Add handling for simple adding/removing of content to realign the folds

lib/ace/edit_session.js

@@ -879,6 +879,15 @@ var EditSession = function(text, mode) {
                 useWrapMode && this.$wrapData.splice(firstRow, len);
                 // TODO: Remove no longer needed folds here.
                 // TODO: Update row data on folds.
+
+                var foldLines = this.$foldData;
+                for (var i = 0; i < foldLines.length; i++) {
+                    var foldLine = foldLines[i];
+                    if (foldLine.start.row >= firstRow + len) {
+                        foldLine.shiftRow(-len);
+                    }
+                }
+
                 lastRow = firstRow;
             } else {
                 var args;
@@ -889,7 +898,45 @@ var EditSession = function(text, mode) {
                 }
 
                 // TODO: Expand folds here if needed.
-                // TODO: Update row data on folds.
+                // TODO: Split foldLine in case there are new lines added in
+                // between of a foldLine.
+                var foldLines = this.$foldData;
+                for (var i = 0; i < foldLines.length; i++) {
+                    var foldLine = foldLines[i];
+                    if (foldLine.start.row >= firstRow) {
+                        foldLine.shiftRow(len);
+                    }
+                }
+            }
+        } else {
+            len = Math.abs(e.data.range.start.column - e.data.range.end.column);
+            var column;
+            if (action.indexOf("insert") != -1) {
+                column = e.data.range.start.column;
+            } else {
+                column = e.data.range.end.column;
+                len = -len;
+            }
+            var foldLine = this.getFoldLine(firstRow);
+            if (foldLine) {
+                // TODO: Adding new characters into a fold range should
+                // expand/remove the fold.
+                // for (var i = 0; i <= )
+                var ret = foldLine.getNextFoldTo(firstRow, column);
+                if (ret) {
+                    if (ret.kind == "inside") {
+                        // TODO
+                    } else if (ret.fold.start.row == firstRow){
+                        var folds = foldLine.folds;
+                        for (var i = folds.indexOf(ret.fold); i < folds.length; i++) {
+                            folds[i].start.column += len;
+                            if (!folds[i].sameLine) {
+                                break;
+                            }
+                            folds[i].end.column += len;
+                        }
+                    }
+                }
             }
         }
 
@@ -1410,6 +1457,15 @@ var EditSession = function(text, mode) {
     }
 
     (function() {
+        this.shiftRow = function(shift) {
+            this.start.row += shift;
+            this.end.row += shift;
+            this.folds.forEach(function(fold) {
+                fold.start.row += shift;
+                fold.end.row += shift;
+            });
+        }
+
         this.addFold = function(fold) {
             if (fold.sameLine) {
                 if (fold.start.row < this.startRow || fold.endRow > this.endRow) {
@@ -1483,11 +1539,32 @@ var EditSession = function(text, mode) {
             callback(null, endRow, endColumn, lastEnd, isNewRow);
         }
 
+        this.getNextFoldTo = function(row, column) {
+            var fold;
+            for (var i = 0; i < this.folds.length; i++) {
+                fold = this.folds[i];
+                cmp = fold.compare(row, column);
+                if (cmp == -1) {
+                    return {
+                        fold: fold,
+                        kind: "after"
+                    };
+                } else if (cmp == 0) {
+                    return {
+                        fold: fold,
+                        kind: "inside"
+                    }
+                }
+            }
+            return null;
+        }
+
         this.getStringAt = function(session, row, column, trim) {
             var fold, lastFold, cmp, str;
             lastFold = {
                 end: { column: 0 }
             };
+            // TODO: Refactor to use getNextFoldTo function.
             for (var i = 0; i < this.folds.length; i++) {
                 fold = this.folds[i];
                 cmp = fold.compare(row, column);