[1.24] conhost: Make screen readers announce search results

.github/actions/spelling/expect/expect.txt

@@ -1044,6 +1044,8 @@ msft
 MSGCMDLINEF
 MSGF
 MSGFILTER
+MSGFINDNORESULT
+MSGFINDRESULT
 MSGFLG
 MSGMARKMODE
 MSGSCROLLMODE

src/host/res.rc

@@ -61,6 +61,11 @@ BEGIN
 
     ID_CONSOLE_FMT_WINDOWTITLE, "%s%s"
 
+/* Find dialog screen reader announcements. %1 is the 1-based index of the current
+   match, %2 is the total number of matches. */
+    ID_CONSOLE_MSGFINDRESULT,   "%1!d! of %2!d!"
+    ID_CONSOLE_MSGFINDNORESULT, "No results"
+
 /* Menu items that replace the standard ones. These don't have the accelerators */
     SC_CLOSE,       "&Close"
 

src/host/resource.h

@@ -28,6 +28,8 @@ Author(s):
 #define ID_CONSOLE_MSGMARKMODE           0x100C
 #define ID_CONSOLE_MSGSCROLLMODE         0x100D
 #define ID_CONSOLE_FMT_WINDOWTITLE       0x100E
+#define ID_CONSOLE_MSGFINDRESULT         0x100F
+#define ID_CONSOLE_MSGFINDNORESULT       0x1010
 
 // Menu Item strings
 #define ID_CONSOLE_COPY         0xFFF0

src/interactivity/inc/IAccessibilityNotifier.hpp

@@ -37,5 +37,7 @@ namespace Microsoft::Console::Interactivity
         virtual void NotifyConsoleLayoutEvent() = 0;
         virtual void NotifyConsoleStartApplicationEvent(_In_ DWORD processId) = 0;
         virtual void NotifyConsoleEndApplicationEvent(_In_ DWORD processId) = 0;
+
+        virtual void AnnounceSearchResults(_In_ ptrdiff_t index, _In_ size_t count) = 0;
     };
 }

src/interactivity/onecore/AccessibilityNotifier.cpp

@@ -38,3 +38,7 @@ void AccessibilityNotifier::NotifyConsoleStartApplicationEvent(_In_ DWORD /*proc
 void AccessibilityNotifier::NotifyConsoleEndApplicationEvent(_In_ DWORD /*processId*/) noexcept
 {
 }
+
+void AccessibilityNotifier::AnnounceSearchResults(_In_ ptrdiff_t /*index*/, _In_ size_t /*count*/) noexcept
+{
+}

src/interactivity/onecore/AccessibilityNotifier.hpp

@@ -31,5 +31,7 @@ namespace Microsoft::Console::Interactivity::OneCore
         void NotifyConsoleLayoutEvent() noexcept override;
         void NotifyConsoleStartApplicationEvent(_In_ DWORD processId) noexcept override;
         void NotifyConsoleEndApplicationEvent(_In_ DWORD processId) noexcept override;
+
+        void AnnounceSearchResults(_In_ ptrdiff_t index, _In_ size_t count) noexcept override;
     };
 }

src/interactivity/win32/AccessibilityNotifier.cpp

@@ -7,6 +7,8 @@
 
 #include "../inc/ServiceLocator.hpp"
 #include "ConsoleControl.hpp"
+#include "resource.h"
+#include "window.hpp"
 
 using namespace Microsoft::Console::Types;
 using namespace Microsoft::Console::Interactivity::Win32;
@@ -133,3 +135,70 @@ void AccessibilityNotifier::NotifyConsoleEndApplicationEvent(_In_ DWORD processI
                        0);
     }
 }
+
+// Routine Description:
+// - Loads a string resource and returns it. Returns an empty string on failure
+static std::wstring _loadString(const UINT id)
+{
+    WCHAR buffer[70];
+    const auto length = LoadStringW(Microsoft::Console::Interactivity::ServiceLocator::LocateGlobals().hInstance, id, buffer, ARRAYSIZE(buffer));
+    return { &buffer[0], gsl::narrow_cast<size_t>(std::max(length, 0)) };
+}
+
+// Routine Description:
+// - Announces the state of the Find dialog's search results to screen readers
+// Arguments:
+// - index: the 0-based index of the current match
+// - count: the total number of matches
+void AccessibilityNotifier::AnnounceSearchResults(_In_ const ptrdiff_t index, _In_ const size_t count)
+try
+{
+    const auto pWindow = ServiceLocator::LocateConsoleWindow<Window>();
+    if (!pWindow)
+    {
+        return;
+    }
+
+    std::wstring announcement;
+
+    if (count == 0)
+    {
+        // No results found
+        announcement = _loadString(ID_CONSOLE_MSGFINDNORESULT);
+    }
+    else
+    {
+        // Results found. Announce as the 1-based index of the total ("2 of 5")
+        const auto format = _loadString(ID_CONSOLE_MSGFINDRESULT);
+        const auto position = std::clamp<size_t>(gsl::narrow_cast<size_t>(std::max<ptrdiff_t>(index, 0)) + 1, 1, count);
+
+        // The resource uses positional inserts (%1, %2) so that translations can reorder them.
+        const DWORD_PTR args[]{
+            gsl::narrow_cast<DWORD_PTR>(position),
+            gsl::narrow_cast<DWORD_PTR>(count),
+        };
+        wil::unique_hlocal_string formatted;
+        const auto length = FormatMessageW(
+            FORMAT_MESSAGE_FROM_STRING | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_ARGUMENT_ARRAY,
+            format.c_str(),
+            0,
+            0,
+            reinterpret_cast<LPWSTR>(formatted.addressof()),
+            0,
+            reinterpret_cast<va_list*>(const_cast<DWORD_PTR*>(&args[0])));
+        if (length == 0)
+        {
+            LOG_LAST_ERROR();
+            return;
+        }
+        announcement.assign(formatted.get(), length);
+    }
+
+    if (announcement.empty())
+    {
+        return;
+    }
+
+    LOG_IF_FAILED(pWindow->SignalUiaAnnouncement(announcement));
+}
+CATCH_LOG()

src/interactivity/win32/AccessibilityNotifier.hpp

@@ -35,5 +35,7 @@ namespace Microsoft::Console::Interactivity::Win32
         void NotifyConsoleLayoutEvent();
         void NotifyConsoleStartApplicationEvent(_In_ DWORD processId);
         void NotifyConsoleEndApplicationEvent(_In_ DWORD processId);
+
+        void AnnounceSearchResults(_In_ ptrdiff_t index, _In_ size_t count);
     };
 }

src/interactivity/win32/find.cpp

@@ -63,6 +63,11 @@ INT_PTR CALLBACK FindDialogProc(HWND hWnd, UINT Message, WPARAM wParam, LPARAM l
                 searcher.FindNext(reverse);
             }
 
+            if (const auto notifier = ServiceLocator::LocateAccessibilityNotifier())
+            {
+                notifier->AnnounceSearchResults(searcher.CurrentMatch(), searcher.Results().size());
+            }
+
             if (searcher.SelectCurrent())
             {
                 return TRUE;

src/interactivity/win32/resource.h

@@ -25,6 +25,8 @@ Author(s):
 #define ID_CONSOLE_MSGMARKMODE           0x100C
 #define ID_CONSOLE_MSGSCROLLMODE         0x100D
 #define ID_CONSOLE_FMT_WINDOWTITLE       0x100E
+#define ID_CONSOLE_MSGFINDRESULT         0x100F
+#define ID_CONSOLE_MSGFINDNORESULT       0x1010
 
 // Menu Item strings
 #define ID_CONSOLE_COPY         0xFFF0

src/interactivity/win32/window.cpp

@@ -1370,6 +1370,15 @@ IRawElementProviderSimple* Window::_GetUiaProvider()
     return S_FALSE;
 }
 
+[[nodiscard]] HRESULT Window::SignalUiaAnnouncement(const std::wstring_view text)
+{
+    if (_pUiaProvider != nullptr)
+    {
+        return _pUiaProvider->SignalAnnouncement(text);
+    }
+    return S_FALSE;
+}
+
 [[nodiscard]] HRESULT Window::UiaSetTextAreaFocus()
 {
     if (_pUiaProvider != nullptr)

src/interactivity/win32/window.hpp

@@ -83,6 +83,7 @@ namespace Microsoft::Console::Interactivity::Win32
         BOOL PostUpdateExtendedEditKeys() const;
 
         [[nodiscard]] HRESULT SignalUia(_In_ EVENTID id);
+        [[nodiscard]] HRESULT SignalUiaAnnouncement(const std::wstring_view text);
 
         void SetOwner();
         BOOL GetCursorPosition(_Out_ til::point* lpPoint);

src/interactivity/win32/windowUiaProvider.cpp

@@ -78,6 +78,33 @@ CATCH_RETURN();
     CATCH_RETURN();
 }
 
+// Routine Description:
+// - Raises a UIA notification event so that screen readers speak the given text
+// Arguments:
+// - text: the text to be announced
+// Return Value:
+// - S_OK, or a suitable HRESULT on failure
+[[nodiscard]] HRESULT WindowUiaProvider::SignalAnnouncement(const std::wstring_view text) noexcept
+try
+{
+    // Raise the announcement on the text area because
+    // that's the element screen readers are actually reading from
+    RETURN_HR_IF_NULL(E_POINTER, _pScreenInfoProvider.Get());
+
+    const wil::unique_bstr announcement{ SysAllocStringLen(text.data(), gsl::narrow<UINT>(text.size())) };
+    RETURN_IF_NULL_ALLOC(announcement);
+
+    static const auto activityId = wil::make_bstr_nothrow(L"ConhostSearchResultAnnouncement");
+    RETURN_IF_NULL_ALLOC(activityId);
+
+    return UiaRaiseNotificationEvent(_pScreenInfoProvider.Get(),
+                                     NotificationKind_ActionCompleted,
+                                     NotificationProcessing_ImportantMostRecent,
+                                     announcement.get(),
+                                     activityId.get());
+}
+CATCH_RETURN();
+
 #pragma region IRawElementProviderSimple
 
 // Implementation of IRawElementProviderSimple::get_ProviderOptions.

src/interactivity/win32/windowUiaProvider.hpp

@@ -49,6 +49,7 @@ namespace Microsoft::Console::Interactivity::Win32
     public:
         [[nodiscard]] virtual HRESULT Signal(_In_ EVENTID id);
         [[nodiscard]] virtual HRESULT SetTextAreaFocus();
+        [[nodiscard]] HRESULT SignalAnnouncement(const std::wstring_view text) noexcept;
 
         // IRawElementProviderSimple methods
         IFACEMETHODIMP get_ProviderOptions(_Out_ ProviderOptions* pOptions) override;