Add support for OSC 52 clipboard copy in conhost

src/host/consoleInformation.cpp

@@ -13,6 +13,7 @@
 #include "srvinit.h"
 
 #include "../interactivity/inc/ServiceLocator.hpp"
+#include "../interactivity/win32/CustomWindowMessages.h"
 #include "../types/inc/convert.hpp"
 
 using Microsoft::Console::Interactivity::ServiceLocator;
@@ -179,6 +180,32 @@ void CONSOLE_INFORMATION::SetBracketedPasteMode(const bool enabled) noexcept
     _bracketedPasteMode = enabled;
 }
 
+void CONSOLE_INFORMATION::CopyTextToClipboard(const std::wstring_view text)
+{
+    const auto window = ServiceLocator::LocateConsoleWindow();
+    if (window)
+    {
+        // The clipboard can only be updated from the main GUI thread, so we
+        // need to post a message to trigger the actual copy operation. But if
+        // the pending clipboard content is already set, a message would have
+        // already been posted, so there's no need to post another one.
+        const auto clipboardMessageSent = _pendingClipboardText.has_value();
+        _pendingClipboardText = text;
+        if (!clipboardMessageSent)
+        {
+            PostMessageW(window->GetWindowHandle(), CM_UPDATE_CLIPBOARD, 0, 0);
+        }
+    }
+}
+
+std::optional<std::wstring> CONSOLE_INFORMATION::UsePendingClipboardText()
+{
+    // Once the pending text has been used, we clear the variable to let the
+    // CopyTextToClipboard method know that the last CM_UPDATE_CLIPBOARD message
+    // has been processed, and future updates will require another message.
+    return std::exchange(_pendingClipboardText, {});
+}
+
 // Method Description:
 // - Return the active screen buffer of the console.
 // Arguments:

src/host/outputStream.cpp

@@ -280,9 +280,9 @@ unsigned int ConhostInternalGetSet::GetInputCodePage() const
 // - content - the text to be copied.
 // Return Value:
 // - <none>
-void ConhostInternalGetSet::CopyToClipboard(const wil::zwstring_view /*content*/)
+void ConhostInternalGetSet::CopyToClipboard(const wil::zwstring_view content)
 {
-    // TODO
+    ServiceLocator::LocateGlobals().getConsoleInformation().CopyTextToClipboard(content);
 }
 
 // Routine Description:

src/host/server.h

@@ -126,6 +126,8 @@ class CONSOLE_INFORMATION :
 
     bool GetBracketedPasteMode() const noexcept;
     void SetBracketedPasteMode(const bool enabled) noexcept;
+    void CopyTextToClipboard(const std::wstring_view text);
+    std::optional<std::wstring> UsePendingClipboardText();
 
     void SetTitle(const std::wstring_view newTitle);
     void SetTitlePrefix(const std::wstring_view newTitlePrefix);
@@ -160,6 +162,7 @@ class CONSOLE_INFORMATION :
     SCREEN_INFORMATION* pCurrentScreenBuffer = nullptr;
     COOKED_READ_DATA* _cookedReadData = nullptr; // non-ownership pointer
     bool _bracketedPasteMode = false;
+    std::optional<std::wstring> _pendingClipboardText;
 
     Microsoft::Console::VirtualTerminal::VtIo _vtIo;
     Microsoft::Console::CursorBlinker _blinker;

src/interactivity/win32/Clipboard.cpp

@@ -24,6 +24,22 @@ using namespace Microsoft::Console::Types;
 
 #pragma region Public Methods
 
+void Clipboard::CopyText(const std::wstring& text)
+{
+    const auto clipboard = _openClipboard(ServiceLocator::LocateConsoleWindow()->GetWindowHandle());
+    if (!clipboard)
+    {
+        LOG_LAST_ERROR();
+        return;
+    }
+
+    EmptyClipboard();
+    // As per: https://learn.microsoft.com/en-us/windows/win32/dataxchg/standard-clipboard-formats
+    //   CF_UNICODETEXT: [...] A null character signals the end of the data.
+    // --> We add +1 to the length. This works because .c_str() is null-terminated.
+    _copyToClipboard(CF_UNICODETEXT, text.c_str(), (text.size() + 1) * sizeof(wchar_t));
+}
+
 // Arguments:
 // - fAlsoCopyFormatting - Place colored HTML & RTF text onto the clipboard as well as the usual plain text.
 // Return Value:

src/interactivity/win32/CustomWindowMessages.h

@@ -29,4 +29,6 @@
 #define CM_SET_KEYBOARD_LAYOUT   (WM_USER+19)
 #endif
 
+#define CM_UPDATE_CLIPBOARD      (WM_USER+20)
+
 // clang-format on

src/interactivity/win32/clipboard.hpp

@@ -29,6 +29,7 @@ namespace Microsoft::Console::Interactivity::Win32
     public:
         static Clipboard& Instance();
 
+        void CopyText(const std::wstring& text);
         void Copy(_In_ const bool fAlsoCopyFormatting = false);
         void Paste();
         void PasteDrop(HDROP drop);

src/interactivity/win32/windowproc.cpp

@@ -773,6 +773,15 @@ static constexpr TsfDataProvider s_tsfDataProvider;
     }
 #endif // DBG
 
+    case CM_UPDATE_CLIPBOARD:
+    {
+        if (const auto clipboardText = gci.UsePendingClipboardText())
+        {
+            Clipboard::Instance().CopyText(clipboardText.value());
+        }
+        break;
+    }
+
     case EVENT_CONSOLE_CARET:
     case EVENT_CONSOLE_UPDATE_REGION:
     case EVENT_CONSOLE_UPDATE_SIMPLE: