[news.eclipse.platform.rcp] Re: [jface.viewers] May CellLabelProvider.up

[Daniel Krügler <dsp@xxxxxxx>]

Daniel Krügler wrote:
> Tom Schindl wrote:
> > I would expect that a redraw leads to callbacks into the ownerdraw
> > listeners who call back to the update()-method.
>
> Hmmh, I can only partially confirm that. What I did is that I replaced
> my current call of
>
> update(activeCell);
>
> - where activeCell is the ViewerCell result from the previous 
> getViewer().getCell(pt) call and update is the member method of my 
> StyledCellLabelProvider derivative - by
>
> Rectangle rect = activeCell.getBounds();
> activeCell.getControl().redraw(rect.x, rect.y, rect.width,
>     rect.height, true);
>
> which is essentially the same call as FocusCellOwnerDrawHighlighter
> does. I see that a short time later the triade SWT.MeasureItem,
> SWT.EraseItem, and SWT.PaintItem of the OwnerDrawLabelProvider base
> class listener are invoked properly delegating to the corresponding 
> StyledCellLabelProvider callbacks, but none of them seems calls the
> update method of my StyledCellLabelProvider derivative. There is no 
> direct observable change (i.e. no color change) in contrast to my 
> previous code.
>
> Can this be correct? Let me note that OwnerDrawLabelProvider#update
> itself calls
>
> // Force a redraw
> Rectangle cellBounds = cell.getBounds();
> cell.getControl().redraw(cellBounds.x, cellBounds.y, cellBounds.width,
>         cellBounds.height, true);
>
> but if this would call update again, this would cause an infinitive
> recursion. Currently I see no alternative to a direct call to my
> StyledCellLabelProvider#update method, but I would be glad if someone
> points to the obvious glitch in my code.

Here some more information:

a) I'm using Eclipse 3.4.2, but my own code (explicit call of update) 
also runs also with Eclipse 3.5.

b) In case it isn't clear what the update method of my CellLabelProvider
does, here is the essential part:

	public final void update(ViewerCell cell) {
                [..]
		Color fg = activeCell != null ?
                        activeLinkColor : linkColor;
		cell.setForeground(fg);
                [..]
		super.update(cell);
	}

Thanks,

Daniel