Implement XTPUSHSGR, XTPOPSGR

This change adds a new pair of methods to ITermDispatch:
PushGraphicsRendition and PopGraphicsRendition, and then plumbs the
change through AdaptDispatch, TerminalDispatch, ITerminalApi and
TerminalApi.

The stack logic is encapsulated in the SgrStack class, to allow it to be
reused between the two APIs (AdaptDispatch and TerminalDispatch).

Like xterm, only ten levels of nesting are supported.

The stack is implemented as a "ring stack": if you push when the stack
is full, the bottom of the stack will be dropped to make room.

.github/actions/spell-check/expect/expect.txt

@@ -2368,6 +2368,7 @@ tosign
 touchpad
 towlower
 towupper
+TParam
 Tpp
 Tpqrst
 tprivapi
@@ -2798,6 +2799,8 @@ XSubstantial
 xtended
 xterm
 XTest
+XTPUSHSGR
+XTPOPSGR
 xutr
 xvalue
 XVIRTUALSCREEN

src/buffer/out/TextAttribute.cpp

@@ -81,6 +81,32 @@ bool TextAttribute::IsLegacy() const noexcept
     return _foreground.IsLegacy() && _background.IsLegacy();
 }
 
+// Routine Description:
+// - Makes this TextAttribute's foreground color the same as the other one.
+// Arguments:
+// - The TextAttribute to copy the foreground color from
+// Return Value:
+// - <none>
+void TextAttribute::SetForegroundFrom(const TextAttribute& other) noexcept
+{
+    _foreground = other._foreground;
+    WI_ClearAllFlags(_wAttrLegacy, FG_ATTRS);
+    _wAttrLegacy |= (other._wAttrLegacy & FG_ATTRS);
+}
+
+// Routine Description:
+// - Makes this TextAttribute's background color the same as the other one.
+// Arguments:
+// - The TextAttribute to copy the background color from
+// Return Value:
+// - <none>
+void TextAttribute::SetBackgroundFrom(const TextAttribute& other) noexcept
+{
+    _background = other._background;
+    WI_ClearAllFlags(_wAttrLegacy, BG_ATTRS);
+    _wAttrLegacy |= (other._wAttrLegacy & BG_ATTRS);
+}
+
 // Routine Description:
 // - Calculates rgb colors based off of current color table and active modification attributes.
 // Arguments:
@@ -255,6 +281,11 @@ bool TextAttribute::IsOverlined() const noexcept
     return WI_IsFlagSet(_wAttrLegacy, COMMON_LVB_GRID_HORIZONTAL);
 }
 
+bool TextAttribute::IsDoublyUnderlined() const noexcept
+{
+    return WI_IsFlagSet(_extendedAttrs, ExtendedAttributes::DoublyUnderlined);
+}
+
 bool TextAttribute::IsReverseVideo() const noexcept
 {
     return WI_IsFlagSet(_wAttrLegacy, COMMON_LVB_REVERSE_VIDEO);
@@ -301,6 +332,11 @@ void TextAttribute::SetOverlined(bool isOverlined) noexcept
     WI_UpdateFlag(_wAttrLegacy, COMMON_LVB_GRID_HORIZONTAL, isOverlined);
 }
 
+void TextAttribute::SetDoublyUnderlined(bool isDoublyUnderlined) noexcept
+{
+    WI_UpdateFlag(_extendedAttrs, ExtendedAttributes::DoublyUnderlined, isDoublyUnderlined);
+}
+
 void TextAttribute::SetReverseVideo(bool isReversed) noexcept
 {
     WI_UpdateFlag(_wAttrLegacy, COMMON_LVB_REVERSE_VIDEO, isReversed);

src/buffer/out/TextAttribute.hpp

@@ -68,6 +68,9 @@ class TextAttribute final
                                                      const COLORREF defaultBgColor,
                                                      const bool reverseScreenMode = false) const noexcept;
 
+    void SetForegroundFrom(const TextAttribute& other) noexcept;
+    void SetBackgroundFrom(const TextAttribute& other) noexcept;
+
     bool IsLeadingByte() const noexcept;
     bool IsTrailingByte() const noexcept;
     bool IsTopHorizontalDisplayed() const noexcept;
@@ -96,6 +99,7 @@ class TextAttribute final
     bool IsCrossedOut() const noexcept;
     bool IsUnderlined() const noexcept;
     bool IsOverlined() const noexcept;
+    bool IsDoublyUnderlined() const noexcept;
     bool IsReverseVideo() const noexcept;
 
     void SetBold(bool isBold) noexcept;
@@ -106,6 +110,7 @@ class TextAttribute final
     void SetCrossedOut(bool isCrossedOut) noexcept;
     void SetUnderlined(bool isUnderlined) noexcept;
     void SetOverlined(bool isOverlined) noexcept;
+    void SetDoublyUnderlined(bool isDoublyUnderlined) noexcept;
     void SetReverseVideo(bool isReversed) noexcept;
 
     ExtendedAttributes GetExtendedAttributes() const noexcept;

src/cascadia/TerminalCore/ITerminalApi.hpp

@@ -58,6 +58,9 @@ namespace Microsoft::Terminal::Core
 
         virtual bool CopyToClipboard(std::wstring_view content) noexcept = 0;
 
+        virtual bool PushGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::SgrSaveRestoreStackOptions> options) noexcept = 0;
+        virtual bool PopGraphicsRendition() noexcept = 0;
+
     protected:
         ITerminalApi() = default;
     };

src/cascadia/TerminalCore/Terminal.hpp

@@ -6,6 +6,7 @@
 #include <conattrs.hpp>
 
 #include "../../buffer/out/textBuffer.hpp"
+#include "../../types/inc/sgrStack.hpp"
 #include "../../renderer/inc/IRenderData.hpp"
 #include "../../terminal/parser/StateMachine.hpp"
 #include "../../terminal/input/terminalInput.hpp"
@@ -110,6 +111,9 @@ class Microsoft::Terminal::Core::Terminal final :
     bool IsVtInputEnabled() const noexcept override;
 
     bool CopyToClipboard(std::wstring_view content) noexcept override;
+
+    bool PushGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::SgrSaveRestoreStackOptions> options) noexcept override;
+    bool PopGraphicsRendition() noexcept override;
 #pragma endregion
 
 #pragma region ITerminalInput
@@ -295,6 +299,8 @@ class Microsoft::Terminal::Core::Terminal final :
     COORD _ConvertToBufferCell(const COORD viewportPos) const;
 #pragma endregion
 
+    Microsoft::Console::VirtualTerminal::SgrStack _sgrStack;
+
 #ifdef UNIT_TESTING
     friend class TerminalCoreUnitTests::TerminalBufferTests;
     friend class TerminalCoreUnitTests::TerminalApiTest;

src/cascadia/TerminalCore/TerminalApi.cpp

@@ -552,3 +552,31 @@ try
     return true;
 }
 CATCH_LOG_RETURN_FALSE()
+
+// Method Description:
+// - Saves the current text attributes to an internal stack.
+// Arguments:
+// - options, cOptions: if present, specify which portions of the current text attributes
+//   should be saved. Only a small subset of GraphicsOptions are actually supported;
+//   others are ignored. If no options are specified, all attributes are stored.
+// Return Value:
+// - true
+bool Terminal::PushGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::SgrSaveRestoreStackOptions> options) noexcept
+{
+    _sgrStack.Push(_buffer->GetCurrentAttributes(), options);
+    return true;
+}
+
+// Method Description:
+// - Restores text attributes from the internal stack. If only portions of text attributes
+//   were saved, combines those with the current attributes.
+// Arguments:
+// - <none>
+// Return Value:
+// - true
+bool Terminal::PopGraphicsRendition() noexcept
+{
+    const TextAttribute current = _buffer->GetCurrentAttributes();
+    _buffer->SetCurrentAttributes(_sgrStack.Pop(current));
+    return true;
+}

src/cascadia/TerminalCore/TerminalDispatch.hpp

@@ -15,6 +15,9 @@ class TerminalDispatch : public Microsoft::Console::VirtualTerminal::TermDispatc
 
     bool SetGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::GraphicsOptions> options) noexcept override;
 
+    bool PushGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::SgrSaveRestoreStackOptions> options) noexcept override;
+    bool PopGraphicsRendition() noexcept override;
+
     bool CursorPosition(const size_t line,
                         const size_t column) noexcept override; // CUP
 

src/cascadia/TerminalCore/TerminalDispatchGraphics.cpp

@@ -275,3 +275,13 @@ bool TerminalDispatch::SetGraphicsRendition(const gsl::span<const DispatchTypes:
     _terminalApi.SetTextAttributes(attr);
     return true;
 }
+
+bool TerminalDispatch::PushGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::SgrSaveRestoreStackOptions> options) noexcept
+{
+    return _terminalApi.PushGraphicsRendition(options);
+}
+
+bool TerminalDispatch::PopGraphicsRendition() noexcept
+{
+    return _terminalApi.PopGraphicsRendition();
+}

src/terminal/adapter/DispatchTypes.hpp

@@ -75,6 +75,40 @@ namespace Microsoft::Console::VirtualTerminal::DispatchTypes
         BrightBackgroundWhite = 107,
     };
 
+    // Many of these correspond directly to SGR parameters (the GraphicsOptions enum), but
+    // these are distinct (notably 10 and 11, which as SGR parameters would select fonts,
+    // are used here to indicate that the foreground/background colors should be saved).
+    // From xterm's ctlseqs doc for XTPUSHSGR:
+    //
+    //      Ps = 1    =>  Bold.
+    //      Ps = 2    =>  Faint.
+    //      Ps = 3    =>  Italicized.
+    //      Ps = 4    =>  Underlined.
+    //      Ps = 5    =>  Blink.
+    //      Ps = 7    =>  Inverse.
+    //      Ps = 8    =>  Invisible.
+    //      Ps = 9    =>  Crossed-out characters.
+    //      Ps = 1 0  =>  Foreground color.
+    //      Ps = 1 1  =>  Background color.
+    //      Ps = 2 1  =>  Doubly-underlined.
+    //
+    enum class SgrSaveRestoreStackOptions : unsigned int
+    {
+        Nothing = 0,
+        Boldness = 1,
+        Faintness = 2,
+        Italics = 3,
+        Underline = 4,
+        Blink = 5,
+        Negative = 7,
+        Invisible = 8,
+        CrossedOut = 9,
+        SaveForegroundColor = 10,
+        SaveBackgroundColor = 11,
+        DoublyUnderlined = 21,
+        Max = DoublyUnderlined
+    };
+
     enum class AnsiStatusType : unsigned int
     {
         OS_OperatingStatus = 5,

src/terminal/adapter/ITermDispatch.hpp

@@ -88,6 +88,9 @@ class Microsoft::Console::VirtualTerminal::ITermDispatch
 
     virtual bool SetGraphicsRendition(const gsl::span<const DispatchTypes::GraphicsOptions> options) = 0; // SGR
 
+    virtual bool PushGraphicsRendition(const gsl::span<const DispatchTypes::SgrSaveRestoreStackOptions> options) = 0; // XTPUSHSGR
+    virtual bool PopGraphicsRendition() = 0; // XTPOPSGR
+
     virtual bool SetPrivateModes(const gsl::span<const DispatchTypes::PrivateModeParams> params) = 0; // DECSET
 
     virtual bool ResetPrivateModes(const gsl::span<const DispatchTypes::PrivateModeParams> params) = 0; // DECRST

src/terminal/adapter/adaptDispatch.hpp

@@ -19,6 +19,7 @@ Author(s):
 #include "conGetSet.hpp"
 #include "adaptDefaults.hpp"
 #include "terminalOutput.hpp"
+#include "..\..\types\inc\sgrStack.hpp"
 
 namespace Microsoft::Console::VirtualTerminal
 {
@@ -56,6 +57,8 @@ namespace Microsoft::Console::VirtualTerminal
         bool InsertCharacter(const size_t count) override; // ICH
         bool DeleteCharacter(const size_t count) override; // DCH
         bool SetGraphicsRendition(const gsl::span<const DispatchTypes::GraphicsOptions> options) override; // SGR
+        bool PushGraphicsRendition(const gsl::span<const DispatchTypes::SgrSaveRestoreStackOptions> options) override; // XTPUSHSGR
+        bool PopGraphicsRendition() override; // XTPOPSGR
         bool DeviceStatusReport(const DispatchTypes::AnsiStatusType statusType) override; // DSR, DSR-OS, DSR-CPR
         bool DeviceAttributes() override; // DA1
         bool SecondaryDeviceAttributes() override; // DA2
@@ -192,6 +195,8 @@ namespace Microsoft::Console::VirtualTerminal
 
         bool _isDECCOLMAllowed;
 
+        SgrStack _sgrStack;
+
         size_t _SetRgbColorsHelper(const gsl::span<const DispatchTypes::GraphicsOptions> options,
                                    TextAttribute& attr,
                                    const bool isForeground) noexcept;

src/terminal/adapter/adaptDispatchGraphics.cpp

@@ -155,6 +155,9 @@ bool AdaptDispatch::SetGraphicsRendition(const gsl::span<const DispatchTypes::Gr
             case CrossedOut:
                 attr.SetCrossedOut(true);
                 break;
+            case DoublyUnderlined:
+                attr.SetDoublyUnderlined(true);
+                break;
             case NotCrossedOut:
                 attr.SetCrossedOut(false);
                 break;
@@ -285,3 +288,48 @@ bool AdaptDispatch::SetGraphicsRendition(const gsl::span<const DispatchTypes::Gr
 
     return success;
 }
+
+// Method Description:
+// - Saves the current text attributes to an internal stack.
+// Arguments:
+// - options: if not empty, specify which portions of the current text attributes should
+//   be saved. Options that are not supported are ignored. If no options are specified,
+//   all attributes are stored.
+// Return Value:
+// - True if handled successfully. False otherwise.
+bool AdaptDispatch::PushGraphicsRendition(const gsl::span<const ::Microsoft::Console::VirtualTerminal::DispatchTypes::SgrSaveRestoreStackOptions> options)
+{
+    bool success = true;
+    TextAttribute currentAttributes;
+
+    success = _pConApi->PrivateGetTextAttributes(currentAttributes);
+
+    if (success)
+    {
+        _sgrStack.Push(currentAttributes, options);
+    }
+
+    return success;
+}
+
+// Method Description:
+// - Restores text attributes from the internal stack. If only portions of text attributes
+//   were saved, combines those with the current attributes.
+// Arguments:
+// - <none>
+// Return Value:
+// - True if handled successfully. False otherwise.
+bool AdaptDispatch::PopGraphicsRendition()
+{
+    bool success = true;
+    TextAttribute currentAttributes;
+
+    success = _pConApi->PrivateGetTextAttributes(currentAttributes);
+
+    if (success)
+    {
+        success = _pConApi->PrivateSetTextAttributes(_sgrStack.Pop(currentAttributes));
+    }
+
+    return success;
+}

src/terminal/adapter/termDispatch.hpp

@@ -82,6 +82,9 @@ class Microsoft::Console::VirtualTerminal::TermDispatch : public Microsoft::Cons
 
     bool SetGraphicsRendition(const gsl::span<const DispatchTypes::GraphicsOptions> /*options*/) noexcept override { return false; } // SGR
 
+    bool PushGraphicsRendition(const gsl::span<const DispatchTypes::SgrSaveRestoreStackOptions> /*options*/) noexcept override { return false; } // XTPUSHSGR
+    bool PopGraphicsRendition() noexcept override { return false; } // XTPOPSGR
+
     bool SetPrivateModes(const gsl::span<const DispatchTypes::PrivateModeParams> /*params*/) noexcept override { return false; } // DECSET
 
     bool ResetPrivateModes(const gsl::span<const DispatchTypes::PrivateModeParams> /*params*/) noexcept override { return false; } // DECRST

src/terminal/adapter/ut_adapter/Adapter.UnitTests.vcxproj

@@ -57,6 +57,9 @@
     <ProjectReference Include="..\lib\adapter.vcxproj">
       <Project>{dcf55140-ef6a-4736-a403-957e4f7430bb}</Project>
     </ProjectReference>
+    <ProjectReference Include="..\..\..\buffer\out\lib\bufferout.vcxproj">
+      <Project>{0cf235bd-2da0-407e-90ee-c467e8bbc714}</Project>
+    </ProjectReference>
   </ItemGroup>
   <ItemDefinitionGroup>
     <ClCompile>