[PowerRename] Handle many items w/o crashing and OOM (#26761)

* [PowerRename] Disable AnimatedIcon (check mark) for CheckBox to prevent crashes
* [PowerRename] Implement lightweight ExplorerItemsSource/VM

src/modules/powerrename/PowerRenameUILib/App.xaml

@@ -1060,7 +1060,36 @@
                     </Setter.Value>
                 </Setter>
             </Style>
+            <!-- Copied from https://github.com/microsoft/microsoft-ui-xaml/blob/210349d9d1e0aeb8ee144ec027071a68ac578bdb/dev/CommonStyles/CheckBox_themeresources.xaml#L794 to remove the AnimatedIcon that caused crashes (see #18478). -->
+            <Style x:Key="CheckBoxDefaultStyleOverride" TargetType="CheckBox">
+                <Setter Property="Background"
+                        Value="{ThemeResource CheckBoxBackgroundUnchecked}" />
+                <Setter Property="Foreground"
+                        Value="{ThemeResource CheckBoxForegroundUnchecked}" />
+                <Setter Property="BorderBrush"
+                        Value="{ThemeResource CheckBoxBorderBrushUnchecked}" />
+                <Setter Property="Padding"
+                        Value="{StaticResource CheckBoxPadding}" />
+                <Setter Property="HorizontalAlignment" Value="Left" />
+                <Setter Property="VerticalAlignment" Value="Center" />
+                <Setter Property="HorizontalContentAlignment" Value="Left" />
+                <Setter Property="VerticalContentAlignment" Value="Top" />
+                <Setter Property="FontFamily"
+                        Value="{ThemeResource ContentControlThemeFontFamily}" />
+                <Setter Property="FontSize"
+                        Value="{ThemeResource ControlContentThemeFontSize}" />
+                <Setter Property="MinWidth"
+                        Value="{StaticResource CheckBoxMinWidth}" />
+                <Setter Property="MinHeight"
+                        Value="{StaticResource CheckBoxHeight}" />
+                <Setter Property="UseSystemFocusVisuals"
+                        Value="{StaticResource UseSystemFocusVisuals}" />
+                <Setter Property="FocusVisualMargin"
+                        Value="{StaticResource CheckBoxFocusVisualMargin}" />
+                <Setter Property="CornerRadius"
+                        Value="{ThemeResource ControlCornerRadius}" />
                 
+            </Style>
         </ResourceDictionary>
     </Application.Resources>
 </Application>

src/modules/powerrename/PowerRenameUILib/App.xaml.cpp

@@ -5,6 +5,7 @@
 
 #include <vector>
 #include <string>
+#include <filesystem>
 
 #include <common/logger/logger.h>
 #include <common/logger/logger_settings.h>
@@ -18,8 +19,9 @@ using namespace winrt::Microsoft::UI::Xaml::Navigation;
 using namespace PowerRenameUI;
 using namespace PowerRenameUI::implementation;
 
-// To learn more about WinUI, the WinUI project structure,
-// and more about our project templates, see: http://aka.ms/winui-project-info.
+namespace fs = std::filesystem;
+
+//#define DEBUG_BENCHMARK_100K_ENTRIES
 
 std::vector<std::wstring> g_files;
 
@@ -34,8 +36,7 @@ App::App()
     InitializeComponent();
 
 #if defined _DEBUG && !defined DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
-    UnhandledException([this](IInspectable const&, UnhandledExceptionEventArgs const& e)
-    {
+    UnhandledException([this](IInspectable const&, UnhandledExceptionEventArgs const& e) {
         if (IsDebuggerPresent())
         {
             auto errorMessage = e.Message();
@@ -112,6 +113,50 @@ void App::OnLaunched(LaunchActivatedEventArgs const&)
         ExitProcess(1);
     }
 
+#ifdef DEBUG_BENCHMARK_100K_ENTRIES
+    const std::wstring_view ROOT_PATH = L"R:\\PowerRenameBenchmark";
+
+    std::wstring subdirectory_name = L"0";
+    std::error_code _;
+
+#if 1
+    constexpr bool recreate_files = true;
+#else
+    constexpr bool recreate_files = false;
+#endif
+    if constexpr (recreate_files)
+        fs::remove_all(ROOT_PATH, _);
+
+    g_files.push_back(fs::path{ ROOT_PATH });
+    constexpr int pow2_threshold = 10;
+    constexpr int num_files = 100'000;
+    for (int i = 0; i < num_files; ++i)
+    {
+        fs::path file_path{ ROOT_PATH };
+        // Create a subdirectory for each subsequent 2^pow2_threshold files, o/w filesystem becomes too slow to create them in a reasonable time.
+        if ((i & ((1 << pow2_threshold) - 1)) == 0)
+        {
+            subdirectory_name = std::to_wstring(i >> pow2_threshold);
+        }
+
+        file_path /= subdirectory_name;
+
+        if constexpr (recreate_files)
+        {
+            fs::create_directories(file_path, _);
+            file_path /= std::to_wstring(i) + L".txt";
+            HANDLE hFile = CreateFileW(
+                file_path.c_str(),
+                GENERIC_WRITE,
+                0,
+                nullptr,
+                CREATE_NEW,
+                FILE_ATTRIBUTE_NORMAL,
+                nullptr);
+            CloseHandle(hFile);
+        }
+    }
+#else
 #define BUFSIZE 4096 * 4
 
     BOOL bSuccess;
@@ -139,6 +184,7 @@ void App::OnLaunched(LaunchActivatedEventArgs const&)
             break;
     }
     CloseHandle(hStdin);
+#endif
 
     Logger::debug(L"Starting PowerRename with {} files selected", g_files.size());
 

src/modules/powerrename/PowerRenameUILib/ExplorerItem.cpp

@@ -41,10 +41,33 @@ namespace
 
 namespace winrt::PowerRenameUI::implementation
 {
-    ExplorerItem::ExplorerItem(int32_t id, hstring const& original, hstring const& renamed, int32_t type, uint32_t depth, bool checked) :
-        m_id{ id }, m_idStr{ std::to_wstring(id) }, m_original{ original }, m_renamed{ renamed }, m_type{ type }, m_depth{ depth }, m_checked{ checked }
+    DependencyProperty ExplorerItem::_CheckedProperty{ nullptr };
+
+    void ExplorerItem::_InitializeProperties()
     {
+        if (!_CheckedProperty)
+        {
+            _CheckedProperty =
+                DependencyProperty::Register(
+                    L"Checked",
+                    xaml_typename<bool>(),
+                    xaml_typename<PowerRenameUI::ExplorerItem>(),
+                    PropertyMetadata{ box_value(true) });
+        }
+    }
+
+    ExplorerItem::ExplorerItem()
+    {
+        _InitializeProperties();
+    }
+
+    ExplorerItem::ExplorerItem(int32_t id, hstring const& original, hstring const& renamed, int32_t type, uint32_t depth, bool checked) :
+        m_id{ id }, m_idStr{ std::to_wstring(id) }, m_original{ original }, m_renamed{ renamed }, m_type{ type }, m_depth{ depth }
+    {
+        _InitializeProperties();
+
         m_imagePath = (m_type == static_cast<UINT>(ExplorerItemType::Folder)) ? folderImagePath : fileImagePath;
+        Checked(checked);
     }
 
     int32_t ExplorerItem::Id()
@@ -52,11 +75,29 @@ namespace winrt::PowerRenameUI::implementation
         return m_id;
     }
 
+    void ExplorerItem::Id(const int32_t value)
+    {
+        if (m_id != value)
+        {
+            m_id = value;
+            m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs{ L"Id" });
+        }
+    }
+
     hstring ExplorerItem::IdStr()
     {
         return m_idStr;
     }
 
+    void ExplorerItem::IdStr(hstring const& value)
+    {
+        if (m_idStr != value)
+        {
+            m_idStr = value;
+            m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs{ L"IdStr" });
+        }
+    }
+
     hstring ExplorerItem::Original()
     {
         return m_original;
@@ -90,11 +131,29 @@ namespace winrt::PowerRenameUI::implementation
         return static_cast<double>(m_depth) * 12;
     }
 
+    void ExplorerItem::Indentation(double value)
+    {
+        if (m_depth != value)
+        {
+            m_depth = static_cast<uint32_t>(value / 12);
+            m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs{ L"Indentation" });
+        }
+    }
+
     hstring ExplorerItem::ImagePath()
     {
         return m_imagePath;
     }
 
+    void ExplorerItem::ImagePath(hstring const& value)
+    {
+        if (m_imagePath != value)
+        {
+            m_imagePath = value;
+            m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs{ L"ImagePath" });
+        }
+    }
+
     int32_t ExplorerItem::Type()
     {
         return m_type;
@@ -109,29 +168,6 @@ namespace winrt::PowerRenameUI::implementation
         }
     }
 
-    bool ExplorerItem::Checked()
-    {
-        return m_checked;
-    }
-
-    void ExplorerItem::Checked(bool value)
-    {
-        if (m_checked != value)
-        {
-            m_checked = value;
-            m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs{ L"Checked" });
-
-            if (m_checked && !m_renamed.empty())
-            {
-                VisualStateManager::GoToState(*this, PowerRenameItemRenameStatusToString(m_state), false);
-            }
-            else
-            {
-                VisualStateManager::GoToState(*this, L"Normal", false);
-            }
-        }
-    }
-
     int32_t ExplorerItem::State()
     {
         return static_cast<int32_t>(m_state);
@@ -182,7 +218,6 @@ namespace winrt::PowerRenameUI::implementation
         default:
             return {};
         }
-
     }
 
 }

src/modules/powerrename/PowerRenameUILib/ExplorerItem.h

@@ -6,6 +6,7 @@
 #include "winrt/Microsoft.UI.Xaml.Controls.Primitives.h"
 #include "ExplorerItem.g.h"
 #include "PowerRenameInterfaces.h"
+#include "Utils.h"
 
 namespace winrt::PowerRenameUI::implementation
 {
@@ -17,27 +18,39 @@ namespace winrt::PowerRenameUI::implementation
             File = 1
         };
 
-        ExplorerItem() = default;
+        ExplorerItem();
 
         ExplorerItem(int32_t id, hstring const& original, hstring const& renamed, int32_t type, uint32_t depth, bool checked);
         int32_t Id();
+        void Id(int32_t);
+
         hstring IdStr();
+        void IdStr(hstring const& value);
+
         hstring Original();
         void Original(hstring const& value);
+
         hstring Renamed();
         void Renamed(hstring const& value);
+
         double Indentation();
+        void Indentation(double value);
+
         hstring ImagePath();
+        void ImagePath(hstring const& value);
         int32_t Type();
         void Type(int32_t value);
-        bool Checked();
-        void Checked(bool value);
         int32_t State();
         void State(int32_t value);
         winrt::event_token PropertyChanged(winrt::Microsoft::UI::Xaml::Data::PropertyChangedEventHandler const& handler);
         void PropertyChanged(winrt::event_token const& token) noexcept;
 
+        DEPENDENCY_PROPERTY(bool, Checked);
+
     private:
+
+        static void _InitializeProperties();
+
         std::wstring StateToErrorMessage();
 
         int32_t m_id{};
@@ -47,7 +60,6 @@ namespace winrt::PowerRenameUI::implementation
         uint32_t m_depth{};
         hstring m_imagePath;
         int32_t m_type{};
-        bool m_checked{};
         PowerRenameItemRenameStatus m_state{};
         winrt::event<Microsoft::UI::Xaml::Data::PropertyChangedEventHandler> m_propertyChanged;
     };

src/modules/powerrename/PowerRenameUILib/ExplorerItem.idl

@@ -4,14 +4,17 @@ namespace PowerRenameUI
     {
         ExplorerItem();
         ExplorerItem(Int32 id, String original, String renamed, Int32 type, UInt32 depth, Boolean checked);
-        Int32 Id { get; };
-        String IdStr { get; };
+        
+        Int32 Id;
+        String IdStr;
         String Original;
         String Renamed;
-        Double Indentation { get; };
-        String ImagePath { get; };
+        Double Indentation;
+        String ImagePath;
         Int32 Type;
         Boolean Checked;
         Int32 State;
+        
+        static Microsoft.UI.Xaml.DependencyProperty CheckedProperty { get; };
     }
 }

src/modules/powerrename/PowerRenameUILib/ExplorerItem.xaml

@@ -49,7 +49,9 @@
                 IsChecked="{x:Bind Checked, Mode=TwoWay}"
                 IsTabStop="True"
                 TabIndex="0"
+                Style="{StaticResource CheckBoxDefaultStyleOverride}"
                 XYFocusKeyboardNavigation="Enabled" />
+            
             <Image
                 Grid.Column="2"
                 Width="16"

src/modules/powerrename/PowerRenameUILib/ExplorerItemViewModel.cpp

@@ -0,0 +1,123 @@
+#include "pch.h"
+
+#include <functional>
+
+#include "ExplorerItemViewModel.h"
+#if __has_include("ExplorerItemViewModel.g.cpp")
+#include "ExplorerItemViewModel.g.cpp"
+#endif
+#include <PowerRenameManager.h>
+#include <Renaming.h>
+
+extern CComPtr<IPowerRenameManager> g_prManager;
+extern std::function<void(void)> g_itemToggledCallback;
+
+namespace
+{
+    const wchar_t fileImagePath[] = L"ms-appx:///Assets/file.png";
+    const wchar_t folderImagePath[] = L"ms-appx:///Assets/folder.png";
+}
+
+namespace winrt::PowerRenameUI::implementation
+{
+    winrt::event_token ExplorerItemViewModel::PropertyChanged(winrt::Microsoft::UI::Xaml::Data::PropertyChangedEventHandler const& handler)
+    {
+        return m_propertyChanged.add(handler);
+    }
+
+    void ExplorerItemViewModel::PropertyChanged(winrt::event_token const& token) noexcept
+    {
+        m_propertyChanged.remove(token);
+    }
+    ExplorerItemViewModel::ExplorerItemViewModel(const uint32_t _index) :
+        _index{ _index }
+    {
+    }
+
+    int32_t ExplorerItemViewModel::IdVM()
+    {
+        return _index;
+    }
+    hstring ExplorerItemViewModel::IdStrVM()
+    {
+        return to_hstring(_index);
+    }
+    hstring ExplorerItemViewModel::OriginalVM()
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+
+        PWSTR originalName = nullptr;
+        winrt::check_hresult(spItem->GetOriginalName(&originalName));
+
+        return hstring{ originalName };
+    }
+    hstring ExplorerItemViewModel::RenamedVM()
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+
+        PWSTR newName = nullptr;
+        spItem->GetNewName(&newName);
+        if (!newName)
+        {
+            return L"";
+        }
+        else
+        {
+            hstring result{ newName };
+            SHFree(newName);
+
+            return result;
+        }
+    }
+
+    double ExplorerItemViewModel::IndentationVM()
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+
+        UINT depth = 0;
+        spItem->GetDepth(&depth);
+
+        return static_cast<double>(depth) * 12;
+    }
+    hstring ExplorerItemViewModel::ImagePathVM()
+    {
+        return TypeVM() ? fileImagePath : folderImagePath;
+    }
+    int32_t ExplorerItemViewModel::TypeVM()
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+
+        bool isFolder = false;
+        spItem->GetIsFolder(&isFolder);
+        return isFolder ? 0 : 1;
+    }
+
+    bool ExplorerItemViewModel::CheckedVM()
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+        bool result = false;
+        winrt::check_hresult(spItem->GetSelected(&result));
+        return result;
+    }
+    void ExplorerItemViewModel::CheckedVM(bool value)
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+        winrt::check_hresult(spItem->PutSelected(value));
+        g_itemToggledCallback();
+    }
+
+    int32_t ExplorerItemViewModel::StateVM()
+    {
+        CComPtr<IPowerRenameItem> spItem;
+        winrt::check_hresult(g_prManager->GetItemByIndex(_index, &spItem));
+        PowerRenameItemRenameStatus status {};
+        spItem->GetStatus(&status);
+        return static_cast<int32_t>(status);
+    }
+}

src/modules/powerrename/PowerRenameUILib/ExplorerItemViewModel.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "ExplorerItemViewModel.g.h"
+
+namespace winrt::PowerRenameUI::implementation
+{
+    struct ExplorerItemViewModel : ExplorerItemViewModelT<ExplorerItemViewModel>
+    {
+        ExplorerItemViewModel() = default;
+        ExplorerItemViewModel(const uint32_t _index);
+
+        int32_t IdVM();
+        hstring IdStrVM();
+        hstring OriginalVM();
+        hstring RenamedVM();
+        double IndentationVM();
+        hstring ImagePathVM();
+        int32_t TypeVM();
+        bool CheckedVM();
+        void CheckedVM(bool value);
+        int32_t StateVM();
+
+        winrt::event_token PropertyChanged(winrt::Microsoft::UI::Xaml::Data::PropertyChangedEventHandler const& handler);
+        void PropertyChanged(winrt::event_token const& token) noexcept;
+
+        uint32_t _index = 0;
+        winrt::event<Microsoft::UI::Xaml::Data::PropertyChangedEventHandler> m_propertyChanged;
+    };
+}
+
+namespace winrt::PowerRenameUI::factory_implementation
+{
+    struct ExplorerItemViewModel : ExplorerItemViewModelT<ExplorerItemViewModel, implementation::ExplorerItemViewModel>
+    {
+    };
+}

src/modules/powerrename/PowerRenameUILib/ExplorerItemViewModel.idl

@@ -0,0 +1,18 @@
+namespace PowerRenameUI
+{
+    [bindable] [default_interface] runtimeclass ExplorerItemViewModel :
+        Microsoft.UI.Xaml.Data.INotifyPropertyChanged
+    {
+        ExplorerItemViewModel();
+
+        Int32 IdVM { get; };
+        String IdStrVM { get; };
+        String OriginalVM { get; };
+        String RenamedVM { get; };
+        Double IndentationVM { get; };
+        String ImagePathVM { get; };
+        Int32 TypeVM { get; };
+        Boolean CheckedVM;
+        Int32 StateVM { get; };
+    }
+}

src/modules/powerrename/PowerRenameUILib/ExplorerItemsSource.cpp

@@ -0,0 +1,12 @@
+#include "pch.h"
+#include "ExplorerItemsSource.h"
+#if __has_include("ExplorerItemsSource.g.cpp")
+#include "ExplorerItemsSource.g.cpp"
+#endif
+
+using namespace winrt;
+using namespace Windows::UI::Xaml;
+
+namespace winrt::PowerRenameUI::implementation
+{
+}

src/modules/powerrename/PowerRenameUILib/ExplorerItemsSource.h

@@ -0,0 +1,287 @@
+#pragma once
+
+#include "winrt/Windows.UI.Xaml.h"
+#include "winrt/Windows.UI.Xaml.Markup.h"
+#include "winrt/Windows.UI.Xaml.Interop.h"
+#include "winrt/Windows.UI.Xaml.Controls.Primitives.h"
+#include "ExplorerItemsSource.g.h"
+#include "ExplorerItemViewModel.h"
+
+#include <PowerRenameInterfaces.h>
+
+using winrt::Microsoft::UI::Xaml::Data::ItemIndexRange;
+using winrt::Windows::Foundation::IInspectable;
+using namespace winrt::Windows::Foundation::Collections;
+
+extern CComPtr<IPowerRenameManager> g_prManager;
+
+namespace winrt::PowerRenameUI::implementation
+{
+    struct ExplorerItemProxyIterator
+    {
+        using iterator_category = std::random_access_iterator_tag;
+        using value_type = IInspectable;
+        using difference_type = std::ptrdiff_t;
+        using pointer = uint32_t;
+        using reference = IInspectable;
+
+        const bool* _filtered = nullptr;
+
+        ExplorerItemProxyIterator(pointer ptr, const bool* filtered) :
+            _index(ptr), _filtered{ filtered } {}
+
+        reference operator*() const
+        {
+            const uint32_t realIndex = g_prManager->GetVisibleItemRealIndex(_index);
+            if (*_filtered)
+            {
+                return winrt::make<ExplorerItemViewModel>(realIndex);
+            }
+            else
+                return winrt::make<ExplorerItemViewModel>(_index);
+        }
+
+        ExplorerItemProxyIterator& operator++()
+        {
+            _index++;
+            return *this;
+        }
+        ExplorerItemProxyIterator operator++(int)
+        {
+            ExplorerItemProxyIterator tmp = *this;
+            ++(*this);
+            return tmp;
+        }
+        ExplorerItemProxyIterator& operator--()
+        {
+            _index--;
+            return *this;
+        }
+        ExplorerItemProxyIterator operator--(int)
+        {
+            ExplorerItemProxyIterator tmp = *this;
+            --(*this);
+            return tmp;
+        }
+
+        friend bool operator==(const ExplorerItemProxyIterator& a, const ExplorerItemProxyIterator& b) { return a._index == b._index; };
+        friend bool operator!=(const ExplorerItemProxyIterator& a, const ExplorerItemProxyIterator& b) { return a._index != b._index; };
+
+        ExplorerItemProxyIterator& operator+=(difference_type n)
+        {
+            _index += static_cast<pointer>(n);
+            return *this;
+        }
+        ExplorerItemProxyIterator operator+(difference_type n) const { return ExplorerItemProxyIterator{ static_cast<pointer>(_index + n), _filtered }; }
+        friend ExplorerItemProxyIterator operator+(difference_type n, const ExplorerItemProxyIterator& iter) { return ExplorerItemProxyIterator(static_cast<pointer>(n + iter._index), iter._filtered); }
+
+        ExplorerItemProxyIterator& operator-=(difference_type n)
+        {
+            _index -= static_cast<pointer>(n);
+            return *this;
+        }
+        ExplorerItemProxyIterator operator-(difference_type n) const { return ExplorerItemProxyIterator{ static_cast<pointer>(_index - n), _filtered }; }
+        difference_type operator-(const ExplorerItemProxyIterator& iter) const { return _index - iter._index; }
+
+        friend bool operator<(const ExplorerItemProxyIterator& a, const ExplorerItemProxyIterator& b) { return a._index < b._index; }
+        friend bool operator>(const ExplorerItemProxyIterator& a, const ExplorerItemProxyIterator& b) { return a._index > b._index; }
+        friend bool operator<=(const ExplorerItemProxyIterator& a, const ExplorerItemProxyIterator& b) { return a._index <= b._index; }
+        friend bool operator>=(const ExplorerItemProxyIterator& a, const ExplorerItemProxyIterator& b) { return a._index >= b._index; }
+
+    private:
+        pointer _index;
+    };
+
+    using ItemT = IInspectable;
+    struct ExplorerItemsSource : ExplorerItemsSourceT<ExplorerItemsSource>, winrt::vector_view_base<ExplorerItemsSource, ItemT>
+    {
+        bool filtered = false;
+
+        struct Container
+        {
+            ExplorerItemProxyIterator first;
+            ExplorerItemProxyIterator last;
+
+            auto begin() const noexcept
+            {
+                return first;
+            }
+
+            auto end() const noexcept
+            {
+                return last;
+            }
+        } container = { { {}, {} }, { {}, {} } };
+
+        void SetIsFiltered(const bool value)
+        {
+            filtered = value;
+
+            if (!g_prManager)
+                return;
+
+            uint32_t item_count = 0;
+            if (value)
+                winrt::check_hresult(g_prManager->GetVisibleItemCount(&item_count));
+            else
+                winrt::check_hresult(g_prManager->GetItemCount(&item_count));
+
+            container = Container{ { 0, &filtered }, { item_count, &filtered } };
+        }
+
+        auto& get_container() const noexcept
+        {
+            return container;
+        }
+
+        // IObservableVector. We don't need a full implementation, since only the items' properties changes
+
+        Windows::Foundation::Collections::IVectorView<ItemT> GetView() const noexcept
+        {
+            return static_cast<ExplorerItemsSource const&>(*this);
+        }
+
+        winrt::event_token VectorChanged(Windows::Foundation::Collections::VectorChangedEventHandler<ItemT> const& handler)
+        {
+            return m_changed.add(handler);
+        }
+
+        void VectorChanged(event_token const cookie)
+        {
+            m_changed.remove(cookie);
+        }
+
+        winrt::event<Windows::Foundation::Collections::VectorChangedEventHandler<ItemT>> m_changed;
+
+        struct args : implements<args, Windows::Foundation::Collections::IVectorChangedEventArgs>
+        {
+            args(Windows::Foundation::Collections::CollectionChange const change, uint32_t const index) noexcept :
+                m_change(change),
+                m_index(index)
+            {
+            }
+
+            Windows::Foundation::Collections::CollectionChange CollectionChange() const noexcept
+            {
+                return m_change;
+            }
+
+            uint32_t Index() const noexcept
+            {
+                return m_index;
+            }
+
+        private:
+            Windows::Foundation::Collections::CollectionChange const m_change;
+            uint32_t const m_index;
+        };
+
+        void call_changed(Windows::Foundation::Collections::CollectionChange const change, uint32_t const index)
+        {
+            m_changed(static_cast<ExplorerItemsSource const&>(*this), make<args>(change, index));
+        }
+
+        void InvalidateCollection()
+        {
+            SetIsFiltered(filtered);
+            call_changed(Windows::Foundation::Collections::CollectionChange::Reset, 0);
+        }
+
+        void InvalidateItemRange(uint32_t const startIdx, uint32_t const count)
+        {
+            for (uint32_t index = startIdx; index < startIdx + count; ++index)
+                call_changed(Windows::Foundation::Collections::CollectionChange::ItemChanged, index);
+        }
+
+        void SetAt(uint32_t const index, ItemT const& /*value*/)
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::ItemChanged, index);
+        }
+
+        void InsertAt(uint32_t const index, ItemT const& /*value*/)
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::ItemInserted, index);
+        }
+
+        void RemoveAt(uint32_t const index)
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::ItemRemoved, index);
+        }
+
+        void Append(ItemT const& /*value*/)
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::ItemInserted, this->Size() - 1);
+        }
+
+        void RemoveAtEnd()
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::ItemRemoved, this->Size());
+        }
+
+        void Clear()
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::Reset, 0);
+        }
+
+        void ReplaceAll(array_view<ItemT const> /*value*/)
+        {
+            call_changed(Windows::Foundation::Collections::CollectionChange::Reset, 0);
+        }
+
+        // IClosable
+        void Close() noexcept
+        {
+        }
+
+        // ISelectionInfo
+        void SelectRange(const ItemIndexRange& /*itemIndexRange*/) noexcept
+        {
+            return;
+        }
+
+        void DeselectRange(const ItemIndexRange& /*itemIndexRange*/) noexcept
+        {
+            return;
+        }
+
+        bool IsSelected(int32_t /*index*/) noexcept
+        {
+            return false;
+        }
+
+        IVectorView<ItemIndexRange> GetSelectedRanges() noexcept
+        {
+            return {};
+        }
+
+        // IItemsRangeInfo
+        void RangesChanged(const ItemIndexRange& /*visibleRange*/, const IVectorView<ItemIndexRange>& /*trackedItems*/)
+        {
+        }
+
+        //INotifyPropertyChanged
+        winrt::event_token PropertyChanged(winrt::Microsoft::UI::Xaml::Data::PropertyChangedEventHandler const& handler)
+        {
+            return m_propertyChanged.add(handler);
+        }
+
+        void PropertyChanged(winrt::event_token const& token) noexcept
+        {
+            m_propertyChanged.remove(token);
+        }
+
+        winrt::event<Microsoft::UI::Xaml::Data::PropertyChangedEventHandler> m_propertyChanged;
+
+        void RaisePropertyChanged(hstring const& propertyName)
+        {
+            m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs(propertyName));
+        }
+    };
+}
+
+namespace winrt::PowerRenameUI::factory_implementation
+{
+    struct ExplorerItemsSource : ExplorerItemsSourceT<ExplorerItemsSource, implementation::ExplorerItemsSource>
+    {
+    };
+}

src/modules/powerrename/PowerRenameUILib/ExplorerItemsSource.idl

@@ -0,0 +1,12 @@
+namespace PowerRenameUI
+{
+    [default_interface] runtimeclass ExplorerItemsSource : 
+        Microsoft.UI.Xaml.Data.IItemsRangeInfo, 
+        Microsoft.UI.Xaml.Data.ISelectionInfo,
+        Windows.Foundation.Collections.IVectorView<IInspectable>,
+        Windows.Foundation.Collections.IObservableVector<IInspectable>,
+        Microsoft.UI.Xaml.Data.INotifyPropertyChanged
+    {
+        ExplorerItemsSource();
+    }
+}

src/modules/powerrename/PowerRenameUILib/MainWindow.idl

@@ -1,4 +1,5 @@
 import "ExplorerItem.idl";
+import "ExplorerItemsSource.idl";
 import "PatternSnippet.idl";
 
 namespace PowerRenameUI
@@ -10,7 +11,7 @@ namespace PowerRenameUI
         Windows.Foundation.Collections.IObservableVector<String> SearchMRU { get; };
         Windows.Foundation.Collections.IObservableVector<String> ReplaceMRU { get; };
 
-        Windows.Foundation.Collections.IObservableVector<ExplorerItem> ExplorerItems { get; };
+        ExplorerItemsSource ExplorerItems { get; };
         Windows.Foundation.Collections.IObservableVector<PatternSnippet> SearchRegExShortcuts { get; };
         Windows.Foundation.Collections.IObservableVector<PatternSnippet> DateTimeShortcuts { get; };
 

src/modules/powerrename/PowerRenameUILib/MainWindow.xaml

@@ -48,6 +48,7 @@
                     Checked="SelectAll"
                     Content=""
                     IsChecked="True"
+                    Style="{StaticResource CheckBoxDefaultStyleOverride}"
                     Unchecked="SelectAll" />
                 <Image
                     Width="16"
@@ -112,6 +113,7 @@
                 HorizontalAlignment="Stretch"
                 VerticalAlignment="Bottom"
                 Fill="{ThemeResource DividerStrokeColorDefaultBrush}" />
+            <!--Changing VirtualizationMode to Recycling introduces the issue with popping indent/icons, but makes scrolling slightly faster -->
             <ListView
                 Grid.Row="1"
                 Grid.ColumnSpan="6"
@@ -119,7 +121,29 @@
                 IsTabStop="false"
                 ItemsSource="{x:Bind ExplorerItems, Mode=OneWay}"
                 SelectionMode="None"
-                XYFocusKeyboardNavigation="Enabled">
+                x:Name="listView_ExplorerItems"
+                XYFocusKeyboardNavigation="Enabled"
+                VirtualizingStackPanel.VirtualizationMode="Standard">
+                <ListView.ItemTemplate>
+                    <DataTemplate x:DataType="local:ExplorerItemViewModel">
+                        <local:ExplorerItem 
+                            Id="{x:Bind IdVM, Mode=OneWay}"
+                            IdStr="{x:Bind IdStrVM}"
+                            Original="{x:Bind OriginalVM}"
+                            Renamed="{x:Bind RenamedVM}"
+                            Indentation="{x:Bind IndentationVM}"
+                            ImagePath="{x:Bind ImagePathVM}"
+                            Type="{x:Bind TypeVM}"
+                            Checked="{x:Bind CheckedVM, Mode=TwoWay, FallbackValue=True}"
+                            State="{x:Bind StateVM}" />
+                    </DataTemplate >
+                </ListView.ItemTemplate>
+                <ListView.ItemsPanel>
+                    <ItemsPanelTemplate>
+                        <VirtualizingStackPanel />
+                    </ItemsPanelTemplate>
+                </ListView.ItemsPanel>
+                
                 <ListView.ItemContainerStyle>
                     <Style TargetType="ListViewItem">
                         <Setter Property="IsTabStop" Value="False" />

src/modules/powerrename/PowerRenameUILib/MainWindow.xaml.cpp

@@ -28,7 +28,6 @@
 using namespace winrt;
 using namespace Windows::UI::Xaml;
 using namespace winrt::Microsoft::Windows::ApplicationModel::Resources;
-
 // Non-localizable
 const std::wstring PowerRenameUIIco = L"PowerRenameUI.ico";
 const wchar_t c_WindowClass[] = L"PowerRename";
@@ -40,13 +39,65 @@ extern std::vector<std::wstring> g_files;
 ThemeListener theme_listener{};
 HWND CurrentWindow;
 
-void handleTheme() {
+void handleTheme()
+{
     auto theme = theme_listener.AppTheme;
     auto isDark = theme == AppTheme::Dark;
     Logger::info(L"Theme is now {}", isDark ? L"Dark" : L"Light");
     ThemeHelpers::SetImmersiveDarkMode(CurrentWindow, isDark);
 }
 
+// Disabled for now, because it causes indentation and icons to appear "asynchronously"
+// #define ENABLE_RECYCLING_VIRTUALIZATION_MODE
+
+CComPtr<IPowerRenameManager> g_prManager;
+std::function<void(void)> g_itemToggledCallback;
+
+winrt::Microsoft::UI::Xaml::Controls::ScrollViewer FindScrollViewer(winrt::Microsoft::UI::Xaml::DependencyObject start)
+{
+    int childrenCount = winrt::Microsoft::UI::Xaml::Media::VisualTreeHelper::GetChildrenCount(start);
+    for (int i = 0; i < childrenCount; i++)
+    {
+        auto obj = winrt::Microsoft::UI::Xaml::Media::VisualTreeHelper::GetChild(start, i);
+
+        if (auto sv = obj.try_as<winrt::Microsoft::UI::Xaml::Controls::ScrollViewer>())
+        {
+            return sv;
+        }
+        else
+        {
+            auto result = FindScrollViewer(obj);
+            if (result)
+            {
+                return result;
+            }
+        }
+    }
+    return nullptr;
+}
+
+PowerRenameUI::ExplorerItem FindFirstExplorerItemRecursive(winrt::Microsoft::UI::Xaml::DependencyObject startNode)
+{
+    auto explorerItem = startNode.try_as<PowerRenameUI::ExplorerItem>();
+    if (explorerItem)
+    {
+        return explorerItem;
+    }
+
+    int childCount = winrt::Microsoft::UI::Xaml::Media::VisualTreeHelper::GetChildrenCount(startNode);
+    for (int i = 0; i < childCount; ++i)
+    {
+        auto child = winrt::Microsoft::UI::Xaml::Media::VisualTreeHelper::GetChild(startNode, i);
+        explorerItem = FindFirstExplorerItemRecursive(child);
+        if (explorerItem)
+        {
+            return explorerItem;
+        }
+    }
+
+    return nullptr;
+}
+
 namespace winrt::PowerRenameUI::implementation
 {
     MainWindow::MainWindow() :
@@ -71,7 +122,7 @@ namespace winrt::PowerRenameUI::implementation
         POINT cursorPosition{};
         if (GetCursorPos(&cursorPosition))
         {
-            ::Windows::Graphics::PointInt32 point{ cursorPosition.x, cursorPosition.y};
+            ::Windows::Graphics::PointInt32 point{ cursorPosition.x, cursorPosition.y };
             Microsoft::UI::Windowing::DisplayArea displayArea = Microsoft::UI::Windowing::DisplayArea::GetFromPoint(point, Microsoft::UI::Windowing::DisplayAreaFallback::Nearest);
 
             HMONITOR hMonitor = MonitorFromPoint(cursorPosition, MONITOR_DEFAULTTOPRIMARY);
@@ -101,7 +152,15 @@ namespace winrt::PowerRenameUI::implementation
         m_searchMRUList = winrt::single_threaded_observable_vector<hstring>();
         m_replaceMRUList = winrt::single_threaded_observable_vector<hstring>();
 
-        m_explorerItems = winrt::single_threaded_observable_vector<PowerRenameUI::ExplorerItem>();
+        std::function<void(void)> toggledCallback = [this] {
+            _TRACER_;
+            UpdateCounts();
+        };
+
+        g_itemToggledCallback.swap(toggledCallback);
+
+        m_explorerItems = winrt::make<ExplorerItemsSource>();
+        get_self<ExplorerItemsSource>(m_explorerItems)->SetIsFiltered(false);
 
         m_searchRegExShortcuts = winrt::single_threaded_observable_vector<PowerRenameUI::PatternSnippet>();
         auto factory = winrt::get_activation_factory<ResourceManager, IResourceManagerFactory>();
@@ -139,8 +198,34 @@ namespace winrt::PowerRenameUI::implementation
 
         InitializeComponent();
 
+        listView_ExplorerItems().ApplyTemplate();
+#ifdef ENABLE_RECYCLING_VIRTUALIZATION_MODE
+        if (auto scrollViewer = FindScrollViewer(listView_ExplorerItems()); scrollViewer)
+        {
+            Microsoft::UI::Xaml::DispatcherTimer debounceTimer = nullptr;
+
+            scrollViewer.ViewChanged([this, scrollViewer, timer = std::move(debounceTimer)](IInspectable const&, Microsoft::UI::Xaml::Controls::ScrollViewerViewChangedEventArgs const&) mutable {
+                if (!timer)
+                {
+                    timer = {};
+                    timer.Tick([this, &timer](auto&, auto&) {
+                        get_self<ExplorerItemsSource>(m_explorerItems)->InvalidateCollection();
+                        timer.Stop();
+                        timer = nullptr;
+                    });
+                }
+
+                using namespace std::chrono_literals;
+
+                winrt::Windows::Foundation::TimeSpan timeSpan{ 200ms };
+                timer.Interval(timeSpan);
+                timer.Start();
+            });
+        }
+#endif
         if (SUCCEEDED(CPowerRenameManager::s_CreateInstance(&m_prManager)))
         {
+            g_prManager = m_prManager;
             // Create the factory for our items
             CComPtr<IPowerRenameItemFactory> prItemFactory;
             if (SUCCEEDED(CPowerRenameItem::s_CreateInstance(nullptr, IID_PPV_ARGS(&prItemFactory))))
@@ -150,13 +235,10 @@ namespace winrt::PowerRenameUI::implementation
                     if (SUCCEEDED(m_prManager->Advise(&m_managerEvents, &m_cookie)))
                     {
                         CComPtr<IShellItemArray> shellItemArray;
-                        // To test PowerRename uncomment this line and update the path to
-                        // your local (absolute or relative) path which you want to see in PowerRename
-                        // g_files.push_back(<path>);
-
+                        // To test PowerRename uncomment DEBUG_BENCHMARK_100K_ENTRIES define
                         if (!g_files.empty())
                         {
-                            if (SUCCEEDED(CreateShellItemArrayFromPaths(g_files, &shellItemArray)))
+                            if (SUCCEEDED(CreateShellItemArrayFromPaths(std::move(g_files), &shellItemArray)))
                             {
                                 CComPtr<IEnumShellItems> enumShellItems;
                                 if (SUCCEEDED(shellItemArray->EnumItems(&enumShellItems)))
@@ -195,6 +277,12 @@ namespace winrt::PowerRenameUI::implementation
         button_rename().IsEnabled(false);
         InitAutoComplete();
         SearchReplaceChanged();
+        InvalidateItemListViewState();
+    }
+
+    void MainWindow::InvalidateItemListViewState()
+    {
+        get_self<ExplorerItemsSource>(m_explorerItems)->InvalidateCollection();
     }
 
     winrt::event_token MainWindow::PropertyChanged(Microsoft::UI::Xaml::Data::PropertyChangedEventHandler const& handler)
@@ -209,7 +297,9 @@ namespace winrt::PowerRenameUI::implementation
 
     hstring MainWindow::OriginalCount()
     {
-        return hstring{ std::to_wstring(m_explorerItems.Size()) };
+        UINT count = 0;
+        m_prManager->GetItemCount(&count);
+        return hstring{ std::to_wstring(count) };
     }
 
     void MainWindow::OriginalCount(hstring)
@@ -227,46 +317,6 @@ namespace winrt::PowerRenameUI::implementation
         m_propertyChanged(*this, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs{ L"RenamedCount" });
     }
 
-    void MainWindow::AddExplorerItem(int32_t id, hstring const& original, hstring const& renamed, int32_t type, uint32_t depth, bool checked)
-    {
-        auto newItem = winrt::make<PowerRenameUI::implementation::ExplorerItem>(id, original, renamed, type, depth, checked);
-        newItem.PropertyChanged([this](Windows::Foundation::IInspectable const& sender, Microsoft::UI::Xaml::Data::PropertyChangedEventArgs const& e) {
-            auto item = sender.as<ExplorerItem>();
-            std::wstring property{ e.PropertyName() };
-
-            if (item && property == L"Checked")
-            {
-                ToggleItem(item->Id(), item->Checked());
-            }
-        });
-        m_explorerItems.Append(newItem);
-        m_explorerItemsMap[id] = newItem;
-    }
-
-    void MainWindow::UpdateExplorerItem(int32_t id, std::optional<hstring> newOriginalName, std::optional<hstring> newName, PowerRenameItemRenameStatus itemStatus)
-    {
-        auto itemToUpdate = FindById(id);
-        if (itemToUpdate != NULL)
-        {
-            if (newOriginalName.has_value())
-            {
-                itemToUpdate.Original(*newOriginalName);
-            }
-
-            if (newName.has_value())
-            {
-                itemToUpdate.Renamed(*newName);
-            }
-
-            itemToUpdate.State(static_cast<int32_t>(itemStatus));
-        }
-    }
-
-    PowerRenameUI::ExplorerItem MainWindow::FindById(int32_t id)
-    {
-        return m_explorerItemsMap.contains(id) ? m_explorerItemsMap[id] : NULL;
-    }
-
     void MainWindow::SelectAll(winrt::Windows::Foundation::IInspectable const&, winrt::Microsoft::UI::Xaml::RoutedEventArgs const&)
     {
         if (checkBox_selectAll().IsChecked().GetBoolean() != m_allSelected)
@@ -275,11 +325,9 @@ namespace winrt::PowerRenameUI::implementation
             m_allSelected = !m_allSelected;
             if (button_showRenamed().IsChecked())
             {
-                m_explorerItems.Clear();
-                m_explorerItemsMap.clear();
-                PopulateExplorerItems();
                 UpdateCounts();
             }
+            InvalidateItemListViewState();
         }
     }
 
@@ -292,11 +340,9 @@ namespace winrt::PowerRenameUI::implementation
         m_prManager->GetFilter(&filter);
         if (filter != PowerRenameFilters::None)
         {
-            m_explorerItems.Clear();
-            m_explorerItemsMap.clear();
             m_prManager->SwitchFilter(0);
-            PopulateExplorerItems();
-            UpdateCounts();
+            get_self<ExplorerItemsSource>(m_explorerItems)->SetIsFiltered(false);
+            InvalidateItemListViewState();
         }
     }
 
@@ -309,11 +355,10 @@ namespace winrt::PowerRenameUI::implementation
         m_prManager->GetFilter(&filter);
         if (filter != PowerRenameFilters::ShouldRename)
         {
-            m_explorerItems.Clear();
-            m_explorerItemsMap.clear();
             m_prManager->SwitchFilter(0);
-            PopulateExplorerItems();
             UpdateCounts();
+            get_self<ExplorerItemsSource>(m_explorerItems)->SetIsFiltered(true);
+            InvalidateItemListViewState();
         }
     }
 
@@ -393,42 +438,6 @@ namespace winrt::PowerRenameUI::implementation
         return hr;
     }
 
-    void MainWindow::PopulateExplorerItems()
-    {
-        _TRACER_;
-
-        UINT count = 0;
-        m_prManager->GetVisibleItemCount(&count);
-        Logger::debug(L"Number of visible items: {}", count);
-
-        for (UINT i = 0; i < count; ++i)
-        {
-            CComPtr<IPowerRenameItem> renameItem;
-            if (SUCCEEDED(m_prManager->GetVisibleItemByIndex(i, &renameItem)))
-            {
-                int id = 0;
-                renameItem->GetId(&id);
-
-                PWSTR originalName = nullptr;
-                renameItem->GetOriginalName(&originalName);
-                PWSTR newName = nullptr;
-                renameItem->GetNewName(&newName);
-
-                bool selected;
-                renameItem->GetSelected(&selected);
-
-                UINT depth = 0;
-                renameItem->GetDepth(&depth);
-
-                bool isFolder = false;
-                winrt::check_hresult(renameItem->GetIsFolder(&isFolder));
-
-                AddExplorerItem(
-                    id, originalName, newName == nullptr ? hstring{} : hstring{ newName }, isFolder ? 0 : 1, depth, selected);
-            }
-        }
-    }
-
     HRESULT MainWindow::InitAutoComplete()
     {
         _TRACER_;
@@ -573,6 +582,8 @@ namespace winrt::PowerRenameUI::implementation
         {
             m_prManager->PutFlags(flags);
         }
+
+        InvalidateItemListViewState();
     }
 
     void MainWindow::SetHandlers()
@@ -742,11 +753,6 @@ namespace winrt::PowerRenameUI::implementation
             if (SUCCEEDED(m_prManager->GetItemByIndex(i, &spItem)))
             {
                 spItem->PutSelected(selected);
-                int id = 0;
-                spItem->GetId(&id);
-                auto item = FindById(id);
-                if (item)
-                    item.Checked(selected);
             }
         }
         UpdateCounts();
@@ -757,7 +763,6 @@ namespace winrt::PowerRenameUI::implementation
         _TRACER_;
 
         m_prManager->SwitchFilter(0);
-        PopulateExplorerItems();
         UpdateCounts();
     }
 
@@ -976,73 +981,11 @@ namespace winrt::PowerRenameUI::implementation
             button_rename().IsEnabled(renamingCount > 0);
         }
 
-        OriginalCount(hstring{ std::to_wstring(m_explorerItems.Size()) });
         RenamedCount(hstring{ std::to_wstring(m_renamingCount) });
     }
 
-    HRESULT MainWindow::OnItemAdded(_In_ IPowerRenameItem* renameItem)
+    HRESULT MainWindow::OnRename(_In_ IPowerRenameItem* /*renameItem*/)
     {
-        int id = 0;
-        renameItem->GetId(&id);
-
-        PWSTR originalName = nullptr;
-        renameItem->GetOriginalName(&originalName);
-        PWSTR newName = nullptr;
-        renameItem->GetNewName(&newName);
-
-        bool selected;
-        renameItem->GetSelected(&selected);
-
-        UINT depth = 0;
-        renameItem->GetDepth(&depth);
-
-        bool isFolder = false;
-        winrt::check_hresult(renameItem->GetIsFolder(&isFolder));
-
-        AddExplorerItem(
-            id, originalName, newName == nullptr ? hstring{} : hstring{ newName }, isFolder ? 0 : 1, depth, selected);
-
-        return S_OK;
-    }
-
-    HRESULT MainWindow::OnUpdate(_In_ IPowerRenameItem* renameItem)
-    {
-        int id;
-        HRESULT hr = renameItem->GetId(&id);
-        if (SUCCEEDED(hr))
-        {
-            PWSTR newName = nullptr;
-            hr = renameItem->GetNewName(&newName);
-            if (SUCCEEDED(hr))
-            {
-                PowerRenameItemRenameStatus status;
-                hr = renameItem->GetStatus(&status);
-                if (SUCCEEDED(hr))
-                {
-                    hstring newNameStr = newName == nullptr ? hstring{} : newName;
-                    UpdateExplorerItem(id, std::nullopt, newNameStr, status);
-                }
-            }
-        }
-
-        return S_OK;
-    }
-
-    HRESULT MainWindow::OnRename(_In_ IPowerRenameItem* renameItem)
-    {
-        int id;
-        HRESULT hr = renameItem->GetId(&id);
-        if (SUCCEEDED(hr))
-        {
-            PWSTR newName = nullptr;
-            hr = renameItem->GetOriginalName(&newName);
-            if (SUCCEEDED(hr))
-            {
-                hstring newNameStr = newName == nullptr ? hstring{} : newName;
-                UpdateExplorerItem(id, newNameStr, L"", PowerRenameItemRenameStatus::Init);
-            }
-        }
-
         UpdateCounts();
         return S_OK;
     }
@@ -1055,18 +998,9 @@ namespace winrt::PowerRenameUI::implementation
         {
             m_flagValidationInProgress = false;
         }
-        else
-        {
-            DWORD filter = 0;
-            m_prManager->GetFilter(&filter);
-            if (filter == PowerRenameFilters::ShouldRename)
-            {
-                m_explorerItems.Clear();
-                PopulateExplorerItems();
-            }
-        }
 
         UpdateCounts();
+        InvalidateItemListViewState();
         return S_OK;
     }
 
@@ -1085,7 +1019,9 @@ namespace winrt::PowerRenameUI::implementation
             // Force renaming work to start so newly renamed items are processed right away
             SearchReplaceChanged(true);
         }
+
+        InvalidateItemListViewState();
+
         return S_OK;
     }
 }
-

src/modules/powerrename/PowerRenameUILib/MainWindow.xaml.h

@@ -8,6 +8,7 @@
 #include "MainWindow.g.h"
 #include "PatternSnippet.h"
 #include "ExplorerItem.h"
+#include "ExplorerItemsSource.h"
 
 #include <map>
 #include <wil/resource.h>
@@ -58,8 +59,6 @@ namespace winrt::PowerRenameUI::implementation
                 return QISearch(this, qit, riid, ppv);
             }
 
-            HRESULT OnItemAdded(_In_ IPowerRenameItem* renameItem) override { return m_app->OnItemAdded(renameItem); }
-            HRESULT OnUpdate(_In_ IPowerRenameItem* renameItem) override { return m_app->OnUpdate(renameItem); }
             HRESULT OnRename(_In_ IPowerRenameItem* renameItem) override { return m_app->OnRename(renameItem); }
             HRESULT OnError(_In_ IPowerRenameItem* renameItem) override { return m_app->OnError(renameItem); }
             HRESULT OnRegExStarted(_In_ DWORD threadId) override { return m_app->OnRegExStarted(threadId); }
@@ -75,9 +74,11 @@ namespace winrt::PowerRenameUI::implementation
 
         MainWindow();
 
+        void InvalidateItemListViewState();
+
         Windows::Foundation::Collections::IObservableVector<hstring> SearchMRU() { return m_searchMRUList; }
         Windows::Foundation::Collections::IObservableVector<hstring> ReplaceMRU() { return m_replaceMRUList; }
-        winrt::Windows::Foundation::Collections::IObservableVector<PowerRenameUI::ExplorerItem> ExplorerItems() { return m_explorerItems; }
+        PowerRenameUI::ExplorerItemsSource ExplorerItems() { return m_explorerItems; }
         winrt::Windows::Foundation::Collections::IObservableVector<PowerRenameUI::PatternSnippet> SearchRegExShortcuts() { return m_searchRegExShortcuts; }
         winrt::Windows::Foundation::Collections::IObservableVector<PowerRenameUI::PatternSnippet> DateTimeShortcuts() { return m_dateTimeShortcuts; }
         hstring OriginalCount();
@@ -87,27 +88,20 @@ namespace winrt::PowerRenameUI::implementation
         winrt::event_token PropertyChanged(winrt::Microsoft::UI::Xaml::Data::PropertyChangedEventHandler const& handler);
         void PropertyChanged(winrt::event_token const& token) noexcept;
 
-        void AddExplorerItem(int32_t id, hstring const& original, hstring const& renamed, int32_t type, uint32_t depth, bool checked);
-        void UpdateExplorerItem(int32_t id, std::optional<hstring> newOriginalName, std::optional<hstring> newName, PowerRenameItemRenameStatus itemStatus);
-
         void SelectAll(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
         void ShowAll(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
         void ShowRenamed(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
 
     private:
         bool m_allSelected;
-        inline PowerRenameUI::ExplorerItem FindById(int32_t id);
 
         winrt::Windows::Foundation::Collections::IObservableVector<hstring> m_searchMRUList;
         winrt::Windows::Foundation::Collections::IObservableVector<hstring> m_replaceMRUList;
-        winrt::Windows::Foundation::Collections::IObservableVector<PowerRenameUI::ExplorerItem> m_explorerItems;
-        std::map<int32_t, PowerRenameUI::ExplorerItem> m_explorerItemsMap;
+        PowerRenameUI::ExplorerItemsSource m_explorerItems;
         winrt::Windows::Foundation::Collections::IObservableVector<PowerRenameUI::PatternSnippet> m_searchRegExShortcuts;
         winrt::Windows::Foundation::Collections::IObservableVector<PowerRenameUI::PatternSnippet> m_dateTimeShortcuts;
 
         // Used by PowerRenameManagerEvents
-        HRESULT OnItemAdded(_In_ IPowerRenameItem* renameItem);
-        HRESULT OnUpdate(_In_ IPowerRenameItem* renameItem);
         HRESULT OnRename(_In_ IPowerRenameItem* renameItem);
         HRESULT OnError(_In_ IPowerRenameItem*) { return S_OK; }
         HRESULT OnRegExStarted(_In_ DWORD) { return S_OK; }
@@ -124,7 +118,6 @@ namespace winrt::PowerRenameUI::implementation
 
         HRESULT CreateShellItemArrayFromPaths(std::vector<std::wstring> files, IShellItemArray** shellItemArray);
 
-        void PopulateExplorerItems();
         HRESULT InitAutoComplete();
         HRESULT EnumerateShellItems(_In_ IEnumShellItems* enumShellItems);
         void SearchReplaceChanged(bool forceRenaming = false);
@@ -155,6 +148,7 @@ namespace winrt::PowerRenameUI::implementation
         winrt::event<Microsoft::UI::Xaml::Data::PropertyChangedEventHandler> m_propertyChanged;
 
         bool m_flagValidationInProgress = false;
+
     public:
         void RegExItemClick(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::Controls::ItemClickEventArgs const& e);
         void DateTimeItemClick(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::Controls::ItemClickEventArgs const& e);

src/modules/powerrename/PowerRenameUILib/PowerRenameUI.vcxproj

@@ -91,6 +91,14 @@
       <DependentUpon>ExplorerItem.xaml</DependentUpon>
       <SubType>Code</SubType>
     </ClInclude>
+    <ClInclude Include="ExplorerItemsSource.h">
+      <DependentUpon>ExplorerItemsSource.idl</DependentUpon>
+      <SubType>Code</SubType>
+    </ClInclude>
+    <ClInclude Include="ExplorerItemViewModel.h">
+      <DependentUpon>ExplorerItemViewModel.idl</DependentUpon>
+      <SubType>Code</SubType>
+    </ClInclude>
     <ClInclude Include="PatternSnippet.h">
       <DependentUpon>PatternSnippet.idl</DependentUpon>
     </ClInclude>
@@ -101,6 +109,7 @@
     <ClInclude Include="MainWindow.xaml.h">
       <DependentUpon>MainWindow.xaml</DependentUpon>
     </ClInclude>
+    <ClInclude Include="Utils.h" />
   </ItemGroup>
   <ItemGroup>
     <ApplicationDefinition Include="App.xaml" />
@@ -114,6 +123,14 @@
       <DependentUpon>ExplorerItem.xaml</DependentUpon>
       <SubType>Code</SubType>
     </ClCompile>
+    <ClCompile Include="ExplorerItemsSource.cpp">
+      <DependentUpon>ExplorerItemsSource.idl</DependentUpon>
+      <SubType>Code</SubType>
+    </ClCompile>
+    <ClCompile Include="ExplorerItemViewModel.cpp">
+      <DependentUpon>ExplorerItemViewModel.idl</DependentUpon>
+      <SubType>Code</SubType>
+    </ClCompile>
     <ClCompile Include="PatternSnippet.cpp">
       <DependentUpon>PatternSnippet.idl</DependentUpon>
     </ClCompile>
@@ -137,6 +154,12 @@
       <DependentUpon>ExplorerItem.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Midl>
+    <Midl Include="ExplorerItemsSource.idl">
+      <SubType>Code</SubType>
+    </Midl>
+    <Midl Include="ExplorerItemViewModel.idl">
+      <SubType>Designer</SubType>
+    </Midl>
     <Midl Include="MainWindow.idl">
       <SubType>Code</SubType>
       <DependentUpon>MainWindow.xaml</DependentUpon>

src/modules/powerrename/PowerRenameUILib/PowerRenameUI.vcxproj.filters

@@ -12,15 +12,19 @@
     <Midl Include="MainWindow.idl" />
     <Midl Include="PatternSnippet.idl" />
     <Midl Include="ExplorerItem.idl" />
+    <Midl Include="ExplorerItemsSource.idl" />
+    <Midl Include="ExplorerItemViewModel.idl" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="pch.cpp" />
     <ClCompile Include="$(GeneratedFilesDir)module.g.cpp" />
     <ClCompile Include="PatternSnippet.cpp" />
+    <ClCompile Include="ExplorerItemsSource.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="pch.h" />
     <ClInclude Include="PatternSnippet.h" />
+    <ClInclude Include="ExplorerItemsSource.h" />
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Assets">

src/modules/powerrename/PowerRenameUILib/Utils.h

@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+
+// This macro defines a dependency property for a WinRT class.
+// Use this in your class' header file after declaring it in the idl.
+// Remember to register your dependency property in the respective cpp file.
+#define DEPENDENCY_PROPERTY(type, name)                                    \
+public:                                                                    \
+    static winrt::Microsoft::UI::Xaml::DependencyProperty name##Property() \
+    {                                                                      \
+        return _##name##Property;                                          \
+    }                                                                      \
+    type name() const                                                      \
+    {                                                                      \
+        return winrt::unbox_value<type>(GetValue(_##name##Property));      \
+    }                                                                      \
+    void name(const type& value)                                           \
+    {                                                                      \
+        SetValue(_##name##Property, winrt::box_value(value));              \
+    }                                                                      \
+                                                                           \
+private:                                                                   \
+    static winrt::Microsoft::UI::Xaml::DependencyProperty _##name##Property;

src/modules/powerrename/PowerRenameUILib/pch.h

@@ -1,4 +1,7 @@
 #pragma once
+
+#define NOMINMAX
+
 #include <windows.h>
 #include <unknwn.h>
 #include <restrictederrorinfo.h>

src/modules/powerrename/lib/MRUListHandler.cpp

@@ -148,7 +148,7 @@ void MRUListHandler::ParseJson()
                 else
                 {
                     std::vector<std::wstring> temp;
-                    for (unsigned int i = 0; i < min(jsonArray.Size(), size); ++i)
+                    for (unsigned int i = 0; i < std::min(jsonArray.Size(), size); ++i)
                     {
                         int idx = (oldPushIdx + oldSize - (i + 1)) % oldSize;
                         temp.push_back(std::wstring(jsonArray.GetStringAt(idx)));

src/modules/powerrename/lib/PowerRenameEnum.cpp

@@ -93,16 +93,16 @@ HRESULT CPowerRenameEnum::_ParseEnumItems(_In_ IEnumShellItems* pesi, _In_ int d
 
         while ((S_OK == pesi->Next(1, &spsi, &celtFetched)))
         {
-            items.push_back(spsi);
+            items.push_back(std::move(spsi));
             spsi = nullptr;
         }
 
-        auto cmpShellItems = [](CComPtr<IShellItem> l, CComPtr<IShellItem> r) {
+        auto cmpShellItems = [](const CComPtr<IShellItem>& l, const CComPtr<IShellItem>& r) {
             int res = 0;
             l->Compare(r, SICHINT_DISPLAY, &res);
             return res < 0;
         };
-        std::sort(items.begin(), items.end(), cmpShellItems);
+        std::sort(begin(items), end(items), cmpShellItems);
 
         for (const auto& item : items)
         {

src/modules/powerrename/lib/PowerRenameInterfaces.h

@@ -95,8 +95,6 @@ public:
 interface __declspec(uuid("87FC43F9-7634-43D9-99A5-20876AFCE4AD")) IPowerRenameManagerEvents : public IUnknown
 {
 public:
-    IFACEMETHOD(OnItemAdded)(_In_ IPowerRenameItem* renameItem) = 0;
-    IFACEMETHOD(OnUpdate)(_In_ IPowerRenameItem * renameItem) = 0;
     IFACEMETHOD(OnRename)(_In_ IPowerRenameItem * renameItem) = 0;
     IFACEMETHOD(OnError)(_In_ IPowerRenameItem * renameItem) = 0;
     IFACEMETHOD(OnRegExStarted)(_In_ DWORD threadId) = 0;
@@ -135,6 +133,7 @@ public:
     IFACEMETHOD(PutRenameRegEx)(_In_ IPowerRenameRegEx* pRegEx) = 0;
     IFACEMETHOD(GetRenameItemFactory)(_COM_Outptr_ IPowerRenameItemFactory** ppItemFactory) = 0;
     IFACEMETHOD(PutRenameItemFactory)(_In_ IPowerRenameItemFactory* pItemFactory) = 0;
+    virtual uint32_t GetVisibleItemRealIndex(const uint32_t index) const = 0;
 };
 
 interface __declspec(uuid("04AAFABE-B76E-4E13-993A-B5941F52B139")) IPowerRenameMRU : public IUnknown

src/modules/powerrename/lib/PowerRenameLib.vcxproj

@@ -39,6 +39,7 @@
     <ClInclude Include="PowerRenameManager.h" />
     <ClInclude Include="PowerRenameMRU.h" />
     <ClInclude Include="PowerRenameRegEx.h" />
+    <ClInclude Include="Renaming.h" />
     <ClInclude Include="Settings.h" />
     <ClInclude Include="srwlock.h" />
     <ClInclude Include="pch.h" />
@@ -53,6 +54,7 @@
     <ClCompile Include="PowerRenameManager.cpp" />
     <ClCompile Include="PowerRenameMRU.cpp" />
     <ClCompile Include="PowerRenameRegEx.cpp" />
+    <ClCompile Include="Renaming.cpp" />
     <ClCompile Include="Settings.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader Condition="'$(CIBuild)'!='true'">Create</PrecompiledHeader>

src/modules/powerrename/lib/PowerRenameManager.cpp

@@ -5,9 +5,8 @@
 #include <shlobj.h>
 #include <cstring>
 #include "helpers.h"
-#include <filesystem>
 #include "trace.h"
-#include <winrt/base.h>
+#include <Renaming.h>
 
 namespace fs = std::filesystem;
 
@@ -174,11 +173,6 @@ IFACEMETHODIMP CPowerRenameManager::AddItem(_In_ IPowerRenameItem* pItem)
         }
     }
 
-    if (SUCCEEDED(hr))
-    {
-        _OnItemAdded(pItem);
-    }
-
     return hr;
 }
 
@@ -212,6 +206,15 @@ IFACEMETHODIMP CPowerRenameManager::GetVisibleItemByIndex(_In_ UINT index, _COM_
     }
     else if (SUCCEEDED(GetVisibleItemCount(&count)) && index < count)
     {
+        const UINT realIndex = GetVisibleItemRealIndex(index);
+        hr = GetItemByIndex(realIndex, ppItem);
+    }
+
+    return hr;
+}
+
+uint32_t CPowerRenameManager::GetVisibleItemRealIndex(const uint32_t index) const
+{
     UINT realIndex = 0, visibleIndex = 0;
     for (size_t i = 0; i < m_isVisible.size(); i++)
     {
@@ -225,10 +228,8 @@ IFACEMETHODIMP CPowerRenameManager::GetVisibleItemByIndex(_In_ UINT index, _COM_
             visibleIndex++;
         }
     }
-        hr = GetItemByIndex(realIndex, ppItem);
-    }
 
-    return hr;
+    return realIndex;
 }
 
 IFACEMETHODIMP CPowerRenameManager::GetItemById(_In_ int id, _COM_Outptr_ IPowerRenameItem** ppItem)
@@ -464,7 +465,7 @@ IFACEMETHODIMP CPowerRenameManager::OnFileTimeChanged(_In_ SYSTEMTIME /*fileTime
 HRESULT CPowerRenameManager::s_CreateInstance(_Outptr_ IPowerRenameManager** ppsrm)
 {
     *ppsrm = nullptr;
-    CPowerRenameManager *psrm = new CPowerRenameManager();
+    CPowerRenameManager* psrm = new CPowerRenameManager();
     HRESULT hr = E_OUTOFMEMORY;
     if (psrm)
     {
@@ -554,12 +555,7 @@ LRESULT CPowerRenameManager::_WndProc(_In_ HWND hwnd, _In_ UINT msg, _In_ WPARAM
     {
     case SRM_REGEX_ITEM_UPDATED:
     {
-        int id = static_cast<int>(lParam);
-        CComPtr<IPowerRenameItem> spItem;
-        if (SUCCEEDED(GetItemById(id, &spItem)))
-        {
-            _OnUpdate(spItem);
-        }
+        // Do nothing.
         break;
     }
     case SRM_REGEX_ITEM_RENAMED_KEEP_UI:
@@ -926,22 +922,10 @@ DWORD WINAPI CPowerRenameManager::s_regexWorkerThread(_In_ void* pv)
 
                 winrt::check_hresult(pwtd->spsrm->GetRenameRegEx(&spRenameRegEx));
 
-                DWORD flags = 0;
-                winrt::check_hresult(spRenameRegEx->GetFlags(&flags));
-
-                PWSTR replaceTerm = nullptr;
-                bool useFileTime = false;
-
-                winrt::check_hresult(spRenameRegEx->GetReplaceTerm(&replaceTerm));
-
-                if (isFileTimeUsed(replaceTerm))
-                {
-                    useFileTime = true;
-                }
-
                 UINT itemCount = 0;
                 unsigned long itemEnumIndex = 1;
                 winrt::check_hresult(pwtd->spsrm->GetItemCount(&itemCount));
+
                 for (UINT u = 0; u < itemCount; u++)
                 {
                     // Check if cancel event is signaled
@@ -956,215 +940,14 @@ DWORD WINAPI CPowerRenameManager::s_regexWorkerThread(_In_ void* pv)
                     CComPtr<IPowerRenameItem> spItem;
                     winrt::check_hresult(pwtd->spsrm->GetItemByIndex(u, &spItem));
 
-                    int id = -1;
-                    winrt::check_hresult(spItem->GetId(&id));
-
-                    bool isFolder = false;
-                    bool isSubFolderContent = false;
-                    winrt::check_hresult(spItem->GetIsFolder(&isFolder));
-                    winrt::check_hresult(spItem->GetIsSubFolderContent(&isSubFolderContent));
-                    if ((isFolder && (flags & PowerRenameFlags::ExcludeFolders)) ||
-                        (!isFolder && (flags & PowerRenameFlags::ExcludeFiles)) ||
-                        (isSubFolderContent && (flags & PowerRenameFlags::ExcludeSubfolders)) ||
-                        (isFolder && (flags & PowerRenameFlags::ExtensionOnly)))
-                    {
-                        // Exclude this item from renaming.  Ensure new name is cleared.
-                        winrt::check_hresult(spItem->PutNewName(nullptr));
-
-                        // Send the manager thread the item processed message
-                        PostMessage(pwtd->hwndManager, SRM_REGEX_ITEM_UPDATED, GetCurrentThreadId(), id);
-
-                        continue;
+                    DoRename(spRenameRegEx, itemEnumIndex, spItem);
                 }
-
-                    PWSTR originalName = nullptr;
-                    winrt::check_hresult(spItem->GetOriginalName(&originalName));
-
-
-                    PWSTR currentNewName = nullptr;
-                    winrt::check_hresult(spItem->GetNewName(&currentNewName));
-
-                    wchar_t sourceName[MAX_PATH] = { 0 };
-
-                    if (isFolder)
-                    {
-                        StringCchCopy(sourceName, ARRAYSIZE(sourceName), originalName);
-                    
-                    }
-                    else
-                    {
-                        if (flags & NameOnly)
-                        {
-                            StringCchCopy(sourceName, ARRAYSIZE(sourceName), fs::path(originalName).stem().c_str());
-                        }
-                        else if (flags & ExtensionOnly)
-                        {
-                            std::wstring extension = fs::path(originalName).extension().wstring();
-                            if (!extension.empty() && extension.front() == '.')
-                            {
-                                extension = extension.erase(0, 1);
-                            }
-                            StringCchCopy(sourceName, ARRAYSIZE(sourceName), extension.c_str());
-                        }
-                        else
-                        {
-                            StringCchCopy(sourceName, ARRAYSIZE(sourceName), originalName);
-                        }
-                    }
-
-                    SYSTEMTIME fileTime = { 0 };
-
-                    if (useFileTime)
-                    {
-                        winrt::check_hresult(spItem->GetTime(&fileTime));
-                        winrt::check_hresult(spRenameRegEx->PutFileTime(fileTime));
-                    }
-
-                    PWSTR newName = nullptr;
-
-                    // Failure here means we didn't match anything or had nothing to match
-                    // Call put_newName with null in that case to reset it
-                    winrt::check_hresult(spRenameRegEx->Replace(sourceName, &newName));
-
-                    if (useFileTime)
-                    {
-                        winrt::check_hresult(spRenameRegEx->ResetFileTime());
-                    }
-
-                    wchar_t resultName[MAX_PATH] = { 0 };
-
-                    PWSTR newNameToUse = nullptr;
-
-                    // newName == nullptr likely means we have an empty search string.  We should leave newNameToUse
-                    // as nullptr so we clear the renamed column
-                    // Except string transformation is selected.
-
-                    if (newName == nullptr && (flags & Uppercase || flags & Lowercase || flags & Titlecase || flags & Capitalized))
-                    {
-                        SHStrDup(sourceName, &newName);
-                    }
-
-                    if (newName != nullptr)
-                    {
-                        newNameToUse = resultName;
-
-                        if (isFolder)
-                        {
-                            StringCchCopy(resultName, ARRAYSIZE(resultName), newName);
-                        }
-                        else
-                        {
-                            if (flags & NameOnly)
-                            {
-                                StringCchPrintf(resultName, ARRAYSIZE(resultName), L"%s%s", newName, fs::path(originalName).extension().c_str());
-                            }
-                            else if (flags & ExtensionOnly)
-                            {
-                                std::wstring extension = fs::path(originalName).extension().wstring();
-                                if (!extension.empty())
-                                {
-                                    StringCchPrintf(resultName, ARRAYSIZE(resultName), L"%s.%s", fs::path(originalName).stem().c_str(), newName);
-                                }
-                                else
-                                {
-                                    StringCchCopy(resultName, ARRAYSIZE(resultName), originalName);
-                                }
-                            }
-                            else
-                            {
-                                StringCchCopy(resultName, ARRAYSIZE(resultName), newName);
-                            }
-                        }
-                    }
-
-                    wchar_t trimmedName[MAX_PATH] = { 0 };
-                    if (newNameToUse != nullptr)
-                    {
-                        winrt::check_hresult(GetTrimmedFileName(trimmedName, ARRAYSIZE(trimmedName), newNameToUse));
-                        newNameToUse = trimmedName;
-                    }
-
-                    wchar_t transformedName[MAX_PATH] = { 0 };
-                    if (newNameToUse != nullptr && (flags & Uppercase || flags & Lowercase || flags & Titlecase || flags & Capitalized))
-                    {
-                        try
-                        {
-                            winrt::check_hresult(GetTransformedFileName(transformedName, ARRAYSIZE(transformedName), newNameToUse, flags, isFolder));
-                        }
-                        catch (...)
-                        {
-                        }
-                        newNameToUse = transformedName;
-                    }
-
-                    // No change from originalName so set newName to
-                    // null so we clear it from our UI as well.
-                    if (lstrcmp(originalName, newNameToUse) == 0)
-                    {
-                        newNameToUse = nullptr;
-                    }
-
-                    wchar_t uniqueName[MAX_PATH] = { 0 };
-                    if (newNameToUse != nullptr && (flags & EnumerateItems))
-                    {
-                        unsigned long countUsed = 0;
-                        if (GetEnumeratedFileName(uniqueName, ARRAYSIZE(uniqueName), newNameToUse, nullptr, itemEnumIndex, &countUsed))
-                        {
-                            newNameToUse = uniqueName;
-                        }
-                        itemEnumIndex++;
-                    }
-
-                    spItem->PutStatus(PowerRenameItemRenameStatus::ShouldRename);
-                    if (newNameToUse != nullptr)
-                    {
-                        std::wstring newNameToUseWstr{ newNameToUse };
-                        PWSTR path = nullptr;
-                        spItem->GetPath(&path);
-
-                        // Following characters cannot be used for file names.
-                        // Ref https://learn.microsoft.com/windows/win32/fileio/naming-a-file#naming-conventions
-                        if (newNameToUseWstr.contains('<') ||
-                            newNameToUseWstr.contains('>') ||
-                            newNameToUseWstr.contains(':') ||
-                            newNameToUseWstr.contains('"') ||
-                            newNameToUseWstr.contains('\\') ||
-                            newNameToUseWstr.contains('/') ||
-                            newNameToUseWstr.contains('|') ||
-                            newNameToUseWstr.contains('?') ||
-                            newNameToUseWstr.contains('*'))
-                        {
-                            spItem->PutStatus(PowerRenameItemRenameStatus::ItemNameInvalidChar);
-                        }
-                        // Max file path is 260 and max folder path is 247.
-                        // Ref https://learn.microsoft.com/windows/win32/fileio/maximum-file-path-limitation?tabs=registry
-                        else if ((isFolder && lstrlen(path) + (lstrlen(newNameToUse) - lstrlen(originalName)) > 247) ||
-                            lstrlen(path) + (lstrlen(newNameToUse) - lstrlen(originalName)) > 260)
-                        {
-                            spItem->PutStatus(PowerRenameItemRenameStatus::ItemNameTooLong);
-                        }
-                    }
-
-                    winrt::check_hresult(spItem->PutNewName(newNameToUse));
-
-                    // Was there a change?
-                    if (lstrcmp(currentNewName, newNameToUse) != 0)
-                    {
-                        // Send the manager thread the item processed message
-                        PostMessage(pwtd->hwndManager, SRM_REGEX_ITEM_UPDATED, GetCurrentThreadId(), id);
-                    }
-                    CoTaskMemFree(newName);
-                    CoTaskMemFree(currentNewName);
-                    CoTaskMemFree(originalName);
-                }
-                CoTaskMemFree(replaceTerm);
             }
 
             // Send the manager thread the completion message
             PostMessage(pwtd->hwndManager, SRM_REGEX_COMPLETE, GetCurrentThreadId(), 0);
 
             delete pwtd;
-            
         }
         CoUninitialize();
     }
@@ -1249,32 +1032,6 @@ void CPowerRenameManager::_ClearRegEx()
     }
 }
 
-void CPowerRenameManager::_OnItemAdded(_In_ IPowerRenameItem* renameItem)
-{
-    CSRWSharedAutoLock lock(&m_lockEvents);
-
-    for (auto it : m_powerRenameManagerEvents)
-    {
-        if (it.pEvents)
-        {
-            it.pEvents->OnItemAdded(renameItem);
-        }
-    }
-}
-
-void CPowerRenameManager::_OnUpdate(_In_ IPowerRenameItem* renameItem)
-{
-    CSRWSharedAutoLock lock(&m_lockEvents);
-
-    for (auto it : m_powerRenameManagerEvents)
-    {
-        if (it.pEvents)
-        {
-            it.pEvents->OnUpdate(renameItem);
-        }
-    }
-}
-
 void CPowerRenameManager::_OnRename(_In_ IPowerRenameItem* renameItem)
 {
     CSRWSharedAutoLock lock(&m_lockEvents);

src/modules/powerrename/lib/PowerRenameManager.h

@@ -16,7 +16,7 @@ public:
     IFACEMETHODIMP_(ULONG) Release();
 
     // IPowerRenameManager
-    IFACEMETHODIMP Advise(_In_ IPowerRenameManagerEvents* renameOpEvent, _Out_ DWORD *cookie);
+    IFACEMETHODIMP Advise(_In_ IPowerRenameManagerEvents* renameOpEvent, _Out_ DWORD* cookie);
     IFACEMETHODIMP UnAdvise(_In_ DWORD cookie);
     IFACEMETHODIMP Start();
     IFACEMETHODIMP Stop();
@@ -43,6 +43,8 @@ public:
     IFACEMETHODIMP GetRenameItemFactory(_COM_Outptr_ IPowerRenameItemFactory** ppItemFactory);
     IFACEMETHODIMP PutRenameItemFactory(_In_ IPowerRenameItemFactory* pItemFactory);
     
+    uint32_t GetVisibleItemRealIndex(const uint32_t index) const override;
+    
     // IPowerRenameRegExEvents
     IFACEMETHODIMP OnSearchTermChanged(_In_ PCWSTR searchTerm);
     IFACEMETHODIMP OnReplaceTermChanged(_In_ PCWSTR replaceTerm);
@@ -60,8 +62,6 @@ protected:
 
     void _Cancel();
 
-    void _OnItemAdded(_In_ IPowerRenameItem* renameItem);
-    void _OnUpdate(_In_ IPowerRenameItem* renameItem);
     void _OnRename(_In_ IPowerRenameItem* renameItem);
     void _OnError(_In_ IPowerRenameItem* renameItem);
     void _OnRegExStarted(_In_ DWORD threadId);

src/modules/powerrename/lib/Renaming.cpp

@@ -0,0 +1,220 @@
+#include "pch.h"
+#include <winrt/base.h>
+
+#include "Renaming.h"
+#include <Helpers.h>
+
+namespace fs = std::filesystem;
+
+bool DoRename(CComPtr<IPowerRenameRegEx>& spRenameRegEx, unsigned long& itemEnumIndex, CComPtr<IPowerRenameItem>& spItem)
+{
+    bool wouldRename = false;
+    DWORD flags = 0;
+    winrt::check_hresult(spRenameRegEx->GetFlags(&flags));
+
+    PWSTR replaceTerm = nullptr;
+    bool useFileTime = false;
+
+    winrt::check_hresult(spRenameRegEx->GetReplaceTerm(&replaceTerm));
+
+    if (isFileTimeUsed(replaceTerm))
+    {
+        useFileTime = true;
+    }
+    CoTaskMemFree(replaceTerm);
+
+    int id = -1;
+    winrt::check_hresult(spItem->GetId(&id));
+
+    bool isFolder = false;
+    bool isSubFolderContent = false;
+    winrt::check_hresult(spItem->GetIsFolder(&isFolder));
+    winrt::check_hresult(spItem->GetIsSubFolderContent(&isSubFolderContent));
+    if ((isFolder && (flags & PowerRenameFlags::ExcludeFolders)) ||
+        (!isFolder && (flags & PowerRenameFlags::ExcludeFiles)) ||
+        (isSubFolderContent && (flags & PowerRenameFlags::ExcludeSubfolders)) ||
+        (isFolder && (flags & PowerRenameFlags::ExtensionOnly)))
+    {
+        // Exclude this item from renaming.  Ensure new name is cleared.
+        winrt::check_hresult(spItem->PutNewName(nullptr));
+
+        return wouldRename;
+    }
+
+    PWSTR originalName = nullptr;
+    winrt::check_hresult(spItem->GetOriginalName(&originalName));
+
+    PWSTR currentNewName = nullptr;
+    winrt::check_hresult(spItem->GetNewName(&currentNewName));
+
+    wchar_t sourceName[MAX_PATH] = { 0 };
+
+    if (isFolder)
+    {
+        StringCchCopy(sourceName, ARRAYSIZE(sourceName), originalName);
+    }
+    else
+    {
+        if (flags & NameOnly)
+        {
+            StringCchCopy(sourceName, ARRAYSIZE(sourceName), fs::path(originalName).stem().c_str());
+        }
+        else if (flags & ExtensionOnly)
+        {
+            std::wstring extension = fs::path(originalName).extension().wstring();
+            if (!extension.empty() && extension.front() == '.')
+            {
+                extension = extension.erase(0, 1);
+            }
+            StringCchCopy(sourceName, ARRAYSIZE(sourceName), extension.c_str());
+        }
+        else
+        {
+            StringCchCopy(sourceName, ARRAYSIZE(sourceName), originalName);
+        }
+    }
+
+    SYSTEMTIME fileTime = { 0 };
+
+    if (useFileTime)
+    {
+        winrt::check_hresult(spItem->GetTime(&fileTime));
+        winrt::check_hresult(spRenameRegEx->PutFileTime(fileTime));
+    }
+
+    PWSTR newName = nullptr;
+
+    // Failure here means we didn't match anything or had nothing to match
+    // Call put_newName with null in that case to reset it
+    winrt::check_hresult(spRenameRegEx->Replace(sourceName, &newName));
+
+    if (useFileTime)
+    {
+        winrt::check_hresult(spRenameRegEx->ResetFileTime());
+    }
+
+    wchar_t resultName[MAX_PATH] = { 0 };
+
+    PWSTR newNameToUse = nullptr;
+
+    // newName == nullptr likely means we have an empty search string.  We should leave newNameToUse
+    // as nullptr so we clear the renamed column
+    // Except string transformation is selected.
+
+    if (newName == nullptr && (flags & Uppercase || flags & Lowercase || flags & Titlecase || flags & Capitalized))
+    {
+        SHStrDup(sourceName, &newName);
+    }
+
+    if (newName != nullptr)
+    {
+        newNameToUse = resultName;
+
+        if (isFolder)
+        {
+            StringCchCopy(resultName, ARRAYSIZE(resultName), newName);
+        }
+        else
+        {
+            if (flags & NameOnly)
+            {
+                StringCchPrintf(resultName, ARRAYSIZE(resultName), L"%s%s", newName, fs::path(originalName).extension().c_str());
+            }
+            else if (flags & ExtensionOnly)
+            {
+                std::wstring extension = fs::path(originalName).extension().wstring();
+                if (!extension.empty())
+                {
+                    StringCchPrintf(resultName, ARRAYSIZE(resultName), L"%s.%s", fs::path(originalName).stem().c_str(), newName);
+                }
+                else
+                {
+                    StringCchCopy(resultName, ARRAYSIZE(resultName), originalName);
+                }
+            }
+            else
+            {
+                StringCchCopy(resultName, ARRAYSIZE(resultName), newName);
+            }
+        }
+    }
+
+    wchar_t trimmedName[MAX_PATH] = { 0 };
+    if (newNameToUse != nullptr)
+    {
+        winrt::check_hresult(GetTrimmedFileName(trimmedName, ARRAYSIZE(trimmedName), newNameToUse));
+        newNameToUse = trimmedName;
+    }
+
+    wchar_t transformedName[MAX_PATH] = { 0 };
+    if (newNameToUse != nullptr && (flags & Uppercase || flags & Lowercase || flags & Titlecase || flags & Capitalized))
+    {
+        try
+        {
+            winrt::check_hresult(GetTransformedFileName(transformedName, ARRAYSIZE(transformedName), newNameToUse, flags, isFolder));
+        }
+        catch (...)
+        {
+        }
+        newNameToUse = transformedName;
+    }
+
+    // No change from originalName so set newName to
+    // null so we clear it from our UI as well.
+    if (lstrcmp(originalName, newNameToUse) == 0)
+    {
+        newNameToUse = nullptr;
+    }
+
+    wchar_t uniqueName[MAX_PATH] = { 0 };
+    if (newNameToUse != nullptr && (flags & EnumerateItems))
+    {
+        unsigned long countUsed = 0;
+        if (GetEnumeratedFileName(uniqueName, ARRAYSIZE(uniqueName), newNameToUse, nullptr, itemEnumIndex, &countUsed))
+        {
+            newNameToUse = uniqueName;
+        }
+        itemEnumIndex++;
+    }
+
+    spItem->PutStatus(PowerRenameItemRenameStatus::ShouldRename);
+    if (newNameToUse != nullptr)
+    {
+        wouldRename = true;
+        std::wstring newNameToUseWstr{ newNameToUse };
+        PWSTR path = nullptr;
+        spItem->GetPath(&path);
+
+        // Following characters cannot be used for file names.
+        // Ref https://learn.microsoft.com/windows/win32/fileio/naming-a-file#naming-conventions
+        if (newNameToUseWstr.contains('<') ||
+            newNameToUseWstr.contains('>') ||
+            newNameToUseWstr.contains(':') ||
+            newNameToUseWstr.contains('"') ||
+            newNameToUseWstr.contains('\\') ||
+            newNameToUseWstr.contains('/') ||
+            newNameToUseWstr.contains('|') ||
+            newNameToUseWstr.contains('?') ||
+            newNameToUseWstr.contains('*'))
+        {
+            spItem->PutStatus(PowerRenameItemRenameStatus::ItemNameInvalidChar);
+            wouldRename = false;
+        }
+        // Max file path is 260 and max folder path is 247.
+        // Ref https://learn.microsoft.com/windows/win32/fileio/maximum-file-path-limitation?tabs=registry
+        else if ((isFolder && lstrlen(path) + (lstrlen(newNameToUse) - lstrlen(originalName)) > 247) ||
+                 lstrlen(path) + (lstrlen(newNameToUse) - lstrlen(originalName)) > 260)
+        {
+            spItem->PutStatus(PowerRenameItemRenameStatus::ItemNameTooLong);
+            wouldRename = false;
+        }
+    }
+
+    winrt::check_hresult(spItem->PutNewName(newNameToUse));
+
+    CoTaskMemFree(newName);
+    CoTaskMemFree(currentNewName);
+    CoTaskMemFree(originalName);
+
+    return wouldRename;
+}

src/modules/powerrename/lib/Renaming.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <PowerRenameInterfaces.h>
+
+bool DoRename(CComPtr<IPowerRenameRegEx>& spRenameRegEx, unsigned long& itemEnumIndex, CComPtr<IPowerRenameItem>& spItem);

src/modules/powerrename/lib/pch.h

@@ -3,11 +3,12 @@
 #include "targetver.h"
 
 #define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers
+#define NOMINMAX
 // Windows Header Files:
 #include <windows.h>
 
-// C RunTime Header Files
 #include <algorithm>
+#include <execution>
 #include <cstdlib>
 #include <malloc.h>
 #include <memory.h>
@@ -19,6 +20,8 @@
 #include <shellapi.h>
 #include <shlwapi.h>
 #include <ShlObj_core.h>
+#include <filesystem>
 
 #include <ProjectTelemetry.h>
 
+#include <winrt/base.h>

src/modules/powerrename/unittests/MockPowerRenameManagerEvents.cpp

@@ -29,18 +29,6 @@ CMockPowerRenameManagerEvents::Release()
 }
 
 // IPowerRenameManagerEvents
-IFACEMETHODIMP CMockPowerRenameManagerEvents::OnItemAdded(_In_ IPowerRenameItem* pItem)
-{
-    m_itemAdded = pItem;
-    return S_OK;
-}
-
-IFACEMETHODIMP CMockPowerRenameManagerEvents::OnUpdate(_In_ IPowerRenameItem* pItem)
-{
-    m_itemUpdated = pItem;
-    return S_OK;
-}
-
 IFACEMETHODIMP CMockPowerRenameManagerEvents::OnRename(_In_ IPowerRenameItem* pItem)
 {
     m_itemRenamed = pItem;

src/modules/powerrename/unittests/MockPowerRenameManagerEvents.h

@@ -32,8 +32,6 @@ public:
     {
     }
 
-    CComPtr<IPowerRenameItem> m_itemAdded;
-    CComPtr<IPowerRenameItem> m_itemUpdated;
     CComPtr<IPowerRenameItem> m_itemRenamed;
     CComPtr<IPowerRenameItem> m_itemError;
     bool m_regExStarted = false;

src/modules/powerrename/unittests/PowerRenameManagerTests.cpp

@@ -68,12 +68,6 @@ namespace PowerRenameManagerTests
                 int itemId = 0;
                 Assert::IsTrue(item->GetId(&itemId) == S_OK);
                 mgr->AddItem(item);
-
-                // Verify the item we added is the same from the event
-                Assert::IsTrue(mockMgrEvents->m_itemAdded != nullptr && mockMgrEvents->m_itemAdded == item);
-                int eventItemId = 0;
-                Assert::IsTrue(mockMgrEvents->m_itemAdded->GetId(&eventItemId) == S_OK);
-                Assert::IsTrue(itemId == eventItemId);
             }
 
             // TODO: Setup match and replace parameters
@@ -146,11 +140,6 @@ namespace PowerRenameManagerTests
             Assert::IsTrue(item->GetId(&itemId) == S_OK);
             mgr->AddItem(item);
 
-            // Verify the item we added is the same from the event
-            Assert::IsTrue(mockMgrEvents->m_itemAdded != nullptr && mockMgrEvents->m_itemAdded == item);
-            int eventItemId = 0;
-            Assert::IsTrue(mockMgrEvents->m_itemAdded->GetId(&eventItemId) == S_OK);
-            Assert::IsTrue(itemId == eventItemId);
             Assert::IsTrue(mgr->Shutdown() == S_OK);
 
             mockMgrEvents->Release();