import “../core/document”; import “../interpolate/interpolate”; import “transition”; import “tween”;

d3_transitionPrototype.style = function(name, value, priority) {

var n = arguments.length;
if (n < 3) {

  // For style(object) or style(object, string), the object specifies the
  // names and values of the attributes to set or remove. The values may be
  // functions that are evaluated for each element. The optional string
  // specifies the priority.
  if (typeof name !== "string") {
    if (n < 2) value = "";
    for (priority in name) this.style(priority, name[priority], value);
    return this;
  }

  // For style(string, string) or style(string, function), use the default
  // priority. The priority is ignored for style(string, null).
  priority = "";
}

// For style(name, null) or style(name, null, priority), remove the style
// property with the specified name. The priority is ignored.
function styleNull() {
  this.style.removeProperty(name);
}

// For style(name, string) or style(name, string, priority), set the style
// property with the specified name, using the specified priority.
// Otherwise, a name, value and priority are specified, and handled as below.
function styleString(b) {
  return b == null ? styleNull : (b += "", function() {
    var a = d3_window.getComputedStyle(this, null).getPropertyValue(name), i;
    return a !== b && (i = d3_interpolate(a, b), function(t) { this.style.setProperty(name, i(t), priority); });
  });
}

return d3_transition_tween(this, "style." + name, value, styleString);

};

d3_transitionPrototype.styleTween = function(name, tween, priority) {

if (arguments.length < 3) priority = "";

function styleTween(d, i) {
  var f = tween.call(this, d, i, d3_window.getComputedStyle(this, null).getPropertyValue(name));
  return f && function(t) { this.style.setProperty(name, f(t), priority); };
}

return this.tween("style." + name, styleTween);

};