Re: Aligning a subview element with text in an NSTextView (was: Finding vertical pos...)
Re: Aligning a subview element with text in an NSTextView (was: Finding vertical pos...)
- Subject: Re: Aligning a subview element with text in an NSTextView (was: Finding vertical pos...)
- From: Douglas Davidson <email@hidden>
- Date: Wed, 15 Dec 2004 15:44:28 -0800
On Dec 15, 2004, at 10:19 AM, Keith Blount wrote:
Hi, sorry to reply to my own post, but I have spent
another day trying to get this right with no luck.
Does anybody know how to constantly get the vertical
position of a character in an NSTextView, even if the
view's size is changed or after the text is edited? I
need to align little notes that are added by the user
with the character nearest where the note was added...
So I have to keep track of a particular character (or
rather, a number of characters) and tell the notes
views whenever the vertical positions of these
characters changes for any reason.
Here is a snippet of code from a previous WWDC example. This is a
method on a custom NSTextView subclass intended to draw bubbles around
each individual paragraph in the text. It's not directly on point for
what you are after, but if you understand how it works you should
understand how to use the layout manager to determine the location of
any piece of text.
Douglas Davidson
- (void)drawViewBackgroundInRect:(NSRect)rect {
NSLayoutManager *layoutManager = [self layoutManager];
NSPoint containerOrigin = [self textContainerOrigin];
NSRange glyphRange, charRange, paragraphCharRange,
paragraphGlyphRange, lineGlyphRange;
NSRect paragraphRect, lineUsedRect;
// Draw the background first, before the bubbles.
[super drawViewBackgroundInRect:rect];
// Convert from view to container coordinates, then to the
corresponding glyph and character ranges.
rect.origin.x -= containerOrigin.x;
rect.origin.y -= containerOrigin.y;
glyphRange = [layoutManager glyphRangeForBoundingRect:rect
inTextContainer:[self textContainer]];
charRange = [layoutManager characterRangeForGlyphRange:glyphRange
actualGlyphRange:NULL];
// Iterate through the character range, paragraph by paragraph.
for (paragraphCharRange = NSMakeRange(charRange.location, 0);
NSMaxRange(paragraphCharRange) < NSMaxRange(charRange);
paragraphCharRange = NSMakeRange(NSMaxRange(paragraphCharRange), 0)) {
// For each paragraph, find the corresponding character and
glyph ranges.
paragraphCharRange = [[[self textStorage] string]
paragraphRangeForRange:paragraphCharRange];
paragraphGlyphRange = [layoutManager
glyphRangeForCharacterRange:paragraphCharRange
actualCharacterRange:NULL];
paragraphRect = NSZeroRect;
// Iterate through the paragraph glyph range, line by line.
for (lineGlyphRange = NSMakeRange(paragraphGlyphRange.location,
0); NSMaxRange(lineGlyphRange) < NSMaxRange(paragraphGlyphRange);
lineGlyphRange = NSMakeRange(NSMaxRange(lineGlyphRange), 0)) {
// For each line, find the used rect and glyph range, and
add the used rect to the paragraph rect.
lineUsedRect = [layoutManager
lineFragmentUsedRectForGlyphAtIndex:lineGlyphRange.location
effectiveRange:&lineGlyphRange];
paragraphRect = NSUnionRect(paragraphRect, lineUsedRect);
}
// Convert back from container to view coordinates, then draw
the bubble.
paragraphRect.origin.x += containerOrigin.x;
paragraphRect.origin.y += containerOrigin.y;
[self drawBubbleAroundTextInRect:paragraphRect];
}
}
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden