terminal/src/interactivity/win32/Clipboard.cpp

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

#include "precomp.h"

#include "clipboard.hpp"
#include "resource.h"

#include "../../host/dbcs.h"
#include "../../host/scrolling.hpp"
#include "../../host/output.h"

#include "../../types/inc/convert.hpp"
#include "../../types/inc/viewport.hpp"

#include "../inc/conint.h"
#include "../inc/EventSynthesis.hpp"
#include "../inc/ServiceLocator.hpp"

#pragma hdrstop

using namespace Microsoft::Console::Interactivity::Win32;
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:
//   <none>
// NOTE:  if the registry is set to always copy color data then we will even if fAlsoCopyFormatting is false
void Clipboard::Copy(bool fAlsoCopyFormatting)
{
    try
    {
        // registry settings may tell us to always copy the color/formatting
        auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();
        fAlsoCopyFormatting = fAlsoCopyFormatting || gci.GetCopyColor();

        // store selection in clipboard
        StoreSelectionToClipboard(fAlsoCopyFormatting);
        Selection::Instance().ClearSelection(); // clear selection in console
    }
    CATCH_LOG();
}

/*++

Perform paste request into old app by pulling out clipboard
contents and writing them to the console's input buffer

--*/
void Clipboard::Paste()
{
    const auto clipboard = _openClipboard(ServiceLocator::LocateConsoleWindow()->GetWindowHandle());
    if (!clipboard)
    {
        LOG_LAST_ERROR();
        return;
    }

    // This handles most cases of pasting text as the OS converts most formats to CF_UNICODETEXT automatically.
    if (const auto handle = GetClipboardData(CF_UNICODETEXT))
    {
        const wil::unique_hglobal_locked lock{ handle };
        const auto str = static_cast<const wchar_t*>(lock.get());
        if (!str)
        {
            return;
        }

        // 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.
        // --> Use wcsnlen() to determine the actual length.
        // NOTE: Some applications don't add a trailing null character. This includes past conhost versions.
        const auto maxLen = GlobalSize(handle) / sizeof(wchar_t);
        StringPaste(str, wcsnlen(str, maxLen));
        return;
    }

    // We get CF_HDROP when a user copied a file with Ctrl+C in Explorer and pastes that into the terminal (among others).
    if (const auto handle = GetClipboardData(CF_HDROP))
    {
        const wil::unique_hglobal_locked lock{ handle };
        const auto drop = static_cast<HDROP>(lock.get());
        if (!drop)
        {
            return;
        }

        PasteDrop(drop);
    }
}

void Clipboard::PasteDrop(HDROP drop)
{
    // NOTE: When asking DragQueryFileW for the required capacity it returns a length without trailing \0,
    // but then expects a capacity that includes it. If you don't make space for a trailing \0
    // then it will silently (!) cut off the end of the string. A somewhat disappointing API design.
    const auto expectedLength = DragQueryFileW(drop, 0, nullptr, 0);
    if (expectedLength == 0)
    {
        return;
    }

    // If the path contains spaces, we'll wrap it in quotes and so this allocates +2 characters ahead of time.
    // We'll first make DragQueryFileW copy its contents in the middle and then check if that contains spaces.
    // If it does, only then we'll add the quotes at the start and end.
    // This is preferable over calling StringPaste 3x (an alternative, simpler approach),
    // because the pasted content should be treated as a single atomic unit by the InputBuffer.
    const auto buffer = std::make_unique_for_overwrite<wchar_t[]>(expectedLength + 2);
    auto str = buffer.get() + 1;
    size_t len = expectedLength;

    const auto actualLength = DragQueryFileW(drop, 0, str, expectedLength + 1);
    if (actualLength != expectedLength)
    {
        return;
    }

    if (wmemchr(str, L' ', len))
    {
        str = buffer.get();
        len += 2;
        til::at(str, 0) = L'"';
        til::at(str, len - 1) = L'"';
    }

    StringPaste(str, len);
}

Clipboard& Clipboard::Instance()
{
    static Clipboard clipboard;
    return clipboard;
}

// Routine Description:
// - This routine pastes given Unicode string into the console window.
// Arguments:
// - pData - Unicode string that is pasted to the console window
// - cchData - Size of the Unicode String in characters
// Return Value:
// - None
void Clipboard::StringPaste(_In_reads_(cchData) const wchar_t* const pData,
                            const size_t cchData)
{
    if (pData == nullptr)
    {
        return;
    }

    auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();

    try
    {
        // Clear any selection or scrolling that may be active.
        Selection::Instance().ClearSelection();
        Scrolling::s_ClearScroll();

        const auto vtInputMode = gci.pInputBuffer->IsInVirtualTerminalInputMode();
        const auto bracketedPasteMode = gci.GetBracketedPasteMode();
        auto inEvents = TextToKeyEvents(pData, cchData, vtInputMode && bracketedPasteMode);
        gci.pInputBuffer->Write(inEvents);

        if (gci.HasActiveOutputBuffer())
        {
            gci.GetActiveOutputBuffer().SnapOnInput(0);
        }
    }
    catch (...)
    {
        LOG_HR(wil::ResultFromCaughtException());
    }
}

#pragma endregion

#pragma region Private Methods

wil::unique_close_clipboard_call Clipboard::_openClipboard(HWND hwnd)
{
    bool success = false;

    // OpenClipboard may fail to acquire the internal lock --> retry.
    for (DWORD sleep = 10;; sleep *= 2)
    {
        if (OpenClipboard(hwnd))
        {
            success = true;
            break;
        }
        // 10 iterations
        if (sleep > 10000)
        {
            break;
        }
        Sleep(sleep);
    }

    return wil::unique_close_clipboard_call{ success };
}

void Clipboard::_copyToClipboard(const UINT format, const void* src, const size_t bytes)
{
    wil::unique_hglobal handle{ THROW_LAST_ERROR_IF_NULL(GlobalAlloc(GMEM_MOVEABLE, bytes)) };

    const auto locked = GlobalLock(handle.get());
    memcpy(locked, src, bytes);
    GlobalUnlock(handle.get());

    THROW_LAST_ERROR_IF_NULL(SetClipboardData(format, handle.get()));
    handle.release();
}

void Clipboard::_copyToClipboardRegisteredFormat(const wchar_t* format, const void* src, size_t bytes)
{
    const auto id = RegisterClipboardFormatW(format);
    if (!id)
    {
        LOG_LAST_ERROR();
        return;
    }
    _copyToClipboard(id, src, bytes);
}

// Routine Description:
// - converts a wchar_t* into a series of KeyEvents as if it was typed
// from the keyboard
// Arguments:
// - pData - the text to convert
// - cchData - the size of pData, in wchars
// - bracketedPaste - should this be bracketed with paste control sequences
// Return Value:
// - deque of KeyEvents that represent the string passed in
// Note:
// - will throw exception on error
InputEventQueue Clipboard::TextToKeyEvents(_In_reads_(cchData) const wchar_t* const pData,
                                           const size_t cchData,
                                           const bool bracketedPaste)
{
    THROW_HR_IF_NULL(E_INVALIDARG, pData);

    InputEventQueue keyEvents;
    const auto pushControlSequence = [&](const std::wstring_view sequence) {
        std::for_each(sequence.begin(), sequence.end(), [&](const auto wch) {
            keyEvents.push_back(SynthesizeKeyEvent(true, 1, 0, 0, wch, 0));
            keyEvents.push_back(SynthesizeKeyEvent(false, 1, 0, 0, wch, 0));
        });
    };

    // When a bracketed paste is requested, we need to wrap the text with
    // control sequences which indicate that the content has been pasted.
    if (bracketedPaste)
    {
        pushControlSequence(L"\x1b[200~");
    }

    for (size_t i = 0; i < cchData; ++i)
    {
        auto currentChar = pData[i];

        const auto charAllowed = FilterCharacterOnPaste(&currentChar);
        // filter out linefeed if it's not the first char and preceded
        // by a carriage return
        const auto skipLinefeed = (i != 0 &&
                                   currentChar == UNICODE_LINEFEED &&
                                   pData[i - 1] == UNICODE_CARRIAGERETURN);
        // filter out escape if bracketed paste mode is enabled
        const auto skipEscape = (bracketedPaste && currentChar == UNICODE_ESC);

        if (!charAllowed || skipLinefeed || skipEscape)
        {
            continue;
        }

        if (currentChar == 0)
        {
            break;
        }

        // MSFT:12123975 / WSL GH#2006
        // If you paste text with ONLY linefeed line endings (unix style) in wsl,
        //      then we faithfully pass those along, which the underlying terminal
        //      interprets as C-j. In nano, C-j is mapped to "Justify text", which
        //      causes the pasted text to get broken at the width of the terminal.
        // This behavior doesn't occur in gnome-terminal, and nothing like it occurs
        //      in vi or emacs.
        // This change doesn't break pasting text into any of those applications
        //      with CR/LF (Windows) line endings either. That apparently always
        //      worked right.
        if (IsInVirtualTerminalInputMode() && currentChar == UNICODE_LINEFEED)
        {
            currentChar = UNICODE_CARRIAGERETURN;
        }

        const auto codepage = ServiceLocator::LocateGlobals().getConsoleInformation().CP;
        CharToKeyEvents(currentChar, codepage, keyEvents);
    }

    if (bracketedPaste)
    {
        pushControlSequence(L"\x1b[201~");
    }

    return keyEvents;
}

// Routine Description:
// - Copies the selected area onto the global system clipboard.
// - NOTE: Throws on allocation and other clipboard failures.
// Arguments:
// - copyFormatting - This will also place colored HTML & RTF text onto the clipboard as well as the usual plain text.
// Return Value:
//   <none>
void Clipboard::StoreSelectionToClipboard(const bool copyFormatting)
{
    std::wstring text;
    std::string htmlData, rtfData;

    const auto& selection = Selection::Instance();

    // See if there is a selection to get
    if (!selection.IsAreaSelected())
    {
        return;
    }

    const auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();
    const auto& buffer = gci.GetActiveOutputBuffer().GetTextBuffer();
    const auto& renderSettings = gci.GetRenderSettings();

    const auto GetAttributeColors = [&](const auto& attr) {
        const auto [fg, bg] = renderSettings.GetAttributeColors(attr);
        const auto ul = renderSettings.GetAttributeUnderlineColor(attr);
        return std::tuple{ fg, bg, ul };
    };

    bool singleLine = false;
    if (WI_IsFlagSet(OneCoreSafeGetKeyState(VK_SHIFT), KEY_PRESSED))
    {
        // When shift is held, put everything in one line
        singleLine = true;
    }

    const auto& [selectionStart, selectionEnd] = selection.GetSelectionAnchors();

    const auto req = TextBuffer::CopyRequest::FromConfig(buffer, selectionStart, selectionEnd, singleLine, !selection.IsLineSelection(), false);
    text = buffer.GetPlainText(req);

    if (copyFormatting)
    {
        const auto& fontData = gci.GetActiveOutputBuffer().GetCurrentFont();
        const auto& fontName = fontData.GetFaceName();
        const auto fontSizePt = fontData.GetUnscaledSize().height * 72 / ServiceLocator::LocateGlobals().dpi;
        const auto bgColor = renderSettings.GetAttributeColors({}).second;
        const auto isIntenseBold = renderSettings.GetRenderMode(::Microsoft::Console::Render::RenderSettings::Mode::IntenseIsBold);

        htmlData = buffer.GenHTML(req, fontSizePt, fontName, bgColor, isIntenseBold, GetAttributeColors);
        rtfData = buffer.GenRTF(req, fontSizePt, fontName, bgColor, isIntenseBold, GetAttributeColors);
    }

    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));

    if (copyFormatting)
    {
        _copyToClipboardRegisteredFormat(L"HTML Format", htmlData.data(), htmlData.size());
        _copyToClipboardRegisteredFormat(L"Rich Text Format", rtfData.data(), rtfData.size());
    }
}

// Returns true if the character should be emitted to the paste stream
// -- in some cases, we will change what character should be emitted, as in the case of "smart quotes"
// Returns false if the character should not be emitted (e.g. <TAB>)
bool Clipboard::FilterCharacterOnPaste(_Inout_ WCHAR* const pwch)
{
    const auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();
    auto fAllowChar = true;
    if (gci.GetFilterOnPaste() &&
        (WI_IsFlagSet(gci.pInputBuffer->InputMode, ENABLE_PROCESSED_INPUT)))
    {
        switch (*pwch)
        {
            // swallow tabs to prevent inadvertent tab expansion
        case UNICODE_TAB:
        {
            fAllowChar = false;
            break;
        }

        // Replace Unicode space with standard space
        case UNICODE_NBSP:
        case UNICODE_NARROW_NBSP:
        {
            *pwch = UNICODE_SPACE;
            break;
        }

        // Replace "smart quotes" with "dumb ones"
        case UNICODE_LEFT_SMARTQUOTE:
        case UNICODE_RIGHT_SMARTQUOTE:
        {
            *pwch = UNICODE_QUOTE;
            break;
        }

        // Replace Unicode dashes with a standard hyphen
        case UNICODE_EM_DASH:
        case UNICODE_EN_DASH:
        {
            *pwch = UNICODE_HYPHEN;
            break;
        }
        }
    }

    return fAllowChar;
}

#pragma endregion