add folding for xml style modes. Also refactor

html, svg and xml modes to reuse code

lib/ace/edit_session/folding.js

@@ -391,7 +391,7 @@ function Folding() {
             this.removeFold(fold);
         }, this);
         this.$modified = true;
-    }
+    };
 
     this.expandFold = function(fold) {
         this.removeFold(fold);
@@ -399,13 +399,13 @@ function Folding() {
             this.addFold(fold);
         }, this);
         fold.subFolds = [];
-    }
+    };
 
     this.expandFolds = function(folds) {
         folds.forEach(function(fold) {
             this.expandFold(fold);
         }, this);
-    }
+    };
 
     this.unfold = function(location, expandInner) {
         var range, folds;
@@ -418,7 +418,7 @@ function Folding() {
         else
             range = location;
 
-        var folds = this.getFoldsInRange(range);
+        folds = this.getFoldsInRange(range);
         if (expandInner) {
             this.removeFolds(folds);
         } else {
@@ -429,7 +429,7 @@ function Folding() {
                 folds = this.getFoldsInRange(range);
             }
         }
-    }
+    };
 
     /**
      * Checks if a given documentRow is folded. This is true if there are some
@@ -458,7 +458,6 @@ function Folding() {
         }
 
         // Build the textline using the FoldLine walker.
-        var line = "";
         var doc = this.doc;
         var textLine = "";
 
@@ -494,7 +493,6 @@ function Folding() {
     };
 
     this.$cloneFoldData = function() {
-        var foldData = this.$foldData;
         var fd = [];
         fd = this.$foldData.map(function(foldLine) {
             var folds = foldLine.folds.map(function(fold) {
@@ -511,9 +509,9 @@ function Folding() {
         var range = selection.getRange();
 
         if (range.isEmpty()) {
-            var cursor = range.start
+            var cursor = range.start;
             var fold = this.getFoldAt(cursor.row, cursor.column);
-            var bracketPos, column;
+            var bracketPos;
 
             if (fold) {
                 this.expandFold(fold);
@@ -601,7 +599,6 @@ function Folding() {
                 continue
 
             var range = this.getFoldWidgetRange(row);
-            console.log(row, range)
             if (range)
                 this.addFold("...", range)
         }
@@ -771,7 +768,98 @@ Folding.commonFoldingRules = {
         }
     },
     // TODO: folding based only on indentation
-    "indentation": null
+    "indentation": null,
+
+    "xml": {
+        getFoldWidget: function(row) {
+            var tags = this.getTokens(row, row)[0].tokens
+                .filter(function(token) {
+                    return token.type === "meta.tag"
+                })
+                .map(function(token) {
+                    return token.value;
+                }).
+                join("")
+                .trim()
+                .replace(/^<|>$|\s+/g, "")
+                .split("><")
+            
+            var fold = tags[0];
+            
+            if (!fold)
+                return;
+            if (fold.charAt(0) == "/")
+                return "end";
+                
+            if (tags.indexOf("/" + fold) !== -1)
+                return;
+                
+            return "start";
+        },
+        
+        getFoldWidgetRange: function(row) {
+            var start, end;
+            var stack = [];
+            
+            var iterator = new TokenIterator(this, row, 0);
+            var step = "stepForward";
+            var isBack = false;
+            
+            do {
+                var token = iterator.getCurrentToken();
+                
+                var value = token.value.trim();
+                if (token && token.type == "meta.tag" && token.value !== ">") {
+                    var tagName = value.replace(/^[<\s]*|[\s*>]$/g, "");
+                    if (!start) {
+                        if (tagName.charAt(0) == "/") {
+                            tagName = tagName.slice(1);
+                            step = "stepBackward";
+                            isBack = true;
+                        }
+                        
+                        start = {
+                            row: row,
+                            column: iterator.getCurrentTokenColumn() + (isBack ? 0 : value.length + 1)
+                        };
+
+                        stack.push(tagName);
+                    }
+                    else {
+                        if (tagName.charAt(0) == "/") {
+                            tagName = tagName.slice(1);
+                            var close = !isBack;
+                        }
+                        else
+                            close = isBack;
+                        
+                        if (close) {
+                            if (stack[stack.length-1] == tagName) {
+                                stack.pop();
+                                if (stack.length == 0) {
+                                    end = {
+                                        row: iterator.getCurrentTokenRow(),
+                                        column: iterator.getCurrentTokenColumn() + (isBack ? value.length : 0)
+                                    };
+                                    if (isBack)
+                                        return Range.fromPoints(end, start);
+                                    else
+                                        return Range.fromPoints(start, end);
+                                }
+                            }
+                            else {
+                                console.error("unmatched tags!", tagName, stack)
+                            }
+                        }
+                        else {
+                            stack.push(tagName);
+                        }
+                    }
+                }
+                
+            } while(token = iterator[step]());
+        }
+    }
 }
 
 exports.Folding = Folding;