IOS CoreText系列四：图文混排之点击事件

主要思路：基于-(void)touchesBegan:(NSSet<UITouch *> )touches withEvent:(UIEvent )event这个方法拿到当前点击到的点，然后通过坐标判断这个点是否在某段文字上，如果在则触发对应事件。

1、首先需要执行touchesBegan这个方法来做相应的判断

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint location = [self systemPointFromScreenPoint:[touch locationInView:self]];
//判断点击的是图片还是文字
if ([self checkIsClickOnImgWithPoint:location]) {
return;
}
[self clickOnStringWithPoint:location];
}

2、点击的是图片做相应的处理，图片的位置我们在图文混排的时候会获取到，这边直接拿过来用，如果图片有很多张的话，需要搞个循环来做判断。
#pragma mark 点击图片
- (BOOL)checkIsClickOnImgWithPoint:(CGPoint)location
{
if ([self isFrame:_imgFrm containsPoint:location]) {
NSLog(@"你点击到了图片");
return YES;
}
return NO;
}

- (BOOL)isFrame:(CGRect)frame containsPoint:(CGPoint)point
{
return CGRectContainsPoint(frame, point);
}3、点击的是字符串，步骤如下：
/*
点击文字判断的大致步骤：
1.根据Frame拿到所有Line
2.计算每个Line中在全文的range
3.计算每个字对应line原点的X值
4.比对对应line的origin求得字对应起点坐标
5.求得下一个字的横坐标和上一行的origin，结合起点坐标得出字的坐标范围
6.屏幕坐标与drawRect坐标转换，判断是否在范围内
*/

#pragma mark 点击字符串
- (void)clickOnStringWithPoint:(CGPoint)point
{
//获取所有CTLine
NSArray *lines = (NSArray *)CTFrameGetLines(self.ctFrm);
//初始化范围数组
CFRange ranges[lines.count];
//初始化原点数组
CGPoint origins[lines.count];
//获取所有CTLine的原点
CTFrameGetLineOrigins(self.ctFrm, CFRangeMake(0, 0), origins);

//获取每个CTLine中包含的富文本在整串富文本中的范围。将所有CTLine中字符串的范围保存下来放入数组中。
for (int i = 0; i < lines.count; i ++) {
CTLineRef line = (__bridge CTLineRef)(lines[i]);
CFRange range = CTLineGetStringRange(line);
ranges[i] = range;
}

for (int i = 0;i < self.strLength; i ++) {
long maxLoc;
int lineNum;
for (int j = 0; j < lines.count; j ++) {
CFRange range = ranges[j];
maxLoc = range.location + range.length - 1;
if (i <= maxLoc) {
lineNum = j;
break;
}
}

CTLineRef line = (__bridge CTLineRef)(lines[lineNum]);
CGPoint origin = origins[lineNum];
CGRect ctRunFrame = [self frameForCTRunWithIndex:i ctLine:line origin:origin];
if ([self isFrame:ctRunFrame containsPoint:point]) {
NSLog(@"您点击到了第 %d 个字符，位于第 %d 行，然而他没有响应事件。",i,lineNum + 1);

return;
}
}
NSLog(@"您没有点击到文字");
}

/**
字符Frame计算

@param index  索引
@param line   索引字符所在CTLine
@param origin line的起点

@return 返回Frame
*/
- (CGRect)frameForCTRunWithIndex:(NSInteger)index ctLine:(CTLineRef)line origin:(CGPoint)origin
{
//获取字符起点相对于CTLine的原点的偏移量
CGFloat offsetX = CTLineGetOffsetForStringIndex(line, index, NULL);
//获取下一个字符的偏移量，两者之间即为字符X范围
CGFloat offsetX2 = CTLineGetOffsetForStringIndex(line, index + 1, NULL);
offsetX += origin.x;
offsetX2 += origin.x;
CGFloat offsetY = origin.y;
CGFloat lineAscent,lineDescent;
//获取当前点击的CTRun
NSArray *runs = (NSArray *)CTLineGetGlyphRuns(line);
CTRunRef runCurrent;
for (int k = 0; k < runs.count; k ++) {
CTRunRef run = (__bridge CTRunRef)(runs[k]);
CFRange range = CTRunGetStringRange(run);
NSRange rangeOC = NSMakeRange(range.location, range.length);
if ([self isIndex:index inRange:rangeOC]) {
runCurrent = run;
break;
}
}
//获得对应CTRun的尺寸信息
CTRunGetTypographicBounds(runCurrent, CFRangeMake(0, 0), &lineAscent, &lineDescent, NULL);
//计算当前点击的CTRun高度
CGFloat height = lineAscent + lineDescent;
return CGRectMake(offsetX, offsetY, offsetX2 - offsetX, height);
}

/**
范围检测

@param index 索引
@param range 范围

@return 范围内返回yes，否则返回no
*/
- (BOOL)isIndex:(NSInteger)index inRange:(NSRange)range
{
if ((index <= (range.location + range.length - 1)) && (index >= range.location)) {
return YES;
}
return NO;
}

完整代码如下:
.h文件

#import <UIKit/UIKit.h>

@interface HSCoreTextView : UIView

@end


.m文件
#import "HSCoreTextView.h"
#import <CoreText/CoreText.h>

@interface HSCoreTextView ()

@property (nonatomic,assign) CGRect imgFrm;

@property (nonatomic,assign) CTFrameRef ctFrm;

@property (nonatomic,assign) NSInteger strLength;

@end

@implementation HSCoreTextView

//图片回调函数
static CGFloat ascentCallBacks(void *ref)
{
//__bridge既是C的结构体转换成OC对象时需要的一个修饰词
return [[(__bridge NSDictionary *)ref valueForKey:@"height"] floatValue];
}

static CGFloat descentCallBacks(void *ref)
{
return 0;
}

static CGFloat widthCallBacks(void *ref)
{
return [[(__bridge NSDictionary *)ref valueForKey:@"width"] floatValue];
}

- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];

//1.绘制上下文
//1.1获取绘制上下文
CGContextRef context = UIGraphicsGetCurrentContext();
//1.2.coreText 起初是为OSX设计的，而OSX得坐标原点是左下角，y轴正方向朝上。iOS中坐标原点是左上角，y轴正方向向下。若不进行坐标转换，则文字从下开始，还是倒着的,因此需要设置以下属性
////设置字形的变换矩阵为不做图形变换
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
//平移方法，将画布向上平移一个屏幕高
CGContextTranslateCTM(context, 0, self.bounds.size.height);
//缩放方法，x轴缩放系数为1，则不变，y轴缩放系数为-1，则相当于以x轴为轴旋转180度
CGContextScaleCTM(context, 1.0, -1.0);

//2.设置图片回调函数
//2.1创建一个回调结构体，设置相关参数
CTRunDelegateCallbacks callBacks;
//memset将已开辟内存空间 callbacks 的首 n 个字节的值设为值 0, 相当于对CTRunDelegateCallbacks内存空间初始化
memset(&callBacks, 0, sizeof(CTRunDelegateCallbacks));
//2.2设置回调版本，默认这个
callBacks.version = kCTRunDelegateVersion1;
//2.3设置图片顶部距离基线的距离
callBacks.getAscent = ascentCallBacks;
//2.4设置图片底部距离基线的距离
callBacks.getDescent = descentCallBacks;
//2.5设置图片宽度
callBacks.getWidth = widthCallBacks;
//2.6创建一个代理
NSDictionary *dicPic = @{@"height":@"60",@"width":@"60"};
CTRunDelegateRef delegate = CTRunDelegateCreate(&callBacks, (__bridge void * _Nullable)(dicPic));

//3.插入图片
//创建空白字符
unichar placeHolder = 0xFFFC;
NSString *placeHolderStr = [NSString stringWithCharacters:&placeHolder length:1];
NSMutableAttributedString *placeHolderMabString = [[NSMutableAttributedString alloc] initWithString:placeHolderStr];
//给字符串中的范围中字符串设置代理
CFAttributedStringSetAttribute((CFMutableAttributedStringRef)placeHolderMabString, CFRangeMake(0, 1), kCTRunDelegateAttributeName, delegate);

//4.设置要显示的文字
NSMutableAttributedString *mabString = [[NSMutableAttributedString alloc] initWithString:@"\n这里在测试图文混排,\n我是富文本"];
[mabString insertAttributedString:placeHolderMabString atIndex:12];

//5.绘制文本
//5.1.创建CTFramesetterRef
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)mabString);

//5.2.创建路径
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddRect(path, NULL, self.bounds);

//5.3.创建CTFrame
NSInteger length = mabString.length;
self.strLength = length;
CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, length), path, NULL);
self.ctFrm = frame;
CTFrameDraw(frame, context);

//6.添加图片并绘制
UIImage *image = [UIImage imageNamed:@"icon-60"];
CGRect imgFrm = [self calculateImageRectWithFrame:frame];
self.imgFrm = imgFrm;
CGContextDrawImage(context, imgFrm, image.CGImage);

//7.释放
CFRelease(delegate);
// CFRelease(frame);
CFRelease(path);
CFRelease(framesetter);
}

#pragma mark 计算图片Frame
- (CGRect)calculateImageRectWithFrame:(CTFrameRef)frame
{
//根据frame获取需要绘制的线的数组
NSArray *arrLines = (NSArray *)CTFrameGetLines(frame);
NSInteger count = arrLines.count;
CGPoint points[count];
//获取起始点位置
CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), points);

for (int i = 0; i < count; i ++) {
CTLineRef line = (__bridge CTLineRef)(arrLines[i]);
//CTRun 或者叫做 Glyph Run，是一组共享想相同attributes（属性）的字形的集合体
NSArray *arrGlyphRun = (NSArray *)CTLineGetGlyphRuns(line);
for (int j = 0; j < arrGlyphRun.count; j ++) {
CTRunRef run = (__bridge CTRunRef)(arrGlyphRun[j]);
//获取CTRun的属性
NSDictionary *attributes = (NSDictionary *)CTRunGetAttributes(run);
CTRunDelegateRef delegate = (__bridge CTRunDelegateRef)[attributes valueForKey:(id)kCTRunDelegateAttributeName];
if (delegate == nil) {
continue;
}

NSDictionary *dic = CTRunDelegateGetRefCon(delegate);
if (![dic isKindOfClass:[NSDictionary class]]) {
continue;
}

//获取一个起点
CGPoint point = points[i];
//获取上下距
CGFloat ascent,desecent;
//创建一个Frame
CGRect boundsRun;
boundsRun.size.width = CTRunGetTypographicBounds(run, CFRangeMake(0, 0), &ascent, &desecent, NULL);
boundsRun.size.height = ascent + desecent;
//获取偏移量
CGFloat xOffset = CTLineGetOffsetForStringIndex(line, CTRunGetStringRange(run).location, NULL);
boundsRun.origin.x = point.x + xOffset;
boundsRun.origin.y = point.y - desecent;
//获取绘制路径
CGPathRef path = CTFrameGetPath(frame);
//获取剪裁区域边框
CGRect colRect = CGPathGetBoundingBox(path);
CGRect imageBounds = CGRectOffset(boundsRun, colRect.origin.x, colRect.origin.y);

return imageBounds;
}
}
return CGRectZero;
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint location = [self systemPointFromScreenPoint:[touch locationInView:self]];
//判断点击的是图片还是文字
if ([self checkIsClickOnImgWithPoint:location]) {
return;
}
[self clickOnStringWithPoint:location];
}

#pragma mark 转化成屏幕坐标
- (CGPoint)systemPointFromScreenPoint:(CGPoint)origin
{
return CGPointMake(origin.x, self.bounds.size.height - origin.y);
}

#pragma mark 点击图片
- (BOOL)checkIsClickOnImgWithPoint:(CGPoint)location
{
if ([self isFrame:_imgFrm containsPoint:location]) {
NSLog(@"你点击到了图片");
return YES;
}
return NO;
}

- (BOOL)isFrame:(CGRect)frame containsPoint:(CGPoint)point
{
return CGRectContainsPoint(frame, point);
}

/*
点击文字判断的大致步骤：
1.根据Frame拿到所有Line
2.计算每个Line中在全文的range
3.计算每个字对应line原点的X值
4.比对对应line的origin求得字对应起点坐标
5.求得下一个字的横坐标和上一行的origin，结合起点坐标得出字的坐标范围
6.屏幕坐标与drawRect坐标转换，判断是否在范围内
*/
#pragma mark 点击字符串 - (void)clickOnStringWithPoint:(CGPoint)point { //获取所有CTLine NSArray *lines = (NSArray *)CTFrameGetLines(self.ctFrm); //初始化范围数组 CFRange ranges[lines.count]; //初始化原点数组 CGPoint origins[lines.count]; //获取所有CTLine的原点 CTFrameGetLineOrigins(self.ctFrm, CFRangeMake(0, 0), origins); //获取每个CTLine中包含的富文本在整串富文本中的范围。将所有CTLine中字符串的范围保存下来放入数组中。 for (int i = 0; i < lines.count; i ++) { CTLineRef line = (__bridge CTLineRef)(lines[i]); CFRange range = CTLineGetStringRange(line); ranges[i] = range; } for (int i = 0;i < self.strLength; i ++) { long maxLoc; int lineNum; for (int j = 0; j < lines.count; j ++) { CFRange range = ranges[j]; maxLoc = range.location + range.length - 1; if (i <= maxLoc) { lineNum = j; break; } } CTLineRef line = (__bridge CTLineRef)(lines[lineNum]); CGPoint origin = origins[lineNum]; CGRect ctRunFrame = [self frameForCTRunWithIndex:i ctLine:line origin:origin]; if ([self isFrame:ctRunFrame containsPoint:point]) { NSLog(@"您点击到了第 %d 个字符，位于第 %d 行，然而他没有响应事件。",i,lineNum + 1); return; } } NSLog(@"您没有点击到文字"); } /** 字符Frame计算 @param index 索引 @param line 索引字符所在CTLine @param origin line的起点 @return 返回Frame */ - (CGRect)frameForCTRunWithIndex:(NSInteger)index ctLine:(CTLineRef)line origin:(CGPoint)origin { //获取字符起点相对于CTLine的原点的偏移量 CGFloat offsetX = CTLineGetOffsetForStringIndex(line, index, NULL); //获取下一个字符的偏移量，两者之间即为字符X范围 CGFloat offsetX2 = CTLineGetOffsetForStringIndex(line, index + 1, NULL); offsetX += origin.x; offsetX2 += origin.x; CGFloat offsetY = origin.y; CGFloat lineAscent,lineDescent; //获取当前点击的CTRun NSArray *runs = (NSArray *)CTLineGetGlyphRuns(line); CTRunRef runCurrent; for (int k = 0; k < runs.count; k ++) { CTRunRef run = (__bridge CTRunRef)(runs[k]); CFRange range = CTRunGetStringRange(run); NSRange rangeOC = NSMakeRange(range.location, range.length); if ([self isIndex:index inRange:rangeOC]) { runCurrent = run; break; } } //获得对应CTRun的尺寸信息 CTRunGetTypographicBounds(runCurrent, CFRangeMake(0, 0), &lineAscent, &lineDescent, NULL); //计算当前点击的CTRun高度 CGFloat height = lineAscent + lineDescent; return CGRectMake(offsetX, offsetY, offsetX2 - offsetX, height); } /** 范围检测 @param index 索引 @param range 范围 @return 范围内返回yes，否则返回no */ - (BOOL)isIndex:(NSInteger)index inRange:(NSRange)range { if ((index <= (range.location + range.length - 1)) && (index >= range.location)) { return YES; } return NO; }

- (void)dealloc
{
CFRelease(_ctFrm);
}

@end