michael@0: (function() {
michael@0:   "use strict";
michael@0: 
michael@0:   CodeMirror.defineOption("foldGutter", false, function(cm, val, old) {
michael@0:     if (old && old != CodeMirror.Init) {
michael@0:       cm.clearGutter(cm.state.foldGutter.options.gutter);
michael@0:       cm.state.foldGutter = null;
michael@0:       cm.off("gutterClick", onGutterClick);
michael@0:       cm.off("change", onChange);
michael@0:       cm.off("viewportChange", onViewportChange);
michael@0:       cm.off("fold", onFold);
michael@0:       cm.off("unfold", onFold);
michael@0:       cm.off("swapDoc", updateInViewport);
michael@0:     }
michael@0:     if (val) {
michael@0:       cm.state.foldGutter = new State(parseOptions(val));
michael@0:       updateInViewport(cm);
michael@0:       cm.on("gutterClick", onGutterClick);
michael@0:       cm.on("change", onChange);
michael@0:       cm.on("viewportChange", onViewportChange);
michael@0:       cm.on("fold", onFold);
michael@0:       cm.on("unfold", onFold);
michael@0:       cm.on("swapDoc", updateInViewport);
michael@0:     }
michael@0:   });
michael@0: 
michael@0:   var Pos = CodeMirror.Pos;
michael@0: 
michael@0:   function State(options) {
michael@0:     this.options = options;
michael@0:     this.from = this.to = 0;
michael@0:   }
michael@0: 
michael@0:   function parseOptions(opts) {
michael@0:     if (opts === true) opts = {};
michael@0:     if (opts.gutter == null) opts.gutter = "CodeMirror-foldgutter";
michael@0:     if (opts.indicatorOpen == null) opts.indicatorOpen = "CodeMirror-foldgutter-open";
michael@0:     if (opts.indicatorFolded == null) opts.indicatorFolded = "CodeMirror-foldgutter-folded";
michael@0:     return opts;
michael@0:   }
michael@0: 
michael@0:   function isFolded(cm, line) {
michael@0:     var marks = cm.findMarksAt(Pos(line));
michael@0:     for (var i = 0; i < marks.length; ++i)
michael@0:       if (marks[i].__isFold && marks[i].find().from.line == line) return true;
michael@0:   }
michael@0: 
michael@0:   function marker(spec) {
michael@0:     if (typeof spec == "string") {
michael@0:       var elt = document.createElement("div");
michael@0:       elt.className = spec;
michael@0:       return elt;
michael@0:     } else {
michael@0:       return spec.cloneNode(true);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   function updateFoldInfo(cm, from, to) {
michael@0:     var opts = cm.state.foldGutter.options, cur = from;
michael@0:     cm.eachLine(from, to, function(line) {
michael@0:       var mark = null;
michael@0:       if (isFolded(cm, cur)) {
michael@0:         mark = marker(opts.indicatorFolded);
michael@0:       } else {
michael@0:         var pos = Pos(cur, 0), func = opts.rangeFinder || CodeMirror.fold.auto;
michael@0:         var range = func && func(cm, pos);
michael@0:         if (range && range.from.line + 1 < range.to.line)
michael@0:           mark = marker(opts.indicatorOpen);
michael@0:       }
michael@0:       cm.setGutterMarker(line, opts.gutter, mark);
michael@0:       ++cur;
michael@0:     });
michael@0:   }
michael@0: 
michael@0:   function updateInViewport(cm) {
michael@0:     var vp = cm.getViewport(), state = cm.state.foldGutter;
michael@0:     if (!state) return;
michael@0:     cm.operation(function() {
michael@0:       updateFoldInfo(cm, vp.from, vp.to);
michael@0:     });
michael@0:     state.from = vp.from; state.to = vp.to;
michael@0:   }
michael@0: 
michael@0:   function onGutterClick(cm, line, gutter) {
michael@0:     var opts = cm.state.foldGutter.options;
michael@0:     if (gutter != opts.gutter) return;
michael@0:     cm.foldCode(Pos(line, 0), opts.rangeFinder);
michael@0:   }
michael@0: 
michael@0:   function onChange(cm) {
michael@0:     var state = cm.state.foldGutter, opts = cm.state.foldGutter.options;
michael@0:     state.from = state.to = 0;
michael@0:     clearTimeout(state.changeUpdate);
michael@0:     state.changeUpdate = setTimeout(function() { updateInViewport(cm); }, opts.foldOnChangeTimeSpan || 600);
michael@0:   }
michael@0: 
michael@0:   function onViewportChange(cm) {
michael@0:     var state = cm.state.foldGutter, opts = cm.state.foldGutter.options;
michael@0:     clearTimeout(state.changeUpdate);
michael@0:     state.changeUpdate = setTimeout(function() {
michael@0:       var vp = cm.getViewport();
michael@0:       if (state.from == state.to || vp.from - state.to > 20 || state.from - vp.to > 20) {
michael@0:         updateInViewport(cm);
michael@0:       } else {
michael@0:         cm.operation(function() {
michael@0:           if (vp.from < state.from) {
michael@0:             updateFoldInfo(cm, vp.from, state.from);
michael@0:             state.from = vp.from;
michael@0:           }
michael@0:           if (vp.to > state.to) {
michael@0:             updateFoldInfo(cm, state.to, vp.to);
michael@0:             state.to = vp.to;
michael@0:           }
michael@0:         });
michael@0:       }
michael@0:     }, opts.updateViewportTimeSpan || 400);
michael@0:   }
michael@0: 
michael@0:   function onFold(cm, from) {
michael@0:     var state = cm.state.foldGutter, line = from.line;
michael@0:     if (line >= state.from && line < state.to)
michael@0:       updateFoldInfo(cm, line, line + 1);
michael@0:   }
michael@0: })();