Pan to center of element need correct coordinate conversion

[Troy Taillefer <tj...@gmail.com>]

Hi all,

Loving batik a lot of cool features. I have tried a lot of different things
reading the mailing lists
but I can not figure out giving an svg dom element how to get JSVGCanvas to
pan to center of that element. I will show my current attempt which
appeared to partially work on a given svg on a certain computer fails
miserably in other cases.


 SVGLocatable textLocatable = (SVGLocatable) textToColor;

                        SVGLocatable parentLocatable = (SVGLocatable)
textToColor.getParentNode();
                        SVGRect bBox = textLocatable.getBBox();

                        // get center of text bbox
                        float domX = bBox.getX() + bBox.getWidth() / 2;
                        float domY = bBox.getY() + bBox.getHeight() / 2;

                        // This close to works it is off center a bit low
on the screen
                        // it is either due to not taking into accunt the
local matrix
                        // as well as the parent matrix or a miss
calculation of the
                        // canvas center
                        SVGPoint svgPoint = rootElement.createSVGPoint();
                        svgPoint.setX(domX);
                        svgPoint.setY( domY );
                        SVGMatrix parentMatrix = parentLocatable.getCTM();
                        SVGMatrix localMatrix = textLocatable.getCTM();

                        SVGPoint screenPoint =
svgPoint.matrixTransform(parentMatrix);

                        AffineTransform tx =
AffineTransform.getTranslateInstance
                                (-screenPoint.getX(),
                                        -screenPoint.getY());

                        Dimension canvasSize = customSvgCanvas.getSize();


tx.preConcatenate(AffineTransform.getTranslateInstance
                                (canvasSize.width/2, canvasSize.height/2));

                        AffineTransform rt = (AffineTransform)
customSvgCanvas.getInitialTransform().clone();

                        rt.preConcatenate(tx);

                        customSvgCanvas.setRenderingTransform(rt);


The structure of this svg is

svg
  |- g
     |- a
        |- text

I want to pan to center of the text giving this text svg dom node how do I
properly convert the coordinates and pan so that this text node appears in
the center of the jsvgcanvas ?

thanks

Troy