ios-chat/wfuikit/WFChatUIKit/Category/AttributedLabel.m

//
//  AttributedLabel.m
//  WildFireChat
//
//  Created by heavyrain.lee on 2018/5/15.
//  Copyright © 2018 WildFireChat. All rights reserved.
//

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


@interface AttributedLabel()
@property(nonatomic, strong)NSMutableArray *stringArray;
@property(nonatomic, strong)NSMutableArray *rangeArray;
@end

@implementation AttributedLabel
- (void)setText:(NSString *)text {
    self.attributedText = [self subStr:text];
    self.userInteractionEnabled = YES;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CFIndex index = [self characterIndexAtPoint:[touch locationInView:self]];
    for(NSValue *value in self.rangeArray) {
        
        NSRange range=[value rangeValue];
        if (range.location <= index && (range.location+range.length) >= index) {
            NSInteger i=[self.rangeArray indexOfObject:value];
            NSString *str = self.stringArray[i];
            NSLog(@"touch url %@", str);
        }
    }
    [super touchesBegan:touches withEvent:event];
}


-(NSMutableAttributedString*)subStr:(NSString *)string {
    NSError *error;
    
    //可以识别url的正则表达式
    NSString *regulaStr = @"((http[s]{0,1}|ftp)://[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\-~!@#$%^&*+?:_/=<>]*)?)|(www.[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\-~!@#$%^&*+?:_/=<>]*)?)";
    
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regulaStr
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:&error];
    
    NSArray *arrayOfAllMatches = [regex matchesInString:string options:0 range:NSMakeRange(0, [string length])];
    NSMutableArray *arr=[[NSMutableArray alloc]init];
    NSMutableArray *rangeArr=[[NSMutableArray alloc]init];

    self.stringArray = arr;
    self.rangeArray = rangeArr;
    
    for (NSTextCheckingResult *match in arrayOfAllMatches) {
        NSString* substringForMatch;
        substringForMatch = [string substringWithRange:match.range];
        [arr addObject:substringForMatch];
    }
    
    NSString *subStr=string;
    for (NSString *str in arr) {
        [rangeArr addObject:[self rangesOfString:str inString:subStr]];
    }
    
    NSMutableAttributedString *attributedText;
    attributedText=[[NSMutableAttributedString alloc]initWithString:subStr attributes:@{NSFontAttributeName :self.font}];
    
    for(NSValue *value in rangeArr) {
        NSInteger index=[rangeArr indexOfObject:value];
        NSRange range=[value rangeValue];
        [attributedText addAttribute:NSLinkAttributeName value:[NSURL URLWithString:[arr objectAtIndex:index]] range:range];
        [attributedText addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:range];
    }
    return attributedText;
}

//获取查找字符串在母串中的NSRange
- (NSValue *)rangesOfString:(NSString *)searchString inString:(NSString *)str {
    NSRange searchRange = NSMakeRange(0, [str length]);
    NSRange range;

    if ((range = [str rangeOfString:searchString options:0 range:searchRange]).location != NSNotFound) {
        searchRange = NSMakeRange(NSMaxRange(range), [str length] - NSMaxRange(range));
    }
    return [NSValue valueWithRange:range];
}

- (CFIndex)characterIndexAtPoint:(CGPoint)point {
    
    ////////
    
    NSMutableAttributedString* optimizedAttributedText = [self.attributedText mutableCopy];
    
    [self.attributedText enumerateAttribute:(NSString*)kCTParagraphStyleAttributeName inRange:NSMakeRange(0, [optimizedAttributedText length]) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {
        
        if (value == nil) {
            return ;
        }
        NSMutableParagraphStyle* paragraphStyle = [value mutableCopy];
        
        if ([paragraphStyle lineBreakMode] == kCTLineBreakByTruncatingTail) {
            [paragraphStyle setLineBreakMode:kCTLineBreakByWordWrapping];
        }
        
        [optimizedAttributedText removeAttribute:(NSString*)kCTParagraphStyleAttributeName range:range];
        [optimizedAttributedText addAttribute:(NSString*)kCTParagraphStyleAttributeName value:paragraphStyle range:range];
        
    }];
    
    ////////
    
    if (!CGRectContainsPoint(self.bounds, point)) {
        return NSNotFound;
    }
    
    CGRect textRect = [self textRect];
    
    if (!CGRectContainsPoint(textRect, point)) {
        return NSNotFound;
    }
    
    // Offset tap coordinates by textRect origin to make them relative to the origin of frame
    point = CGPointMake(point.x - textRect.origin.x, point.y - textRect.origin.y);
    // Convert tap coordinates (start at top left) to CT coordinates (start at bottom left)
    point = CGPointMake(point.x, textRect.size.height - point.y);
    
    //////
    
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFAttributedStringRef)optimizedAttributedText);
    
    CGMutablePathRef path = CGPathCreateMutable();
    CGPathAddRect(path, NULL, textRect);
    
    CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, [self.attributedText length]), path, NULL);
    
    if (frame == NULL) {
        CFRelease(path);
        return NSNotFound;
    }
    
    CFArrayRef lines = CTFrameGetLines(frame);
    
    NSInteger numberOfLines = self.numberOfLines > 0 ? MIN(self.numberOfLines, CFArrayGetCount(lines)) : CFArrayGetCount(lines);
    
    //NSLog(@"num lines: %d", numberOfLines);
    
    if (numberOfLines == 0) {
        CFRelease(frame);
        CFRelease(path);
        return NSNotFound;
    }
    
    NSUInteger idx = NSNotFound;
    
    CGPoint lineOrigins[numberOfLines];
    CTFrameGetLineOrigins(frame, CFRangeMake(0, numberOfLines), lineOrigins);
    
    for (CFIndex lineIndex = 0; lineIndex < numberOfLines; lineIndex++) {
        
        CGPoint lineOrigin = lineOrigins[lineIndex];
        CTLineRef line = CFArrayGetValueAtIndex(lines, lineIndex);
        
        // Get bounding information of line
        CGFloat ascent, descent, leading, width;
        width = CTLineGetTypographicBounds(line, &ascent, &descent, &leading);
        CGFloat yMin = floor(lineOrigin.y - descent);
        CGFloat yMax = ceil(lineOrigin.y + ascent);
        
        // Check if we've already passed the line
        if (point.y > yMax) {
            break;
        }
        
        // Check if the point is within this line vertically
        if (point.y >= yMin) {
            
            // Check if the point is within this line horizontally
            if (point.x >= lineOrigin.x && point.x <= lineOrigin.x + width) {
                
                // Convert CT coordinates to line-relative coordinates
                CGPoint relativePoint = CGPointMake(point.x - lineOrigin.x, point.y - lineOrigin.y);
                idx = CTLineGetStringIndexForPosition(line, relativePoint);
                
                break;
            }
        }
    }
    
    CFRelease(frame);
    CFRelease(path);
    
    return idx;
}

- (CGRect)textRect {
    
    CGRect textRect = [self textRectForBounds:self.bounds limitedToNumberOfLines:self.numberOfLines];
    textRect.origin.y = (self.bounds.size.height - textRect.size.height)/2;
    
    if (self.textAlignment == NSTextAlignmentCenter) {
        textRect.origin.x = (self.bounds.size.width - textRect.size.width)/2;
    }
    if (self.textAlignment == NSTextAlignmentRight) {
        textRect.origin.x = self.bounds.size.width - textRect.size.width;
    }
    
    return textRect;
}
@end