A typical shape file may look something like this:
<?xml version="1.0"?>
<shape xmlns="http://www.daa.com.au/~james/dia-shape-ns"
xmlns:svg="http://www.w3.org/2000/svg">
<name>Circuit with identifiers - NPN Transistor</name>
<icon>npn.xpm</icon>
<connections>
<point x="0" y="0"/>
<point x="6" y="-4" main="yes"/>
<point x="6" y="4"/>
</connections>
<aspectratio type="fixed"/>
<textbox x1="4" y1="-3" x2="12" y2="3" />
<svg:svg>
<svg:line x1="0" y1="0" x2="3" y2="0" />
<svg:line x1="3" y1="-3" x2="3" y2="3" />
<svg:line x1="3" y1="-2" x2="6" y2="-4" />
<svg:line x1="3" y1="2" x2="6" y2="4" />
<svg:polyline points="5,4 6,4 5.6154,3.0769" />
</svg:svg>
</shape>
Only the name and svg elements
are required in the shape file. The
rest are optional.
The name element give the name of the object. The
name is a unique identifier for this shape that is used for saving and
loading.
As in the example, you may use "compound names". Many shapes have first part of its name to indicate the sheet in which they appear, but this is optional.
The icon element specifies an xpm file or a png
file that is used as
the icon in the dia toolbox. The filename can be relative to the shape
file. If it is not given, a default custom shape icon will be used.
The connections section specifies a number
of connection points for
the shape. The coordinate system for these points is the same as the
coordinate system used in the svg shape description.
The aspectratio element allows you to specify
how the shape can be
distorted. The three possibilities are:
<aspectratio type="free"/>
- Any aspect ratio is OK (the default)
<aspectratio type="fixed"/>
- Fix the aspect ratio for this shape.
<aspectratio type="range" min="n" max="m"/>
- Give a range of values.
The last option allows you to specify a range of allowable amounts of distortion, which may be useful in some cases.
The textbox element allows you to associate some text with
the shape. The syntax is:
<textbox x1="left" y1="top" x2="right" y2="bottom"/>
(Only one textbox per shape) Where the attributes give the bounds of the text box in the same coordinate system as the SVG shape description.
There are some optional attributes on <textbox/> namely
Shapes are given a default size on creation. If that default size does not fit your needs you can overwrite it by (one or both): <default-width>1cm</default-width> <default-height>3cm</default-height> The default unit "cm" can be omitted.
The svg element describes the shape.
The width and height attributes
are ignored, and only given to comply with the SVG specification. For
more information on SVG, see the W3C pages about the format at:
http://www.w3.org/Graphics/SVG
The next section details what parts of the SVG spec can be used in shape files.