Frank R. Frank R. - 3 months ago 23
iOS Question

iOS7 TextKit: bullet point alignment

I'm writing an app for iOS 7 only and I'm trying to get decent formatting on bullet points in a non-editable UITextView.

It's easy enough to just insert a bullet point character, but of course the left indentation won't follow. What's the easiest way on iOS 7 to set a left indent after a bullet point?

Thanks in advance,

Frank

Answer

Below it the code I use to set a bulleted paragraph. This comes straight out of a working app and is used to apply the style to the entire paragraph in response to a user clicking on a formatting button. I have tried to put in all the dependent methods but may have missed some.

Note that I am setting most indents in centimetres and hence the use of the conversion functions at the end of the listing.

I am also checking for the presence of a tab character (no tab key on iOS!) and automatically insert a dash and a tab.

If all you need is the paragraph style then look at the last few methods below where the firstLineIndent etc get set up.

Note that these calls all get wrapped in [textStorage beginEditing/endEditing]. Despite the (IBAction) below the method is not getting called by a UI object directly.

        - (IBAction) styleBullet1:(id)sender
        {
            NSRange charRange = [self rangeForUserParagraphAttributeChange];
            NSTextStorage *myTextStorage = [self textStorage];

            // Check for "-\t" at beginning of string and add if not found
            NSAttributedString *attrString = [myTextStorage attributedSubstringFromRange:charRange];
            NSString *string = [attrString string];

            if ([string rangeOfString:@"\t"].location == NSNotFound) {
                NSLog(@"string does not contain tab so insert one");
                NSAttributedString * aStr = [[NSAttributedString alloc] initWithString:@"-\t"];
                // Insert a bullet and tab
                [[self textStorage] insertAttributedString:aStr atIndex:charRange.location];

            } else {
                NSLog(@"string contains tab");
            }

            if ([self isEditable] && charRange.location != NSNotFound)
            {
                [myTextStorage setAttributes:[self bullet1Style] range:charRange];
            }
        }

        - (NSDictionary*)bullet1Style
        {
            return [self createStyle:[self getBullet1ParagraphStyle] font:[self normalFont] fontColor:[UIColor blackColor] underlineStyle:NSUnderlineStyleNone];

        }

        - (NSDictionary*)createStyle:(NSParagraphStyle*)paraStyle font:(UIFont*)font fontColor:(UIColor*)color underlineStyle:(int)underlineStyle
        {
            NSMutableDictionary *style = [[NSMutableDictionary alloc] init];
            [style setValue:paraStyle forKey:NSParagraphStyleAttributeName];
            [style setValue:font forKey:NSFontAttributeName];
            [style setValue:color forKey:NSForegroundColorAttributeName];
            [style setValue:[NSNumber numberWithInt: underlineStyle] forKey:NSUnderlineStyleAttributeName];

            FLOG(@" font is %@", font);

            return style;
        }

        - (NSParagraphStyle*)getBullet1ParagraphStyle
        {
            NSMutableParagraphStyle *para;
            para = [self getDefaultParagraphStyle];
            NSMutableArray *tabs = [[NSMutableArray alloc] init];
            [tabs addObject:[[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentLeft location:[self ptsFromCMF:1.0] options:nil]];
            //[tabs addObject:[[NSTextTab alloc] initWithType:NSLeftTabStopType location:[self ptsFromCMF:1.0]]];
            [para setTabStops:tabs];
            [para setDefaultTabInterval:[self ptsFromCMF:2.0]];
            [para setFirstLineHeadIndent:[self ptsFromCMF:0.0]];
            //[para setHeaderLevel:0];
            [para setHeadIndent:[self ptsFromCMF:1.0]];
            [para setParagraphSpacing:3];
            [para setParagraphSpacingBefore:3];
            return para;
        }
    - (NSMutableParagraphStyle*)getDefaultParagraphStyle
    {
        NSMutableParagraphStyle *para;
        para = [[NSParagraphStyle defaultParagraphStyle]mutableCopy];
        [para setTabStops:nil];
        [para setAlignment:NSTextAlignmentLeft];
        [para setBaseWritingDirection:NSWritingDirectionLeftToRight];
        [para setDefaultTabInterval:[self ptsFromCMF:3.0]];
        [para setFirstLineHeadIndent:0];
        //[para setHeaderLevel:0];
        [para setHeadIndent:0.0];
        [para setHyphenationFactor:0.0];
        [para setLineBreakMode:NSLineBreakByWordWrapping];
        [para setLineHeightMultiple:1.0];
        [para setLineSpacing:0.0];
        [para setMaximumLineHeight:0];
        [para setMinimumLineHeight:0];
        [para setParagraphSpacing:6];
        [para setParagraphSpacingBefore:3];
        //[para setTabStops:<#(NSArray *)#>];
        [para setTailIndent:0.0];
        return para;
    }
-(NSNumber*)ptsFromCMN:(float)cm
{
    return [NSNumber numberWithFloat:[self ptsFromCMF:cm]];
}
-(float)ptsFromCMF:(float)cm
{
    return cm * 28.3464567;
}