這段時間在搞電子書,把這些天出現的問題歸總下,我還是希望電子書的格式包括返回的數據,可直觀的反應出客戶端想表達的內容;原生的體驗還是比較好的,希望對coretext再深入。 1.判斷點擊的位置是否在某個NSRange範圍內 2.通過CFRange與CTFrameRef獲取要操作(塗色,劃線)的CGR ...
這段時間在搞電子書,把這些天出現的問題歸總下,我還是希望電子書的格式包括返回的數據,可直觀的反應出客戶端想表達的內容;原生的體驗還是比較好的,希望對coretext再深入。
1.判斷點擊的位置是否在某個NSRange範圍內
#pragma mark 判斷點擊的位置是否在 range內
/**
將點擊的位置轉換成字元串的偏移量,如果沒有找到,則返回-1
view:view
point:點擊位置
frameRef:當前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);
// 獲得每一行的origin坐標
CGPoint origins[count];
CTFrameGetLineOrigins(textFrame, CFRangeMake(0,0), origins);
// 翻轉坐標系
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);
// 獲得每一行的CGRect信息
CGRect flippedRect = [self wkj_getLineBounds:line point:linePoint];
CGRect rect = CGRectApplyAffineTransform(flippedRect, transform);
if (CGRectContainsPoint(rect, point)) {
// 將點擊的坐標轉換成相對於當前行的坐標cocoapods
CGPoint relativePoint = CGPointMake(point.x-CGRectGetMinX(rect),
point.y-CGRectGetMinY(rect));
// 獲得當前點擊坐標對應的字元串偏移
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);
}
/**
此處判斷
根據上面返回的字元串的偏移量,對比range是否在點擊的位置
*/
+ (BOOL)wkj_judgeAtIndex:(CFIndex)index range:(NSRange)range {
if (NSLocationInRange(index, range)) {
///點擊處在range內
return YES;
}
return NO;
}
2.通過CFRange與CTFrameRef獲取要操作(塗色,劃線)的CGRect數組
#pragma mark 通過range獲取rect集合【用於劃線、塗色】
+ (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];
//獲取整個CTFrame的大小
CGPathRef path = CTFrameGetPath(frameRef);
CGRect frameRefRect = CGPathGetBoundingBox(path);
//獲取所有行的起點
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.塗色劃線
- (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;
///劃線時可設置高度為1 塗色是可根據字體大小設置
rect.size.height = 1;
rect.size.width -= 1.5;
CGContextFillRect(context, rect);
}
}
4.CoreText 分頁
#pragma mark 分頁
/**
CoreText 分頁
str: NSAttributedString屬性字元串
textFrame: 繪製區域
*/
+ (NSArray *)wkj_coreTextPaging:(NSAttributedString *)str textArea:(CGRect)textFrame{
///分頁NSAttributedString結果
// NSMutableArray *arrayPagingStr = [NSMutableArray array];
///分頁NSRange結果
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) {
//設置路徑
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]];
//移動
textPos += frameRange.length;
CFRelease(frame);
}
CGPathRelease(path);
CFRelease(framesetterRef);
// return arrayPagingStr;
return arrayPagingRange;
}
5.獲取繪製區域的高度
/** str:NSAttributedString 內容屬性 width: 繪製的寬度 */ + (CGFloat)coretextContentHeight:(NSAttributedString *)str width:(CGFloat)width{ //創建CTFramesetterRef CTFramesetterRef framesetterRef = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)str); // 獲得要繪製的區域高度 CGSize restrictSize = CGSizeMake(width, CGFLOAT_MAX); CGSize coreTextSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetterRef, CFRangeMake(0,0), nil, restrictSize, nil); return coreTextSize.height; }