iOS-CoreText的那些事【电子书的那些事】
这段时间在搞电子书，把这些天出现的问题归总下，我还是希望电子书的格式包括返回的数据，可直观的反应出客户端想表达的内容；原生的体验还是比较好的，希望对coretext再深入。
1.判断点击的位置是否在某个NSRange范围内
#pragma mark 判断点击的位置是否在 range内
/**
将点击的位置转换成字符串的偏移量，如果没有找到，则返回-1
view：view
point：点击位置
frameRef：当前view的frameRef
*/
+ (CFIndex)wkj_touchContentOffsetInView:(UIView *)view
point:(CGPoint)point
frameRef:(CTFrameRef)frameRef{
CTFrameRef textFrame = frameRef;
CFArrayRef lines = CTFrameGetLines(textFrame);
if (!lines) {
return -1;
}
CFIndex count = CFArrayGetCount(lines);
// 获得每一行的origin坐标
CGPoint origins[count];
CTFrameGetLineOrigins(textFrame, CFRangeMake(0,0), origins);
// 翻转坐标系
CGAffineTransform transform = CGAffineTransformMakeTranslation(0, view.bounds.size.height);
transform = CGAffineTransformScale(transform, 1.f, -1.f);
CFIndex idx = -1;
for (int i = 0; i < count; i++) {
CGPoint linePoint = origins[i];
CTLineRef line = CFArrayGetValueAtIndex(lines, i);
// 获得每一行的CGRect信息
CGRect flippedRect = [self wkj_getLineBounds:line point:linePoint];
CGRect rect = CGRectApplyAffineTransform(flippedRect, transform);
if (CGRectContainsPoint(rect, point)) {
// 将点击的坐标转换成相对于当前行的坐标cocoapods
CGPoint relativePoint = CGPointMake(point.x-CGRectGetMinX(rect),
point.y-CGRectGetMinY(rect));
// 获得当前点击坐标对应的字符串偏移
idx = CTLineGetStringIndexForPosition(line, relativePoint);
}
}
return idx;
}
+ (CGRect)wkj_getLineBounds:(CTLineRef)line point:(CGPoint)point {
CGFloat ascent = 0.0f;
CGFloat descent = 0.0f;
CGFloat leading = 0.0f;
CGFloat width = (CGFloat)CTLineGetTypographicBounds(line, &ascent, &descent, &leading);
CGFloat height = ascent + descent;
return CGRectMake(point.x, point.y - descent, width, height);
}
/**
此处判断
根据上面返回的字符串的偏移量，对比range是否在点击的位置
*/
+ (BOOL)wkj_judgeAtIndex:(CFIndex)index range:(NSRange)range {
if (NSLocationInRange(index, range)) {
///点击处在range内
return YES;
}
return NO;
}
2.通过CFRange与CTFrameRef获取要操作（涂色，划线）的CGRect数组
#pragma mark 通过range获取rect集合【用于划线、涂色】
+ (NSArray*)wkj_frameGetFrameOfStringInRange:(CTFrameRef)frameRef range:(CFRange)range{
CFRange frameRefRange = CTFrameGetStringRange(frameRef);
range = [self wkj_cfRangeInsection:frameRefRange range:range];
if ([self wkj_cfRangeEqualToRange:range range:CFRangeZero]) {
return nil;
}
NSArray *lines = (NSArray*)CTFrameGetLines(frameRef);
NSInteger lineCount = [lines count];
//获取整个CTFrame的大小
CGPathRef path = CTFrameGetPath(frameRef);
CGRect frameRefRect = CGPathGetBoundingBox(path);
//获取所有行的起点
CGPoint *origins = (CGPoint*)malloc(lineCount * sizeof(CGPoint));
CTFrameGetLineOrigins(frameRef, CFRangeMake(0, 0), origins);
NSMutableArray *rects = [NSMutableArray array];
for (CFIndex index = 0; index<lines.count; index++) {
CTLineRef line = (__bridge CTLineRef)[lines objectAtIndex:index];
CFRange rangeOfLine = CTLineGetStringRange(line);
CFRange rangeOfInsection = [self wkj_cfRangeInsection:rangeOfLine range:range];
if (![self wkj_cfRangeEqualToRange:rangeOfInsection range:CFRangeZero]) {
CGRect frame = [self wkj_lineGetFrame:line point:origins[index] range:rangeOfInsection];
frame = CGRectOffset(frame, frameRefRect.origin.x, frameRefRect.origin.y);
[rects addObject:[NSValue valueWithCGRect:frame]];
}
}
free(origins);
return [rects copy];
}
+ (CGRect)wkj_lineGetFrame:(CTLineRef)line
point:(CGPoint)origin
range:(CFRange)range{
CFRange lineRange = CTLineGetStringRange(line);
range = [self wkj_cfRangeInsection:lineRange range:range];
CGFloat trailingWhitespaceWidth = CTLineGetTrailingWhitespaceWidth(line);
if ([self wkj_cfRangeGetEndLocation:range]==[self wkj_cfRangeGetEndLocation:lineRange]&&trailingWhitespaceWidth>0) {
--range.length;
}
CGFloat xStart = CTLineGetOffsetForStringIndex(line, range.location, NULL);
CGFloat xEnd = CTLineGetOffsetForStringIndex(line, [self wkj_cfRangeGetEndLocation:range]+1, NULL);
CGFloat ascent, descent, leading;
CTLineGetTypographicBounds(line, &ascent, &descent, &leading);
CGRect selectionRect = CGRectMake(origin.x + xStart,
origin.y - descent,
xEnd - xStart,
ascent + descent + leading);
return selectionRect;
}
+ (CFRange)wkj_cfRangeInsection:(CFRange)range1 range:(CFRange)range2{
if ([self wkj_cfRangeGreaterThanRange:range1 range:range2]||[self wkj_cfRangeGreaterThanRange:range2 range:range1]) {
return CFRangeZero;
}
CFIndex beginLocation = MAX(range1.location, range2.location);
CFIndex endLocation = MIN([self wkj_cfRangeGetEndLocation:range1], [self wkj_cfRangeGetEndLocation:range2]);
return [self wkj_cfRangeMakeWithInterval:beginLocation endIndex:endLocation];
}
+ (BOOL)wkj_cfRangeGreaterThanRange:(CFRange)range1 range:(CFRange)range2{
return range1.location>[self wkj_cfRangeGetEndLocation:range2];
}
+ (CFIndex)wkj_cfRangeGetEndLocation:(CFRange)range{
return range.location+range.length-1;
}
+ (CFRange)wkj_cfRangeMakeWithInterval:(CFIndex)startIndex endIndex:(CFIndex)endIndex{
return CFRangeMake(startIndex, endIndex - startIndex + 1);
}
+ (BOOL)wkj_cfRangeEqualToRange:(CFRange)range1 range:(CFRange)range2{
return range1.location == range2.location&&range1.length==range2.length;
}
3.涂色划线
- (void)wkj_drawLineForSelectArea{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [[UIColor redColor] colorWithAlphaComponent:0.3].CGColor);
for (NSValue *rectValue in _arraySelectRect) {
CGRect rect = [rectValue CGRectValue];
rect.origin.y -= 2.5;
///划线时可设置高度为1 涂色是可根据字体大小设置
rect.size.height = 1;
rect.size.width -= 1.5;
CGContextFillRect(context, rect);
}
}
4.CoreText 分页
#pragma mark 分页
/**
CoreText 分页
str: NSAttributedString属性字符串
textFrame: 绘制区域
*/
+ (NSArray *)wkj_coreTextPaging:(NSAttributedString *)str textArea:(CGRect)textFrame{
///分页NSAttributedString结果
// NSMutableArray *arrayPagingStr = [NSMutableArray array];
///分页NSRange结果
NSMutableArray *arrayPagingRange = [NSMutableArray array];
CFAttributedStringRef cfStrRef = (__bridge CFAttributedStringRef)str;
CTFramesetterRef framesetterRef = CTFramesetterCreateWithAttributedString(cfStrRef);
CGPathRef path = CGPathCreateWithRect(textFrame, NULL);
int textPos = 0;
NSUInteger strLength = [str length];
while (textPos < strLength) {
//设置路径
CTFrameRef frame = CTFramesetterCreateFrame(framesetterRef, CFRangeMake(textPos, 0), path, NULL);
CFRange frameRange = CTFrameGetVisibleStringRange(frame);
NSRange range = NSMakeRange(frameRange.location, frameRange.length);
[arrayPagingRange addObject:[NSValue valueWithRange:range]];
// [arrayPagingStr addObject:[str attributedSubstringFromRange:range]];
//移动
textPos += frameRange.length;
CFRelease(frame);
}
CGPathRelease(path);
CFRelease(framesetterRef);
// return arrayPagingStr;
return arrayPagingRange;
}
5.获取绘制区域的高度
/** str:NSAttributedString 内容属性 width: 绘制的宽度 */ + (CGFloat)coretextContentHeight:(NSAttributedString *)str width:(CGFloat)width{ //创建CTFramesetterRef CTFramesetterRef framesetterRef = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)str); // 获得要绘制的区域高度 CGSize restrictSize = CGSizeMake(width, CGFLOAT_MAX); CGSize coreTextSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetterRef, CFRangeMake(0,0), nil, restrictSize, nil); return coreTextSize.height; }
项目笔记
#import "BookDataTool.h" #import "CoreTextDataModel.h" @implementation BookDataTool /** CoreText 分页 str: NSAttributedString属性字符串 textFrame: 绘制区域 */ + (NSArray *)wkj_coreTextPaging:(NSAttributedString *)str textArea:(CGRect)textFrame{ // textFrame.size.height = textFrame.size.height; ///分页NSAttributedString结果 // NSMutableArray *arrayPagingStr = [NSMutableArray array]; ///分页NSRange结果 NSMutableArray *arrayCoretext = [NSMutableArray array]; CFAttributedStringRef cfStrRef = (__bridge CFAttributedStringRef)str; CTFramesetterRef framesetterRef = CTFramesetterCreateWithAttributedString(cfStrRef); CGPathRef path = CGPathCreateWithRect(textFrame, NULL); int textPos = 0; NSUInteger strLength = [str length]; while (textPos < strLength) { //设置路径 CTFrameRef frame = CTFramesetterCreateFrame(framesetterRef, CFRangeMake(textPos, 0), path, NULL); CFRange frameRange = CTFrameGetVisibleStringRange(frame); NSRange range = NSMakeRange(frameRange.location, frameRange.length); // [arrayPagingRange addObject:[NSValue valueWithRange:range]]; // [arrayPagingStr addObject:[str attributedSubstringFromRange:range]]; CoreTextDataModel *model = [[CoreTextDataModel alloc]init]; model.ctFrame = frame; model.range = range; model.content = [str attributedSubstringFromRange:range]; [arrayCoretext addObject:model]; //移动 textPos += frameRange.length; CFRelease(frame); } CGPathRelease(path); CFRelease(framesetterRef); // return arrayPagingStr; return arrayCoretext; } ///获取属性字符串 + (NSAttributedString *)wkj_loadTemplateFile:(NSString *)path{ NSMutableAttributedString *resultAtt = [[NSMutableAttributedString alloc] init]; NSData *data = [NSData dataWithContentsOfFile:path]; if (data) { NSArray *array = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil]; if ([array isKindOfClass:[NSArray class]]) { for (NSDictionary *dic in array) { if ([dic[@"type"] isEqualToString:@"txt"]) { NSAttributedString *att = [self parseAttributedContentFromDictionary:dic]; [resultAtt appendAttributedString:att]; } } } } return resultAtt; } ///获取属性字符串 + (NSAttributedString *)parseAttributedContentFromDictionary:(NSDictionary *)dict{ NSMutableDictionary *attributes = [self attributes]; if ([dict[@"type1"] isEqualToString:@"0"]) { CTFontRef fontRef = CTFontCreateWithName((CFStringRef)@"ArialMT", 35, NULL); attributes[(id)kCTFontAttributeName] = (__bridge id)fontRef; CFRelease(fontRef); } NSString *content = dict[@"content"]; return [[NSAttributedString alloc] initWithString:content attributes:attributes]; } ///获取属性字符串字典 + (NSMutableDictionary *)attributes{ CGFloat fontSize = [BookThemeManager sharedManager].fontSize; CTFontRef fontRef = CTFontCreateWithName((CFStringRef)@"ArialMT", fontSize, NULL); CGFloat lineSpacing = [BookThemeManager sharedManager].lineSpace; const CFIndex kNumberOfSettings = 3; CTParagraphStyleSetting theSettings[kNumberOfSettings] = { { kCTParagraphStyleSpecifierLineSpacingAdjustment, sizeof(CGFloat), &lineSpacing }, { kCTParagraphStyleSpecifierMaximumLineSpacing, sizeof(CGFloat), &lineSpacing }, { kCTParagraphStyleSpecifierMinimumLineSpacing, sizeof(CGFloat), &lineSpacing } }; CTParagraphStyleRef theParagraphRef = CTParagraphStyleCreate(theSettings, kNumberOfSettings); UIColor * textColor = [BookThemeManager sharedManager].textColor; NSMutableDictionary * dict = [NSMutableDictionary dictionary]; dict[(id)kCTForegroundColorAttributeName] = (id)textColor.CGColor; dict[(id)kCTFontAttributeName] = (__bridge id)fontRef; dict[(id)kCTParagraphStyleAttributeName] = (__bridge id)theParagraphRef; CFRelease(theParagraphRef); CFRelease(fontRef); return dict; } @end
