/**
 *
 * Author: Antoine Quint <antoine@graougraou.com>
 * Copyleft 2002
 *
 * This EcmaScript resource file implements the
 * XForms <button> element as embedded in an SVG
 * document. The child <caption> element is also
 * supported.
 *
 **/

function SVG () {}
function XForms () {}

SVG.ns = "http://www.w3.org/2000/svg";
XForms.ns = "http://www.w3.org/2002/01/forms";

// called onload on the SVG element
XForms.init = function () {
  Button.init(document.documentElement);
}






/**
 *
 * XForms <button> element
 *
 **/

function Button (element) {
  this.element = element;
  this.style = this.generateSVGStyle();
  this.SVGElement = null;
  this.caption = new Caption(this.getCaptionElement(), this);
  this.marginLeft = 15;     // the horizontal margin around the caption
  this.marginTop = 6;       // the vertical margin around the caption
}

// Called onload to initialize buttons
Button.init = function (root) {
  // find all the <button> elements
  var buttonElements = root.getElementsByTagNameNS(XForms.ns, 'button');
  // recurse through them to instantiate EcmaScript proxies and render them
  for (var i=0; i<buttonElements.length; i++) {
    var elem = buttonElements.item(i);
    var button = new Button(elem);
    button._draw();
  }
}

Button.prototype.getCaptionElement = function () {
  var elems = this.element.getElementsByTagNameNS(XForms.ns, 'caption');
  return elems.item(0);
}

Button.prototype.generateSVGStyle = function () {
  var style = this.element.getAttribute('style');
  var dummy = document.createElementNS(SVG.ns, 'rect');
  dummy.setAttribute('style', style);
  var fill = dummy.style.getPropertyValue('background-color');
  var stroke = dummy.style.getPropertyValue('border-color');
  var strokeWidth = dummy.style.getPropertyValue('border-width');
  if (fill == '') {
    fill = '#d4d0c8';
  }
  if (stroke == '') {
    stroke = '#404040';
  }
  if (strokeWidth == '') {
    strokeWidth = '1px';
  }
  style = '';
  style += 'shape-rendering: optimizeSpeed; ';
  style += 'fill: ' + fill + '; ';
  style += 'stroke: ' + stroke + '; ';
  style += 'stroke-width: ' + strokeWidth + '; ';
  return style;
}

Button.prototype.generateSVG = function () {
  this.caption.generateSVG();
  this.SVGElement = document.createElementNS(SVG.ns, 'rect');
  var width = Math.round(this.caption.getSize().width + this.marginLeft * 2);
  var height = Math.round(this.caption.getSize().height + this.marginTop * 2);
  this.SVGElement.setAttribute('width', width);
  this.SVGElement.setAttribute('height', height);
  this.SVGElement.setAttribute('style', this.style);
}

// private
Button.prototype._draw = function () {
  this.generateSVG();
  var g = this.element.parentNode;
  g.appendChild(this.SVGElement);
  g.appendChild(this.caption.SVGElement);
}






/**
 *
 * XForms <caption> element
 *
 **/

function Caption (element, button) {
  this.element = element;     // pointer to the XForms element
  this.SVGElement = null;     // pointer to the SVG element
  this.button = button;       // pointer to the parent Button
  this.SVGStyle = this.generateSVGStyle();
}

Caption.prototype.generateSVGStyle = function () {
  var style = this.button.element.getAttribute('style');
  var dummy = document.createElementNS(SVG.ns, 'rect');
  dummy.setAttribute('style', style);
  var fill = dummy.style.getPropertyValue('color');
  style = '';
  style += 'text-rendering: optimizeSpeed; ';
  style += 'font-family: Tahoma; ';
  style += 'font-size: 11px; ';
  style += 'pointer-events: none; ';
  if (fill != '') {
    style += 'fill: ' + fill + '; ';
  }
  return style;
}

Caption.prototype.generateSVG = function () {
  this.SVGElement = document.createElementNS(SVG.ns, 'text');
  var textNode = document.createTextNode(this.getText());
  this.SVGElement.appendChild(textNode);
  var x = this.button.marginLeft;
  var y = this.getSize().height + this.button.marginTop;
  this.SVGElement.setAttribute('x', x);
  this.SVGElement.setAttribute('y', y);
  this.SVGElement.setAttribute('style', this.SVGStyle);
}

// returns the caption data
Caption.prototype.getText = function () {
  this.element.normalize();
  return this.element.firstChild.data;
}

// returns the caption size as SVGRect
Caption.prototype.getSize = function () {
  return this.SVGElement.getBBox();
}