Fixing problems with fold information degrading when lines inserted and

removed.
New notifications before inserting and deleting text.

6 files changed, 114 insertions, 34 deletions

diff --git a/src/CellBuffer.cxx b/src/CellBuffer.cxx
index 0f33d48c4..e6aa4a013 100644
--- a/src/CellBuffer.cxx
+++ b/src/CellBuffer.cxx
@@ -200,10 +200,13 @@ void LineVector::InsertValue(int pos, int value) {
 		for (int j = lines; j > pos; j--) {
 			levels[j] = levels[j - 1];
 		}
-		if (pos == (lines-1))	// Last line will not be a folder
+		if (pos == 0) {
 			levels[pos] = SC_FOLDLEVELBASE;
-		else
-			levels[pos] = SC_FOLDLEVELBASE | SC_FOLDLEVELHEADERFLAG;
+		} else if (pos == (lines-1)) {	// Last line will not be a folder
+			levels[pos] = SC_FOLDLEVELBASE;
+		} else {
+			levels[pos] = levels[pos-1];
+		}
 	}
 }
 
@@ -230,6 +233,15 @@ void LineVector::Remove(int pos) {
 	for (int i = pos; i < lines; i++) {
 		linesData[i] = linesData[i + 1];
 	}
+	if (levels) {
+        // Level information merges back onto previous line
+        int posAbove = pos-1;
+        if (posAbove < 0)
+            posAbove = 0;
+		for (int j = posAbove; j < lines; j++) {
+			levels[j] = levels[j + 1];
+		}
+	}
 	lines--;
 }
 
@@ -514,8 +526,12 @@ int UndoHistory::StartUndo() {
 	return currentAction - act;
 }
 
-const Action &UndoHistory::UndoStep() {
-	return actions[currentAction--];
+const Action &UndoHistory::GetUndoStep() const {
+	return actions[currentAction];
+}
+
+void UndoHistory::CompletedUndoStep() {
+	currentAction--;
 }
 
 bool UndoHistory::CanRedo() const {
@@ -535,15 +551,19 @@ int UndoHistory::StartRedo() {
 	return act - currentAction;
 }
 
-const Action &UndoHistory::RedoStep() {
-	return actions[currentAction++];
+const Action &UndoHistory::GetRedoStep() const {
+	return actions[currentAction];
+}
+
+void UndoHistory::CompletedRedoStep() {
+	currentAction++;
 }
 
 CellBuffer::CellBuffer(int initialLength) {
 	body = new char[initialLength];
 	size = initialLength;
 	length = 0;
-	part1len = 0;
+	part1len = 0;   
 	gaplen = initialLength;
 	part2body = body + gaplen;
 	readOnly = false;
@@ -962,8 +982,12 @@ int CellBuffer::StartUndo() {
 	return uh.StartUndo();
 }
 
-const Action &CellBuffer::UndoStep() {
-	const Action &actionStep = uh.UndoStep();
+const Action &CellBuffer::GetUndoStep() const {
+	return uh.GetUndoStep();
+}
+
+void CellBuffer::PerformUndoStep() {
+	const Action &actionStep = uh.GetUndoStep();
 	if (actionStep.at == insertAction) {
 		BasicDeleteChars(actionStep.position, actionStep.lenData*2);
 	} else if (actionStep.at == removeAction) {
@@ -975,7 +999,7 @@ const Action &CellBuffer::UndoStep() {
 		BasicInsertString(actionStep.position, styledData, actionStep.lenData*2);
 		delete []styledData;
 	}
-	return actionStep;
+    uh.CompletedUndoStep();
 }
 
 bool CellBuffer::CanRedo() {
@@ -986,8 +1010,12 @@ int CellBuffer::StartRedo() {
 	return uh.StartRedo();
 }
 
-const Action &CellBuffer::RedoStep() {
-	const Action &actionStep = uh.RedoStep();
+const Action &CellBuffer::GetRedoStep() const {
+	return uh.GetRedoStep();
+}
+
+void CellBuffer::PerformRedoStep() {
+	const Action &actionStep = uh.GetRedoStep();
 	if (actionStep.at == insertAction) {
 		char *styledData = new char[actionStep.lenData * 2];
 		for (int i = 0; i < actionStep.lenData; i++) {
@@ -999,7 +1027,7 @@ const Action &CellBuffer::RedoStep() {
 	} else if (actionStep.at == removeAction) {
 		BasicDeleteChars(actionStep.position, actionStep.lenData*2);
 	}
-	return actionStep;
+    uh.CompletedRedoStep();
 }
 
 int CellBuffer::SetLineState(int line, int state) {
diff --git a/src/CellBuffer.h b/src/CellBuffer.h
index 2fcaca3a5..409a8749d 100644
--- a/src/CellBuffer.h
+++ b/src/CellBuffer.h
@@ -120,10 +120,12 @@ public:
 	// called that many times. Similarly for redo.
 	bool CanUndo() const;
 	int StartUndo();
-	const Action &UndoStep();
+	const Action &GetUndoStep() const;
+	void CompletedUndoStep();
 	bool CanRedo() const;
 	int StartRedo();
-	const Action &RedoStep();
+	const Action &GetRedoStep() const;
+	void CompletedRedoStep();
 };
 
 // Holder for an expandable array of characters that supports undo and line markers
@@ -207,10 +209,12 @@ public:
 	// called that many times. Similarly for redo.
 	bool CanUndo();
 	int StartUndo();
-	const Action &UndoStep();
+	const Action &GetUndoStep() const;
+	void PerformUndoStep();
 	bool CanRedo();
 	int StartRedo();
-	const Action &RedoStep();
+	const Action &GetRedoStep() const;
+	void PerformRedoStep();
 	
 	int SetLineState(int line, int state);
 	int GetLineState(int line);
diff --git a/src/ContractionState.cxx b/src/ContractionState.cxx
index b01081588..82bf40994 100644
--- a/src/ContractionState.cxx
+++ b/src/ContractionState.cxx
@@ -131,10 +131,11 @@ void ContractionState::DeleteLines(int lineDoc, int lineCount) {
 	}
 	int delta = 0;
 	for (int d=0;d<lineCount;d++)
-		if (lines[lineDoc+d].visible)
+		if (lines[lineDoc+d].visible && (lineDoc+d != 0))
 			delta--;
 	for (int i = lineDoc; i < linesInDoc-lineCount; i++) {
-		lines[i].visible = lines[i + lineCount].visible;
+        if (i != 0) // Line zero is always visible
+		    lines[i].visible = lines[i + lineCount].visible;
 		lines[i].expanded = lines[i + lineCount].expanded;
 	}
 	linesInDoc -= lineCount;
@@ -153,6 +154,10 @@ bool ContractionState::GetVisible(int lineDoc) const {
 }
 
 bool ContractionState::SetVisible(int lineDocStart, int lineDocEnd, bool visible) {
+    if (lineDocStart == 0)
+        lineDocStart++;
+    if (lineDocStart > lineDocEnd)
+        return false;
 	if (size == 0) {
 		Grow(linesInDoc + growSize);
 	}
diff --git a/src/Document.cxx b/src/Document.cxx
index 709deaf80..6614a7fc9 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -342,15 +342,22 @@ void Document::DeleteChars(int pos, int len) {
 	if (enteredCount == 0) {
 		enteredCount++;
 		if (!cb.IsReadOnly()) {
+			NotifyModified(
+                DocModification(
+                    SC_MOD_BEFOREDELETE | SC_PERFORMED_USER, 
+                    pos, len, 
+                    0, 0));
 			int prevLinesTotal = LinesTotal();
 			bool startSavePoint = cb.IsSavePoint();
 			const char *text = cb.DeleteChars(pos*2, len * 2);
 			if (startSavePoint && cb.IsCollectingUndo())
 				NotifySavePoint(!startSavePoint);
 			ModifiedAt(pos);
-			int modFlags = SC_MOD_DELETETEXT | SC_PERFORMED_USER;
-			DocModification mh(modFlags, pos, len, LinesTotal() - prevLinesTotal, text);
-			NotifyModified(mh);
+			NotifyModified(
+                DocModification(
+                    SC_MOD_DELETETEXT | SC_PERFORMED_USER, 
+                    pos, len, 
+                    LinesTotal() - prevLinesTotal, text));
 		}
 		enteredCount--;
 	}
@@ -365,16 +372,22 @@ void Document::InsertStyledString(int position, char *s, int insertLength) {
 	if (enteredCount == 0) {
 		enteredCount++;
 		if (!cb.IsReadOnly()) {
+			NotifyModified(
+                DocModification(
+                    SC_MOD_BEFOREINSERT | SC_PERFORMED_USER, 
+                    position / 2, insertLength / 2, 
+                    0, 0));
 			int prevLinesTotal = LinesTotal();
 			bool startSavePoint = cb.IsSavePoint();
 			const char *text = cb.InsertString(position, s, insertLength);
 			if (startSavePoint && cb.IsCollectingUndo())
 				NotifySavePoint(!startSavePoint);
 			ModifiedAt(position / 2);
-	
-			int modFlags = SC_MOD_INSERTTEXT | SC_PERFORMED_USER;
-			DocModification mh(modFlags, position / 2, insertLength / 2, LinesTotal() - prevLinesTotal, text);
-			NotifyModified(mh);
+			NotifyModified(
+                DocModification(
+                    SC_MOD_INSERTTEXT | SC_PERFORMED_USER, 
+                    position / 2, insertLength / 2, 
+                    LinesTotal() - prevLinesTotal, text));
 		}
 		enteredCount--;
 	}
@@ -389,7 +402,15 @@ int Document::Undo() {
 		//Platform::DebugPrintf("Steps=%d\n", steps);
 		for (int step=0; step<steps; step++) {
 			int prevLinesTotal = LinesTotal();
-			const Action &action = cb.UndoStep();
+			const Action &action = cb.GetUndoStep();
+			if (action.at == removeAction) {
+			    NotifyModified(DocModification(
+                    SC_MOD_BEFOREINSERT | SC_PERFORMED_UNDO, action));
+            } else {
+			    NotifyModified(DocModification(
+                    SC_MOD_BEFOREDELETE | SC_PERFORMED_UNDO, action));
+            }
+			cb.PerformUndoStep();
 			int cellPosition = action.position / 2;
 			ModifiedAt(cellPosition);
 			newPos = cellPosition;
@@ -424,10 +445,17 @@ int Document::Redo() {
 		int steps = cb.StartRedo();
 		for (int step=0; step<steps; step++) {
 			int prevLinesTotal = LinesTotal();
-			const Action &action = cb.RedoStep();
-			int cellPosition = action.position / 2;
-			ModifiedAt(cellPosition);
-			newPos = cellPosition;
+			const Action &action = cb.GetRedoStep();
+			if (action.at == insertAction) {
+			    NotifyModified(DocModification(
+                    SC_MOD_BEFOREINSERT | SC_PERFORMED_REDO, action));
+            } else {
+			    NotifyModified(DocModification(
+                    SC_MOD_BEFOREDELETE | SC_PERFORMED_REDO, action));
+            }
+			cb.PerformRedoStep();
+			ModifiedAt(action.position / 2);
+			newPos = action.position / 2;
 			
 			int modFlags = SC_PERFORMED_REDO;
 			if (action.at == insertAction) {
@@ -438,7 +466,8 @@ int Document::Redo() {
 			}
 			if (step == steps-1)
 				modFlags |= SC_LASTSTEPINUNDOREDO;
-			NotifyModified(DocModification(modFlags, cellPosition, action.lenData, 
+			NotifyModified(
+                DocModification(modFlags, action.position / 2, action.lenData, 
 				LinesTotal() - prevLinesTotal, action.data));
 		}
 	
diff --git a/src/Document.h b/src/Document.h
index 15f8f1121..92e4ff14f 100644
--- a/src/Document.h
+++ b/src/Document.h
@@ -220,6 +220,16 @@ public:
 		line(0),
 		foldLevelNow(0),
 		foldLevelPrev(0) {}
+
+    DocModification(int modificationType_, const Action &act, int linesAdded_=0) :
+		modificationType(modificationType_),
+		position(act.position / 2),
+		length(act.lenData),
+		linesAdded(linesAdded_),
+		text(act.data),
+		line(0),
+		foldLevelNow(0),
+		foldLevelPrev(0) {}
 };
 
 // A class that wants to receive notifications from a Document must be derived from DocWatcher 
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 440cdeff1..e8e0f755c 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -1599,6 +1599,11 @@ void Editor::NotifyModified(Document*, DocModification mh, void *) {
 					}
 				}
 			}
+			if (mh.modificationType & SC_MOD_BEFOREINSERT) {
+				NotifyNeedShown(mh.position, 0);
+            } else if (mh.modificationType & SC_MOD_BEFOREDELETE) {
+				NotifyNeedShown(mh.position, mh.length);
+            }
 			if (mh.linesAdded != 0) {
 
 				// Update contraction state for inserted and removed lines
@@ -1606,7 +1611,6 @@ void Editor::NotifyModified(Document*, DocModification mh, void *) {
 				int lineOfPos = pdoc->LineFromPosition(mh.position);
 				if (mh.linesAdded > 0) {
 					cs.InsertLines(lineOfPos, mh.linesAdded);
-					NotifyNeedShown(mh.position, mh.length);
 				} else {
 					cs.DeleteLines(lineOfPos, -mh.linesAdded);
 				}