New folding scheme that allows "} else {" to be a fold header.

2 files changed, 43 insertions, 251 deletions

diff --git a/src/Editor.cxx b/src/Editor.cxx
index 2eba8a471..0cb693ba6 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -1576,8 +1576,15 @@ void Editor::PaintSelMargin(Surface *surfWindow, PRectangle &rc) {
 					number[0] = '\0';
 					if (firstSubLine)
 						sprintf(number, "%d", lineDoc + 1);
-					if (foldFlags & SC_FOLDFLAG_LEVELNUMBERS)
-						sprintf(number, "%X", pdoc->GetLevel(lineDoc));
+					if (foldFlags & SC_FOLDFLAG_LEVELNUMBERS) {
+						int lev = pdoc->GetLevel(lineDoc);
+						sprintf(number, "%c%c %03X %03X",
+							(lev & SC_FOLDLEVELHEADERFLAG) ? 'H' : '_',
+							(lev & SC_FOLDLEVELWHITEFLAG) ? 'W' : '_',
+							lev & SC_FOLDLEVELNUMBERMASK,
+							lev >> 16
+						);
+					}
 					PRectangle rcNumber = rcMarker;
 					// Right justify
 					int width = surface->WidthText(vs.styles[STYLE_LINENUMBER].font, number, strlen(number));
@@ -2476,7 +2483,7 @@ void Editor::Paint(Surface *surfaceWindow, PRectangle rcArea) {
 				} else {
 					int FoldLevelCurr = (pdoc->GetLevel(lineDoc) & SC_FOLDLEVELNUMBERMASK) - SC_FOLDLEVELBASE;
 					int FoldLevelPrev = (pdoc->GetLevel(lineDoc - 1) & SC_FOLDLEVELNUMBERMASK) - SC_FOLDLEVELBASE;
-					int FoldLevelFlags = (pdoc->GetLevel(lineDoc) & ~SC_FOLDLEVELNUMBERMASK);
+					int FoldLevelFlags = (pdoc->GetLevel(lineDoc) & ~SC_FOLDLEVELNUMBERMASK) & ~(0xFFF0000);
 					int indentationStep = (pdoc->indentInChars ? pdoc->indentInChars : pdoc->tabInChars);
 					// Draw line above fold
 					if ((FoldLevelPrev < FoldLevelCurr)
diff --git a/src/LexCPP.cxx b/src/LexCPP.cxx
index 3be8c91f1..9c8ea416a 100644
--- a/src/LexCPP.cxx
+++ b/src/LexCPP.cxx
@@ -282,237 +282,23 @@ static bool IsStreamCommentStyle(int style) {
 	       style == SCE_C_COMMENTDOCKEYWORDERROR;
 }
 
-static bool matchKeyword(unsigned int start, WordList &keywords, Accessor &styler, int keywordtype) {
-	bool FoundKeyword = false;
-
-	for (unsigned int i = 0;
-	        strlen(keywords[i]) > 0 && !FoundKeyword;
-	        i++) {
-		if (atoi(keywords[i]) == keywordtype) {
-			FoundKeyword = styler.Match(start, ((char *)keywords[i]) + 2);
-		}
-	}
-	return FoundKeyword;
-}
-
-static bool IsCommentLine(int line, Accessor &styler) {
-	unsigned int Pos = styler.LineStart(line);
-	while (styler.GetLine(Pos) == line) {
-		int PosStyle = styler.StyleAt(Pos);
-
-		if (	!IsStreamCommentStyle(PosStyle)
-		        &&
-		        PosStyle != SCE_C_COMMENTLINEDOC
-		        &&
-		        PosStyle != SCE_C_COMMENTLINE
-		        &&
-		        !IsASpace(styler.SafeGetCharAt(Pos))
-		   )
-			return false;
-		Pos++;
-	}
-
-	return true;
-}
-
-static void FoldBoxCppDoc(unsigned int startPos, int length, int initStyle, WordList *keywordlists[],
-                          Accessor &styler) {
-
-	WordList &keywords4 = *keywordlists[3];
-
-	bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
-	bool foldPreprocessor = styler.GetPropertyInt("fold.preprocessor") != 0;
-	bool foldCompact = styler.GetPropertyInt("fold.compact", 1) != 0;
-	bool firstLine = true;
-	unsigned int endPos = startPos + length;
-	int visibleChars = 0;
-	int lineCurrent = styler.GetLine(startPos);
-	int levelPrev = styler.LevelAt(lineCurrent) & SC_FOLDLEVELNUMBERMASK;
-	int levelCurrent = levelPrev;
-	int levelPrevPrev;
-	int levelFlags = 0;
-	int levelUnindent = 0;
-	char chNext = styler[startPos];
-	int styleNext = styler.StyleAt(startPos);
-	int style = initStyle;
-
-	if (lineCurrent == 0) {
-		levelPrevPrev = levelPrev;
-	} else {
-		levelPrevPrev = styler.LevelAt(lineCurrent - 1) & SC_FOLDLEVELNUMBERMASK;
-	}
-
-	for (unsigned int i = startPos; i < endPos; i++) {
-		char ch = chNext;
-		chNext = styler.SafeGetCharAt(i + 1);
-		int stylePrev = style;
-		style = styleNext;
-		styleNext = styler.StyleAt(i + 1);
-
-		bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
-
-		if (foldComment && IsStreamCommentStyle(style)) {
-			if (!IsStreamCommentStyle(stylePrev)) {
-				levelCurrent++;
-			} else if (!IsStreamCommentStyle(styleNext) && !atEOL) {
-				// Comments don't end at end of line and the next character may be unstyled.
-				levelCurrent--;
-			}
-		}
-
-		if (foldComment && (style == SCE_C_COMMENTLINE)) {
-			if ((ch == '/') && (chNext == '/')) {
-				char chNext2 = styler.SafeGetCharAt(i + 2);
-				if (chNext2 == '{') {
-					levelCurrent++;
-				} else if (chNext2 == '}') {
-					levelCurrent--;
-				}
-			}
-		}
-
-		if (foldPreprocessor && (style == SCE_C_PREPROCESSOR)) {
-			if (ch == '#') {
-				unsigned int j = i + 1;
-				while ((j < endPos) && IsASpaceOrTab(styler.SafeGetCharAt(j))) {
-					j++;
-				}
-
-				if (styler.Match(j, "region") || styler.Match(j, "if")) {
-					levelCurrent++;
-				} else if (styler.Match(j, "end")) {
-					levelCurrent--;
-				}
-			}
-		}
-
-		if (style == SCE_C_OPERATOR
-		        ||
-		        style == SCE_C_COMMENT
-		        ||
-		        style == SCE_C_COMMENTLINE) {
-
-			if (ch == '{') {
-				levelCurrent++;
-				// Special handling if line has closing brace followed by opening brace.
-				if (levelCurrent == levelPrev) {
-					if (firstLine)
-						levelUnindent = 1;
-					else
-						levelUnindent = -1;
-				}
-			} else if (ch == '}') {
-				levelCurrent--;
-			}
-		}
-
-		/* Check for fold header keyword at beginning of word */
-		if ((style == SCE_C_WORD || style == SCE_C_COMMENT || style == SCE_C_COMMENTLINE)
-		        &&
-		        (style != stylePrev)) {
-			if (matchKeyword(i, keywords4, styler, KEYWORD_BOXHEADER)) {
-				int line;
-				/* Loop backwards all empty or comment lines */
-				for (line = lineCurrent - 1;
-				        line >= 0
-				        &&
-				        levelCurrent == (styler.LevelAt(line) & SC_FOLDLEVELNUMBERMASK)
-				        &&
-				        (styler.LevelAt(line) & SC_FOLDLEVELBOXFOOTERFLAG) == 0
-				        &&
-				        IsCommentLine(line, styler);
-				        line--) {
-					/* just loop backwards */;
-				}
-
-				line++;
-				/* Set Box header flag (if the previous line has no footer line) */
-				if ((styler.LevelAt(line) & SC_FOLDLEVELBOXFOOTERFLAG) == 0) {
-					if (line == lineCurrent) {
-						/* in current line */
-						levelFlags |= SC_FOLDLEVELBOXHEADERFLAG;
-					} else {
-						/* at top of all preceding comment lines */
-						styler.SetLevel(line, styler.LevelAt(line)
-						                | SC_FOLDLEVELBOXHEADERFLAG);
-					}
-				}
-			}
-		}
-
-		if (matchKeyword(i, keywords4, styler, KEYWORD_FOLDCONTRACTED)) {
-			levelFlags |= SC_FOLDLEVELCONTRACTED;
-		}
-
-		if (atEOL) {
-			int lev;
-			// Compute level correction for special case: '} else {'
-			if (levelUnindent < 0) {
-				levelPrev += levelUnindent;
-			} else {
-				levelCurrent += levelUnindent;
-			}
-
-			lev = levelPrev;
-			if (visibleChars == 0 && foldCompact)
-				lev |= SC_FOLDLEVELWHITEFLAG;
-			// Produce additional footer line (e.g. after closed if)
-			if (visibleChars == 0
-			        &&
-			        (levelPrev < levelPrevPrev))
-				lev |= SC_FOLDLEVELBOXFOOTERFLAG;
-			// Produce footer line at line before (special handling for '} else {'
-			if (levelPrev < levelPrevPrev) {
-				styler.SetLevel(lineCurrent - 1,
-				                styler.LevelAt(lineCurrent - 1) | SC_FOLDLEVELBOXFOOTERFLAG);
-			}
-			// Mark the fold header (the line that is always visible)
-			if ((levelCurrent > levelPrev) && (visibleChars > 0))
-				lev |= SC_FOLDLEVELHEADERFLAG;
-			// Show a footer line at end of fold
-			if (levelCurrent < levelPrev)
-				lev |= SC_FOLDLEVELBOXFOOTERFLAG;
-			/* Show a footer line at the end of each procedure (level == SC_FOLDLEVELBASE) */
-			if ((levelPrev == SC_FOLDLEVELBASE)
-			        &&
-			        (levelPrevPrev > SC_FOLDLEVELBASE)
-			        &&
-			        (visibleChars == 0)) {
-				lev |= SC_FOLDLEVELBOXFOOTERFLAG;
-			}
-
-			lev |= levelFlags;
-			if (lev != styler.LevelAt(lineCurrent)) {
-				styler.SetLevel(lineCurrent, lev);
-			}
-
-			lineCurrent++;
-			levelPrevPrev = levelPrev;
-			levelPrev = levelCurrent;
-			levelUnindent = 0;
-			visibleChars = 0;
-			levelFlags = 0;
-			firstLine = false;
-		}
-
-		if (!isspacechar(ch))
-			visibleChars++;
-	}
-	// Fill in the real level of the next line, keeping the current flags as they will be filled in later
-	int flagsNext = styler.LevelAt(lineCurrent) & ~SC_FOLDLEVELNUMBERMASK;
-	styler.SetLevel(lineCurrent, levelPrev | flagsNext);
-}
-
+// Store both the current line's fold level and the next lines in the
+// level store to make it easy to pick up with each increment
+// and to make it possible to fiddle the current level for "} else {".
 static void FoldNoBoxCppDoc(unsigned int startPos, int length, int initStyle,
                             Accessor &styler) {
 	bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
 	bool foldPreprocessor = styler.GetPropertyInt("fold.preprocessor") != 0;
 	bool foldCompact = styler.GetPropertyInt("fold.compact", 1) != 0;
+	bool foldAtElse = styler.GetPropertyInt("fold.at.else", 0) != 0;
 	unsigned int endPos = startPos + length;
 	int visibleChars = 0;
 	int lineCurrent = styler.GetLine(startPos);
-	int levelPrev = styler.LevelAt(lineCurrent) & SC_FOLDLEVELNUMBERMASK;
-	int levelCurrent = levelPrev;
+	int levelCurrent = SC_FOLDLEVELBASE;
+	if (lineCurrent > 0)
+		levelCurrent = styler.LevelAt(lineCurrent-1) >> 16;
+	int levelMinCurrent = levelCurrent;
+	int levelNext = levelCurrent;
 	char chNext = styler[startPos];
 	int styleNext = styler.StyleAt(startPos);
 	int style = initStyle;
@@ -525,19 +311,19 @@ static void FoldNoBoxCppDoc(unsigned int startPos, int length, int initStyle,
 		bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
 		if (foldComment && IsStreamCommentStyle(style)) {
 			if (!IsStreamCommentStyle(stylePrev)) {
-				levelCurrent++;
+				levelNext++;
 			} else if (!IsStreamCommentStyle(styleNext) && !atEOL) {
 				// Comments don't end at end of line and the next character may be unstyled.
-				levelCurrent--;
+				levelNext--;
 			}
 		}
 		if (foldComment && (style == SCE_C_COMMENTLINE)) {
 			if ((ch == '/') && (chNext == '/')) {
 				char chNext2 = styler.SafeGetCharAt(i + 2);
 				if (chNext2 == '{') {
-					levelCurrent++;
+					levelNext++;
 				} else if (chNext2 == '}') {
-					levelCurrent--;
+					levelNext--;
 				}
 			}
 		}
@@ -548,58 +334,57 @@ static void FoldNoBoxCppDoc(unsigned int startPos, int length, int initStyle,
 					j++;
 				}
 				if (styler.Match(j, "region") || styler.Match(j, "if")) {
-					levelCurrent++;
+					levelNext++;
 				} else if (styler.Match(j, "end")) {
-					levelCurrent--;
+					levelNext--;
 				}
 			}
 		}
 		if (style == SCE_C_OPERATOR) {
 			if (ch == '{') {
-				levelCurrent++;
+				// Measure the minimum before a '{' to allow
+				// folding on "} else {"
+				if (levelMinCurrent > levelNext) {
+					levelMinCurrent = levelNext;
+				}
+				levelNext++;
 			} else if (ch == '}') {
-				levelCurrent--;
+				levelNext--;
 			}
 		}
 		if (atEOL) {
-			int lev = levelPrev;
+			int levelUse = levelCurrent;
+			if (foldAtElse) {
+				levelUse = levelMinCurrent;
+			}
+			int lev = levelUse | levelNext << 16;
 			if (visibleChars == 0 && foldCompact)
 				lev |= SC_FOLDLEVELWHITEFLAG;
-			if ((levelCurrent > levelPrev) && (visibleChars > 0))
+			if (levelUse < levelNext)
 				lev |= SC_FOLDLEVELHEADERFLAG;
 			if (lev != styler.LevelAt(lineCurrent)) {
 				styler.SetLevel(lineCurrent, lev);
 			}
 			lineCurrent++;
-			levelPrev = levelCurrent;
+			levelCurrent = levelNext;
+			levelMinCurrent = levelCurrent;
 			visibleChars = 0;
 		}
 		if (!isspacechar(ch))
 			visibleChars++;
 	}
-	// Fill in the real level of the next line, keeping the current flags as they will be filled in later
-	int flagsNext = styler.LevelAt(lineCurrent) & ~SC_FOLDLEVELNUMBERMASK;
-	styler.SetLevel(lineCurrent, levelPrev | flagsNext);
 }
 
-static void FoldCppDoc(unsigned int startPos, int length, int initStyle, WordList *keywordlists[],
+static void FoldCppDoc(unsigned int startPos, int length, int initStyle, WordList *[],
                        Accessor &styler) {
-
-	int foldFlags = styler.GetPropertyInt("fold.flags") ;
-	bool foldBox = ((foldFlags & SC_FOLDFLAG_BOX) == SC_FOLDFLAG_BOX);
-
-	if (foldBox) {
-		FoldBoxCppDoc(startPos, length, initStyle, keywordlists, styler);
-	} else {
-		FoldNoBoxCppDoc(startPos, length, initStyle, styler);
-	}
+	FoldNoBoxCppDoc(startPos, length, initStyle, styler);
 }
 
 static const char * const cppWordLists[] = {
             "Primary keywords and identifiers",
             "Secondary keywords and identifiers",
             "Documentation comment keywords",
-            "Fold header keywords",
+            "Unused",
             "Global classes and typedefs",
             0,
         };