MSLabel.m

//
//  MSLabel.m
//  Miso
//
//  Created by Joshua Wu on 11/15/11.
//  Copyright (c) 2011 Miso. All rights reserved.
//

#import "MSLabel.h"

// small buffer to allow for characters like g,y etc 
static const int kAlignmentBuffer = 5;

@interface MSLabel ()

- (void)setup;
- (NSArray *)stringsFromText:(NSString *)string;

@end

@implementation MSLabel

@synthesize lineHeight = _lineHeight;
@synthesize verticalAlignment = _verticalAlignment;


#pragma mark - Initilisation

- (id)initWithFrame:(CGRect)frame 
{
    self = [super initWithFrame:frame];
    
    if (self) 
    {
        [self setup];
    }
    
    return self;
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    
    if(self)
    {
        [self setup];
    }
    
    return self;
}


#pragma mark - Drawing

- (void)drawTextInRect:(CGRect)rect 
{
    NSArray *slicedStrings = [self stringsFromText:self.text];
    if (self.highlighted) {
        [self.highlightedTextColor set]; 
    }
    else {
        [self.textColor set];   
    }
    
    int numLines = slicedStrings.count;
    if (numLines > self.numberOfLines && self.numberOfLines != 0)
    {
        numLines = self.numberOfLines;
    }
    
    int drawY = (self.frame.size.height / 2 - (_lineHeight * numLines) / 2) - kAlignmentBuffer;    
    
    for (int i = 0; i < numLines; i++) 
    {        
        
        NSString *line = [slicedStrings objectAtIndex:i];
        
        // calculate draw Y based on alignment
        switch (_verticalAlignment) 
        {
            case MSLabelVerticalAlignmentTop:
            {
                drawY = i * _lineHeight;
            }
                break;
            case MSLabelVerticalAlignmentMiddle:
            {
                if(i > 0)
                {
                    drawY += _lineHeight;            
                }
            }
                break;
            case MSLabelVerticalAlignmentBottom:
            {
                drawY = (self.frame.size.height - _lineHeight * numLines) + ((i  * _lineHeight) - kAlignmentBuffer);
            }
                break;
            default:
            {
                if(i > 0)
                {
                    drawY += _lineHeight;            
                }
            }
                break;
        }
        
        // calculate draw X based on textAlignmentment
        int drawX = 0; 
        
        if (self.textAlignment == UITextAlignmentCenter) 
        {
            drawX = floorf((self.frame.size.width - [line sizeWithFont:self.font].width) / 2);
        } 
        else if (self.textAlignment == UITextAlignmentRight) 
        {
            drawX = (self.frame.size.width - [line sizeWithFont:self.font].width);
        }
        
        [line drawAtPoint:CGPointMake(drawX, drawY) forWidth:self.frame.size.width withFont:self.font fontSize:self.font.pointSize lineBreakMode:UILineBreakModeClip baselineAdjustment:UIBaselineAdjustmentNone];
    }
}


#pragma mark - Properties

- (void)setLineHeight:(int)lineHeight 
{
    if (_lineHeight == lineHeight) 
    { 
        return; 
    }
    
    _lineHeight = lineHeight;
    [self setNeedsDisplay];
}


#pragma mark - Private Methods

- (void)setup
{
    _lineHeight = 10;
    _verticalAlignment = MSLabelVerticalAlignmentMiddle;
}

- (NSArray *)stringsFromText:(NSString *)string 
{
    NSMutableArray *stringsArray = [[[string componentsSeparatedByString:@" "] mutableCopy] autorelease];
    NSMutableArray *slicedString = [NSMutableArray array];
    
    while (stringsArray.count != 0) 
    {
        NSString *line = @"";
        NSMutableIndexSet *wordsToRemove = [NSMutableIndexSet indexSet];
        
        for (int i = 0; i < [stringsArray count]; i++) 
        {
            NSString *word = [stringsArray objectAtIndex:i];
            
            if ([[line stringByAppendingFormat:@"%@ ", word] sizeWithFont:self.font].width <= self.frame.size.width) 
            {
                line = [line stringByAppendingFormat:@"%@ ", word];
                [wordsToRemove addIndex:i];
            } 
            else 
            {
                if (line.length == 0) 
                {
                    line = [line stringByAppendingFormat:@"%@ ", word];
                    [wordsToRemove addIndex:i];
                }
                break;
            }
        }
        
        [slicedString addObject:[line stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]];
        [stringsArray removeObjectsAtIndexes:wordsToRemove];
    }
    
    if (slicedString.count > self.numberOfLines && self.numberOfLines != 0) 
    {
        NSString *line = [slicedString objectAtIndex:(self.numberOfLines - 1)];
        if ([line length] >= 3) {
            line = [line stringByReplacingCharactersInRange:NSMakeRange(line.length - 3, 3) withString:@"..."];
        } else {
            line = @"...";
        }
        [slicedString removeObjectAtIndex:(self.numberOfLines - 1)];
        [slicedString insertObject:line atIndex:(self.numberOfLines - 1)];
    }
    
    return slicedString;
}

@end