From 72eb3a5d829cd6354215257b298172a1c039e031 Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Tue, 17 Mar 2020 00:34:32 +1100
Subject: [PATCH] nodeview: worked around qt issue where the selection signal
 would still be sent after an item was deleted

---
 app/widget/nodeview/nodeview.cpp      | 12 ++----------
 app/widget/nodeview/nodeviewscene.cpp | 27 +++++++++++++++++++++++++++
 app/widget/nodeview/nodeviewscene.h   |  3 +++
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/app/widget/nodeview/nodeview.cpp b/app/widget/nodeview/nodeview.cpp
index 2c728acf3..571559926 100644
--- a/app/widget/nodeview/nodeview.cpp
+++ b/app/widget/nodeview/nodeview.cpp
@@ -104,20 +104,12 @@ void NodeView::DeleteSelected()
 
 void NodeView::SelectAll()
 {
-  QList<QGraphicsItem *> all_items = this->items();
-
-  foreach (QGraphicsItem* i, all_items) {
-    i->setSelected(true);
-  }
+  scene_.SelectAll();
 }
 
 void NodeView::DeselectAll()
 {
-  QList<QGraphicsItem *> selected_items = scene_.selectedItems();
-
-  foreach (QGraphicsItem* i, selected_items) {
-    i->setSelected(false);
-  }
+  scene_.DeselectAll();
 }
 
 void NodeView::Select(const QList<Node *> &nodes)
diff --git a/app/widget/nodeview/nodeviewscene.cpp b/app/widget/nodeview/nodeviewscene.cpp
index a514eb898..dffd8702f 100644
--- a/app/widget/nodeview/nodeviewscene.cpp
+++ b/app/widget/nodeview/nodeviewscene.cpp
@@ -10,6 +10,15 @@ NodeViewScene::NodeViewScene(QObject *parent) :
 
 void NodeViewScene::clear()
 {
+  // Deselect everything (prevents signals that a selection has changed after deleting an object)
+  DeselectAll();
+
+  // HACK: QGraphicsScene contains some sort of internal hashing of the selected items which doesn't update unless
+  //       we call a function like this. That means even though we deselect all items above, QGraphicsScene will
+  //       continue to incorrectly signal selectionChanged() when items that were selected (but are now not) get
+  //       deleted. Calling this function appears to update the internal cache and prevent this.
+  selectedItems();
+
   {
     QHash<Node*, NodeViewItem*>::const_iterator i;
     for (i=item_map_.begin();i!=item_map_.end();i++) {
@@ -27,6 +36,24 @@ void NodeViewScene::clear()
   }
 }
 
+void NodeViewScene::SelectAll()
+{
+  QList<QGraphicsItem *> all_items = this->items();
+
+  foreach (QGraphicsItem* i, all_items) {
+    i->setSelected(true);
+  }
+}
+
+void NodeViewScene::DeselectAll()
+{
+  QList<QGraphicsItem *> selected_items = this->selectedItems();
+
+  foreach (QGraphicsItem* i, selected_items) {
+    i->setSelected(false);
+  }
+}
+
 NodeViewItem *NodeViewScene::NodeToUIObject(Node *n)
 {
   return item_map_.value(n);
diff --git a/app/widget/nodeview/nodeviewscene.h b/app/widget/nodeview/nodeviewscene.h
index 014791759..8a2c22933 100644
--- a/app/widget/nodeview/nodeviewscene.h
+++ b/app/widget/nodeview/nodeviewscene.h
@@ -16,6 +16,9 @@ public:
 
   void clear();
 
+  void SelectAll();
+  void DeselectAll();
+
   /**
    * @brief Retrieve the graphical widget corresponding to a specific Node
    *