Once again, thank you for replying to my email. On 8/24/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > Hi Jake, > > "Jake B" <[EMAIL PROTECTED]> wrote on 08/22/2007 11:20:50 PM: > > > The goal is to take a meta-modelling environment which we > > have implemented in Python/Tkinter, construct a lightweight front- > > end, and use pieces of the original environment to power the back-end. > > Well I hope it goes well for you, and hopefully we will be able > to help you past any rough spots. > > > I'm currently working on a small prototype in order to get familiar > > with Batik, and become a bit more knowlegable about the details of > > the technologies involved. Basically, I am trying to construct a few > > basic user interface widgets (a button, a panel, and a menu) in SVG. > > I know that the idea of building standard user interface widgets has > been > > discussed, and even implemented, but my version will have a slightly > > different twist to it, which is that the layout and reactive > > behavior of the widgets will be modelled using statecharts (our tool > > can generate executable python code). This statecharts will be kept > > on the server. The goal of this prototype is to show that widget > > behavior can be modelled using statecharts, and to get aquainted > > with the technologies that the rest of the project will rely upon. > > > > That's pretty much the gist of what I'm trying to do. I have a few > > question to start out. These are fairly open questions, and there > > may not be a straightforward way to answer them, or a single correct > > answer, but I would nevertheless appreciate any advice anyone could > offer: > > 1. In the context of the SVG specification, what would be the most > > appropriate way to represent a widget? It would either have to be a > > <g>,<svg> or <symbol>. I think any of these would work, but I'm not > > sure which one would be the truest to the spec. > > I would tend to use a 'g'. The advantage of 'svg' (and also symbol) > is that it establishes a viewport which first adds a default clip region > (which could be good or bad) and second gives you some fairly simple > control of the coordinate system. That said you actually have more > control over the coordinate system with 'g' since you can use the > transform > but the interface is a bit more complex. > > Symbol is useful if you want to have multiple copies of the > _exact_ same thing. As soon as you start creating tweaked versions of > things to add as 'symbol' elements that you then 'use' you are almost > always better off just adding the tweaked elements where the use would > be. > > > 2. In the context of extending Batik, what would be the most > > appropriate way to represent a widget? If, for example, in the SVG > > spec, a widget would best be represented as <g> element, then in the > > context of Batik, would the most appropriate way to represent a > > widget be to create a subclass of SVGOMGElement? Or would there be a > > better way? > > Don't subclass our DOM Elements unless you want to create custom > DOM Elements. I would probably build a separate 'widget tree' with > your own classes (not directly tied to DOM). Then I would have > references to the DOM tree in my widget objects. The widget objects > would register callbacks on the DOM objects for events they care about. > > If you need to you could also have a hash table that allowed one > to go from an arbitrary DOM object to the associated Widget Object > but in my experience that isn't normally needed (the event listeners > know what object registered them, so this generally only needed if > the need to map graphics->widget comes outside of the scope of an > event). > > > 3. I'd like to leverage the Factory classes in org.apache.batik.dom.svg > > , but I can't figure out how to initialize the attributes of the > > Element objects I've created. They do not have public set methods, > > and even though they implement the Element interface, calling > setAttributeNS > > on them does not change their attributes. What is the proper way to > > set the attributes on these objects? > > What Factory classes in batik.dom.svg? The only two I see are the > Factory classes for producing Documents. Documents don't have > attributes - so perhaps that is your problem?
These were the factory classes I was talking about: SVGDOMImplementation.AElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AElementFactory.html> SVGDOMImplementation.AltGlyphDefElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AltGlyphDefElementFactory.html> SVGDOMImplementation.AltGlyphElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AltGlyphElementFactory.html> SVGDOMImplementation.AltGlyphItemElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AltGlyphItemElementFactory.html> SVGDOMImplementation.AnimateColorElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AnimateColorElementFactory.html> SVGDOMImplementation.AnimateElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AnimateElementFactory.html> SVGDOMImplementation.AnimateMotionElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AnimateMotionElementFactory.html> SVGDOMImplementation.AnimateTransformElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.AnimateTransformElementFactory.html> SVGDOMImplementation.CircleElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.CircleElementFactory.html> SVGDOMImplementation.ClipPathElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.ClipPathElementFactory.html> SVGDOMImplementation.ColorProfileElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.ColorProfileElementFactory.html> SVGDOMImplementation.CursorElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.CursorElementFactory.html> SVGDOMImplementation.DefinitionSrcElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.DefinitionSrcElementFactory.html> SVGDOMImplementation.DefsElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.DefsElementFactory.html> SVGDOMImplementation.DescElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.DescElementFactory.html> SVGDOMImplementation.EllipseElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.EllipseElementFactory.html> SVGDOMImplementation.FeBlendElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeBlendElementFactory.html> SVGDOMImplementation.FeColorMatrixElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeColorMatrixElementFactory.html> SVGDOMImplementation.FeComponentTransferElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeComponentTransferElementFactory.html> SVGDOMImplementation.FeCompositeElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeCompositeElementFactory.html> SVGDOMImplementation.FeConvolveMatrixElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeConvolveMatrixElementFactory.html> SVGDOMImplementation.FeDiffuseLightingElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeDiffuseLightingElementFactory.html> SVGDOMImplementation.FeDisplacementMapElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeDisplacementMapElementFactory.html> SVGDOMImplementation.FeDistantLightElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeDistantLightElementFactory.html> SVGDOMImplementation.FeFloodElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeFloodElementFactory.html> SVGDOMImplementation.FeFuncAElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeFuncAElementFactory.html> SVGDOMImplementation.FeFuncBElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeFuncBElementFactory.html> SVGDOMImplementation.FeFuncGElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeFuncGElementFactory.html> SVGDOMImplementation.FeFuncRElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeFuncRElementFactory.html> SVGDOMImplementation.FeGaussianBlurElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeGaussianBlurElementFactory.html> SVGDOMImplementation.FeImageElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeImageElementFactory.html> SVGDOMImplementation.FeMergeElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeMergeElementFactory.html> SVGDOMImplementation.FeMergeNodeElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeMergeNodeElementFactory.html> SVGDOMImplementation.FeMorphologyElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeMorphologyElementFactory.html> SVGDOMImplementation.FeOffsetElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeOffsetElementFactory.html> SVGDOMImplementation.FePointLightElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FePointLightElementFactory.html> SVGDOMImplementation.FeSpecularLightingElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeSpecularLightingElementFactory.html> SVGDOMImplementation.FeSpotLightElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeSpotLightElementFactory.html> SVGDOMImplementation.FeTileElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeTileElementFactory.html> SVGDOMImplementation.FeTurbulenceElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FeTurbulenceElementFactory.html> SVGDOMImplementation.FilterElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FilterElementFactory.html> SVGDOMImplementation.FontElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FontElementFactory.html> SVGDOMImplementation.FontFaceElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FontFaceElementFactory.html> SVGDOMImplementation.FontFaceFormatElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FontFaceFormatElementFactory.html> SVGDOMImplementation.FontFaceNameElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FontFaceNameElementFactory.html> SVGDOMImplementation.FontFaceSrcElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FontFaceSrcElementFactory.html> SVGDOMImplementation.FontFaceUriElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.FontFaceUriElementFactory.html> SVGDOMImplementation.ForeignObjectElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.ForeignObjectElementFactory.html> SVGDOMImplementation.GElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.GElementFactory.html> SVGDOMImplementation.GlyphElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.GlyphElementFactory.html> SVGDOMImplementation.GlyphRefElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.GlyphRefElementFactory.html> SVGDOMImplementation.HkernElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.HkernElementFactory.html> SVGDOMImplementation.ImageElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.ImageElementFactory.html> SVGDOMImplementation.LinearGradientElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.LinearGradientElementFactory.html> SVGDOMImplementation.LineElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.LineElementFactory.html> SVGDOMImplementation.MarkerElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.MarkerElementFactory.html> SVGDOMImplementation.MaskElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.MaskElementFactory.html> SVGDOMImplementation.MetadataElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.MetadataElementFactory.html> SVGDOMImplementation.MissingGlyphElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.MissingGlyphElementFactory.html> SVGDOMImplementation.MpathElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.MpathElementFactory.html> SVGDOMImplementation.PathElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.PathElementFactory.html> SVGDOMImplementation.PatternElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.PatternElementFactory.html> SVGDOMImplementation.PolygonElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.PolygonElementFactory.html> SVGDOMImplementation.PolylineElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.PolylineElementFactory.html> SVGDOMImplementation.RadialGradientElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.RadialGradientElementFactory.html> SVGDOMImplementation.RectElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.RectElementFactory.html> SVGDOMImplementation.ScriptElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.ScriptElementFactory.html> SVGDOMImplementation.SetElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.SetElementFactory.html> SVGDOMImplementation.StopElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.StopElementFactory.html> SVGDOMImplementation.StyleElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.StyleElementFactory.html> SVGDOMImplementation.SvgElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.SvgElementFactory.html> SVGDOMImplementation.SwitchElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.SwitchElementFactory.html> SVGDOMImplementation.SymbolElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.SymbolElementFactory.html> SVGDOMImplementation.TextElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.TextElementFactory.html> SVGDOMImplementation.TextPathElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.TextPathElementFactory.html> SVGDOMImplementation.TitleElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.TitleElementFactory.html> SVGDOMImplementation.TrefElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.TrefElementFactory.html> SVGDOMImplementation.TspanElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.TspanElementFactory.html> SVGDOMImplementation.UseElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.UseElementFactory.html> SVGDOMImplementation.ViewElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.ViewElementFactory.html> SVGDOMImplementation.VkernElementFactory<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGDOMImplementation.VkernElementFactory.html> I'm quite certain now that I was truly misunderstanding the purpose of these classes. I understand now that the proper thing to do is to use the interfaces in org.w3c.dom.svg. Right now I'm trying to figure out how bounding boxes work. To do this, I'm trying to implement a simple program that will compute the bounding box of an SVGRectElement. My code is mostly taken from the Batik documentation on the SVG DOM API (http://xmlgraphics.apache.org/batik/using/dom-api.html), and it is as follows: package org.msdl.jdui.test; import org.apache.batik.dom.svg.SVGDOMImplementation; import org.w3c.dom.DOMImplementation; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.svg.SVGRect; import org.w3c.dom.svg.SVGRectElement; import org.apache.batik.util.gui.DOMViewer; public class Test { /** * @param args */ public static void main(String[] args) { DOMImplementation impl = SVGDOMImplementation.getDOMImplementation (); String svgNS = SVGDOMImplementation.SVG_NAMESPACE_URI; Document doc = impl.createDocument(svgNS, "svg", null); // Get the root element (the 'svg' element). Element svgRoot = doc.getDocumentElement(); // Set the width and height attributes on the root 'svg' element. svgRoot.setAttributeNS(null, "width", "400"); svgRoot.setAttributeNS(null, "height", "450"); // Create the rectangle. //Element rectangle = doc.createElementNS(svgNS, "rect"); SVGRectElement rectangle = (SVGRectElement)doc.createElementNS(svgNS, "rect"); rectangle.setAttributeNS(null, "x", "10"); rectangle.setAttributeNS(null, "y", "20"); rectangle.setAttributeNS(null, "width", "100"); rectangle.setAttributeNS(null, "height", "50"); rectangle.setAttributeNS(null, "fill", "red"); SVGRect bbox = rectangle.getBBox(); } } Unfortunately, rectangle.getBBox() consistently evaluates to null. I think the reason for this might be alluded to in the documentation on the SVG DOM API, when it states that, "Though the DOM implementation of Batik is an SVG DOM implementation, the SVG-specific methods that rely on the document having been rendered (particularly geometry related methods, such as SVGLocatable.getBBox<http://xmlgraphics.apache.org/batik/javadoc/org/w3c/dom/svg/SVGLocatable.html#getBBox%28%29>) cannot be used at this point." My question is, what do I need to do to make the getBBox method work? If I need to render the document, is it possible to minimally do so in order to simple retrieve the Element's bounding box, or is it necessary to fully render the document in, for example, JSVGCanvas in order to make getBBox work? Also, as a sidenote, I was looking up the javadoc information on the interfaces in org.w3c.dom.svg, and I discovered that the Batik javadocs link to several classes in org.w3c.dom.svg, but these links appear to be dead. For example, you have: *SVGOMElement<http://xmlgraphics.apache.org/batik/javadoc/org/apache/batik/dom/svg/SVGOMElement.html> * This class implements the SVGElement<http://www.w3.org/2003/01/dom2-javadoc/org/w3c/dom/svg.SVGElement.html?is-external=true>interface. But SVGElement<http://www.w3.org/2003/01/dom2-javadoc/org/w3c/dom/svg.SVGElement.html?is-external=true>takes you to someplace dead. Also, going up the directory tree takes you to here: http://www.w3.org/2003/01/dom2-javadoc/ But, these javadocs do not show an svg package in org.w3c.dom. I searched a bit more and was unable to find any "official" javadocs for org.w3c.dom.svg. I ended up just pulling org.w3c.dom.svg out of CVS and generating my own javadocs. Does anyone know where the official javadocs for these interfaces are? I would greatly appreciate any guidance anyone can offer. Thanks. Jake
