Merge branch 'folding-poc'. Todo: add GUI option.

Components/ScintEdit.pas

@@ -225,6 +225,7 @@   TScintEdit = class(TWinControl)
     procedure DeleteMarker(const Line: Integer; const Marker: TScintMarkerNumber);
     procedure DPIChanged(const Message: TMessage);
     procedure EndUndoAction;
+    procedure EnsureLineVisible(const Line: Integer);
     function FindRawText(const StartPos, EndPos: Integer; const S: TScintRawString;
       const Options: TScintFindOptions; out MatchRange: TScintRange): Boolean;
     function FindText(const StartPos, EndPos: Integer; const S: String;
@@ -272,6 +273,7 @@   TScintEdit = class(TWinControl)
     procedure ScrollCaretIntoView;
     procedure SelectAll;
     procedure SelectAllOccurrences(const Options: TScintFindOptions);
+    procedure SelectAndEnsureVisible(const Range: TScintRange);
     procedure SelectNextOccurrence(const Options: TScintFindOptions);
     function SelEmpty: Boolean;
     function SelNotEmpty(out Sel: TScintRange): Boolean;
@@ -441,6 +443,8 @@   TScintCustomStyler = class(TComponent)
     function ConsumeString(const Chars: TScintRawCharSet): TScintRawString;
     function CurCharIn(const Chars: TScintRawCharSet): Boolean;
     function CurCharIs(const C: AnsiChar): Boolean;
+    procedure GetFoldLevel(const LineState: TScintLineState; var Level: Integer;
+      var Header: Boolean); virtual; abstract;
     procedure GetStyleAttributes(const Style: Integer;
       var Attributes: TScintStyleAttributes); virtual; abstract;
     function LineTextSpans(const S: TScintRawString): Boolean; virtual;
@@ -754,6 +758,12 @@ procedure TScintEdit.EndUndoAction;
   Call(SCI_ENDUNDOACTION, 0, 0);
 end;
 
+procedure TScintEdit.EnsureLineVisible(const Line: Integer);
+begin
+  FLines.CheckIndexRange(Line);
+  Call(SCI_ENSUREVISIBLE, Line, 0);
+end;
+
 class function TScintEdit.GetErrorException(const S: String): EScintEditError;
 begin
   Result := EScintEditError.Create('TScintEdit error: ' + S);
@@ -1307,13 +1317,31 @@ procedure TScintEdit.ScrollCaretIntoView;
 
 
 procedure TScintEdit.SelectAllOccurrences(const Options: TScintFindOptions);
+{ At the moment this does not automatically expand folds, unlike VSCode. Also
+  see SelectNextOccurrence. }
 begin
   Call(SCI_TARGETWHOLEDOCUMENT, 0, 0);
   Call(SCI_SETSEARCHFLAGS, GetSearchFlags(Options), 0);
   Call(SCI_MULTIPLESELECTADDEACH, 0, 0);
 end;
 
+procedure TScintEdit.SelectAndEnsureVisible(const Range: TScintRange);
+begin
+  CheckPosRange(Range.StartPos, Range.EndPos);
+
+  { If the range is in a contracted section, expand it }
+  var StartLine := GetLineFromPosition(Range.StartPos);
+  var EndLine := GetLineFromPosition(Range.EndPos);
+  for var Line := StartLine to EndLine do
+    EnsureLineVisible(Line);
+
+  { Select }
+  Selection := Range;
+end;
+
 procedure TScintEdit.SelectNextOccurrence(const Options: TScintFindOptions);
+{ At the moment this does not automatically expand folds, unlike VSCode. Also
+  see SelectAllOccurrences. }
 begin
   Call(SCI_TARGETWHOLEDOCUMENT, 0, 0);
   Call(SCI_SETSEARCHFLAGS, GetSearchFlags(Options), 0);
@@ -1793,10 +1821,26 @@ procedure TScintEdit.StyleNeeded(const EndPos: Integer);
       FStyler.FText := '';
     end;
 
+    var FoldLevel: Integer;
+    var FoldHeader: Boolean;
+    FStyler.GetFoldLevel(FStyler.FLineState, FoldLevel, FoldHeader);
+    Inc(FoldLevel, SC_FOLDLEVELBASE);
+    if FoldHeader then
+      FoldLevel := FoldLevel or SC_FOLDLEVELHEADERFLAG;
+    { Setting SC_FOLDLEVELWHITEFLAG on empty lines causes a problem: when
+      Scintilla auto expands a contracted section (for example after removing ']'
+      from a section header) all the empty lines stay invisible, even any which
+      are in the middle of the section. }
+
     for var I := FirstLine to LastLine do begin
       var OldState := FLines.GetState(I);
       if FStyler.FLineState <> OldState then
         Call(SCI_SETLINESTATE, I, FStyler.FLineState);
+      { To display/debug fold levels use: Call(SCI_SETFOLDFLAGS, SC_FOLDFLAG_LEVELNUMBERS, 0);
+        And then also update UpdateLineNumbersWidth to make the margin wider. }
+      var OldLevel := Call(SCI_GETFOLDLEVEL, I, 0);
+      if FoldLevel <> OldLevel then
+        Call(SCI_SETFOLDLEVEL, I, FoldLevel);
     end;
 
     Result := LastLine;

Components/ScintStylerInnoSetup.pas

@@ -21,7 +21,8 @@ interface
 
 type
   TInnoSetupStylerSection = (
-    scNone,            { Not inside a section (start of file, or last section was closed) }
+    scNone,            { Not inside a section (start of file, or previous section was closed )
+                         Section tags themselves are not associated with any section! }
     scUnknown,         { Inside an unrecognized section }
     scThirdParty,      { Inside a '_' section (reserved for third-party tools) }
     scCode,
@@ -104,6 +105,8 @@   TInnoSetupStyler = class(TScintCustomStyler)
     procedure SetISPPInstalled(const Value: Boolean);
   protected
     procedure CommitStyle(const Style: TInnoSetupStylerStyle);
+    procedure GetFoldLevel(const LineState: TScintLineState; var Level: Integer;
+      var Header: Boolean); override;
     procedure GetStyleAttributes(const Style: Integer;
       var Attributes: TScintStyleAttributes); override;
     function LineTextSpans(const S: TScintRawString): Boolean; override;
@@ -934,6 +937,34 @@ function TInnoSetupStyler.GetFlagsWordList(Section: TInnoSetupStylerSection): An
   Result := FFlagsWordList[Section];
 end;
 
+procedure TInnoSetupStyler.GetFoldLevel(const LineState: TScintLineState;
+  var Level: Integer; var Header: Boolean);
+begin
+  { Set folding per section. To keep our code as simple as possible we simply
+    give all lines outside of a section (=lines at the start of the document and
+    section tags and section end tags and lines after section end tags) a header
+    flag. This avoids having to look at the previous line. Doesn't mean
+    Scintilla will display folding markers on all these header lines: it only
+    does that when there is something to fold, so when the header line is
+    followed a by non-header line which is only the case for a section tag line
+    followed by a section line.
+
+    Did notice an issue (Scintilla automatic folding bug?): Add a section with
+    some lines. Contract it. Break the section header for example by removing ']'.
+    Scintialla now auto expands the section and removes the fold mark.
+    Retype the ']'. Scintilla now displays the old fold mark to expand the
+    section but it's already expanded.  }
+
+  var Section := TInnoSetupStyler.GetSectionFromLineState(LineState);
+  if Section <> scNone then begin
+    Level := 1;
+    Header := False;
+  end else begin
+    Level := 0;
+    Header := True;
+  end;
+end;
+
 function TInnoSetupStyler.GetKeywordsWordList(Section: TInnoSetupStylerSection): AnsiString;
 begin
   Result := FKeywordsWordList[Section];