Experiments

src/host/_stream.cpp

@@ -97,17 +97,6 @@ static void AdjustCursorPosition(SCREEN_INFORMATION& screenInfo, _In_ til::point
         coordCursor.y = bufferSize.height - 1;
     }
 
-    const auto cursorMovedPastViewport = coordCursor.y > screenInfo.GetViewport().BottomInclusive();
-
-    // if at right or bottom edge of window, scroll right or down one char.
-    if (cursorMovedPastViewport)
-    {
-        til::point WindowOrigin;
-        WindowOrigin.x = 0;
-        WindowOrigin.y = coordCursor.y - screenInfo.GetViewport().BottomInclusive();
-        LOG_IF_FAILED(screenInfo.SetViewportOrigin(false, WindowOrigin, true));
-    }
-
     LOG_IF_FAILED(screenInfo.SetCursorPosition(coordCursor, false));
 }
 
@@ -167,7 +156,7 @@ void WriteCharsLegacy(SCREEN_INFORMATION& screenInfo, const std::wstring_view& t
     auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();
     auto writer = gci.GetVtWriterForBuffer(&screenInfo);
 
-    screenInfo.SnapOnOutput();
+    const auto snap = screenInfo.SnapOnOutput();
 
     // If we enter this if condition, then someone wrote text in VT mode and now switched to non-VT mode.
     // Since the Console APIs don't support delayed EOL wrapping, we need to first put the cursor back
@@ -208,7 +197,6 @@ void WriteCharsLegacy(SCREEN_INFORMATION& screenInfo, const std::wstring_view& t
             writer.Submit();
         }
 
-        screenInfo.SnapOnOutput();
         return;
     }
 
@@ -331,8 +319,6 @@ void WriteCharsLegacy(SCREEN_INFORMATION& screenInfo, const std::wstring_view& t
     {
         writer.Submit();
     }
-
-    screenInfo.SnapOnOutput();
 }
 
 // This is the main entrypoint for conhost to write VT to the buffer.
@@ -345,7 +331,7 @@ void WriteCharsVT(SCREEN_INFORMATION& screenInfo, const std::wstring_view& str)
     // may change, so get the VtIo reference now, just in case.
     auto writer = gci.GetVtWriterForBuffer(&screenInfo);
 
-    screenInfo.SnapOnOutput();
+    const auto snap = screenInfo.SnapOnOutput();
 
     stateMachine.ProcessString(str);
 
@@ -387,8 +373,6 @@ void WriteCharsVT(SCREEN_INFORMATION& screenInfo, const std::wstring_view& str)
         write(offset, std::wstring_view::npos);
         writer.Submit();
     }
-
-    screenInfo.SnapOnOutput();
 }
 
 // Erases all contents of the given screenInfo, including the current screen and scrollback.

src/host/screenInfo.cpp

@@ -1685,24 +1685,6 @@ static constexpr bool IsInputKey(WORD vkey)
 }
 
 void SCREEN_INFORMATION::MakeCursorVisible(til::point position)
-{
-    _makeLocationVisible(position, true, true);
-}
-
-void SCREEN_INFORMATION::SnapOnInput(const WORD vkey)
-{
-    if (IsInputKey(vkey))
-    {
-        _makeLocationVisible(_textBuffer->GetCursor().GetPosition(), true, false);
-    }
-}
-
-void SCREEN_INFORMATION::SnapOnOutput()
-{
-    _makeLocationVisible(_textBuffer->GetCursor().GetPosition(), false, true);
-}
-
-void SCREEN_INFORMATION::_makeLocationVisible(til::point position, bool vertical, bool horizontal)
 {
     const auto viewportOrigin = _viewport.Origin();
     const auto viewportSize = _viewport.Dimensions();
@@ -1713,21 +1695,31 @@ void SCREEN_INFORMATION::_makeLocationVisible(til::point position, bool vertical
     position.x = std::clamp(position.x, 0, bufferSize.width - 1);
     position.y = std::clamp(position.y, 0, bufferSize.height - 1);
 
-    if (vertical)
+    origin.y = std::min(origin.y, position.y); // shift up if above
+    origin.y = std::max(origin.y, position.y - (viewportSize.height - 1)); // shift down if below
+
+    origin.x = std::min(origin.x, position.x); // shift left if left
+    origin.x = std::max(origin.x, position.x - (viewportSize.width - 1)); // shift right if right
+
+    if (origin != viewportOrigin)
     {
-        origin.y = std::min(origin.y, position.y); // shift up if above
-        origin.y = std::max(origin.y, position.y - (viewportSize.height - 1)); // shift down if below
+        std::ignore = SetViewportOrigin(true, origin, false);
     }
+}
 
-    if (horizontal)
+void SCREEN_INFORMATION::SnapOnInput(const WORD vkey)
+{
+    if (IsInputKey(vkey))
     {
-        origin.x = std::min(origin.x, position.x); // shift left if left
-        origin.x = std::max(origin.x, position.x - (viewportSize.width - 1)); // shift right if right
+        _makeCursorVisible();
     }
+}
 
-    if (origin != viewportOrigin)
+void SCREEN_INFORMATION::_makeCursorVisible()
+{
+    if (_textBuffer->GetCursor().IsOn())
     {
-        std::ignore = SetViewportOrigin(true, origin, false);
+        MakeCursorVisible(_textBuffer->GetCursor().GetPosition());
     }
 }
 

src/host/screenInfo.hpp

@@ -73,7 +73,16 @@ class SCREEN_INFORMATION : public ConsoleObjectHeader, public Microsoft::Console
     void MakeCurrentCursorVisible();
     void MakeCursorVisible(til::point position);
     void SnapOnInput(WORD vkey);
-    void SnapOnOutput();
+    auto SnapOnOutput()
+    {
+        const auto inBounds = _viewport.IsInBounds(_textBuffer->GetCursor().GetPosition());
+        return wil::scope_exit([this, inBounds]() {
+            if (inBounds)
+            {
+                _makeCursorVisible();
+            }
+        });
+    }
 
     void ClipToScreenBuffer(_Inout_ til::inclusive_rect* const psrClip) const;
 
@@ -233,7 +242,7 @@ class SCREEN_INFORMATION : public ConsoleObjectHeader, public Microsoft::Console
     void _CalculateViewportSize(const til::rect* const prcClientArea, _Out_ til::size* const pcoordSize);
     void _AdjustViewportSize(const til::rect* const prcClientNew, const til::rect* const prcClientOld, const til::size* const pcoordSize);
     void _InternalSetViewportSize(const til::size* pcoordSize, const bool fResizeFromTop, const bool fResizeFromLeft);
-    void _makeLocationVisible(til::point position, bool vertical, bool horizontal);
+    void _makeCursorVisible();
 
     static void s_CalculateScrollbarVisibility(const til::rect* const prcClientArea,
                                                const til::size* const pcoordBufferSize,