Add support for the DECRQM escape sequence (#14444)

This PR adds support for the `DECRQM` (Request Mode) escape sequence,
which allows applications to query the state of the various modes
supported by the terminal. It also adds support for the `DECNKM` mode,
which aliases the existing `DECKPAM` and `DECKPNM` operations, so they
can be queried with `DECRQM` too.

This is one solution for #10153 (saving and restoring the state of
bracketed paste mode), and should also help with #1040 (providing a way
for clients to determine the capabilities of the terminal).

Prior to adding `DECRQM`, I also did some refactoring of the mode
handling to get rid of the mode setting methods in the `ITermDispatch`
interface that had no need to be there. Most of them were essentially a
single line of code that could easily be executed directly from the
`_ModeParamsHelper` handler anyway.

As part of this refactoring I combined all the internal `AdaptDispatch`
modes into an `enumset` to allow for easier management, and made sure
all modes were correctly reset in the `HardReset` method (prior to this,
there were a number of modes that we weren't restoring when we should
have been).

And note that there are some differences in behavior between conhost and
Windows Terminal. In conhost, `DECRQM` will report bracketed paste mode
as unsupported, and in Terminal, both `DECCOLM` and `AllowDECCOLM` are
reported as unsupported. And `DECCOLM` is now explicitly ignored in
conpty mode, to avoid the conpty client and conhost getting out of sync.
 
## Validation Steps Performed

I've manually confirmed that all the supported modes are reported in the
`DECRQM` tests in Vttest, and I have my own test scripts which I've used
to confirm that `RIS` is now resetting the modes correctly.

I've also added a unit test in `AdapterTest` that iterates through the
modes, checking the responses from `DECRQM` for both the set and reset
states.

I should also mention that I had to do some refactoring of the existing
tests to compensate for methods that were removed from `ITermDispatch`,
particularly in `OutputEngineTest`. In many cases, though, these tests
weren't doing much more than testing the test framework.

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

@@ -61,7 +61,6 @@ argb
 ARRAYSIZE
 ARROWKEYS
 asan
-ASBRST
 ASBSET
 ASDF
 asdfghjkl
@@ -433,6 +432,7 @@ DECRARA
 DECRC
 DECREQTPARM
 DECRLM
+DECRPM
 DECRQM
 DECRQSS
 DECRQTSR

src/buffer/out/cursor.cpp

@@ -101,6 +101,13 @@ void Cursor::SetIsOn(const bool fIsOn) noexcept
 void Cursor::SetBlinkingAllowed(const bool fBlinkingAllowed) noexcept
 {
     _fBlinkingAllowed = fBlinkingAllowed;
+    // GH#2642 - From what we've gathered from other terminals, when blinking is
+    // disabled, the cursor should remain On always, and have the visibility
+    // controlled by the IsVisible property. So when you do a printf "\e[?12l"
+    // to disable blinking, the cursor stays stuck On. At this point, only the
+    // cursor visibility property controls whether the user can see it or not.
+    // (Yes, the cursor can be On and NOT Visible)
+    _fIsOn = true;
     _RedrawCursorAlways();
 }
 

src/cascadia/TerminalCore/Terminal.hpp

@@ -115,6 +115,7 @@ class Microsoft::Terminal::Core::Terminal final :
     void SetViewportPosition(const til::point position) noexcept override;
     void SetTextAttributes(const TextAttribute& attrs) noexcept override;
     void SetAutoWrapMode(const bool wrapAtEOL) noexcept override;
+    bool GetAutoWrapMode() const noexcept override;
     void SetScrollingRegion(const til::inclusive_rect& scrollMargins) noexcept override;
     void WarningBell() override;
     bool GetLineFeedMode() const noexcept override;
@@ -124,7 +125,8 @@ class Microsoft::Terminal::Core::Terminal final :
     bool ResizeWindow(const til::CoordType width, const til::CoordType height) noexcept override;
     void SetConsoleOutputCP(const unsigned int codepage) noexcept override;
     unsigned int GetConsoleOutputCP() const noexcept override;
-    void EnableXtermBracketedPasteMode(const bool enabled) noexcept override;
+    void SetBracketedPasteMode(const bool enabled) noexcept override;
+    std::optional<bool> GetBracketedPasteMode() const noexcept override;
     void CopyToClipboard(std::wstring_view content) override;
     void SetTaskbarProgress(const ::Microsoft::Console::VirtualTerminal::DispatchTypes::TaskbarState state, const size_t progress) override;
     void SetWorkingDirectory(std::wstring_view uri) override;

src/cascadia/TerminalCore/TerminalApi.cpp

@@ -60,6 +60,12 @@ void Terminal::SetAutoWrapMode(const bool /*wrapAtEOL*/) noexcept
     // TODO: This will be needed to support DECAWM.
 }
 
+bool Terminal::GetAutoWrapMode() const noexcept
+{
+    // TODO: This will be needed to support DECAWM.
+    return true;
+}
+
 void Terminal::SetScrollingRegion(const til::inclusive_rect& /*scrollMargins*/) noexcept
 {
     // TODO: This will be needed to fully support DECSTBM.
@@ -123,11 +129,16 @@ unsigned int Terminal::GetConsoleOutputCP() const noexcept
     return CP_UTF8;
 }
 
-void Terminal::EnableXtermBracketedPasteMode(const bool enabled) noexcept
+void Terminal::SetBracketedPasteMode(const bool enabled) noexcept
 {
     _bracketedPasteMode = enabled;
 }
 
+std::optional<bool> Terminal::GetBracketedPasteMode() const noexcept
+{
+    return _bracketedPasteMode;
+}
+
 void Terminal::CopyToClipboard(std::wstring_view content)
 {
     _pfnCopyToClipboard(content);

src/host/outputStream.cpp

@@ -159,6 +159,18 @@ void ConhostInternalGetSet::SetAutoWrapMode(const bool wrapAtEOL)
     WI_UpdateFlag(outputMode, ENABLE_WRAP_AT_EOL_OUTPUT, wrapAtEOL);
 }
 
+// Routine Description:
+// - Retrieves the current state of ENABLE_WRAP_AT_EOL_OUTPUT mode.
+// Arguments:
+// - <none>
+// Return Value:
+// - true if the mode is enabled. false otherwise.
+bool ConhostInternalGetSet::GetAutoWrapMode() const
+{
+    const auto outputMode = _io.GetActiveOutputBuffer().OutputMode;
+    return WI_IsFlagSet(outputMode, ENABLE_WRAP_AT_EOL_OUTPUT);
+}
+
 // Routine Description:
 // - Sets the top and bottom scrolling margins for the current page. This creates
 //     a subsection of the screen that scrolls when input reaches the end of the
@@ -325,9 +337,24 @@ unsigned int ConhostInternalGetSet::GetConsoleOutputCP() const
 // - enable - set to true to enable bracketing, false to disable.
 // Return Value:
 // - <none>
-void ConhostInternalGetSet::EnableXtermBracketedPasteMode(const bool /*enabled*/)
+void ConhostInternalGetSet::SetBracketedPasteMode(const bool enabled)
 {
-    // TODO
+    // TODO GH#395: Bracketed Paste Mode is not yet supported in conhost, but we
+    // still keep track of the state so it can be reported by DECRQM.
+    _bracketedPasteMode = enabled;
+}
+
+// Routine Description:
+// - Gets the current state of XTerm bracketed paste mode.
+// Arguments:
+// - <none>
+// Return Value:
+// - true if the mode is enabled, false if not, nullopt if unsupported.
+std::optional<bool> ConhostInternalGetSet::GetBracketedPasteMode() const
+{
+    // TODO GH#395: Bracketed Paste Mode is not yet supported in conhost, so we
+    // only report the state if we're tracking it for conpty.
+    return IsConsolePty() ? std::optional{ _bracketedPasteMode } : std::nullopt;
 }
 
 // Routine Description:

src/host/outputStream.hpp

@@ -40,6 +40,7 @@ class ConhostInternalGetSet final : public Microsoft::Console::VirtualTerminal::
     void SetTextAttributes(const TextAttribute& attrs) override;
 
     void SetAutoWrapMode(const bool wrapAtEOL) override;
+    bool GetAutoWrapMode() const override;
 
     void SetScrollingRegion(const til::inclusive_rect& scrollMargins) override;
 
@@ -63,7 +64,8 @@ class ConhostInternalGetSet final : public Microsoft::Console::VirtualTerminal::
     void SetConsoleOutputCP(const unsigned int codepage) override;
     unsigned int GetConsoleOutputCP() const override;
 
-    void EnableXtermBracketedPasteMode(const bool enabled) override;
+    void SetBracketedPasteMode(const bool enabled) override;
+    std::optional<bool> GetBracketedPasteMode() const override;
     void CopyToClipboard(const std::wstring_view content) override;
     void SetTaskbarProgress(const ::Microsoft::Console::VirtualTerminal::DispatchTypes::TaskbarState state, const size_t progress) override;
     void SetWorkingDirectory(const std::wstring_view uri) override;
@@ -78,4 +80,5 @@ class ConhostInternalGetSet final : public Microsoft::Console::VirtualTerminal::
 
 private:
     Microsoft::Console::IIoProvider& _io;
+    bool _bracketedPasteMode{ false };
 };

src/terminal/adapter/DispatchTypes.hpp

@@ -403,6 +403,7 @@ namespace Microsoft::Console::VirtualTerminal::DispatchTypes
         ATT610_StartCursorBlink = DECPrivateMode(12),
         DECTCEM_TextCursorEnableMode = DECPrivateMode(25),
         XTERM_EnableDECCOLMSupport = DECPrivateMode(40),
+        DECNKM_NumericKeypadMode = DECPrivateMode(66),
         DECBKM_BackarrowKeyMode = DECPrivateMode(67),
         VT200_MOUSE_MODE = DECPrivateMode(1000),
         BUTTON_EVENT_MOUSE_MODE = DECPrivateMode(1002),

src/terminal/adapter/ITermDispatch.hpp

@@ -45,43 +45,24 @@ class Microsoft::Console::VirtualTerminal::ITermDispatch
     virtual bool CursorPosition(const VTInt line, const VTInt column) = 0; // CUP, HVP
     virtual bool CursorSaveState() = 0; // DECSC
     virtual bool CursorRestoreState() = 0; // DECRC
-    virtual bool CursorVisibility(const bool isVisible) = 0; // DECTCEM
     virtual bool InsertCharacter(const VTInt count) = 0; // ICH
     virtual bool DeleteCharacter(const VTInt count) = 0; // DCH
     virtual bool ScrollUp(const VTInt distance) = 0; // SU
     virtual bool ScrollDown(const VTInt distance) = 0; // SD
     virtual bool InsertLine(const VTInt distance) = 0; // IL
     virtual bool DeleteLine(const VTInt distance) = 0; // DL
-    virtual bool SetColumns(const VTInt columns) = 0; // DECCOLM
-    virtual bool SetCursorKeysMode(const bool applicationMode) = 0; // DECCKM
     virtual bool SetKeypadMode(const bool applicationMode) = 0; // DECKPAM, DECKPNM
-    virtual bool EnableWin32InputMode(const bool win32InputMode) = 0; // win32-input-mode
-    virtual bool EnableCursorBlinking(const bool enable) = 0; // ATT610
     virtual bool SetAnsiMode(const bool ansiMode) = 0; // DECANM
-    virtual bool SetScreenMode(const bool reverseMode) = 0; // DECSCNM
-    virtual bool SetOriginMode(const bool relativeMode) = 0; // DECOM
-    virtual bool SetAutoWrapMode(const bool wrapAtEOL) = 0; // DECAWM
     virtual bool SetTopBottomScrollingMargins(const VTInt topMargin, const VTInt bottomMargin) = 0; // DECSTBM
     virtual bool WarningBell() = 0; // BEL
     virtual bool CarriageReturn() = 0; // CR
     virtual bool LineFeed(const DispatchTypes::LineFeedType lineFeedType) = 0; // IND, NEL, LF, FF, VT
     virtual bool ReverseLineFeed() = 0; // RI
     virtual bool SetWindowTitle(std::wstring_view title) = 0; // OscWindowTitle
-    virtual bool UseAlternateScreenBuffer() = 0; // ASBSET
-    virtual bool UseMainScreenBuffer() = 0; // ASBRST
     virtual bool HorizontalTabSet() = 0; // HTS
     virtual bool ForwardTab(const VTInt numTabs) = 0; // CHT, HT
     virtual bool BackwardsTab(const VTInt numTabs) = 0; // CBT
     virtual bool TabClear(const DispatchTypes::TabClearType clearType) = 0; // TBC
-    virtual bool EnableDECCOLMSupport(const bool enabled) = 0; // ?40
-    virtual bool EnableVT200MouseMode(const bool enabled) = 0; // ?1000
-    virtual bool EnableUTF8ExtendedMouseMode(const bool enabled) = 0; // ?1005
-    virtual bool EnableSGRExtendedMouseMode(const bool enabled) = 0; // ?1006
-    virtual bool EnableButtonEventMouseMode(const bool enabled) = 0; // ?1002
-    virtual bool EnableAnyEventMouseMode(const bool enabled) = 0; // ?1003
-    virtual bool EnableFocusEventMode(const bool enabled) = 0; // ?1004
-    virtual bool EnableAlternateScroll(const bool enabled) = 0; // ?1007
-    virtual bool EnableXtermBracketedPasteMode(const bool enabled) = 0; // ?2004
     virtual bool SetColorTableEntry(const size_t tableIndex, const DWORD color) = 0; // OSCColorTable
     virtual bool SetDefaultForeground(const DWORD color) = 0; // OSCDefaultForeground
     virtual bool SetDefaultBackground(const DWORD color) = 0; // OSCDefaultBackground
@@ -109,8 +90,8 @@ class Microsoft::Console::VirtualTerminal::ITermDispatch
     virtual bool PopGraphicsRendition() = 0; // XTPOPSGR
 
     virtual bool SetMode(const DispatchTypes::ModeParams param) = 0; // DECSET
-
     virtual bool ResetMode(const DispatchTypes::ModeParams param) = 0; // DECRST
+    virtual bool RequestMode(const DispatchTypes::ModeParams param) = 0; // DECRQM
 
     virtual bool DeviceStatusReport(const DispatchTypes::StatusType statusType) = 0; // DSR, DSR-OS, DSR-CPR
     virtual bool DeviceAttributes() = 0; // DA1

src/terminal/adapter/ITerminalApi.hpp

@@ -50,6 +50,7 @@ namespace Microsoft::Console::VirtualTerminal
         virtual void SetTextAttributes(const TextAttribute& attrs) = 0;
 
         virtual void SetAutoWrapMode(const bool wrapAtEOL) = 0;
+        virtual bool GetAutoWrapMode() const = 0;
 
         virtual void SetScrollingRegion(const til::inclusive_rect& scrollMargins) = 0;
         virtual void WarningBell() = 0;
@@ -66,7 +67,8 @@ namespace Microsoft::Console::VirtualTerminal
         virtual void SetConsoleOutputCP(const unsigned int codepage) = 0;
         virtual unsigned int GetConsoleOutputCP() const = 0;
 
-        virtual void EnableXtermBracketedPasteMode(const bool enabled) = 0;
+        virtual void SetBracketedPasteMode(const bool enabled) = 0;
+        virtual std::optional<bool> GetBracketedPasteMode() const = 0;
         virtual void CopyToClipboard(const std::wstring_view content) = 0;
         virtual void SetTaskbarProgress(const DispatchTypes::TaskbarState state, const size_t progress) = 0;
         virtual void SetWorkingDirectory(const std::wstring_view uri) = 0;