function snapr_add_tag()

{

  var image = document.getElementById('snapr_preview_img');

  image.parentNode.onclick = function(e)

  {

    canvas_click(this);

  }

  image.parentNode.setAttribute('canvas:oncomplete', 'snapr_process_canvas_add(this);');

  image.parentNode.setAttribute('canvas:oncancel', 'obj.onclick = null;');

}

function snapr_process_canvas_add(obj, tag_data)

{

  obj.onclick = null;

  var abs_x = $(obj).Left() + obj.canvas.left;

  var abs_y = $(obj).Top()  + obj.canvas.top;

  var height = obj.canvas.height + 2;

  var entry_div = document.createElement('div');

  entry_div.className = 'snapr_tag_entry';

  entry_div.style.position = 'absolute';

  entry_div.style.top = String(abs_y + height) + 'px';

  entry_div.style.left = String(abs_x)+ 'px';

  entry_div.appendChild(document.createTextNode('Enter a tag:'));

  entry_div.appendChild(document.createElement('br'));

  var ta = document.createElement('textarea');

  ta.rows = '7';

  ta.cols = '30';

  if ( typeof(tag_data) == 'string' )

    ta.value = tag_data;

  entry_div.appendChild(ta);

  entry_div.appendChild(document.createElement('br'));

  var a_add = document.createElement('a');

  a_add.href = '#';

  a_add.onclick = function()

  {

    snapr_finalize_canvas_add(this.parentNode, this.parentNode.parentNode.canvas, this.previousSibling.previousSibling.value);

    return false;

  }

  a_add.appendChild(document.createTextNode('Add tag'));

  entry_div.appendChild(a_add);

  entry_div.appendChild(document.createTextNode(' | '));

  var a_cancel = document.createElement('a');

  a_cancel.href = '#';

  a_cancel.onclick = function()

  {

    snapr_finalize_canvas_cancel(this.parentNode);

    return false;

  }

  a_cancel.appendChild(document.createTextNode('Cancel'));

  entry_div.appendChild(a_cancel);

  obj.appendChild(entry_div);

  ta.focus();

}

function snapr_finalize_canvas_add(obj, canvas_data, tag)

{

  // add the new box

  var id = obj.parentNode.getAttribute('snapr:imgid');

  if ( !id )

    return false;

  // destroy form, etc.

  var parent = obj.parentNode;

  parent.removeChild(parent.canvas_box_obj);

  parent.removeChild(obj);

  var canvas_json = toJSONString(canvas_data);

  ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=add_tag&tag=' + ajaxEscape(tag) + '&canvas_params=' + ajaxEscape(canvas_json), snapr_process_ajax_tag_packet);

}

function snapr_finalize_canvas_cancel(obj)

{

  var parent = obj.parentNode;

  parent.removeChild(parent.canvas_box_obj);

  parent.removeChild(obj);

}

function snapr_finalize_canvas_edit_cancel(obj)

{

  var old_value = obj.getElementsByTagName('textarea')[0];

  old_value = old_value.OriginalValue;

  var canvas = obj.parentNode;

  var canvas_data = canvas.canvas;

  var note_id = canvas.tag_id;

  var auth_delete = canvas.auth_delete;

  var parent = canvas.parentNode;

  canvas.removeChild(obj);

  parent.removeChild(canvas);

  // redraw the note

  snapr_draw_note(parent, old_value, canvas_data, note_id, false, auth_delete);

}

function snapr_finalize_canvas_edit_delete(obj)

{

  var old_value = obj.getElementsByTagName('textarea')[0];

  old_value = old_value.OriginalValue;

  var canvas = obj.parentNode;

  var canvas_data = canvas.canvas;

  var note_id = canvas.tag_id;

  var auth_delete = canvas.auth_delete;

  var parent = canvas.parentNode;

  canvas.removeChild(obj);

  parent.removeChild(canvas);

  // redraw the note

  var note = snapr_draw_note(parent, old_value, canvas_data, note_id, false, auth_delete);

  // now nuke it

  snapr_nuke_tag(note);

}

function snapr_draw_note(obj, tag, canvas_data, note_id, initial_hide, auth_delete)

{

  var newbox = canvas_create_box(obj, canvas_data.left, canvas_data.top, canvas_data.width, canvas_data.height);

  newbox.tag_id = note_id;

  newbox.canvas = canvas_data;

  newbox.auth_delete = auth_delete;

  obj.onmouseover = function()

  {

    var boxen = this.getElementsByTagName('div');

    for ( var i = 0; i < boxen.length; i++ )

      if ( boxen[i].className == 'canvasbox' )

        boxen[i].style.display = 'block';

  }

  obj.onmouseout = function()

  {

    var boxen = this.getElementsByTagName('div');

    for ( var i = 0; i < boxen.length; i++ )

      if ( boxen[i].className == 'canvasbox' )

        boxen[i].style.display = 'none';

  }

  newbox.onmouseover = function()

  {

    this.style.borderColor = '#FFFF00';

    this.firstChild.style.borderColor = '#000000';

    snapr_display_note(this.noteObj);

  }

  newbox.onmouseout = function()

  {

    this.style.borderColor = '#000000';

    this.firstChild.style.borderColor = '#FFFFFF';

    snapr_hide_note(this.noteObj);

  }

  if ( auth_delete )

  {

    /*

    var p = document.createElement('p');

    p.style.cssFloat = 'right';

    p.style.styleFloat = 'right';

    p.style.fontWeight = 'bold';

    p.style.margin = '5px';

    var a_del = document.createElement('a');

    a_del.style.color = '#FF0000';

    a_del.href = '#';

    a_del.onclick = function()

    {

      snapr_nuke_tag(this.parentNode.parentNode.parentNode);

      return false;

    }

    a_del.appendChild(document.createTextNode('[X]'));

    p.appendChild(a_del);

    newbox.firstChild.appendChild(p);

    */

    newbox.style.cursor = 'pointer';

    newbox.onclick = function()

    {

      snapr_run_tag_editor(this);

    }

  }

  var abs_x = $(newbox).Left();

  var abs_y = $(newbox).Top() + $(newbox).Height() + 2;

  var noteObj = document.createElement('div');

  newbox.noteObj = noteObj;

  noteObj.className = 'snapr_tag';

  noteObj.style.display = 'none';

  noteObj.style.position = 'absolute';

  noteObj.style.top = abs_y + 'px';

  noteObj.style.left = abs_x + 'px';

  noteObj.style.zIndex = '100';

  var re = new RegExp(unescape('%0A'), 'g');

  noteObj.innerHTML = tag.replace(re, "<br />\n");

  obj.appendChild(noteObj);

  if ( initial_hide )

    newbox.style.display = 'none';

  return newbox;

}

function snapr_display_note(note)

{

  //domObjChangeOpac(0, note);

  note.style.display = 'block';

  //domOpacity(note, 0, 100, 500);

}

function snapr_hide_note(note)

{

  //domOpacity(note, 100, 0, 500);

  //setTimeout(function()

  //  {

      note.style.display = 'none';

  //  }, 600);

}

function snapr_nuke_tag(obj)

{

  // add the new box

  var parent_obj = document.getElementById('snapr_preview_img').parentNode;

  var id = parent_obj.getAttribute('snapr:imgid');

  if ( !id )

    return false;

  ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=del_tag&tag_id=' + obj.tag_id, snapr_process_ajax_tag_packet);

}

function snapr_run_tag_editor(obj)

{

  obj.onclick = null;

  var abs_x = $(obj).Left();

  var abs_y = $(obj).Top();

  var height = $(obj).Height() + 2;

  var value = obj.nextSibling.innerHTML;

  var regex = new RegExp('<br>', 'g');

  value = value.replace(regex, '');

  obj.parentNode.removeChild(obj.nextSibling);

  var entry_div = document.createElement('div');

  entry_div.className = 'snapr_tag_entry';

  entry_div.style.position = 'absolute';

  entry_div.style.top = String(height) + 'px';

  entry_div.style.left = '0px';

  entry_div.style.zIndex = '100';

  entry_div.appendChild(document.createTextNode('Enter a tag:'));

  entry_div.appendChild(document.createElement('br'));

  var ta = document.createElement('textarea');

  ta.rows = '7';

  ta.cols = '30';

  ta.value = value;

  ta.style.backgroundColor = '#FFFFFF';

  ta.style.borderWidth = '0';

  ta.style.color = '#000000';

  ta.OriginalValue = value;

  entry_div.appendChild(ta);

  entry_div.appendChild(document.createElement('br'));

  var a_add = document.createElement('a');

  a_add.href = '#';

  a_add.onclick = function()

  {

    snapr_finalize_canvas_edit(this.parentNode.parentNode, this.parentNode.getElementsByTagName('textarea')[0]['value'], this.parentNode);

    return false;

  }

  a_add.appendChild(document.createTextNode('Save tag'));

  entry_div.appendChild(a_add);

  entry_div.appendChild(document.createTextNode(' | '));

  var a_cancel = document.createElement('a');

  a_cancel.href = '#';

  a_cancel.onclick = function()

  {

    snapr_finalize_canvas_edit_cancel(this.parentNode);

    return false;

  }

  a_cancel.appendChild(document.createTextNode('Cancel'));

  entry_div.appendChild(a_cancel);

  entry_div.appendChild(document.createTextNode(' | '));

  var a_del = document.createElement('a');

  a_del.href = '#';

  a_del.onclick = function()

  {

    snapr_finalize_canvas_edit_delete(this.parentNode);

    return false;

  }

  a_del.style.color = '#FF0000';

  a_del.appendChild(document.createTextNode('Delete'));

  entry_div.appendChild(a_del);

  obj.appendChild(entry_div);

  ta.focus();

}

function snapr_finalize_canvas_edit(canvas, value, editor)

{

  var canvas_data = canvas.canvas;

  var note_id = canvas.tag_id;

  var parent = canvas.parentNode;

  canvas.removeChild(editor);

  parent.removeChild(canvas);

  // send the edit across the 'net

  var parent_obj = document.getElementById('snapr_preview_img').parentNode;

  var id = parent_obj.getAttribute('snapr:imgid');

  if ( !id )

    return false;

  var canvas_json = toJSONString(canvas_data);

  ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=edit_tag&tag=' + ajaxEscape(value) + '&canvas_params=' + ajaxEscape(canvas_json) + '&tag_id=' + note_id, snapr_process_ajax_tag_packet);

}

function snapr_process_ajax_tag_packet()

{

  if ( ajax.readyState == 4 && ajax.status == 200 )

  {

    var response = String(ajax.responseText + '');

    if ( response.substr(0, 1) != '[' && response.substr(0, 1) != '{' )

    {

      new messagebox(MB_OK|MB_ICONSTOP, 'JSON response invalid', 'Received unexpected response:<pre>' + response + '</pre>');

      return false;

    }

    response = parseJSON(response);

    if ( response.mode )

    {

      if ( response.mode == 'error' )

      {

        alert(response.error);

        return false;

      }

    }

    var parent_obj = document.getElementById('snapr_preview_img').parentNode;

    for ( var i = 0; i < response.length; i++ )

    {

      var packet = response[i];

      switch(packet.mode)

      {

        case 'add':

          snapr_draw_note(parent_obj, packet.tag, packet.canvas_data, packet.note_id, packet.initial_hide, packet.auth_delete);

          break;

        case 'remove':

          // Server requested to remove a tag

          var divs = parent_obj.getElementsByTagName('div');

          for ( var i = 0; i < divs.length; i++ )

          {

            var box = divs[i];

            if ( box.className == 'canvasbox' )

            {

              if ( box.tag_id == packet.note_id )

              {

                // You. We have orders to shoot. Stand in front of wall.

                var sibling = box.nextSibling;

                var parent = box.parentNode;

                // BLAM.

                parent.removeChild(sibling);

                parent.removeChild(box);

                break;

              }

            }

          }

          break;

      }

    }

  }

}

// Don't fire the tag init until JS init *and* image are finished.

// Thanks to pmccullough for pointing out this race condition.

var snapr_lock_onload_js = true;

var snapr_lock_onload_img = true;

var snapr_tags_onload_real = function()

{

  // make sure we aren't waiting...

  if ( snapr_lock_onload_img || snapr_lock_onload_js )

    return false;

  // add the new box

  var parent_obj = document.getElementById('snapr_preview_img').parentNode;

  var id = parent_obj.getAttribute('snapr:imgid');

  if ( !id )

    return false;

  ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=get_tags', snapr_process_ajax_tag_packet);

}

var snapr_tags_onload = function()

{

  snapr_lock_onload_js = false;

  snapr_tags_onload_real();

}

addOnloadHook(snapr_tags_onload);