SVG Positioning

Question

I'm having a play with SVG and am having a few problems with positioning. I have a series of shapes which are contained in the g group tag. I was hoping to use it like a container, so I could set its x position and then all the elements in that group would also move. But that doesn't seem to be possible.

1. How do most people go about positioning a group of elements which you wish to move in tandem?
2. Is there any concept of relative positioning? e.g. relative to its parent

Answer 1

As mentioned in the other comment, the transform attribute on the g element is what you want. Use transform="translate(x,y)" to move the g around and things within the g will move in relation to the g.

Answer 2

There are two ways to group multiple SVG shapes and position the group:

The first to use <g> with transform attribute as Aaron wrote. But you can't just use a x attribute on the <g> element.

The other way is to use nested <svg> element.

<svg id="parent">
   <svg id="group1" x="10">
      <!-- some shapes -->
   </svg>
</svg>

In this way, the #group1 svg is nested in #parent, and the x=10 is relative to the parent svg. However, you can't use transform attribute on <svg> element, which is quite the contrary of <g> element.

Answer 3

Everything in the g element is positioned relative to the current transform matrix.

To move the content, just put the transformation in the g element:

<g transform="translate(20,2.5) rotate(10)">
    <rect x="0" y="0" width="60" height="10"/>
</g>

Links: Example from the SVG 1.1 spec

Answer 4

There is a shorter alternative to the previous answer. SVG Elements can also be grouped by nesting svg elements:

<svg xmlns="http://www.w3.org/2000/svg"
  xmlns:xlink="http://www.w3.org/1999/xlink">
  <svg x="10">
    <rect x="10" y="10" height="100" width="100" style="stroke:#ff0000;fill: #0000ff"/>
  </svg>
  <svg x="200">
    <rect x="10" y="10" height="100" width="100" style="stroke:#009900;fill: #00cc00"/>
  </svg>
</svg>

The two rectangles are identical (apart from the colors), but the parent svg elements have different x values.

See http://tutorials.jenkov.com/svg/svg-element.html.