// A utility for creating "full size" graphics programs with D3.js.
// Useful for full-screen graphics, or graphics indended for use inside iFrames.
function fullsize(render){
  
  // Append a div to the body,
  // make it fill the display using CSS,
  // store a reference to the DOM node for later use.
  var div = d3.select("body")
    .append("div")
      .style("position", "fixed")
      .style("left", "0px")
      .style("right", "0px")
      .style("top", "0px")
      .style("bottom", "0px")
    .node();

  // Append an SVG as a child of the container DOM node.
  var svg = d3.select(div)
  	.append("svg");
  
  // This function updates the size of the SVG
  // and invokes the render() function.
  function redraw(){

    // Extract the width and height that was computed by CSS.
    var width = div.clientWidth;
    var height = div.clientHeight;

    // Use the extracted size to set the size of an SVG element.
    svg
      .attr("width", width)
      .attr("height", height);

    // Invoke the render function passed into fullsize().
    render(svg, width, height);
  }
  
  // Draw for the first time to initialize.
  redraw();
  
  // Redraw based on the new size whenever the browser window is resized.
  window.addEventListener("resize", redraw);
}