HTMLEditorKit, Foreground, NullPointerException in text.html.* ?

Question

hi!
after changing the foreground color of the HTMLEditorKit's document I get NullPointerExceptions.
Changing the color actually works, it is visible afterwards. But after that i have the impression SWING is totally confused (especially with caret movements this happens, dump from a JDK 1.4 JVM):
java.lang.NullPointerException
at javax.swing.text.FlowView$FlowStrategy.createView(FlowView.java:568)
at javax.swing.text.FlowView$FlowStrategy.layoutRow(FlowView.java:441)
at
javax.swing.text.FlowView$FlowStrategy.layout(FlowView.java:397)
at javax.swing.text.FlowView.layout(FlowView.java:182)
at javax.swing.text.BoxView.setSize(BoxView.java:379)
at javax.swing.text.BoxView.modelToView(BoxView.java:456)
at javax.swing.text.CompositeView.modelToView(CompositeView.java:248)
at javax.swing.text.BoxView.modelToView(BoxView.java:458)
at
javax.swing.text.CompositeView.modelToView(CompositeView.java:248)
at javax.swing.text.BoxView.modelToView(BoxView.java:458)
at
javax.swing.plaf.basic.BasicTextUI$RootView.modelToView(BasicTextUI.java:1323)
at
javax.swing.plaf.basic.BasicTextUI.modelToView(BasicTextUI.java:865)
at javax.swing.text.DefaultCaret.paint(DefaultCaret.java:464)
at
javax.swing.plaf.basic.BasicTextUI.paintSafely(BasicTextUI.java:569)
at javax.swing.plaf.basic.BasicTextUI.paint(BasicTextUI.java:699)
at javax.swing.plaf.basic.BasicTextUI.update(BasicTextUI.java:678)
at javax.swing.JComponent.paintComponent(JComponent.java:537)
at javax.swing.JComponent.paint(JComponent.java:804)
at javax.swing.JComponent.paintChildren(JComponent.java:643)
at javax.swing.JComponent.paint(JComponent.java:813)
at javax.swing.JViewport.paint(JViewport.java:707)
at javax.swing.JComponent.paintChildren(JComponent.java:643)
at javax.swing.JComponent.paint(JComponent.java:813)
at javax.swing.JComponent.paintChildren(JComponent.java:643)
at javax.swing.JComponent.paint(JComponent.java:813)
at javax.swing.JComponent.paintChildren(JComponent.java:643)
at javax.swing.JComponent.paint(JComponent.java:813)
at javax.swing.JComponent.paintChildren(JComponent.java:643)
at javax.swing.JComponent.paint(JComponent.java:813)
at javax.swing.JLayeredPane.paint(JLayeredPane.java:552)
at javax.swing.JComponent.paintChildren(JComponent.java:643)
at
javax.swing.JComponent.paintWithOffscreenBuffer(JComponent.java:4742)
at
javax.swing.JComponent.paintDoubleBuffered(JComponent.java:4688)
at javax.swing.JComponent.paint(JComponent.java:794)
at
java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:21)
at
sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:60)
at
sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:97)
at java.awt.Container.paint(Container.java:1123)
at sun.awt.RepaintArea.paint(RepaintArea.java:180)
at sun.awt.motif.MComponentPeer.handleEvent(MComponentPeer.java:339)
at java.awt.Component.dispatchEventImpl(Component.java:3586)
at java.awt.Container.dispatchEventImpl(Container.java:1437)
at java.awt.Window.dispatchEventImpl(Window.java:1566)
at java.awt.Component.dispatchEvent(Component.java:3367)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:445)
at
java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:190)
at
java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:144)
at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:130)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:98)
The function throwing the NULL pointer is therefore ((c) SUN
Microsystems):
         * Creates a view that can be used to represent the current piece
         * of the flow.  This can be either an entire view from the
         * logical view, or a fragment of the logical view.
         * @param fv the view holding the flow
         * @param startOffset the start location for the view being created
         * @param spanLeft the about of span left to fill in the row
         * @param rowIndex the row the view will be placed into
        protected View createView(FlowView fv, int startOffset, int spanLeft, int rowIndex) {
            // Get the child view that contains the given starting position
            View lv = getLogicalView(fv);
            int childIndex = lv.getViewIndex(startOffset,Position.Bias.Forward);
            View v = lv.getView(childIndex);
            if (startOffset==v.getStartOffset()) {
                // return the entire view
                return v;
            // return a fragment.
            v = v.createFragment(startOffset, v.getEndOffset());
            return v;
        }in the line with the if (startOffset==v.getStartOffset()) the exception occurs...
why does lv.getView(...) return null??
If I'm making a mistake when changing the color, I'd expect that an exception is thrown right away or while redrawing. But redrawing with the correct colors works.

Answer 1

I'm changing the foreground color with
MutableAttributeSet attr = new SimpleAttributeSet();
StyleConstants.setForeground(attr, newColor);
int start=MyJTextPane..getSelectionStart();
int end=MyJTextPane.getSelectionEnd();
if (start != end) {
htmlDoc.setCharacterAttributes(start, end, attr, false);
else {
MutableAttributeSet inputAttributes =htmlEditorKit.getInputAttributes();
inputAttributes.addAttributes(attr);