Reimplement TextBuffer::Reflow

src/buffer/out/Row.cpp

@@ -266,11 +266,16 @@ void ROW::TransferAttributes(const til::small_rle<TextAttribute, uint16_t, 1>& a
 
 void ROW::CopyFrom(const ROW& source)
 {
-    RowCopyTextFromState state{ .source = source };
-    CopyTextFrom(state);
-    TransferAttributes(source.Attributes(), _columnCount);
     _lineRendition = source._lineRendition;
     _wrapForced = source._wrapForced;
+
+    RowCopyTextFromState state{
+        .source = source,
+        .columnLimit = LineRenditionColumns(),
+    };
+    CopyTextFrom(state);
+
+    TransferAttributes(source.Attributes(), _columnCount);
 }
 
 // Returns the previous possible cursor position, preceding the given column.
@@ -284,7 +289,17 @@ til::CoordType ROW::NavigateToPrevious(til::CoordType column) const noexcept
 // Returns the row width if column is beyond the width of the row.
 til::CoordType ROW::NavigateToNext(til::CoordType column) const noexcept
 {
-    return _adjustForward(_clampedColumn(column + 1));
+    return _adjustForward(_clampedColumnInclusive(column + 1));
+}
+
+til::CoordType ROW::AdjustBackward(til::CoordType column) const noexcept
+{
+    return _adjustBackward(_clampedColumn(column));
+}
+
+til::CoordType ROW::AdjustForward(til::CoordType column) const noexcept
+{
+    return _adjustForward(_clampedColumnInclusive(column));
 }
 
 uint16_t ROW::_adjustBackward(uint16_t column) const noexcept
@@ -641,11 +656,12 @@ try
     if (sourceColBeg < sourceColLimit)
     {
         charOffsets = source._charOffsets.subspan(sourceColBeg, static_cast<size_t>(sourceColLimit) - sourceColBeg + 1);
-        const auto charsOffset = charOffsets.front() & CharOffsetsMask;
+        const auto beg = size_t{ charOffsets.front() } & CharOffsetsMask;
+        const auto end = size_t{ charOffsets.back() } & CharOffsetsMask;
         // We _are_ using span. But C++ decided that string_view and span aren't convertible.
         // _chars is a std::span for performance and because it refers to raw, shared memory.
 #pragma warning(suppress : 26481) // Don't use pointer arithmetic. Use span instead (bounds.1).
-        chars = { source._chars.data() + charsOffset, source._chars.size() - charsOffset };
+        chars = { source._chars.data() + beg, end - beg };
     }
 
     WriteHelper h{ *this, state.columnBegin, state.columnLimit, chars };
@@ -867,6 +883,16 @@ til::CoordType ROW::MeasureLeft() const noexcept
 
 til::CoordType ROW::MeasureRight() const noexcept
 {
+    if (_wrapForced)
+    {
+        auto width = _columnCount;
+        if (_doubleBytePadded)
+        {
+            width--;
+        }
+        return width;
+    }
+
     const auto text = GetText();
     const auto beg = text.begin();
     const auto end = text.end();

src/buffer/out/Row.hpp

@@ -114,6 +114,8 @@ class ROW final
 
     til::CoordType NavigateToPrevious(til::CoordType column) const noexcept;
     til::CoordType NavigateToNext(til::CoordType column) const noexcept;
+    til::CoordType AdjustBackward(til::CoordType column) const noexcept;
+    til::CoordType AdjustForward(til::CoordType column) const noexcept;
 
     void ClearCell(til::CoordType column);
     OutputCellIterator WriteCells(OutputCellIterator it, til::CoordType columnBegin, std::optional<bool> wrap = std::nullopt, std::optional<til::CoordType> limitRight = std::nullopt);