TreeView: Fixed a potential crash when dragging a TreeViewItem with a custom component

modules/juce_gui_basics/widgets/juce_TreeView.cpp

@@ -265,7 +265,10 @@ public:
     ItemComponent* getItemComponentAt (Point<int> p)
     {
         auto iter = std::find_if (itemComponents.cbegin(), itemComponents.cend(),
-                                  [p] (const std::unique_ptr<ItemComponent>& c) { return c->getBounds().contains (p); });
+                                  [p] (const std::unique_ptr<ItemComponent>& c)
+                                  {
+                                      return c->getBounds().contains (p);
+                                  });
 
         if (iter != itemComponents.cend())
             return iter->get();
@@ -275,21 +278,35 @@ public:
 
     ItemComponent* getComponentForItem (const TreeViewItem* item) const
     {
-        if (item != nullptr)
-        {
-            auto iter = std::find_if (itemComponents.cbegin(), itemComponents.cend(),
-                                      [item] (const std::unique_ptr<ItemComponent>& c)
-                                      {
-                                          return &c->getRepresentedItem() == item;
-                                      });
-
-            if (iter != itemComponents.cend())
-                return iter->get();
-        }
+        const auto iter = std::find_if (itemComponents.begin(), itemComponents.end(),
+                                        [item] (const std::unique_ptr<ItemComponent>& c)
+                                        {
+                                            return &c->getRepresentedItem() == item;
+                                        });
+
+        if (iter != itemComponents.end())
+            return iter->get();
 
         return nullptr;
     }
 
+    void itemBeingDeleted (const TreeViewItem* item)
+    {
+        const auto iter = std::find_if (itemComponents.begin(), itemComponents.end(),
+                                        [item] (const std::unique_ptr<ItemComponent>& c)
+                                        {
+                                            return &c->getRepresentedItem() == item;
+                                        });
+
+        if (iter != itemComponents.end())
+        {
+            if (isMouseDraggingInChildComp (*(iter->get())))
+                owner.hideDragHighlight();
+
+            itemComponents.erase (iter);
+        }
+    }
+
     void updateComponents()
     {
         std::vector<ItemComponent*> componentsToKeep;
@@ -324,10 +341,7 @@ public:
             }
             else
             {
-                if (isMouseDraggingInChildComp (*comp))
-                    comp->setSize (0, 0);
-                else
-                    itemComponents.erase (itemComponents.begin() + i);
+                itemComponents.erase (itemComponents.begin() + i);
             }
         }
     }
@@ -445,7 +459,7 @@ private:
     void mouseMoveInternal (const MouseEvent& e)  { updateItemUnderMouse (e); }
     void mouseExitInternal (const MouseEvent& e)  { updateItemUnderMouse (e); }
 
-    bool isMouseDraggingInChildComp (const Component& comp) const
+    static bool isMouseDraggingInChildComp (const Component& comp)
     {
         for (auto& ms : Desktop::getInstance().getMouseSources())
             if (ms.isDragging())
@@ -1373,6 +1387,12 @@ TreeViewItem::TreeViewItem()
     uid = nextUID++;
 }
 
+TreeViewItem::~TreeViewItem()
+{
+    if (ownerView != nullptr)
+        ownerView->viewport->getContentComp()->itemBeingDeleted (this);
+}
+
 String TreeViewItem::getUniqueName() const
 {
     return {};

modules/juce_gui_basics/widgets/juce_TreeView.h

@@ -52,7 +52,7 @@ public:
     TreeViewItem();
 
     /** Destructor. */
-    virtual ~TreeViewItem() = default;
+    virtual ~TreeViewItem();
 
     //==============================================================================
     /** Returns the number of sub-items that have been added to this item.
@@ -313,13 +313,9 @@ public:
         callback. But if you do return a component, it will be positioned in the
         TreeView so that it can be used to represent this item.
 
-        The component returned will be managed by the TreeView, so always return
-        a new component, and don't keep a reference to it, as the TreeView will
-        delete it later when it goes off the screen or is no longer needed. Also
-        bear in mind that if the component keeps a reference to the item that
-        created it, that item could be deleted before the component. Its position
-        and size will be completely managed by the tree, so don't attempt to move it
-        around.
+        The component returned will be managed by the TreeView and will be deleted
+        later when it goes off the screen or is no longer needed. Its position and
+        size will be completely managed by the tree, so don't attempt to move it around.
 
         Something you may want to do with your component is to give it a pointer to
         the TreeView that created it. This is perfectly safe, and there's no danger