1 files changed, 73 insertions, 0 deletions
diff --git a/lexers/LexIndent.cxx b/lexers/LexIndent.cxx
new file mode 100644
index 000000000..ac25938c0
--- /dev/null
+++ b/lexers/LexIndent.cxx
@@ -0,0 +1,73 @@
+// Scintilla source code edit control
+/** @file LexIndent.cxx
+ ** Lexer for no language. Used for indentation-based folding of files.
+ **/
+// The License.txt file describes the conditions under which this software may be distributed.
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <ctype.h>
+
+#include "ILexer.h"
+#include "Scintilla.h"
+#include "SciLexer.h"
+
+#include "WordList.h"
+#include "LexAccessor.h"
+#include "Accessor.h"
+#include "StyleContext.h"
+#include "CharacterSet.h"
+#include "LexerModule.h"
+
+#ifdef SCI_NAMESPACE
+using namespace Scintilla;
+#endif
+
+static void ColouriseIndentDoc(Sci_PositionU startPos, Sci_Position length, int, WordList *[],
+                            Accessor &styler) {
+	// Indent language means all style bytes are 0 so just mark the end - no need to fill in.
+	if (length > 0) {
+		styler.StartAt(startPos + length - 1);
+		styler.StartSegment(startPos + length - 1);
+		styler.ColourTo(startPos + length - 1, 0);
+	}
+}
+
+static void FoldIndentDoc(Sci_PositionU startPos, Sci_Position length, int /* initStyle */, WordList *[], Accessor &styler) {
+	int visibleCharsCurrent, visibleCharsNext;
+	int levelCurrent, levelNext;
+	Sci_PositionU i, lineEnd;
+	Sci_PositionU lengthDoc   = startPos + length;
+	Sci_Position  lineCurrent = styler.GetLine(startPos);
+
+	i       = styler.LineStart(lineCurrent  );
+	lineEnd = styler.LineStart(lineCurrent+1)-1;
+	if(lineEnd>=lengthDoc) lineEnd = lengthDoc-1;
+	while(styler[lineEnd]=='\n' || styler[lineEnd]=='\r') lineEnd--;
+	for(visibleCharsCurrent=0, levelCurrent=SC_FOLDLEVELBASE; !visibleCharsCurrent && i<=lineEnd; i++){
+		if(isspacechar(styler[i])) levelCurrent++;
+		else                       visibleCharsCurrent=1;
+	}
+
+	for(; i<lengthDoc; lineCurrent++) {
+		i       = styler.LineStart(lineCurrent+1);
+		lineEnd = styler.LineStart(lineCurrent+2)-1;
+		if(lineEnd>=lengthDoc) lineEnd = lengthDoc-1;
+		while(styler[lineEnd]=='\n' || styler[lineEnd]=='\r') lineEnd--;
+		for(visibleCharsNext=0, levelNext=SC_FOLDLEVELBASE; !visibleCharsNext && i<=lineEnd; i++){
+			if(isspacechar(styler[i])) levelNext++;
+			else                       visibleCharsNext=1;
+		}
+		int lev = levelCurrent;
+		if(!visibleCharsCurrent) lev |= SC_FOLDLEVELWHITEFLAG;
+		else if(levelNext > levelCurrent) lev |= SC_FOLDLEVELHEADERFLAG;
+		styler.SetLevel(lineCurrent, lev);
+		levelCurrent = levelNext;
+		visibleCharsCurrent = visibleCharsNext;
+	}
+}
+
+LexerModule lmIndent(SCLEX_INDENT, ColouriseIndentDoc, "indent", FoldIndentDoc);