Unexpected change in UndoManager

I’m getting the following exception from the UndoManager:

java.lang.IllegalArgumentException: Unexpected change received.
Expected:
[RichTextChange{
        position: 980
        removed: Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@67d7424 style=14,Georgia,0x000000ff)]
Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@67d7424 style=14,Georgia,0x000000ff)]
Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@d2a730f style=14,Georgia,0x000000ff)]
        inserted: Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@67d7424 style=14,Georgia,0x000000ff)]
}]
Received:
[RichTextChange{
        position: 980
        removed: Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@67d7424 style=14,Georgia,0x000000ff)]
Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@67d7424 style=14,Georgia,0x000000ff)]
Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@53d2627e style=14,Georgia,0x000000ff), StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@2295669d style=14,Georgia,0x000000ff)]
        inserted: Par[[]; StyledSegment(segment=com.quollwriter.ui.fx.components.TextEditor$TextSegment@67d7424 style=14,Georgia,0x000000ff)]
}]
        at org.fxmisc.undo.impl.UndoManagerImpl.changeObserved(UndoManagerImpl.java:234)

This is because it is trying to undo a change to text that has a style that has not been recorded.

The style in this case is a “spelling error” indicator for a word.

I’m adding the style to the word using:

this.suspendUndos.suspendWhile (() -> {
   this.getContent ().setStyleSpans (r.getStart (), this.getContent ().getStyleSpans (r.getStart (), r.getEnd ()).mapStyles (ss -> {
   TextStyle _s = new TextStyle (ss);
    _s.setSpellingError (true);
    return _s;
 }));
  });

The suspendWhile is blocking the change from being recorded.

My undo manager is created using:

UndoManagerFactory.unlimitedHistoryFactory ().createMultiChangeUM(this.multiRichChanges ().conditionOn (this.suspendUndos), TextChange::invert, UndoUtils.applyMultiRichTextChange(this), TextChange::mergeWith, TextChange::isIdentity)

And my segment has the following equals method (which is returning true when it’s trying to do an undo):

@Override public boolean equals( Object obj )
{
    if ( obj == this )  return true;
    else if ( obj instanceof AbstractSegment && getClass().equals( obj.getClass() ) )
    {
        boolean v = getText().equals( ((AbstractSegment) obj).getText() );
        return v;
    }
    return false;
}

So the question is how can I add the spelling error style (which I don’t want to record in the undo list) but still have the undo work?

[garybentley]

Hi Jugen, Don’t worry I haven’t forgotten, I have just started a university degree and have been trying to get some free time to check this out. I’ve been following the discussion, just haven’t had chance to implement your fixes yet, I’m hoping to set aside some free time in the next couple of days to look into it.

[cengels]

Hey again. I tested the new richTextSuspendableUndoManager and found no issues or changes in behaviour compared to the unchecked one. From what I’ve been able to determine, it works just as well (but is now presumably safer).