diff options
Diffstat (limited to 'macosx/tkMacOSXDraw.c')
| -rw-r--r-- | macosx/tkMacOSXDraw.c | 43 |
1 files changed, 40 insertions, 3 deletions
diff --git a/macosx/tkMacOSXDraw.c b/macosx/tkMacOSXDraw.c index 40400c2..6631b4f 100644 --- a/macosx/tkMacOSXDraw.c +++ b/macosx/tkMacOSXDraw.c @@ -1460,12 +1460,12 @@ XMaxRequestSize( * a damage region. * * Results: - * Returns 0 if the scroll generated no additional damage. + * Returns 0 if the scroll genereated no additional damage. * Otherwise, sets the region that needs to be repainted after * scrolling and returns 1. * * Side effects: - * Scrolls the rectangle in the window. + * Scrolls the bits in the window. * *---------------------------------------------------------------------- */ @@ -1518,9 +1518,46 @@ TkScrollWindow( /* Scroll the rectangle. */ [view scrollRect:NSRectFromCGRect(scroll_src) by:NSMakeSize(dx, -dy)]; [view displayRect:NSRectFromCGRect(scroll_dst)]; + + /* + * When a Text widget contains embedded images, scrolling generates + * lots of artifacts involving multiple copies of the images + * displayed on top of each other. Extensive experimentation, with + * very little help from the Apple documentation, indicates that + * whenever an image is displayed it gets added as a subview, which + * then gets automatically redisplayed in its original location. + * + * We do two things to combat this. First, each subview that meets + * the scroll area is added as a damage rectangle. Second, we + * redisplay the subviews after the scroll. + */ + + /* + * Step 1: Find any subviews that meet the scroll area and mark + * them as damaged. Use Tk coordinates, shifted to account for the + * future scrolling. + */ + + for (NSView *subview in [view subviews] ) { + NSRect frame = [subview frame]; + CGRect subviewRect = CGRectMake( + frame.origin.x - macDraw->xOff + dx, + (bounds.size.height - frame.origin.y - frame.size.height) - macDraw->yOff + dy, + frame.size.width, frame.size.height); + /* Rectangles with negative coordinates seem to cause trouble. */ + if (subviewRect.origin.y < 0 && subviewRect.origin.y + subviewRect.size.height > 0) { + subviewRect.origin.y = 0; + } + CGRect intersection = CGRectIntersection(srcRect, subviewRect); + if (! CGRectIsEmpty(intersection) ){ + dstRgn = HIShapeCreateWithRect(&subviewRect); + ChkErr(HIShapeUnion, dmgRgn, dstRgn, (HIMutableShapeRef) dmgRgn); + CFRelease(dstRgn); + } + } + } } - if ( dmgRgn == NULL ) { |