Syntax of canvas nodes

The AUI tree contains the XML representation of the canvas, with a variety of elements defining shapes.

Canvas areas are defined in forms with the following XML syntax:

<Canvas colName="name" >
{ <CanvasArc canvasitem-attribute="value" [...] />
| <CanvasCircle canvasitem-attribute="value"[...] />
| <CanvasLine canvasitem-attribute="value"[...] />
| <CanvasOval canvasitem-attribute="value"[...] />
| <CanvasPolygon canvasitem-attribute="value"[...] />
| <CanvasRectangle canvasitem-attribute="value"[...] />
| <CanvasText canvasitem-attribute="value"[...] />
} [...]
</Canvas>
[...]
Table 1. Types of canvas element
Name Description
CanvasArc Arc defined by the bounding square top left point, a diameter, a start angle, an end angle, and a fill color.
CanvasCircle Circle defined by the bounding square top left point, a diameter, and a fill color.
CanvasLine Line defined by a start point, an end point, width, and a fill color.
CanvasOval Oval defined by rectangle (with start point and endpoint), and a fill color.
CanvasPolygon Polygon defined by a list of points, and a fill color.
CanvasRectangle Rectangle defined by a start point, an end point, and a fill color.
CanvasText Text defined by a start point, an anchor hint, the text, and a fill color.
Table 2. Attributes of canvas elements
Name Values Description
startX INTEGER (0->1000) X position of starting point.
startY INTEGER (0->1000) Y position of starting point.
endX INTEGER (0->1000) X position of ending point.
endY INTEGER (0->1000) Y position of ending point.
xyList STRING Space-separated list of XY coordinates. For example: "23 45 56 78" defines (x=23,y=45) (x=56,y=78).
width INTEGER Width of the shape.
height INTEGER Height of the shape.
diameter INTEGER Diameter for circles and arcs.
startDegrees INTEGER Beginning of the angular range occupied by an arc.
extentDegrees INTEGER Size of the angular range occupied by an arc.
text STRING The text to draw.
anchor "n","e","w","s" Anchor hint to give the draw direction for texts.
fillColor STRING Name of the color to be used for the element.
acceleratorKey1 STRING Name of the key associated to a left button click.
acceleratorKey3 STRING Name of the key associated to a right button click.