Hi,
not the resizing triggers the exception. The occurance of the exception seems
completely arbitrary to me and is not reproduced easily.
I think it only occurs when I move the cursor over an svg element where the set
attribute is used so that the fill attribute changes. Resizing repaints the
canvas. So my first (and dirty) solution was to make this kind of repaint when
the variable is null.
Of course it would be better when I would understand why I get this NullPointer
Exception.
I have following classes (SVGArea and SVGAreaPainter) which displays the
document. The SVGArea is used by the SVGAreaPainter. The SVGAreaPainter has a
lot methods. The one that makes the mouseover effect for some elements is
private void addMouseOverEffect(Element el, String color) {
Element mouseOver = doc.createElementNS(svgNS, "set");
mouseOver.setAttributeNS(null, "attributeName", "fill");
mouseOver.setAttributeNS(null, "attributeType", "XML");
mouseOver.setAttributeNS(null, "to", color);
mouseOver.setAttributeNS(null, "begin", "mouseover");
el.appendChild(mouseOver);
Element mouseOut = doc.createElementNS(svgNS, "set");
mouseOut.setAttributeNS(null, "attributeName", "fill");
mouseOut.setAttributeNS(null, "attributeType", "XML");
mouseOut.setAttributeNS(null, "to", el.getAttribute("fill"));
mouseOut.setAttributeNS(null, "begin", "mouseout");
el.appendChild(mouseOut);
}
----------------------------------------------------------------
SVGArea class:
package de.unidue.inf.xmlvis.gui.svg;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import javax.swing.SwingUtilities;
import org.apache.batik.dom.svg.SVGDOMImplementation;
import org.apache.batik.swing.JSVGCanvas;
import org.apache.batik.swing.gvt.GVTTreeRendererEvent;
import org.apache.batik.swing.gvt.GVTTreeRendererListener;
import org.apache.batik.swing.svg.GVTTreeBuilderEvent;
import org.apache.batik.swing.svg.GVTTreeBuilderListener;
import org.apache.batik.swing.svg.SVGLoadEventDispatcherEvent;
import org.apache.batik.swing.svg.SVGLoadEventDispatcherListener;
import org.apache.log4j.Logger;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.svg.SVGDocument;
import de.unidue.inf.xmlvis.gui.StatusBarManager;
public class SVGArea extends JSVGCanvas implements
SVGLoadEventDispatcherListener, GVTTreeRendererListener, GVTTreeBuilderListener,
MouseWheelListener {
private static final long serialVersionUID = -4835732750510548844L;
@SuppressWarnings("unused")
private static final Logger logger = Logger.getLogger(SVGArea.class);
private static final String svgNS =
SVGDOMImplementation.SVG_NAMESPACE_URI;
private static final DOMImplementation impl =
SVGDOMImplementation.getDOMImplementation();
private int width;
private int height;
private Document doc = null;
private Element svgRoot;
private JSVGScrollPane scroll;
public SVGArea() {
super(null, true, false);
addSVGLoadEventDispatcherListener(this);
addGVTTreeRendererListener(this);
addGVTTreeBuilderListener(this);
addMouseWheelListener(this);
setDocumentState(JSVGCanvas.ALWAYS_DYNAMIC);
doc = impl.createDocument(svgNS, "svg", null);
svgRoot = doc.getDocumentElement();
}
public void setDocument() {
setSVGDocument((SVGDocument) doc);
}
public Document getDocument() {
return doc;
}
public void resetSVGDocument() {
doc = impl.createDocument(svgNS, "svg", null);
svgRoot = doc.getDocumentElement();
}
@Override
public void svgLoadEventDispatchCancelled(SVGLoadEventDispatcherEvent
e) {
StatusBarManager.svgLoadEventDispatchCancelled();
}
@Override
public void svgLoadEventDispatchCompleted(SVGLoadEventDispatcherEvent
e) {
}
@Override
public void svgLoadEventDispatchFailed(SVGLoadEventDispatcherEvent e) {
StatusBarManager.svgLoadEventDispatchFailed();
}
@Override
public void svgLoadEventDispatchStarted(SVGLoadEventDispatcherEvent e) {
StatusBarManager.svgLoadEventDispatchStarted();
}
@Override
public void gvtRenderingCancelled(GVTTreeRendererEvent e) {
}
@Override
public void gvtRenderingCompleted(GVTTreeRendererEvent e) {
StatusBarManager.gvtRenderingCompleted();
}
@Override
public void gvtRenderingFailed(GVTTreeRendererEvent e) {
}
@Override
public void gvtRenderingPrepare(GVTTreeRendererEvent e) {
}
@Override
public void gvtRenderingStarted(GVTTreeRendererEvent e) {
}
@Override
public void gvtBuildCancelled(GVTTreeBuilderEvent e) {
}
@Override
public void gvtBuildCompleted(GVTTreeBuilderEvent e) {
}
@Override
public void gvtBuildFailed(GVTTreeBuilderEvent e) {
}
@Override
public void gvtBuildStarted(GVTTreeBuilderEvent e) {
}
public void setSVGSize(int width, int height) {
this.width = width;
this.height = height;
svgRoot.setAttributeNS(null, "width", String.valueOf(width));
svgRoot.setAttributeNS(null, "height", String.valueOf(height));
SVGAreaPainter painter = new SVGAreaPainter(this);
painter.drawText(0, 0, ".", 1);
painter.drawText(width, height, ".", 1);
}
public float getSVGWidth() {
return width;
}
public float getSVGHeight() {
return height;
}
@Override
public void mouseWheelMoved(final MouseWheelEvent e) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
// An das passende ScrollPane weiterleiten
if (scroll != null) {
scroll.dispatchEvent(e);
}
}
});
}
public void setScroll(JSVGScrollPane scroll) {
this.scroll = scroll;
}
}
--- Cameron McCormack <[EMAIL PROTECTED]> schrieb am Mi, 28.5.2008:
Von: Cameron McCormack <[EMAIL PROTECTED]>
Betreff: Re: Repainting a JSVGCanvas
An: [email protected]
Datum: Mittwoch, 28. Mai 2008, 9:04
aaaa aaaa: > the problem is that I get occasionally a NullPointerException in
the > ScrollListener of the JSVGCanvas. The variable "newview" is null in > the
updateCompleted method . Hmm. I’m not sure what would cause getViewBoxRect()
to return null if all you are doing is resizing, unless there’s a threading
issue. > Rectangle2D newview = getViewBoxRect(); > > So sometimes the canvas
gets white and it has to be repaint. It's > immediatly repainted when I resize
the frame or when I'm using the > scrollbars. But I've inserted > > if (newview
== null) { >
canvas.getUpdateManager().getUpdateRunnableQueue().invokeLater(new Runnable() {
> > @Override >
public void run() { >
canvas.repaint(); > } > >
}); > return; > } > >
and this does not have any effect. Another solution maybe would be to > avoid
to get the Exception. But I don't see what I'm doing wrong. I don’t think
calling canvas.repaint() is the right
thing to fix the problem. It sounds like there is a problem with
JSVGScrollPane or JSVGCanvas. Are you able to provide a reduced test case that
demonstrates the problem (perhaps just loading a small SVG document in a
JSVGScrollPane/JSVGCanvas, where continually resizing it will trigger the bug)?
Thanks, Cameron -- Cameron McCormack ≝ http://mcc.id.au/
--------------------------------------------------------------------- To
unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL
PROTECTED]
__________________________________________________________
Gesendet von Yahoo! Mail.
Dem pfiffigeren Posteingang.
http://de.overview.mail.yahoo.com
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
