terminal/src/renderer/vt/Xterm256Engine.cpp

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

#include "precomp.h"
#include "Xterm256Engine.hpp"
#pragma hdrstop
using namespace Microsoft::Console;
using namespace Microsoft::Console::Render;
using namespace Microsoft::Console::Types;

Xterm256Engine::Xterm256Engine(_In_ wil::unique_hfile hPipe,
                               const Viewport initialViewport) :
    XtermEngine(std::move(hPipe), initialViewport, false)
{
}

// Routine Description:
// - Write a VT sequence to change the current colors of text. Writes true RGB
//      color sequences.
// Arguments:
// - textAttributes - Text attributes to use for the colors and character rendition
// - pData - The interface to console data structures required for rendering
// - usingSoftFont - Whether we're rendering characters from a soft font
// - isSettingDefaultBrushes: indicates if we should change the background color of
//      the window. Unused for VT
// Return Value:
// - S_OK if we succeeded, else an appropriate HRESULT for failing to allocate or write.
[[nodiscard]] HRESULT Xterm256Engine::UpdateDrawingBrushes(const TextAttribute& textAttributes,
                                                           const gsl::not_null<IRenderData*> pData,
                                                           const bool /*usingSoftFont*/,
                                                           const bool /*isSettingDefaultBrushes*/) noexcept
{
    RETURN_IF_FAILED(VtEngine::_RgbUpdateDrawingBrushes(textAttributes));

    RETURN_IF_FAILED(_UpdateHyperlinkAttr(textAttributes, pData));

    // Only do extended attributes in xterm-256color, as to not break telnet.exe.
    return _UpdateExtendedAttrs(textAttributes);
}

// Routine Description:
// - Write a VT sequence to update the character rendition attributes.
// Arguments:
// - textAttributes - text attributes (bold, italic, underline, etc.) to use.
// Return Value:
// - S_OK if we succeeded, else an appropriate HRESULT for failing to allocate or write.
[[nodiscard]] HRESULT Xterm256Engine::_UpdateExtendedAttrs(const TextAttribute& textAttributes) noexcept
{
    // Turning off Bold and Faint must be handled at the same time,
    // since there is only one sequence that resets both of them.
    const auto boldTurnedOff = !textAttributes.IsBold() && _lastTextAttributes.IsBold();
    const auto faintTurnedOff = !textAttributes.IsFaint() && _lastTextAttributes.IsFaint();
    if (boldTurnedOff || faintTurnedOff)
    {
        RETURN_IF_FAILED(_SetBold(false));
        _lastTextAttributes.SetBold(false);
        _lastTextAttributes.SetFaint(false);
    }

    // Once we've handled the cases where they need to be turned off,
    // we can then check if either should be turned back on again.
    if (textAttributes.IsBold() && !_lastTextAttributes.IsBold())
    {
        RETURN_IF_FAILED(_SetBold(true));
        _lastTextAttributes.SetBold(true);
    }
    if (textAttributes.IsFaint() && !_lastTextAttributes.IsFaint())
    {
        RETURN_IF_FAILED(_SetFaint(true));
        _lastTextAttributes.SetFaint(true);
    }

    // Turning off the underline styles must be handled at the same time,
    // since there is only one sequence that resets both of them.
    const auto singleTurnedOff = !textAttributes.IsUnderlined() && _lastTextAttributes.IsUnderlined();
    const auto doubleTurnedOff = !textAttributes.IsDoublyUnderlined() && _lastTextAttributes.IsDoublyUnderlined();
    if (singleTurnedOff || doubleTurnedOff)
    {
        RETURN_IF_FAILED(_SetUnderlined(false));
        _lastTextAttributes.SetUnderlined(false);
        _lastTextAttributes.SetDoublyUnderlined(false);
    }

    // Once we've handled the cases where they need to be turned off,
    // we can then check if either should be turned back on again.
    if (textAttributes.IsUnderlined() && !_lastTextAttributes.IsUnderlined())
    {
        RETURN_IF_FAILED(_SetUnderlined(true));
        _lastTextAttributes.SetUnderlined(true);
    }
    if (textAttributes.IsDoublyUnderlined() && !_lastTextAttributes.IsDoublyUnderlined())
    {
        RETURN_IF_FAILED(_SetDoublyUnderlined(true));
        _lastTextAttributes.SetDoublyUnderlined(true);
    }

    if (textAttributes.IsOverlined() != _lastTextAttributes.IsOverlined())
    {
        RETURN_IF_FAILED(_SetOverlined(textAttributes.IsOverlined()));
        _lastTextAttributes.SetOverlined(textAttributes.IsOverlined());
    }

    if (textAttributes.IsItalic() != _lastTextAttributes.IsItalic())
    {
        RETURN_IF_FAILED(_SetItalic(textAttributes.IsItalic()));
        _lastTextAttributes.SetItalic(textAttributes.IsItalic());
    }

    if (textAttributes.IsBlinking() != _lastTextAttributes.IsBlinking())
    {
        RETURN_IF_FAILED(_SetBlinking(textAttributes.IsBlinking()));
        _lastTextAttributes.SetBlinking(textAttributes.IsBlinking());
    }

    if (textAttributes.IsInvisible() != _lastTextAttributes.IsInvisible())
    {
        RETURN_IF_FAILED(_SetInvisible(textAttributes.IsInvisible()));
        _lastTextAttributes.SetInvisible(textAttributes.IsInvisible());
    }

    if (textAttributes.IsCrossedOut() != _lastTextAttributes.IsCrossedOut())
    {
        RETURN_IF_FAILED(_SetCrossedOut(textAttributes.IsCrossedOut()));
        _lastTextAttributes.SetCrossedOut(textAttributes.IsCrossedOut());
    }

    if (textAttributes.IsReverseVideo() != _lastTextAttributes.IsReverseVideo())
    {
        RETURN_IF_FAILED(_SetReverseVideo(textAttributes.IsReverseVideo()));
        _lastTextAttributes.SetReverseVideo(textAttributes.IsReverseVideo());
    }

    return S_OK;
}

// Routine Description:
// - Write a VT sequence to start/stop a hyperlink
// Arguments:
// - textAttributes - Text attributes to use for the hyperlink ID
// - pData - The interface to console data structures required for rendering
// Return Value:
// - S_OK if we succeeded, else an appropriate HRESULT for failing to allocate or write.
HRESULT Microsoft::Console::Render::Xterm256Engine::_UpdateHyperlinkAttr(const TextAttribute& textAttributes,
                                                                         const gsl::not_null<IRenderData*> pData) noexcept
{
    if (textAttributes.GetHyperlinkId() != _lastTextAttributes.GetHyperlinkId())
    {
        if (textAttributes.IsHyperlink())
        {
            const auto id = textAttributes.GetHyperlinkId();
            const auto customId = pData->GetHyperlinkCustomId(id);
            RETURN_IF_FAILED(_SetHyperlink(pData->GetHyperlinkUri(id), customId, id));
        }
        else
        {
            RETURN_IF_FAILED(_EndHyperlink());
        }
        _lastTextAttributes.SetHyperlinkId(textAttributes.GetHyperlinkId());
    }

    return S_OK;
}

// Method Description:
// - Manually emit a "Erase Scrollback" sequence to the connected terminal. We
//   need to do this in certain cases that we've identified where we believe the
//   client wanted the entire terminal buffer cleared, not just the viewport.
//   For more information, see GH#3126.
// Arguments:
// - <none>
// Return Value:
// - S_OK if we wrote the sequences successfully, otherwise an appropriate HRESULT
[[nodiscard]] HRESULT Xterm256Engine::ManuallyClearScrollback() noexcept
{
    return _ClearScrollback();
}