTreeView->setCurrentNode(boneNode);
+      }
+    }
+}
+
 //-----------------------------------------------------------------------------
 void qSlicerArmaturesModuleWidgetPrivate
 ::setCoordinatesFromBoneNode(vtkMRMLBoneNode* boneNode)
@@ -507,8 +526,7 @@ ::onParentNodeChanged(vtkMRMLNode* node)
 }
 
 //-----------------------------------------------------------------------------
-void qSlicerArmaturesModuleWidgetPrivate
-::onLinkedWithParentChanged(int linked)
+void qSlicerArmaturesModuleWidgetPrivate::onLinkedWithParentChanged(int linked)
 {
   if (!this->BoneNode)
     {
@@ -518,6 +536,21 @@ ::onLinkedWithParentChanged(int linked)
   this->BoneNode->SetBoneLinkedWithParent(linked);
 }
 
+//-----------------------------------------------------------------------------
+void qSlicerArmaturesModuleWidgetPrivate::selectCurrentBoneDisplayNode(int select)
+{
+  if (!this->BoneNode)
+    {
+    return;
+    }
+
+  vtkMRMLBoneDisplayNode* displayNode = this->BoneNode->GetBoneDisplayNode();
+  if (displayNode)
+    {
+    displayNode->SetSelected(select);
+    }
+}
+
 //-----------------------------------------------------------------------------
 // qSlicerArmaturesModuleWidget methods
 
@@ -548,6 +581,9 @@ ::setMRMLArmatureNode(vtkMRMLArmatureNode* armatureNode)
   Q_D(qSlicerArmaturesModuleWidget);
   this->qvtkReconnect(d->ArmatureNode, armatureNode,
     vtkCommand::ModifiedEvent, this, SLOT(updateWidgetFromArmatureNode()));
+  this->qvtkReconnect(d->ArmatureNode, armatureNode,
+    vtkMRMLArmatureNode::ArmatureBoneModified,
+    d, SLOT(selectBoneNode(vtkObject*, void*)));
   d->ArmatureNode = armatureNode;
 
   d->logic()->SetActiveArmature(armatureNode);
@@ -718,9 +754,12 @@ void qSlicerArmaturesModuleWidget::onTreeNodeSelected(vtkMRMLNode* node)
     this->qvtkReconnect(d->BoneNode, boneNode, vtkCommand::ModifiedEvent,
       this, SLOT(updateWidgetFromBoneNode()));
     }
-  d->BoneNode = boneNode;
 
   d->updateArmatureWidget(boneNode);
+
+  d->selectCurrentBoneDisplayNode(0); // Unselect previous bone node
+  d->BoneNode = boneNode; // Update bone node
+  d->selectCurrentBoneDisplayNode(1); // Select new bone node
 }
 
 //-----------------------------------------------------------------------------

Modules/Loadable/Armatures/qSlicerArmaturesModuleWidget_p.h

@@ -29,6 +29,7 @@
 class qSlicerWidget;
 class vtkMRMLArmatureNode;
 class vtkMRMLBoneNode;
+class vtkObject;
 class vtkSlicerArmaturesLogic;
 
 //------------------------------------------------------------------------------
@@ -78,6 +79,8 @@ public slots:
   void setCoordinatesFromBoneNode(vtkMRMLBoneNode* boneNode);
   void setCoordinatesToBoneNode(vtkMRMLBoneNode* boneNode);
 
+  void selectBoneNode(vtkObject*, void*);
+
 protected slots:
 
   void onPositionTypeChanged();
@@ -87,6 +90,10 @@ protected slots:
   void onParentNodeChanged(vtkMRMLNode* node);
   void onLinkedWithParentChanged(int linked);
 
+protected:
+  // Select/Unselect the current bone node.
+  void selectCurrentBoneDisplayNode(int select);
+
 private:
   vtkMRMLArmatureNode* ArmatureNode;
   vtkMRMLBoneNode* BoneNode;