Re: Replacing views with setContentView

[Andreas Höschler]

Hello Fred,

> > in our apps we have to replace views with setContentView:, e.g. in the
> > inspector depending on the context. Our code works perfectly on MacOSX
> > but failed under GNUstep. I spent 2 days on debugging this in the
> > GNUstep sources. I finally figured out that this has to do with
> > resizeWithOldSuperviewSize: and probably a no longer valid reference
> > size after the replacing the contentView. Finally the following
> > modification fixed the problem (last three lines):
> >
> > GSWindowDecorationView:
> >
> > - (void) setFrame: (NSRect)frameRect
> > {
> >   NSSize oldSize = _frame.size;
> >   NSView *cv = [_window contentView];
> >
> >   frameRect = [isa windowFrameRectForFrameRect: frameRect
> >                      styleMask: [window styleMask]];
> >
> >   _autoresizes_subviews = NO;
> >   [super setFrame: frameRect];
> >
> >   contentRect = [isa contentRectForWindowFrameRect: frameRect
> >                      styleMask: [window styleMask]];
> >
> >   // Safety Check.
> > //  [cv setAutoresizingMask: NSViewWidthSizable | 
> > NSViewHeightSizable];
> > //  [cv resizeWithOldSuperviewSize: oldSize];
> >   [cv setFrame: contentRect];
> > }
> >
> > I don't understand what the author intended to do with this safety
> > check, but it definitely makes our code fai. I checked 8 applications
> > after my modification and all behave well. I therefore recommend to
> > apply this patch.
>
> I tried to understand this change, but failed to. I most cases I would
> expect the current GNUstep code to be more or less equivalent to your
> code. Where would there be any difference?
> The safety check is only about resetting the resize attributes of the
> content view, which should not be needed and doesn't make any
> difference. And for normal views the resizeWithOldSuperviewSize: method
> call should be equivalent to the setFrame: call. What I need to
> understand is, why this makes a difference in your case, so what is the
> resize behaviour of your content view? And what is the problem you
> experience?

I am exchanging the contentView of the window as follows:

- (void)setClientView:(NSView *)view
{
   NSRect rect = [[mainWin contentView] frame];
   [view removeFromSuperviewWithoutNeedingDisplay];
   [view setFrame:rect];
   [mainWin setContentView:view];
   [view setAutoresizesSubviews:NO];    
   [view setAutoresizingMask:0];        
}

The view I am passing to this method is a direct subclass of NSView. 
This view should not do standard autoresizing of its subviews. I 
implemented my own mechanism to do so in setFrame:. Now with my GNUstep 
fix everything works fine. Without the fix resizing of the view (not 
even initial sizing) does not work. The view gets a wrong width and 
height!

Regards,

  Andreas