NSTextView overdraw bug in Leopard?
NSTextView overdraw bug in Leopard?
- Subject: NSTextView overdraw bug in Leopard?
- From: Martin Wierschin <email@hidden>
- Date: Mon, 21 Jul 2008 16:10:09 -0700
Hi everyone,
We've had a report or two from users where text will incorrectly draw
in an area it's not supposed to. Basically a line fragment (or part
of one) from the prior NSTextContainer will draw over text in the
current container. The odd part is that both line fragments are the
last ones in each of their respective containers. In other words, the
glyphs for the fragments are separated from each other by quite a bit
of content.
It looks like this (hopefully the PNG comes through):
Attachment:
Picture 1.png
Description: application/applefile
Admittedly we have heavily customized the text layout system, but in
the end it's just a series of non-overlapping text views. It could be
our drawing code, which I've include below, but it hasn't given us
problems before Leopard. We aren't using noncontiguous layout, but
even so adding calls to ensureLayoutForTextContainer in drawRect
doesn't fix the problem.
Has anyone else seen this before? Unfortunately we've been unable to
reproduce the problem ourselves. We didn't receive any reports until
after Leopard was released. Searching around the web there appear to
be other Leopard related redraw issues, but I haven't seen anything
about the Cocoa text system specifically.
Thanks for any help,
~Martin
PS: Our NSTextView subclass handles drawing like this:
- (void) drawRect:(NSRect)rect
{
if( rect.size.height <= 0 ) return;
NSLayoutManager* lm = [self layoutManager];
NSTextContainer* tc = [self textContainer];
NSPoint origin = [self textContainerOrigin];
NSRange glyphRng = (nil == tc) ? NSZeroRange : [lm
glyphRangeForBoundingRect:rect inTextContainer:tc];
// background
[self drawViewBackgroundInRect:rect];
if( 0 != glyphRng.length ) [lm drawBackgroundForGlyphRange:glyphRng
inTextContainer:tc atPoint:origin];
[lm drawSelectionForGlyphRange:glyphRng inTextContainer:tc
atPoint:origin];
// text
if( 0 != glyphRng.length ) {
[NSBezierPath clipRect:rect]; // in case the glyphs being drawn are
not entirely in the redraw rect
[lm drawGlyphsForGlyphRange:glyphRng atPoint:origin];
}
}
- (void) drawViewBackgroundInRect:(NSRect)rect
{
if( [self drawsBackground] ) {
[[self backgroundColor] set];
[NSBezierPath fillRect:rect];
}
}_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden