D3 Drag Rectangle with drag handles

README.markdown

This is an example of the power of the D3 library and how you can use the drag behavior of D3 to control the position and shape of the SVG element.

dragrect.js

var w = 750,
    h = 450,
    r = 120;

var isXChecked = true,
    isYChecked = true;

var width = 300,
    height = 200,
    dragbarw = 20;

var drag = d3.behavior.drag()
    .origin(Object)
    .on("drag", dragmove);

var dragright = d3.behavior.drag()
    .origin(Object)
    .on("drag", rdragresize);

var dragleft = d3.behavior.drag()
    .origin(Object)
    .on("drag", ldragresize);

var dragtop = d3.behavior.drag()
    .origin(Object)
    .on("drag", tdragresize);

var dragbottom = d3.behavior.drag()
    .origin(Object)
    .on("drag", bdragresize);

var svg = d3.select("body").append("svg")
    .attr("width", w)
    .attr("height", h)

var newg = svg.append("g")
      .data([{x: width / 2, y: height / 2}]);

var dragrect = newg.append("rect")
      .attr("id", "active")
      .attr("x", function(d) { return d.x; })
      .attr("y", function(d) { return d.y; })
      .attr("height", height)
      .attr("width", width)
      .attr("fill-opacity", .5)
      .attr("cursor", "move")
      .call(drag);

var dragbarleft = newg.append("rect")
      .attr("x", function(d) { return d.x - (dragbarw/2); })
      .attr("y", function(d) { return d.y + (dragbarw/2); })
      .attr("height", height - dragbarw)
      .attr("id", "dragleft")
      .attr("width", dragbarw)
      .attr("fill", "lightblue")
      .attr("fill-opacity", .5)
      .attr("cursor", "ew-resize")
      .call(dragleft);

var dragbarright = newg.append("rect")
      .attr("x", function(d) { return d.x + width - (dragbarw/2); })
      .attr("y", function(d) { return d.y + (dragbarw/2); })
      .attr("id", "dragright")
      .attr("height", height - dragbarw)
      .attr("width", dragbarw)
      .attr("fill", "lightblue")
      .attr("fill-opacity", .5)
      .attr("cursor", "ew-resize")
      .call(dragright);

var dragbartop = newg.append("rect")
      .attr("x", function(d) { return d.x + (dragbarw/2); })
      .attr("y", function(d) { return d.y - (dragbarw/2); })
      .attr("height", dragbarw)
      .attr("id", "dragleft")
      .attr("width", width - dragbarw)
      .attr("fill", "lightgreen")
      .attr("fill-opacity", .5)
      .attr("cursor", "ns-resize")
      .call(dragtop);

var dragbarbottom = newg.append("rect")
      .attr("x", function(d) { return d.x + (dragbarw/2); })
      .attr("y", function(d) { return d.y + height - (dragbarw/2); })
      .attr("id", "dragright")
      .attr("height", dragbarw)
      .attr("width", width - dragbarw)
      .attr("fill", "lightgreen")
      .attr("fill-opacity", .5)
      .attr("cursor", "ns-resize")
      .call(dragbottom);

function dragmove(d) {
  if (isXChecked) {
      dragrect
          .attr("x", d.x = Math.max(0, Math.min(w - width, d3.event.x)))
      dragbarleft 
          .attr("x", function(d) { return d.x - (dragbarw/2); })
      dragbarright 
          .attr("x", function(d) { return d.x + width - (dragbarw/2); })
      dragbartop 
          .attr("x", function(d) { return d.x + (dragbarw/2); })
      dragbarbottom 
          .attr("x", function(d) { return d.x + (dragbarw/2); })
  }
  if (isYChecked) {
      dragrect
          .attr("y", d.y = Math.max(0, Math.min(h - height, d3.event.y)));
      dragbarleft 
          .attr("y", function(d) { return d.y + (dragbarw/2); });
      dragbarright 
          .attr("y", function(d) { return d.y + (dragbarw/2); });
      dragbartop 
          .attr("y", function(d) { return d.y - (dragbarw/2); });
      dragbarbottom 
          .attr("y", function(d) { return d.y + height - (dragbarw/2); });
  }
}

function ldragresize(d) {
   if (isXChecked) {
      var oldx = d.x; 
     //Max x on the right is x + width - dragbarw
     //Max x on the left is 0 - (dragbarw/2)
      d.x = Math.max(0, Math.min(d.x + width - (dragbarw / 2), d3.event.x)); 
      width = width + (oldx - d.x);
      dragbarleft
        .attr("x", function(d) { return d.x - (dragbarw / 2); });
       
      dragrect
        .attr("x", function(d) { return d.x; })
        .attr("width", width);

     dragbartop 
        .attr("x", function(d) { return d.x + (dragbarw/2); })
        .attr("width", width - dragbarw)
     dragbarbottom 
        .attr("x", function(d) { return d.x + (dragbarw/2); })
        .attr("width", width - dragbarw)
  }
}

function rdragresize(d) {
   if (isXChecked) {
     //Max x on the left is x - width 
     //Max x on the right is width of screen + (dragbarw/2)
     var dragx = Math.max(d.x + (dragbarw/2), Math.min(w, d.x + width + d3.event.dx));

     //recalculate width
     width = dragx - d.x;

     //move the right drag handle
     dragbarright
        .attr("x", function(d) { return dragx - (dragbarw/2) });

     //resize the drag rectangle
     //as we are only resizing from the right, the x coordinate does not need to change
     dragrect
        .attr("width", width);
     dragbartop 
        .attr("width", width - dragbarw)
     dragbarbottom 
        .attr("width", width - dragbarw)
  }
}

function tdragresize(d) {
 
   if (isYChecked) {
      var oldy = d.y; 
     //Max x on the right is x + width - dragbarw
     //Max x on the left is 0 - (dragbarw/2)
      d.y = Math.max(0, Math.min(d.y + height - (dragbarw / 2), d3.event.y)); 
      height = height + (oldy - d.y);
      dragbartop
        .attr("y", function(d) { return d.y - (dragbarw / 2); });
       
      dragrect
        .attr("y", function(d) { return d.y; })
        .attr("height", height);

      dragbarleft 
        .attr("y", function(d) { return d.y + (dragbarw/2); })
        .attr("height", height - dragbarw);
      dragbarright 
        .attr("y", function(d) { return d.y + (dragbarw/2); })
        .attr("height", height - dragbarw);
  }
}

function bdragresize(d) {
   if (isYChecked) {
     //Max x on the left is x - width 
     //Max x on the right is width of screen + (dragbarw/2)
     var dragy = Math.max(d.y + (dragbarw/2), Math.min(h, d.y + height + d3.event.dy));

     //recalculate width
     height = dragy - d.y;

     //move the right drag handle
     dragbarbottom
        .attr("y", function(d) { return dragy - (dragbarw/2) });

     //resize the drag rectangle
     //as we are only resizing from the right, the x coordinate does not need to change
     dragrect
        .attr("height", height);
     dragbarleft 
        .attr("height", height - dragbarw);
     dragbarright 
        .attr("height", height - dragbarw);
  }
}

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
    <style type="text/css">
svg {
  border: solid 1px #aaa;
}

#checks {
  margin: 10px;
}
    </style>
  </head>
  <body>
    <script type="text/javascript" src="http://mbostock.github.com/d3/d3.js"></script>
    <script type="text/javascript" src="dragrect.js"></script>
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
    <div id="checks">
    	X-axis:<input type="checkbox" id="xChecked" checked/>
    	Y-axis:<input type="checkbox" id="yChecked" checked/>
    </div>

    <script>
$('#xChecked').click(function() {
    isXChecked = !isXChecked;
     dragbarleft 
        .attr("fill-opacity", (isXChecked ? 0.5 : 0))
        .attr("cursor", (isXChecked ? "ew-resize" : "move"));
     dragbarright 
        .attr("fill-opacity", (isXChecked ? 0.5 : 0))
        .attr("cursor", (isXChecked ? "ew-resize" : "move"));
});

$('#yChecked').click(function() {
    isYChecked = !isYChecked;
     dragbartop 
        .attr("fill-opacity", (isYChecked ? 0.5 : 0))
        .attr("cursor", (isYChecked ? "ns-resize" : "move"));
     dragbarbottom 
        .attr("fill-opacity", (isYChecked ? 0.5 : 0))
        .attr("cursor", (isYChecked ? "ns-resize" : "move"));
});
    </script>
  </body>
</html>