Accessibility: Correctly report number of disclosed rows in TreeView on macOS

modules/juce_gui_basics/accessibility/interfaces/juce_AccessibilityCellInterface.h

@@ -56,6 +56,9 @@ public:
 
     /** Returns the AccessibilityHandler of the table which contains the cell. */
     virtual const AccessibilityHandler* getTableHandler() const = 0;
+
+    /** Returns a list of the accessibility elements that are disclosed by this element, if any. */
+    virtual std::vector<const AccessibilityHandler*> getDisclosedRows() const { return {}; }
 };
 
 } // namespace juce

modules/juce_gui_basics/native/accessibility/juce_mac_Accessibility.mm

@@ -528,6 +528,33 @@ private:
                 return 0;
             });
 
+            addMethod (@selector (accessibilityDisclosedRows), [] (id self, SEL) -> id
+            {
+                if (auto* handler = getHandler (self))
+                {
+                    if (auto* cellInterface = handler->getCellInterface())
+                    {
+                        const auto rows = cellInterface->getDisclosedRows();
+                        auto* result = [NSMutableArray arrayWithCapacity: rows.size()];
+
+                        for (const auto& row : rows)
+                        {
+                            if (row != nullptr)
+                                [result addObject: static_cast<id> (row->getNativeImplementation())];
+                            else
+                                [result addObject: [NSAccessibilityElement accessibilityElementWithRole: NSAccessibilityRowRole
+                                                                                                  frame: NSZeroRect
+                                                                                                  label: @"Offscreen Row"
+                                                                                                 parent: self]];
+                        }
+
+                        return result;
+                    }
+                }
+
+                return nil;
+            });
+
             addMethod (@selector (isAccessibilityExpanded), [] (id self, SEL) -> BOOL
             {
                 if (auto* handler = getHandler (self))

modules/juce_gui_basics/widgets/juce_TreeView.cpp

@@ -161,6 +161,34 @@ private:
                 return getItemDepth (&itemComponent.getRepresentedItem());
             }
 
+            std::vector<const AccessibilityHandler*> getDisclosedRows() const override
+            {
+                const auto& representedItem = itemComponent.getRepresentedItem();
+                const auto* tree = representedItem.getOwnerView();
+
+                if (tree == nullptr)
+                    return {};
+
+                const auto numSubItems = representedItem.isOpen() ? representedItem.getNumSubItems() : 0;
+
+                std::vector<const AccessibilityHandler*> result;
+                result.reserve ((size_t) numSubItems);
+
+                for (auto i = 0; i < numSubItems; ++i)
+                {
+                    result.push_back ([&]() -> const AccessibilityHandler*
+                    {
+                        if (auto* subItem = representedItem.getSubItem (i))
+                            if (auto* component = tree->getItemComponent (subItem))
+                                return component->getAccessibilityHandler();
+
+                        return nullptr;
+                    }());
+                }
+
+                return result;
+            }
+
             const AccessibilityHandler* getTableHandler() const override
             {
                 if (auto* tree = itemComponent.getRepresentedItem().getOwnerView())