Avoid covering current search highlight with search box (#17516)

## Summary of the Pull Request
Adds a scroll offset to avoid hiding the current search highlight with
the search box.
- Offset is based on the number of rows that the search box takes up.
  (I am not totally sure I am calculating this right)
- This won't help when the current highlight is in the first couple
  rows of the buffer.

Fixes: #4407

src/cascadia/TerminalControl/ControlCore.cpp

@@ -1689,22 +1689,22 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     // - resetOnly: If true, only Reset() will be called, if anything. FindNext() will never be called.
     // Return Value:
     // - <none>
-    SearchResults ControlCore::Search(const std::wstring_view& text, const bool goForward, const bool caseSensitive, const bool regularExpression, const bool resetOnly)
+    SearchResults ControlCore::Search(SearchRequest request)
     {
         const auto lock = _terminal->LockForWriting();
         SearchFlag flags{};
-        WI_SetFlagIf(flags, SearchFlag::CaseInsensitive, !caseSensitive);
+        WI_SetFlagIf(flags, SearchFlag::CaseInsensitive, !request.CaseSensitive);
-        WI_SetFlagIf(flags, SearchFlag::RegularExpression, regularExpression);
+        WI_SetFlagIf(flags, SearchFlag::RegularExpression, request.RegularExpression);
-        const auto searchInvalidated = _searcher.IsStale(*_terminal.get(), text, flags);
+        const auto searchInvalidated = _searcher.IsStale(*_terminal.get(), request.Text, flags);
 
-        if (searchInvalidated || !resetOnly)
+        if (searchInvalidated || !request.Reset)
         {
             std::vector<til::point_span> oldResults;
 
             if (searchInvalidated)
             {
                 oldResults = _searcher.ExtractResults();
-                _searcher.Reset(*_terminal.get(), text, flags, !goForward);
+                _searcher.Reset(*_terminal.get(), request.Text, flags, !request.GoForward);
 
                 if (SnapSearchResultToSelection())
                 {
@@ -1716,12 +1716,12 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             }
             else
             {
-                _searcher.FindNext(!goForward);
+                _searcher.FindNext(!request.GoForward);
             }
 
             if (const auto idx = _searcher.CurrentMatch(); idx >= 0)
             {
-                _terminal->SetSearchHighlightFocused(gsl::narrow<size_t>(idx));
+                _terminal->SetSearchHighlightFocused(gsl::narrow<size_t>(idx), request.ScrollOffset);
             }
             _renderer->TriggerSearchHighlight(oldResults);
         }
@@ -1751,7 +1751,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     {
         const auto lock = _terminal->LockForWriting();
         _terminal->SetSearchHighlights({});
-        _terminal->SetSearchHighlightFocused({});
+        _terminal->SetSearchHighlightFocused({}, 0);
         _renderer->TriggerSearchHighlight(_searcher.Results());
         _searcher = {};
     }
@@ -2938,5 +2938,4 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     {
         _terminal->PreviewText(input);
     }
-
 }

src/cascadia/TerminalControl/ControlCore.h

@@ -225,7 +225,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void SetSelectionAnchor(const til::point position);
         void SetEndSelectionPoint(const til::point position);
 
-        SearchResults Search(const std::wstring_view& text, bool goForward, bool caseSensitive, bool regularExpression, bool reset);
+        SearchResults Search(SearchRequest request);
         const std::vector<til::point_span>& SearchResultRows() const noexcept;
         void ClearSearch();
         void SnapSearchResultToSelection(bool snap) noexcept;

src/cascadia/TerminalControl/ControlCore.idl

@@ -49,6 +49,16 @@ namespace Microsoft.Terminal.Control
         Boolean EndAtRightBoundary;
     };
 
+    struct SearchRequest
+    {
+        String Text;
+        Boolean GoForward;
+        Boolean CaseSensitive;
+        Boolean RegularExpression;
+        Boolean Reset;
+        Int32 ScrollOffset;
+    };
+
     struct SearchResults
     {
         Int32 TotalMatches;
@@ -136,7 +146,7 @@ namespace Microsoft.Terminal.Control
         void ResumeRendering();
         void BlinkAttributeTick();
 
-        SearchResults Search(String text, Boolean goForward, Boolean caseSensitive, Boolean regularExpression, Boolean reset);
+        SearchResults Search(SearchRequest request);
         void ClearSearch();
         Boolean SnapSearchResultToSelection;
 

src/cascadia/TerminalControl/TermControl.cpp

@@ -584,6 +584,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
                 _searchBox->Open([weakThis = get_weak()]() {
                     if (const auto self = weakThis.get(); self && !self->_IsClosing())
                     {
+                        self->_searchScrollOffset = self->_calculateSearchScrollOffset();
                         self->_searchBox->SetFocusOnTextbox();
                         self->_refreshSearch();
                     }
@@ -605,7 +606,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         }
         else
         {
-            _handleSearchResults(_core.Search(_searchBox->Text(), goForward, _searchBox->CaseSensitive(), _searchBox->RegularExpression(), false));
+            const auto request = SearchRequest{ _searchBox->Text(), goForward, _searchBox->CaseSensitive(), _searchBox->RegularExpression(), false, _searchScrollOffset };
+            _handleSearchResults(_core.Search(request));
         }
     }
 
@@ -639,7 +641,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     {
         if (_searchBox && _searchBox->IsOpen())
         {
-            _handleSearchResults(_core.Search(text, goForward, caseSensitive, regularExpression, false));
+            const auto request = SearchRequest{ text, goForward, caseSensitive, regularExpression, false, _searchScrollOffset };
+            _handleSearchResults(_core.Search(request));
         }
     }
 
@@ -660,7 +663,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         {
             // We only want to update the search results based on the new text. Set
             // `resetOnly` to true so we don't accidentally update the current match index.
-            const auto result = _core.Search(text, goForward, caseSensitive, regularExpression, true);
+            const auto request = SearchRequest{ text, goForward, caseSensitive, regularExpression, true, _searchScrollOffset };
+            const auto result = _core.Search(request);
             _handleSearchResults(result);
         }
     }
@@ -3572,6 +3576,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             QuickFixIcon().FontSize(static_cast<double>(args.Width() / dpiScale));
             RefreshQuickFixMenu();
         }
+
+        _searchScrollOffset = _calculateSearchScrollOffset();
     }
 
     void TermControl::_coreRaisedNotice(const IInspectable& /*sender*/,
@@ -3702,7 +3708,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         const auto goForward = _searchBox->GoForward();
         const auto caseSensitive = _searchBox->CaseSensitive();
         const auto regularExpression = _searchBox->RegularExpression();
-        _handleSearchResults(_core.Search(text, goForward, caseSensitive, regularExpression, true));
+        const auto request = SearchRequest{ text, goForward, caseSensitive, regularExpression, true, _calculateSearchScrollOffset() };
+        _handleSearchResults(_core.Search(request));
     }
 
     void TermControl::_handleSearchResults(SearchResults results)
@@ -3982,6 +3989,19 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         SearchMissingCommand.raise(*this, args);
     }
 
+    til::CoordType TermControl::_calculateSearchScrollOffset() const
+    {
+        auto result = 0;
+        if (_searchBox)
+        {
+            const auto displayInfo = DisplayInformation::GetForCurrentView();
+            const auto scaleFactor = _core.FontSize().Height / displayInfo.RawPixelsPerViewPixel();
+            const auto searchBoxRows = _searchBox->ActualHeight() / scaleFactor;
+            result = static_cast<int32_t>(std::ceil(searchBoxRows));
+        }
+        return result;
+    }
+
     void TermControl::ClearQuickFix()
     {
         _core.ClearQuickFix();

src/cascadia/TerminalControl/TermControl.h

@@ -289,6 +289,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         bool _isBackgroundLight{ false };
         bool _detached{ false };
+        til::CoordType _searchScrollOffset = 0;
 
         Windows::Foundation::Collections::IObservableVector<Windows::UI::Xaml::Controls::ICommandBarElement> _originalPrimaryElements{ nullptr };
         Windows::Foundation::Collections::IObservableVector<Windows::UI::Xaml::Controls::ICommandBarElement> _originalSecondaryElements{ nullptr };
@@ -409,6 +410,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void _showContextMenuAt(const til::point& controlRelativePos);
 
         void _bubbleSearchMissingCommand(const IInspectable& sender, const Control::SearchMissingCommandEventArgs& args);
+        til::CoordType _calculateSearchScrollOffset() const;
 
         void _PasteCommandHandler(const IInspectable& sender, const IInspectable& args);
         void _CopyCommandHandler(const IInspectable& sender, const IInspectable& args);

src/cascadia/TerminalCore/Terminal.cpp

@@ -1251,7 +1251,7 @@ void Terminal::SetSearchHighlights(const std::vector<til::point_span>& highlight
 // Method Description:
 // - Stores the focused search highlighted region in the terminal
 // - If the region isn't empty, it will be brought into view
-void Terminal::SetSearchHighlightFocused(const size_t focusedIdx)
+void Terminal::SetSearchHighlightFocused(const size_t focusedIdx, til::CoordType searchScrollOffset)
 {
     _assertLocked();
     _searchHighlightFocused = focusedIdx;
@@ -1260,7 +1260,9 @@ void Terminal::SetSearchHighlightFocused(const size_t focusedIdx)
     if (focusedIdx < _searchHighlights.size())
     {
         const auto focused = til::at(_searchHighlights, focusedIdx);
-        _ScrollToPoints(focused.start, focused.end);
+        const auto adjustedStart = til::point{ focused.start.x, std::max(0, focused.start.y - searchScrollOffset) };
+        const auto adjustedEnd = til::point{ focused.end.x, std::max(0, focused.end.y - searchScrollOffset) };
+        _ScrollToPoints(adjustedStart, adjustedEnd);
     }
 }
 

src/cascadia/TerminalCore/Terminal.hpp

@@ -232,7 +232,7 @@ public:
     void SetSearchMissingCommandCallback(std::function<void(std::wstring_view)> pfn) noexcept;
     void SetClearQuickFixCallback(std::function<void()> pfn) noexcept;
     void SetSearchHighlights(const std::vector<til::point_span>& highlights) noexcept;
-    void SetSearchHighlightFocused(const size_t focusedIdx);
+    void SetSearchHighlightFocused(const size_t focusedIdx, til::CoordType searchScrollOffset);
 
     void BlinkCursor() noexcept;
     void SetCursorOn(const bool isOn) noexcept;