iOS UITableView with dynamic text and images rendered together (NSAttributedString + images)

Question

My problem is this: I have dynamic content in an iOS app (such as twits - although this is not a twitter app) that include both text and images (mostly icons/emoticons and t

Answer 1

This post may get you going in the right direction for calculating row height:

Retrieve custom prototype cell height from storyboard?

As for performance, have you run Time Profiler to narrow down what is causing lag?

Answer 2

I ran into the same issue und solved it today. I am drawing custom objects between the text with the CTRunDelegateCallbacks, but boundingRectWithSize:options:context:did not give me the correct height. (It ignores my custom objects).

Instead I found a lower level API in Core Text, which fulfils all requirements and is totally correct. I created a category for that issue. Have fun using it! :-)

Header file:

#import <Foundation/Foundation.h>

@interface NSAttributedString (boundsForWidth)

- (CGRect)boundsForWidth:(float)width;

@end

Implementation file:

#import "NSAttributedString+boundsForWidth.h"
#import <CoreText/CoreText.h>

@implementation NSAttributedString (boundsForWidth)

- (CGRect)boundsForWidth:(float)width
{
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)self);

    CGSize maxSize = CGSizeMake(width, 0);

    CGSize size = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0, 0), NULL, maxSize, nil);

    CFRelease(framesetter);

    return CGRectMake(0, 0, ceilf(size.width), ceilf(size.height));
}

@end