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cocoacore-textmultiple-columns

Core Text multiple columns with different heights


I need to create a view that renders text in columns with a first column height that is shorter than the rest of the columns and all of the columns are even at the bottom. When I try to change the first column height all of the columns shrink to the same size and are aligned at the top. If I try to add negative numbers for the y value it lowers the column but cuts off some of the text at the bottom of the rect. Any help would be greatly appreciated.

Here is the code:

#import "StoryCoreTextView.h"
#import <CoreText/CoreText.h>


@implementation StoryCoreTextView

@synthesize story;


- (id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code.
    }
    return self;
}


// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code.
    NSString *myLongText = [self getLongText]; /* ... */

    NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:myLongText];

    // make a few words bold
    CTFontRef georgia = CTFontCreateWithName(CFSTR("Georgia"), 14.0, NULL);
    CTFontRef georgiaBold = CTFontCreateWithName(CFSTR("Georgia-Bold"), 14.0, NULL);

    [string addAttribute:(id)kCTFontAttributeName
                   value:(id)georgia
                   range:NSMakeRange(0, [string length])];

                   range:NSMakeRange(223, 6)];

    //    create paragraph style and assign text alignment to it
    CTTextAlignment alignment = kCTJustifiedTextAlignment;
    CTParagraphStyleSetting _settings[] = { {kCTParagraphStyleSpecifierAlignment, sizeof(alignment), &alignment} };
    CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(_settings, sizeof(_settings) / sizeof(_settings[0]));

    //    set paragraph style attribute
    CFAttributedStringSetAttribute(string, CFRangeMake(0, CFAttributedStringGetLength(string)), kCTParagraphStyleAttributeName, paragraphStyle);


    // layout master
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);

    // column 1 form
    CGMutablePathRef column1Path = CGPathCreateMutable();
    CGPathAddRect(column1Path, NULL, 
                  CGRectMake(10, -200, self.bounds.size.width / 6.0 - 20, self.bounds.size.height - 200));

    // column 1 frame
    CTFrameRef column1Frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), column1Path, NULL);

    // column 2 form
    CGMutablePathRef column2Path = CGPathCreateMutable();
    CGPathAddRect(column2Path, NULL, 
                  CGRectMake(self.bounds.size.width/6.0 + 10, 10, 
                             self.bounds.size.width/6.0 - 20,
                             self.bounds.size.height - 20));

    NSInteger colum2Start = CTFrameGetVisibleStringRange(column1Frame).length;

    // column 2 frame
    CTFrameRef column2Frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(colum2Start - 250, 0), column2Path, NULL);

    // column 3 form
    CGMutablePathRef column3Path = CGPathCreateMutable();
    CGPathAddRect(column3Path, NULL, 
                  CGRectMake(2 * self.bounds.size.width/6.0+10, 10, 
                             self.bounds.size.width/6.0 -20,
                             self.bounds.size.height-20));

    NSInteger colum3Start = CTFrameGetVisibleStringRange(column2Frame).length;

    // column 3 frame
    CTFrameRef column3Frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(colum3Start, 0), column3Path, NULL);

    // column 4 form
    CGMutablePathRef column4Path = CGPathCreateMutable();
    CGPathAddRect(column4Path, NULL, 
                  CGRectMake(3 *self.bounds.size.width/6.0+10, 10, 
                             self.bounds.size.width/6.0-20,
                             self.bounds.size.height-20));

    NSInteger colum4Start = CTFrameGetVisibleStringRange(column3Frame).length;

    // column 4 frame
    CTFrameRef column4Frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(colum4Start, 0), column4Path, NULL);

    // flip the coordinate system
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetTextMatrix(context, CGAffineTransformIdentity);
    CGContextTranslateCTM(context, 0, self.bounds.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    // draw
    CTFrameDraw(column1Frame, context);
    CTFrameDraw(column2Frame, context);
    CTFrameDraw(column3Frame, context);
    CTFrameDraw(column4Frame, context);
    CTFrameDraw(column5Frame, context);
    CTFrameDraw(column6Frame, context);

    // cleanup
    CFRelease(column1Frame);
    CGPathRelease(column1Path);
    CFRelease(column2Frame);
    CGPathRelease(column2Path);
    CFRelease(column3Frame);
    CGPathRelease(column3Path);
    CFRelease(column4Frame);
    CGPathRelease(column4Path);
    CFRelease(framesetter);
    CFRelease(georgia);
    CFRelease(georgiaBold);
    [string release];
}


- (void)dealloc {
    [super dealloc];
}

- (NSString *)getLongText {

    NSString *longText = @"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum facilisis imperdiet sem, eu fermentum metus rhoncus ac. Nunc luctus ligula at erat varius at laoreet dolor iaculis. Nulla facilisi. Vivamus vestibulum massa tristique magna convallis ut suscipit dolor aliquet. Aliquam mollis porttitor tortor a venenatis. In tincidunt ornare posuere. In varius augue ut orci interdum in hendrerit tortor volutpat. Integer nec libero vel eros dignissim porta in nec nibh. Aenean sollicitudin justo vel augue pulvinar tincidunt. Phasellus dictum convallis dui in semper. Nam eros leo, dapibus eu porta non, aliquet id velit. Integer felis nisl, fermentum facilisis rutrum eget, consequat non nisl.";
    return longText;
}


@end

Solution

  • I'd rather suggest you to make path from multiple rectangles:

      // column 1 and 2 form
        CGMutablePathRef columnPath = CGPathCreateMutable();
        CGPathAddRect(column1Path, NULL, 
                      CGRectMake(10, -200, self.bounds.size.width / 6.0 - 20, self.bounds.size.height - 200));
        CGPathAddRect(column2Path, NULL, 
                      CGRectMake(self.bounds.size.width/6.0 + 10, 10, 
                                 self.bounds.size.width/6.0 - 20,
                                 self.bounds.size.height - 20));
    ...
        // use this CGPathRef for CTFramesetterRef
    ...