

methodDraw.addExtension("Markers", function(S) {
  var svgcontent = S.svgcontent,
  addElem = S.addSvgElementFromJson,
  selElems;

  var mtypes = ['start','mid','end'];

  var marker_prefix = 'se_marker_';
  var id_prefix = 'mkr_';
    
  // note - to add additional marker types add them below with a unique id
  // and add the associated icon(s) to marker-icons.svg
  // the geometry is normallized to a 100x100 box with the origin at lower left
  // Safari did not like negative values for low left of viewBox
  // remember that the coordinate system has +y downward
  var marker_types = {
    nomarker: {},  
    leftarrow:  
      {element:'path', attr:{d:'M0,50 L100,90 L70,50 L100,10 Z'}},
    rightarrow:
      {element:'path', attr:{d:'M100,50 L0,90 L30,50 L0,10 Z'}},
    textmarker:
      {element:'text', attr: {x:0, y:0,'stroke-width':0,'stroke':'none','font-size':75,'font-family':'serif','text-anchor':'left',
        'xml:space': 'preserve'}},
    forwardslash:
      {element:'path', attr:{d:'M30,100 L70,0'}},
    reverseslash:
      {element:'path', attr:{d:'M30,0 L70,100'}},
    verticalslash:
      {element:'path', attr:{d:'M50,0 L50,100'}},
    box:
      {element:'path', attr:{d:'M20,20 L20,80 L80,80 L80,20 Z'}},
    star:
      {element:'path', attr:{d:'M10,30 L90,30 L20,90 L50,10 L80,90 Z'}},
    xmark:
      {element:'path', attr:{d:'M20,80 L80,20 M80,80 L20,20'}},
    triangle:
      {element:'path', attr:{d:'M10,80 L50,20 L80,80 Z'}},
    mcircle:
      {element:'circle', attr:{r:30, cx:50, cy:50}}
  }
  
  
  var lang_list = {
    "en":[
      {id: "start_marker_list", title: "Select start marker type" },
      {id: "mid_marker_list", title: "Select mid marker type" },
      {id: "end_marker_list", title: "Select end marker type" },
      {id: "nomarker", title: "No Marker" },
      {id: "leftarrow", title: "Left Arrow" },
      {id: "rightarrow", title: "Right Arrow" },
      {id: "textmarker", title: "Text Marker" },
      {id: "forwardslash", title: "Forward Slash" },
      {id: "reverseslash", title: "Reverse Slash" },
      {id: "verticalslash", title: "Vertical Slash" },
      {id: "box", title: "Box" },
      {id: "star", title: "Star" },
      {id: "xmark", title: "X" },
      {id: "triangle", title: "Triangle" },
      {id: "mcircle", title: "Circle" },
      {id: "leftarrow_o", title: "Open Left Arrow" },
      {id: "rightarrow_o", title: "Open Right Arrow" },
      {id: "box_o", title: "Open Box" },
      {id: "star_o", title: "Open Star" },
      {id: "triangle_o", title: "Open Triangle" },
      {id: "mcircle_o", title: "Open Circle" }
    ]
  };


  // duplicate shapes to support unfilled (open) marker types with an _o suffix
  $.each(['leftarrow','rightarrow','box','star','mcircle','triangle'],function(i,v) {
    marker_types[v+'_o'] = marker_types[v];
  });
  
  // elem = a graphic element will have an attribute like marker-start
  // attr - marker-start, marker-mid, or marker-end
  // returns the marker element that is linked to the graphic element
  function getLinked(elem, attr) {
    var str = elem.getAttribute(attr);
    if(!str) return null;
    var m = str.match(/\(\#(.*)\)/);
    if(!m || m.length !== 2) {
      return null;
    }
    return S.getElem(m[1]);
  }

  //toggles context tool panel off/on
  //sets the controls with the selected element's settings
  function showPanel(on) {
    $('#marker_panel').toggle(on);
    if ($('#marker_panel_title').length < 1) {
      $('#marker_panel').prepend("<h4 id='marker_panel_title'>Arrows</h4>")
    }

    if(on) {
      var el = selElems[0];
      var val;
      var ci;

      $.each(mtypes, function(i, pos) {
        var m=getLinked(el,"marker-"+pos);
        var txtbox = $('#'+pos+'_marker');
        if (!m) {
          val='\\nomarker';
          ci=val;
          txtbox.hide() // hide text box
        } else {
          if (!m.attributes.se_type) return; // not created by this extension
          val='\\'+m.attributes.se_type.textContent;
          ci=val;
          if (val=='\\textmarker') {
            val=m.lastChild.textContent;
            //txtbox.show(); // show text box
          } else {
            txtbox.hide() // hide text box
          }
        }
        txtbox.val(val);        
        setIcon(pos,ci);
      })
    }
  } 

  function addMarker(id, val) {
    var txt_box_bg = '#ffffff';
    var txt_box_border = 'none';
    var txt_box_stroke_width = 0;
    
    var marker = S.getElem(id);

    if (marker) return;

    if (val=='' || val=='\\nomarker') return;

    var el = selElems[0];    
    var color = el.getAttribute('stroke');
    //NOTE: Safari didn't like a negative value in viewBox
    //so we use a standardized 0 0 100 100
    //with 50 50 being mapped to the marker position
    var refX = 50;
    var refY = 50;
    var viewBox = "0 0 100 100";
    var markerWidth = 5;
    var markerHeight = 5;
    var strokeWidth = 10;
    if (val.substr(0,1)=='\\') se_type=val.substr(1);
    else se_type='textmarker';

    if (!marker_types[se_type]) return; // an unknown type!
    
    // create a generic marker
    marker = addElem({
      "element": "marker",
      "attr": {
      "id": id,
      "markerUnits": "strokeWidth",
      "orient": "auto",
      "style": "pointer-events:none",
      "se_type": se_type
    }
    });

    if (se_type!='textmarker') {
      var mel = addElem(marker_types[se_type]);
      var fillcolor = color;
      if (se_type.substr(-2)=='_o') fillcolor='none';
      mel.setAttribute('fill',fillcolor);
      mel.setAttribute('stroke',color);
      mel.setAttribute('stroke-width',strokeWidth);
      marker.appendChild(mel);
    } else {
      var text = addElem(marker_types[se_type]);
      // have to add text to get bounding box
      text.textContent = val;
      var tb=text.getBBox();
      //alert( tb.x + " " + tb.y + " " + tb.width + " " + tb.height);
      var pad=1;
      var bb = tb;
      bb.x = 0;
      bb.y = 0;
      bb.width += pad*2;
      bb.height += pad*2;
      // shift text according to its size
      text.setAttribute('x', pad);
      text.setAttribute('y', bb.height - pad - tb.height/4); // kludge?
      text.setAttribute('fill',color);
      refX = bb.width/2+pad;
      refY = bb.height/2+pad;
      viewBox = bb.x + " " + bb.y + " " + bb.width + " " + bb.height;
      markerWidth =bb.width/10;
      markerHeight = bb.height/10;

      var box = addElem({
        "element": "rect",
        "attr": {
        "x": bb.x,
        "y": bb.y,
        "width": bb.width,
        "height": bb.height,
        "fill": txt_box_bg,
        "stroke": txt_box_border,
        "stroke-width": txt_box_stroke_width
      }
      });
      marker.setAttribute("orient",0);
      marker.appendChild(box);
      marker.appendChild(text);
    } 

    marker.setAttribute("viewBox",viewBox);
    marker.setAttribute("markerWidth", markerWidth);
    marker.setAttribute("markerHeight", markerHeight);
    marker.setAttribute("refX", refX);
    marker.setAttribute("refY", refY);
    S.findDefs().appendChild(marker);

    return marker;
  }


  function setMarker() {
    var poslist={'start_marker':'start','mid_marker':'mid','end_marker':'end'};
    var pos = poslist[this.id];
    var marker_name = 'marker-'+pos;
    var val = this.value;
    var el = selElems[0];
    var marker = getLinked(el, marker_name);
    if (marker) $(marker).remove();
    el.removeAttribute(marker_name);
    if (val=='') val='\\nomarker';
    if (val=='\\nomarker') {
      setIcon(pos,val);
      S.call("changed", selElems);
      return;
    }
    // Set marker on element
    var id = marker_prefix + pos + '_' + el.id;
    addMarker(id, val);
    svgCanvas.changeSelectedAttribute(marker_name, "url(#" + id + ")");
    if (el.tagName == "line" && pos=='mid') el=convertline(el);
    S.call("changed", selElems);
    setIcon(pos,val);
  }

  function convertline(elem) {
    // this routine came from the connectors extension
    // it is needed because midpoint markers don't work with line elements
    if (!(elem.tagName == "line")) return elem;

    // Convert to polyline to accept mid-arrow

    var x1 = elem.getAttribute('x1')-0;
    var x2 = elem.getAttribute('x2')-0;
    var y1 = elem.getAttribute('y1')-0;
    var y2 = elem.getAttribute('y2')-0;
    var id = elem.id;

    var mid_pt = (' '+((x1+x2)/2)+','+((y1+y2)/2) + ' ');
    var pline = addElem({
      "element": "polyline",
      "attr": {
      "points": (x1+','+y1+ mid_pt +x2+','+y2),
      "stroke": elem.getAttribute('stroke'),
      "stroke-width": elem.getAttribute('stroke-width'),
      "fill": "none",
      "opacity": elem.getAttribute('opacity') || 1
    }
    });
    $.each(mtypes, function(i, pos) { // get any existing marker definitions
      var nam = 'marker-'+pos;
      var m = elem.getAttribute(nam);
      if (m) pline.setAttribute(nam,elem.getAttribute(nam));
    });
    
    var batchCmd = new S.BatchCommand();
    batchCmd.addSubCommand(new S.RemoveElementCommand(elem, elem.parentNode));
    batchCmd.addSubCommand(new S.InsertElementCommand(pline));
    
    $(elem).after(pline).remove();
    svgCanvas.clearSelection();
    pline.id = id;
    svgCanvas.addToSelection([pline]);
    S.addCommandToHistory(batchCmd);
    return pline;
  }

  // called when the main system modifies an object
  // this routine changes the associated markers to be the same color
  function colorChanged(elem) {
    var color = elem.getAttribute('stroke');

    $.each(mtypes, function(i, pos) {
      var marker = getLinked(elem, 'marker-'+pos);
      if (!marker) return;
      if (!marker.attributes.se_type) return; //not created by this extension
      var ch = marker.lastElementChild;
      if (!ch) return;
      var curfill = ch.getAttribute("fill");
      var curstroke = ch.getAttribute("stroke")
      if (curfill && curfill!='none') ch.setAttribute("fill",color);
      if (curstroke && curstroke!='none') ch.setAttribute("stroke",color);
    });
  }

  // called when the main system creates or modifies an object
  // primary purpose is create new markers for cloned objects
  function updateReferences(el) {
    $.each(mtypes, function (i,pos) {
      var id = marker_prefix + pos + '_' + el.id;
      var marker_name = 'marker-'+pos;
      var marker = getLinked(el, marker_name);
      if (!marker || !marker.attributes.se_type) return; //not created by this extension
      var url = el.getAttribute(marker_name);
      if (url) {
        var len = el.id.length;
        var linkid = url.substr(-len-1,len);
        if (el.id != linkid) {
          var val = $('#'+pos+'_marker').attr('value');
          addMarker(id, val);
          svgCanvas.changeSelectedAttribute(marker_name, "url(#" + id + ")");
          if (el.tagName == "line" && pos=='mid') el=convertline(el);
          S.call("changed", selElems);
        }
      }
    });
  }

  // simulate a change event a text box that stores the current element's marker type
  function triggerTextEntry(pos,val) {
    $('#'+pos+'_marker').val(val);
    $('#'+pos+'_marker').change();
    var txtbox = $('#'+pos+'_marker');
    //if (val.substr(0,1)=='\\') txtbox.hide();
    //else txtbox.show();
  }
  
  function setIcon(pos,id) {
    if (id.substr(0,1)!='\\') id='\\textmarker'
    var ci = '#'+id_prefix+pos+'_'+id.substr(1);
    methodDraw.setIcon('#cur_' + pos +'_marker_list', $(ci).children());
    $(ci).addClass('current').siblings().removeClass('current');
  }
    
  function setMarkerSet(obj) {
    var parts = this.id.split('_');
    var set = parts[2];
    switch (set) {
    case 'off':
      triggerTextEntry('start','\\nomarker');
      triggerTextEntry('mid','\\nomarker');
      triggerTextEntry('end','\\nomarker');
      break;
    case 'dimension':
      triggerTextEntry('start','\\leftarrow');
      triggerTextEntry('end','\\rightarrow');
      showTextPrompt('mid');
      break;
    case 'label':
      triggerTextEntry('mid','\\nomarker');
      triggerTextEntry('end','\\rightarrow');
      showTextPrompt('start');
      break;
    }
  }
    
  function showTextPrompt(pos) {
    var def = $('#'+pos+'_marker').val();
    if (def.substr(0,1)=='\\') def='';
    $.prompt('Enter text for ' + pos + ' marker', def , function(txt) { if (txt) triggerTextEntry(pos,txt); });
  }
  
  // callback function for a toolbar button click
  function setArrowFromButton(obj) {
    
    var parts = this.id.split('_');
    var pos = parts[1];
    var val = parts[2];
    if (parts[3]) val+='_'+parts[3];
    
    if (val!='textmarker') {
      triggerTextEntry(pos,'\\'+val);
    } else {
      showTextPrompt(pos);
    }
  }
  
  function getTitle(lang,id) {
    var list = lang_list[lang];
    for (var i in list) {
      if (list[i].id==id) return list[i].title;
    }
    return id;
  }
  
  
  // build the toolbar button array from the marker definitions
  // TODO: need to incorporate language specific titles
  function buildButtonList() {
    var buttons=[];
    var i=0;
/*
    buttons.push({
      id:id_prefix + 'markers_off',
      title:'Turn off all markers',
      type:'context',
      events: { 'click': setMarkerSet },
      panel: 'marker_panel'
    });
    buttons.push({
      id:id_prefix + 'markers_dimension',
      title:'Dimension',
      type:'context',
      events: { 'click': setMarkerSet },
      panel: 'marker_panel'
    });
    buttons.push({
      id:id_prefix + 'markers_label',
      title:'Label',
      type:'context',
      events: { 'click': setMarkerSet },
      panel: 'marker_panel'
    });
*/
    $.each(mtypes,function(k,pos) {
      var listname = pos + "_marker_list";
      var def = true;
    $.each(marker_types,function(id,v) {
      var title = getTitle('en',id);
      buttons.push({
          id:id_prefix + pos + "_" + id,
          svgicon:id,
          title:title,
          type:'context',
          events: { 'click': setArrowFromButton },
          panel:'marker_panel',
          list: listname,
          isDefault: def
      });
      def = false;
    });
    });
    return buttons;
  }

  return {
    name: "Markers",
    svgicons: "extensions/markers-icons.xml",
    buttons: buildButtonList(),
    context_tools: [
       {
      type: "input",
      panel: "marker_panel",
      title: "Start marker",
      id: "start_marker",
      label: "Start",
      size: 3,
      events: { change: setMarker }
    },{
      type: "button-select",
      panel: "marker_panel",
      title: getTitle('en','start_marker_list'),
      id: "start_marker_list",
      colnum: 3,
      events: { change: setArrowFromButton }
    },{
      type: "input",
      panel: "marker_panel",
      title: "Middle marker",
      id: "mid_marker",
      label: "Middle",
      defval: "",
      size: 3,
      events: { change: setMarker }
    },{
      type: "button-select",
      panel: "marker_panel",
      title: getTitle('en','mid_marker_list'),
      id: "mid_marker_list",
      colnum: 3,
      events: { change: setArrowFromButton }
    },{
      type: "input",
      panel: "marker_panel",
      title: "End marker",
      id: "end_marker",
      label: "End",
      size: 3,
      events: { change: setMarker }
    },{
      type: "button-select",
      panel: "marker_panel",
      title: getTitle('en','end_marker_list'),
      id: "end_marker_list",
      colnum: 3,
      events: { change: setArrowFromButton }
    } ],
    callback: function() {
      $('#marker_panel').addClass('toolset').hide();
      
    },
    addLangData: function(lang) {
      return { data: lang_list[lang] };
    },

  selectedChanged: function(opts) {
    // Use this to update the current selected elements
    //console.log('selectChanged',opts);
    selElems = opts.elems;

    var i = selElems.length;
    var marker_elems = ['line','path','polyline','polygon'];

    while(i--) {
      var elem = selElems[i];
      if(elem && $.inArray(elem.tagName, marker_elems) != -1) {
        if(opts.selectedElement && !opts.multiselected) {
          showPanel(true);
        } else {
          showPanel(false);
        }
      } else {
        showPanel(false);
      }
    }
  },

  elementChanged: function(opts) {    
    //console.log('elementChanged',opts);
    var elem = opts.elems[0];
    if(elem && (
        elem.getAttribute("marker-start") ||
        elem.getAttribute("marker-mid") ||
        elem.getAttribute("marker-end")
    )) {
      colorChanged(elem);
      updateReferences(elem);
    }
    changing_flag = false;
  }
  };
});

