Show attributedString as PDF - ios

I want to show a NSAttributedString in a PDF document.
Creating the PDF is working well but there is only plain text without any attributes.
If I change:
CFAttributedStringRef currentText = CFAttributedStringCreateCopy(NULL,(__bridge CFAttributedStringRef)**enterText.text**);
to"
CFAttributedStringRef currentText = CFAttributedStringCreateCopy(NULL,(__bridge CFAttributedStringRef)**enterText.attributedText**);
the code is not working anymore.
Thats the code a actually wrote:
- (IBAction)createPDF:(id)sender {
//Get Document Directory path
NSArray * dirPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
//Define path for PDF file
documentPath = [[dirPath objectAtIndex:0] stringByAppendingPathComponent:#"/Editortext.pdf"];
// Prepare the text using a Core Text Framesetter.
CFAttributedStringRef currentText = CFAttributedStringCreateCopy(NULL,(__bridge CFAttributedStringRef)enterText.text);
if (currentText) {
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(currentText);
if (framesetter) {
// Create the PDF context using the default page size of 612 x 792.
UIGraphicsBeginPDFContextToFile(documentPath, CGRectZero, nil);
CFRange currentRange = CFRangeMake(0, 0);
NSInteger currentPage = 0;
BOOL done = NO;
do {
// Mark the beginning of a new page.
UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, 612, 792), nil);
// Draw a page number at the bottom of each page.
currentPage++;
[self drawPageNbr:currentPage];
// Render the current page and update the current range to
// point to the beginning of the next page.
currentRange = *[self updatePDFPage:currentPage setTextRange:&currentRange setFramesetter:&framesetter];
// If we're at the end of the text, exit the loop.
if (currentRange.location == CFAttributedStringGetLength((CFAttributedStringRef)currentText))
done = YES;
} while (!done);
// Close the PDF context and write the contents out.
UIGraphicsEndPDFContext();
// Release the framewetter.
CFRelease(framesetter);
// [self pdfsenden];
} else {
NSLog(#"Could not create the framesetter..");
}
// Release the attributed string.
CFRelease(currentText);
} else {
NSLog(#"currentText could not be created");
}
}
-(CFRange*)updatePDFPage:(int)pageNumber setTextRange:(CFRange*)pageRange setFramesetter:(CTFramesetterRef*)framesetter
{
// Get the graphics context.
CGContextRef currentContext = UIGraphicsGetCurrentContext();
// Put the text matrix into a known state. This ensures
// that no old scaling factors are left in place.
CGContextSetTextMatrix(currentContext, CGAffineTransformIdentity);
// Create a path object to enclose the text. Use 72 point
// margins all around the text.
CGRect frameRect = CGRectMake(72, 72, 468, 648);
CGMutablePathRef framePath = CGPathCreateMutable();
CGPathAddRect(framePath, NULL, frameRect);
// Get the frame that will do the rendering.
// The currentRange variable specifies only the starting point. The framesetter
// lays out as much text as will fit into the frame.
CTFrameRef frameRef = CTFramesetterCreateFrame(*framesetter, *pageRange,
framePath, NULL);
CGPathRelease(framePath);
// Core Text draws from the bottom-left corner up, so flip
// the current transform prior to drawing.
CGContextTranslateCTM(currentContext, 0, 792);
CGContextScaleCTM(currentContext, 1.0, -1.0);
// Draw the frame.
CTFrameDraw(frameRef, currentContext);
// Update the current range based on what was drawn.
*pageRange = CTFrameGetVisibleStringRange(frameRef);
pageRange->location += pageRange->length;
pageRange->length = 0;
CFRelease(frameRef);
return pageRange;
}
Thanks for help!

It seems like it a bug in iOS7. Follow the bellow threads.
Stackoverflow Thread,
Another Thread

Related

Add UIImage at End of PDF

I used Apple's documentation to create a Multi-page PDF. I need to place a UIImage underneath the text that is rendered in the PDF. Here's what I have so far:
UIGraphicsBeginPDFContextToFile(pdfFileName, CGRectZero, nil);
pageSize = CGSizeMake(612, 792);
CFRange currentRange = CFRangeMake(0, 0);
NSInteger currentPage = 0;
BOOL done = NO;
do {
UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil);
currentPage++;
[self drawPageNumber:currentPage];
[self drawHeader];
currentRange = [self renderPage:currentPage withTextRange:currentRange andFramesetter:framesetter];
// If we're at the end of the text, exit the loop.
if (currentRange.location == CFAttributedStringGetLength((CFAttributedStringRef)currentText))
done = YES;
}
while (!done);
Then, I add an image in a separate PDF page:
UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil);
currentPage++;
[self drawPageNumber:currentPage];
[self drawHeader];
[self drawImages];
// Close the PDF context and write the contents out.
UIGraphicsEndPDFContext();
However, if there is very little text on the PDF that is created, there will be a lot of unfilled white space. I need to place the image at the bottom of the current PDF if there is space, and create a new PDF if not. So, I need to check for a "y" position of the text.
How would I do that?

CATextLayer blurry text after rotation

I have problem related with question
I've set contentsScale and after that text looking good but if I apply the 3d rotation transformation the text comes out blurry.
image here
initialization code
// init text
textLayer_ = [CATextLayer layer];
…
textLayer_.contentsScale = [[UIScreen mainScreen] scale];
// init body path
pathLayer_ = [CAShapeLayer layer];
…
[pathLayer_ addSublayer:textLayer_];
rotation code
// make the mirror
pathLayer_.transform = CATransform3DRotate(pathLayer_.transform, M_PI, 0, 1, 0);
textLayer_.transform = CATransform3DRotate(textLayer_.transform, M_PI, 0, 1, 0);
[textLayer_ setNeedsDisplay];
For test i've rotated text separately during the initialization.
// init text
textLayer_ = [CATextLayer layer];
…
textLayer_.transform = CATransform3DRotate(textLayer_.transform, M_PI, 0, 1, 0);
textLayer_.contentsScale = [[UIScreen mainScreen] scale];
Text can be rotated and remains clear
image here
Rasterizing
What's probably happening here is that it decides it has to render the textLayer to pixels. Note the warning for shouldRasterize in the CALayer Class Reference:
When the value of this property is NO, the layer is composited directly into the destination whenever possible. The layer may still be rasterized prior to compositing if certain features of the compositing model (such as the inclusion of filters) require it.
So, CATextLayer may suddenly decide to rasterize. It decides to rasterize if it's a sublayer of a rotated layer. So, don't make that happen.
Single-Sided Layers
That takes you back to your solution that causes the reversed text. You can prevent this by turning off doubleSided on the text layers. Your signs will now be blank on the far side, so add a second text layer, rotated 180 degrees relative to the first.
Declare two text layers:
#property (retain) CAShapeLayer *pathLayer;
#property (retain) CATextLayer *textLayerFront;
#property (retain) CATextLayer *textLayerBack;
Then, initialize them to be single-sided, with the back layer rotated 180 degrees:
CAShapeLayer *pathLayer = [CAShapeLayer layer];
// Also need to store a UIBezierPath in the pathLayer.
CATextLayer *textLayerFront = [CATextLayer layer];
textLayerFront.doubleSided = NO;
textLayerFront.string = #"Front";
textLayerFront.contentsScale = [[UIScreen mainScreen] scale];
CATextLayer *textLayerBack = [CATextLayer layer];
textLayerBack.doubleSided = NO;
// Eventually both sides will have the same text, but for demonstration purposes we will label them differently.
textLayerBack.string = #"Back";
// Rotate the back layer 180 degrees relative to the front layer.
textLayerBack.transform = CATransform3DRotate(textLayerBack.transform, M_PI, 0, 1, 0);
textLayerBack.contentsScale = [[UIScreen mainScreen] scale];
// Make all the layers siblings. These means they must all be rotated independently of each other.
// The layers can flicker if their Z position is close to the background, so move them forward.
// This will not work if the main layer has a perspective transform on it.
textLayerFront.zPosition = 256;
textLayerBack.zPosition = 256;
// It would make sense to make the text layers siblings of the path layer, but this seems to mean they get pre-rendered, blurring them.
[self.layer addSublayer:pathLayer];
[self.layer addSublayer:textLayerBack];
[self.layer addSublayer:textLayerFront];
// Store the layers constructed at this time for later use.
[self setTextLayerFront:textLayerFront];
[self setTextLayerBack:textLayerBack];
[self setPathLayer:pathLayer];
You can then rotate the layers. They will appear correct as long as you always rotate by the same amount.
CGFloat angle = M_PI;
self.pathLayer.transform = CATransform3DRotate(self.pathLayer.transform, angle, 0, 1, 0);
self.textLayerFront.transform = CATransform3DRotate(self.textLayerFront.transform, angle, 0, 1, 0);
self.textLayerBack.transform = CATransform3DRotate(self.textLayerBack.transform, angle, 0, 1, 0);
You should then find that you can rotate your sign to any angle while the text remains sharp.
Text to Path
There is an alternative, if you really need to manipulate your text display in ways that cause CATextLayer to rasterize: convert the text to a UIBezierPath representation. This can then be placed in a CAShapeLayer. Doing so requires delving deep into Core Text, but the results are powerful. For example, you can animate the text being drawn.
// - (UIBezierPath*) bezierPathWithString:(NSString*) string font:(UIFont*) font inRect:(CGRect) rect;
// Requires CoreText.framework
// This creates a graphical version of the input screen, line wrapped to the input rect.
// Core Text involves a whole hierarchy of objects, all requiring manual management.
- (UIBezierPath*) bezierPathWithString:(NSString*) string font:(UIFont*) font inRect:(CGRect) rect;
{
UIBezierPath *combinedGlyphsPath = nil;
CGMutablePathRef combinedGlyphsPathRef = CGPathCreateMutable();
if (combinedGlyphsPathRef)
{
// It would be easy to wrap the text into a different shape, including arbitrary bezier paths, if needed.
UIBezierPath *frameShape = [UIBezierPath bezierPathWithRect:rect];
// If the font name wasn't found while creating the font object, the result is a crash.
// Avoid this by falling back to the system font.
CTFontRef fontRef;
if ([font fontName])
fontRef = CTFontCreateWithName((__bridge CFStringRef) [font fontName], [font pointSize], NULL);
else if (font)
fontRef = CTFontCreateUIFontForLanguage(kCTFontUserFontType, [font pointSize], NULL);
else
fontRef = CTFontCreateUIFontForLanguage(kCTFontUserFontType, [UIFont systemFontSize], NULL);
if (fontRef)
{
CGPoint basePoint = CGPointMake(0, CTFontGetAscent(fontRef));
CFStringRef keys[] = { kCTFontAttributeName };
CFTypeRef values[] = { fontRef };
CFDictionaryRef attributesRef = CFDictionaryCreate(NULL, (const void **)&keys, (const void **)&values,
sizeof(keys) / sizeof(keys[0]), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
if (attributesRef)
{
CFAttributedStringRef attributedStringRef = CFAttributedStringCreate(NULL, (__bridge CFStringRef) string, attributesRef);
if (attributedStringRef)
{
CTFramesetterRef frameSetterRef = CTFramesetterCreateWithAttributedString(attributedStringRef);
if (frameSetterRef)
{
CTFrameRef frameRef = CTFramesetterCreateFrame(frameSetterRef, CFRangeMake(0,0), [frameShape CGPath], NULL);
if (frameRef)
{
CFArrayRef lines = CTFrameGetLines(frameRef);
CFIndex lineCount = CFArrayGetCount(lines);
CGPoint lineOrigins[lineCount];
CTFrameGetLineOrigins(frameRef, CFRangeMake(0, lineCount), lineOrigins);
for (CFIndex lineIndex = 0; lineIndex<lineCount; lineIndex++)
{
CTLineRef lineRef = CFArrayGetValueAtIndex(lines, lineIndex);
CGPoint lineOrigin = lineOrigins[lineIndex];
CFArrayRef runs = CTLineGetGlyphRuns(lineRef);
CFIndex runCount = CFArrayGetCount(runs);
for (CFIndex runIndex = 0; runIndex<runCount; runIndex++)
{
CTRunRef runRef = CFArrayGetValueAtIndex(runs, runIndex);
CFIndex glyphCount = CTRunGetGlyphCount(runRef);
CGGlyph glyphs[glyphCount];
CGSize glyphAdvances[glyphCount];
CGPoint glyphPositions[glyphCount];
CFRange runRange = CFRangeMake(0, glyphCount);
CTRunGetGlyphs(runRef, CFRangeMake(0, glyphCount), glyphs);
CTRunGetPositions(runRef, runRange, glyphPositions);
CTFontGetAdvancesForGlyphs(fontRef, kCTFontDefaultOrientation, glyphs, glyphAdvances, glyphCount);
for (CFIndex glyphIndex = 0; glyphIndex<glyphCount; glyphIndex++)
{
CGGlyph glyph = glyphs[glyphIndex];
// For regular UIBezierPath drawing, we need to invert around the y axis.
CGAffineTransform glyphTransform = CGAffineTransformMakeTranslation(lineOrigin.x+glyphPositions[glyphIndex].x, rect.size.height-lineOrigin.y-glyphPositions[glyphIndex].y);
glyphTransform = CGAffineTransformScale(glyphTransform, 1, -1);
CGPathRef glyphPathRef = CTFontCreatePathForGlyph(fontRef, glyph, &glyphTransform);
if (glyphPathRef)
{
// Finally carry out the appending.
CGPathAddPath(combinedGlyphsPathRef, NULL, glyphPathRef);
CFRelease(glyphPathRef);
}
basePoint.x += glyphAdvances[glyphIndex].width;
basePoint.y += glyphAdvances[glyphIndex].height;
}
}
basePoint.x = 0;
basePoint.y += CTFontGetAscent(fontRef) + CTFontGetDescent(fontRef) + CTFontGetLeading(fontRef);
}
CFRelease(frameRef);
}
CFRelease(frameSetterRef);
}
CFRelease(attributedStringRef);
}
CFRelease(attributesRef);
}
CFRelease(fontRef);
}
// Casting a CGMutablePathRef to a CGPathRef seems to be the only way to convert what was just built into a UIBezierPath.
combinedGlyphsPath = [UIBezierPath bezierPathWithCGPath:(CGPathRef) combinedGlyphsPathRef];
CGPathRelease(combinedGlyphsPathRef);
}
return combinedGlyphsPath;
}
Here is rotating outlined text, created with the method above. It was also possible to add perspective without the z positions of the text layers becoming apparent.
This worked for me:
myTextLayer.contentsScale = UIScreen.mainScreen.scale;
The text will render crisp even when transformed.

Dynamically change view height with Core Text

I have a view in which I want to draw a text with Text Core (on the iPad). When text grown up I'd like to increase a height of the view, but I don't know how to calculate needed height of frame.
I use it to draw a text in drawRect method:
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextTranslateCTM(context, 0, self.bounds.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)currentTexts);
CGMutablePathRef textPath = CGPathCreateMutable();
CGRect textRect = CGRectMake(PADDING, PADDING, self.frame.size.width - 2 * PADDING, self.frame.size.height - 2 * PADDING);
CGPathAddRect(textPath, NULL, textRect);
CTFrameRef textFrame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), textPath, NULL);
CTFrameDraw(textFrame, context);
CFRelease(textFrame);
CGPathRelease(textPath);
CFRelease(framesetter);
I tried to get a height of text using sizeWithFont and also that:
- (CGSize) measureFrame: (CTFrameRef) frame
{
CGPathRef framePath = CTFrameGetPath(frame);
CGRect frameRect = CGPathGetBoundingBox(framePath);
CFArrayRef lines = CTFrameGetLines(frame);
CFIndex numLines = CFArrayGetCount(lines);
CGFloat maxWidth = 0;
CGFloat textHeight = 0;
// Now run through each line determining the maximum width of all the lines.
// We special case the last line of text. While we've got it's descent handy,
// we'll use it to calculate the typographic height of the text as well.
CFIndex lastLineIndex = numLines - 1;
for(CFIndex index = 0; index < numLines; index++)
{
CGFloat ascent, descent, leading, width;
CTLineRef line = (CTLineRef) CFArrayGetValueAtIndex(lines, index);
width = CTLineGetTypographicBounds(line, &ascent, &descent, &leading);
if(width > maxWidth)
{
maxWidth = width;
}
if(index == lastLineIndex)
{
// Get the origin of the last line. We add the descent to this
// (below) to get the bottom edge of the last line of text.
CGPoint lastLineOrigin;
CTFrameGetLineOrigins(frame, CFRangeMake(lastLineIndex, 1), &lastLineOrigin);
// The height needed to draw the text is from the bottom of the last line
// to the top of the frame.
textHeight = CGRectGetMaxY(frameRect) - lastLineOrigin.y + descent;
}
}
// For some text the exact typographic bounds is a fraction of a point too
// small to fit the text when it is put into a context. We go ahead and round
// the returned drawing area up to the nearest point. This takes care of the
// discrepencies.
return CGSizeMake(ceil(maxWidth), ceil(textHeight));
}
I use that to create an attrubuted string:
CTParagraphStyleSetting setting[1] = {
{kCTParagraphStyleSpecifierMinimumLineSpacing, sizeof(CGFloat), &minimumLineSpacing}
};
CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(setting, 1);
NSDictionary *attr = [NSDictionary dictionaryWithObjectsAndKeys:
(id)textColor.CGColor, kCTForegroundColorAttributeName,
(id)currentFont, kCTFontAttributeName,
(id)paragraphStyle, kCTParagraphStyleAttributeName,
nil];
When I use sizeWithFont, at the begin everything is ok, but when text has more lines, the frame is bigger and bigger than a text and I want it to fit exactly the text. How can I make it?
To calculate the height of the text, have you tried using CTFramesetterSuggestFrameSizeWithConstraints ?
http://foobarpig.com/iphone/using-ctframesettersuggestframesizewithconstraints-and-sizewithfont-to-calculate-text-height.html

Multi-line NSAttributedString with truncated text

I need a UILabel subcass with multiline attributed text with support for links, bold styles, etc. I also need tail truncation with an ellipsis. None of the open source code that supports attributed text inside UILabels (TTTAttributedLabel, OHAttributedLabel, TTStyledTextLabel) seem to support tail truncation for multi-line text. Is there an easy way to get this?
Maybe I'm missing something, but whats wrong with? :
NSMutableAttributedString *text = [[NSMutableAttributedString alloc] initWithString:#"test"];
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
style.lineBreakMode = NSLineBreakByTruncatingTail;
[text addAttribute:NSParagraphStyleAttributeName
value:style
range:NSMakeRange(0, text.length)];
label.attributedText = text;
This works perfectly and will add a ellipsis to the end.
Hi I am the developer of OHAttributedLabel.
There is no easy way to achieve this (as explained in the associated issue I opened on the github repository of my project), because CoreText does not offer such feature.
The only way to do this would be to implement the text layout yourself using CoreText objects (CTLine, etc) instead of using the CTFrameSetter that does this for you (but w/o managing line truncation). The idea would be to build all the CTLines to lay them out (depending on the glyphs in your NSAttributedString it contains and the word wrapping policy) one after the other and manage the ellipsis at the end yourself.
I would really appreciate if someone propose a solution to do this propery as it seems a bit of work to do and you have to manage a range of special/unusual cases too (emoji cases, fonts with odd metrics and unusual glyphs, vertical alignment, take into account the size of the ellipsis itself at the end to know when to stop).
So feel free to dig around and try to implement the framing of the lines yourself it would be really appreciated!
Based on what I found here and over at https://groups.google.com/forum/?fromgroups=#!topic/cocoa-unbound/Qin6gjYj7XU, I came up with the following which works very well.
- (void)drawString:(CFAttributedStringRef)attString inRect:(CGRect)frameRect inContext: (CGContextRef)context
{
CGContextSaveGState(context);
// Flip the coordinate system
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextTranslateCTM(context, 0, self.bounds.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGFloat height = self.frame.size.height;
frameRect.origin.y = (height - frameRect.origin.y) - frameRect.size.height ;
// Create a path to render text in
// don't set any line break modes, etc, just let the frame draw as many full lines as will fit
CGMutablePathRef framePath = CGPathCreateMutable();
CGPathAddRect(framePath, nil, frameRect);
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attString);
CFRange fullStringRange = CFRangeMake(0, CFAttributedStringGetLength(attString));
CTFrameRef aFrame = CTFramesetterCreateFrame(framesetter, fullStringRange, framePath, NULL);
CFRelease(framePath);
CFArrayRef lines = CTFrameGetLines(aFrame);
CFIndex count = CFArrayGetCount(lines);
CGPoint *origins = malloc(sizeof(CGPoint)*count);
CTFrameGetLineOrigins(aFrame, CFRangeMake(0, count), origins);
// note that we only enumerate to count-1 in here-- we draw the last line separately
for (CFIndex i = 0; i < count-1; i++)
{
// draw each line in the correct position as-is
CGContextSetTextPosition(context, origins[i].x + frameRect.origin.x, origins[i].y + frameRect.origin.y);
CTLineRef line = (CTLineRef)CFArrayGetValueAtIndex(lines, i);
CTLineDraw(line, context);
}
// truncate the last line before drawing it
if (count) {
CGPoint lastOrigin = origins[count-1];
CTLineRef lastLine = CFArrayGetValueAtIndex(lines, count-1);
// truncation token is a CTLineRef itself
CFRange effectiveRange;
CFDictionaryRef stringAttrs = CFAttributedStringGetAttributes(attString, 0, &effectiveRange);
CFAttributedStringRef truncationString = CFAttributedStringCreate(NULL, CFSTR("\u2026"), stringAttrs);
CTLineRef truncationToken = CTLineCreateWithAttributedString(truncationString);
CFRelease(truncationString);
// now create the truncated line -- need to grab extra characters from the source string,
// or else the system will see the line as already fitting within the given width and
// will not truncate it.
// range to cover everything from the start of lastLine to the end of the string
CFRange rng = CFRangeMake(CTLineGetStringRange(lastLine).location, 0);
rng.length = CFAttributedStringGetLength(attString) - rng.location;
// substring with that range
CFAttributedStringRef longString = CFAttributedStringCreateWithSubstring(NULL, attString, rng);
// line for that string
CTLineRef longLine = CTLineCreateWithAttributedString(longString);
CFRelease(longString);
CTLineRef truncated = CTLineCreateTruncatedLine(longLine, frameRect.size.width, kCTLineTruncationEnd, truncationToken);
CFRelease(longLine);
CFRelease(truncationToken);
// if 'truncated' is NULL, then no truncation was required to fit it
if (truncated == NULL)
truncated = (CTLineRef)CFRetain(lastLine);
// draw it at the same offset as the non-truncated version
CGContextSetTextPosition(context, lastOrigin.x + frameRect.origin.x, lastOrigin.y + frameRect.origin.y);
CTLineDraw(truncated, context);
CFRelease(truncated);
}
free(origins);
CGContextRestoreGState(context);
}
Heres a Swift 5 version of #Toydor's answer:
let attributedString = NSMutableAttributedString(string: "my String")
let style: NSMutableParagraphStyle = NSMutableParagraphStyle()
style.lineBreakMode = .byTruncatingTail
attributedString.addAttribute(NSAttributedString.Key.paragraphStyle,
value: style,
range: NSMakeRange(0, attributedString.length))
I haven't tried this in all cases, but something like this could work for truncation:
NSAttributedString *string = self.attributedString;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CFAttributedStringRef attributedString = (__bridge CFTypeRef)string;
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attributedString);
CGPathRef path = CGPathCreateWithRect(self.bounds, NULL);
CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), path, NULL);
BOOL needsTruncation = CTFrameGetVisibleStringRange(frame).length < string.length;
CFArrayRef lines = CTFrameGetLines(frame);
NSUInteger lineCount = CFArrayGetCount(lines);
CGPoint *origins = malloc(sizeof(CGPoint) * lineCount);
CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), origins);
for (NSUInteger i = 0; i < lineCount; i++) {
CTLineRef line = CFArrayGetValueAtIndex(lines, i);
CGPoint point = origins[i];
CGContextSetTextPosition(context, point.x, point.y);
BOOL truncate = (needsTruncation && (i == lineCount - 1));
if (!truncate) {
CTLineDraw(line, context);
}
else {
NSDictionary *attributes = [string attributesAtIndex:string.length-1 effectiveRange:NULL];
NSAttributedString *token = [[NSAttributedString alloc] initWithString:#"\u2026" attributes:attributes];
CFAttributedStringRef tokenRef = (__bridge CFAttributedStringRef)token;
CTLineRef truncationToken = CTLineCreateWithAttributedString(tokenRef);
double width = CTLineGetTypographicBounds(line, NULL, NULL, NULL) - CTLineGetTrailingWhitespaceWidth(line);
CTLineRef truncatedLine = CTLineCreateTruncatedLine(line, width-1, kCTLineTruncationEnd, truncationToken);
if (truncatedLine) { CTLineDraw(truncatedLine, context); }
else { CTLineDraw(line, context); }
if (truncationToken) { CFRelease(truncationToken); }
if (truncatedLine) { CFRelease(truncatedLine); }
}
}
free(origins);
CGPathRelease(path);
CFRelease(frame);
CFRelease(framesetter);
Multi Line Vertical Glyph With Truncated. Swift3 and Swift4 version.
Add: Xcode9.1 Swift4 Compatibility. ( use block "#if swift(>=4.0)" )
class MultiLineVerticalGlyphWithTruncated: UIView, SimpleVerticalGlyphViewProtocol {
var text:String!
var font:UIFont!
var isVertical:Bool!
func setupProperties(text: String?, font:UIFont?, isVertical:Bool) {
self.text = text ?? ""
self.font = font ?? UIFont.systemFont(ofSize: UIFont.systemFontSize)
self.isVertical = isVertical
}
override func draw(_ rect: CGRect) {
if self.text == nil {
return
}
// Create NSMutableAttributedString
let attributed = NSMutableAttributedString(string: text) // if no ruby
//let attributed = text.attributedStringWithRuby() // if with ruby, Please create custom method
#if swift(>=4.0)
attributed.addAttributes([
NSAttributedStringKey.font: font,
NSAttributedStringKey.verticalGlyphForm: isVertical,
],
range: NSMakeRange(0, attributed.length))
#else
attributed.addAttributes([
kCTFontAttributeName as String: font,
kCTVerticalFormsAttributeName as String: isVertical,
],
range: NSMakeRange(0, attributed.length))
#endif
drawContext(attributed, textDrawRect: rect, isVertical: isVertical)
}
}
protocol SimpleVerticalGlyphViewProtocol {
}
extension SimpleVerticalGlyphViewProtocol {
func drawContext(_ attributed:NSMutableAttributedString, textDrawRect:CGRect, isVertical:Bool) {
guard let context = UIGraphicsGetCurrentContext() else { return }
var path:CGPath
if isVertical {
context.rotate(by: .pi / 2)
context.scaleBy(x: 1.0, y: -1.0)
path = CGPath(rect: CGRect(x: textDrawRect.origin.y, y: textDrawRect.origin.x, width: textDrawRect.height, height: textDrawRect.width), transform: nil)
}
else {
context.textMatrix = CGAffineTransform.identity
context.translateBy(x: 0, y: textDrawRect.height)
context.scaleBy(x: 1.0, y: -1.0)
path = CGPath(rect: textDrawRect, transform: nil)
}
let framesetter = CTFramesetterCreateWithAttributedString(attributed)
let frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, attributed.length), path, nil)
// Check need for truncate tail
if (CTFrameGetVisibleStringRange(frame).length as Int) < attributed.length {
// Required truncate
let linesNS: NSArray = CTFrameGetLines(frame)
let linesAO: [AnyObject] = linesNS as [AnyObject]
var lines: [CTLine] = linesAO as! [CTLine]
let boundingBoxOfPath = path.boundingBoxOfPath
let lastCTLine = lines.removeLast()
let truncateString:CFAttributedString = CFAttributedStringCreate(nil, "\u{2026}" as CFString, CTFrameGetFrameAttributes(frame))
let truncateToken:CTLine = CTLineCreateWithAttributedString(truncateString)
let lineWidth = CTLineGetTypographicBounds(lastCTLine, nil, nil, nil)
let tokenWidth = CTLineGetTypographicBounds(truncateToken, nil, nil, nil)
let widthTruncationBegins = lineWidth - tokenWidth
if let truncatedLine = CTLineCreateTruncatedLine(lastCTLine, widthTruncationBegins, .end, truncateToken) {
lines.append(truncatedLine)
}
var lineOrigins = Array<CGPoint>(repeating: CGPoint.zero, count: lines.count)
CTFrameGetLineOrigins(frame, CFRange(location: 0, length: lines.count), &lineOrigins)
for (index, line) in lines.enumerated() {
context.textPosition = CGPoint(x: lineOrigins[index].x + boundingBoxOfPath.origin.x, y:lineOrigins[index].y + boundingBoxOfPath.origin.y)
CTLineDraw(line, context)
}
}
else {
// Not required truncate
CTFrameDraw(frame, context)
}
}
}
How to use
class ViewController: UIViewController {
#IBOutlet weak var multiLineVerticalGlyphWithTruncated: MultiLineVerticalGlyphWithTruncated! // UIView
let font:UIFont = UIFont(name: "HiraMinProN-W3", size: 17.0) ?? UIFont.systemFont(ofSize: 17.0)
override func viewDidLoad() {
super.viewDidLoad()
let text = "iOS 11 sets a new standard for what is already the world’s most advanced mobile operating system. It makes iPhone better than before. It makes iPad more capable than ever. And now it opens up both to amazing possibilities for augmented reality in games and apps. With iOS 11, iPhone and iPad are the most powerful, personal, and intelligent devices they’ve ever been."
// If check for Japanese
// let text = "すでに世界で最も先進的なモバイルオペレーティングシステムであるiOSに、iOS 11が新たな基準を打ち立てます。iPhoneは今まで以上に優れたものになり、iPadはかつてないほどの能力を手に入れます。さらにこれからはどちらのデバイスにも、ゲームやアプリケーションの拡張現実のための驚くような可能性が広がります。iOS 11を搭載するiPhoneとiPadは、間違いなくこれまでで最もパワフルで、最もパーソナルで、最も賢いデバイスです。"
// if not vertical text, isVertical = false
multiLineVerticalGlyphWithTruncated.setupProperties(text: text, font: font, isVertical: true)
}
}
You may be able to use follow code to have a more simple solution.
// last line.
if (_limitToNumberOfLines && count == _numberOfLines-1)
{
// check if we reach end of text.
if (lineRange.location + lineRange.length < [_text length])
{
CFDictionaryRef dict = ( CFDictionaryRef)attributes;
CFAttributedStringRef truncatedString = CFAttributedStringCreate(NULL, CFSTR("\u2026"), dict);
CTLineRef token = CTLineCreateWithAttributedString(truncatedString);
// not possible to display all text, add tail ellipsis.
CTLineRef truncatedLine = CTLineCreateTruncatedLine(line, self.bounds.size.width - 20, kCTLineTruncationEnd, token);
CFRelease(line); line = nil;
line = truncatedLine;
}
}
I'm using MTLabel in my project and it's a really nice solution for my project.
I integrated wbyoung's solution into OHAttributedLabel drawTextInRect: method if anyone is interested:
- (void)drawTextInRect:(CGRect)aRect
{
if (_attributedText)
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSaveGState(ctx);
// flipping the context to draw core text
// no need to flip our typographical bounds from now on
CGContextConcatCTM(ctx, CGAffineTransformScale(CGAffineTransformMakeTranslation(0, self.bounds.size.height), 1.f, -1.f));
if (self.shadowColor)
{
CGContextSetShadowWithColor(ctx, self.shadowOffset, 0.0, self.shadowColor.CGColor);
}
[self recomputeLinksInTextIfNeeded];
NSAttributedString* attributedStringToDisplay = _attributedTextWithLinks;
if (self.highlighted && self.highlightedTextColor != nil)
{
NSMutableAttributedString* mutAS = [attributedStringToDisplay mutableCopy];
[mutAS setTextColor:self.highlightedTextColor];
attributedStringToDisplay = mutAS;
(void)MRC_AUTORELEASE(mutAS);
}
if (textFrame == NULL)
{
CFAttributedStringRef cfAttrStrWithLinks = (BRIDGE_CAST CFAttributedStringRef)attributedStringToDisplay;
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(cfAttrStrWithLinks);
drawingRect = self.bounds;
if (self.centerVertically || self.extendBottomToFit)
{
CGSize sz = CTFramesetterSuggestFrameSizeWithConstraints(framesetter,CFRangeMake(0,0),NULL,CGSizeMake(drawingRect.size.width,CGFLOAT_MAX),NULL);
if (self.extendBottomToFit)
{
CGFloat delta = MAX(0.f , ceilf(sz.height - drawingRect.size.height))+ 10 /* Security margin */;
drawingRect.origin.y -= delta;
drawingRect.size.height += delta;
}
if (self.centerVertically) {
drawingRect.origin.y -= (drawingRect.size.height - sz.height)/2;
}
}
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddRect(path, NULL, drawingRect);
CFRange fullStringRange = CFRangeMake(0, CFAttributedStringGetLength(cfAttrStrWithLinks));
textFrame = CTFramesetterCreateFrame(framesetter,fullStringRange, path, NULL);
CGPathRelease(path);
CFRelease(framesetter);
}
// draw highlights for activeLink
if (_activeLink)
{
[self drawActiveLinkHighlightForRect:drawingRect];
}
BOOL hasLinkFillColorSelector = [self.delegate respondsToSelector:#selector(attributedLabel:fillColorForLink:underlineStyle:)];
if (hasLinkFillColorSelector) {
[self drawInactiveLinkHighlightForRect:drawingRect];
}
if (self.truncLastLine) {
CFArrayRef lines = CTFrameGetLines(textFrame);
CFIndex count = MIN(CFArrayGetCount(lines),floor(self.size.height/self.font.lineHeight));
CGPoint *origins = malloc(sizeof(CGPoint)*count);
CTFrameGetLineOrigins(textFrame, CFRangeMake(0, count), origins);
// note that we only enumerate to count-1 in here-- we draw the last line separately
for (CFIndex i = 0; i < count-1; i++)
{
// draw each line in the correct position as-is
CGContextSetTextPosition(ctx, origins[i].x + drawingRect.origin.x, origins[i].y + drawingRect.origin.y);
CTLineRef line = (CTLineRef)CFArrayGetValueAtIndex(lines, i);
CTLineDraw(line, ctx);
}
// truncate the last line before drawing it
if (count) {
CGPoint lastOrigin = origins[count-1];
CTLineRef lastLine = CFArrayGetValueAtIndex(lines, count-1);
// truncation token is a CTLineRef itself
CFRange effectiveRange;
CFDictionaryRef stringAttrs = CFAttributedStringGetAttributes((BRIDGE_CAST CFAttributedStringRef)_attributedTextWithLinks, 0, &effectiveRange);
CFAttributedStringRef truncationString = CFAttributedStringCreate(NULL, CFSTR("\u2026"), stringAttrs);
CTLineRef truncationToken = CTLineCreateWithAttributedString(truncationString);
CFRelease(truncationString);
// now create the truncated line -- need to grab extra characters from the source string,
// or else the system will see the line as already fitting within the given width and
// will not truncate it.
// range to cover everything from the start of lastLine to the end of the string
CFRange rng = CFRangeMake(CTLineGetStringRange(lastLine).location, 0);
rng.length = CFAttributedStringGetLength((BRIDGE_CAST CFAttributedStringRef)_attributedTextWithLinks) - rng.location;
// substring with that range
CFAttributedStringRef longString = CFAttributedStringCreateWithSubstring(NULL, (BRIDGE_CAST CFAttributedStringRef)_attributedTextWithLinks, rng);
// line for that string
CTLineRef longLine = CTLineCreateWithAttributedString(longString);
CFRelease(longString);
CTLineRef truncated = CTLineCreateTruncatedLine(longLine, drawingRect.size.width, kCTLineTruncationEnd, truncationToken);
CFRelease(longLine);
CFRelease(truncationToken);
// if 'truncated' is NULL, then no truncation was required to fit it
if (truncated == NULL){
truncated = (CTLineRef)CFRetain(lastLine);
}
// draw it at the same offset as the non-truncated version
CGContextSetTextPosition(ctx, lastOrigin.x + drawingRect.origin.x, lastOrigin.y + drawingRect.origin.y);
CTLineDraw(truncated, ctx);
CFRelease(truncated);
}
free(origins);
}
else{
CTFrameDraw(textFrame, ctx);
}
CGContextRestoreGState(ctx);
} else {
[super drawTextInRect:aRect];
}
}
Ran into this issue here in 2021.
I wrapped #Toydor's and #gypsyDev's answer into a UILabel extension so it can be applied where needed. Swift 5.
extension UILabel {
func ensureAttributedTextShowsTruncation() {
guard let text = attributedText else { return }
let attributedString = NSMutableAttributedString(attributedString: text)
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = .byTruncatingTail
attributedString.addAttribute(.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: attributedString.length))
attributedText = attributedString
}
}
I used as sample MTLabel. It allows to manage line height.
I needed the draw method exactly, so i just put away most stuff i did not need.
This method allows me to draw multilined text in rect with tail truncation.
CGRect CTLineGetTypographicBoundsAsRect(CTLineRef line, CGPoint lineOrigin)
{
CGFloat ascent = 0;
CGFloat descent = 0;
CGFloat leading = 0;
CGFloat width = CTLineGetTypographicBounds(line, &ascent, &descent, &leading);
CGFloat height = ascent + descent;
return CGRectMake(lineOrigin.x,
lineOrigin.y - descent,
width,
height);
}
- (void)drawText:(NSString*) text InRect:(CGRect)rect withFont:(UIFont*)aFont inContext:(CGContextRef)context {
if (!text) {
return;
}
BOOL _limitToNumberOfLines = YES;
int _numberOfLines = 2;
float _lineHeight = 22;
//Create a CoreText font object with name and size from the UIKit one
CTFontRef font = CTFontCreateWithName((CFStringRef)aFont.fontName ,
aFont.pointSize,
NULL);
//Setup the attributes dictionary with font and color
NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:
(id)font, (id)kCTFontAttributeName,
[UIColor lightGrayColor].CGColor, kCTForegroundColorAttributeName,
nil];
NSAttributedString *attributedString = [[[NSAttributedString alloc]
initWithString:text
attributes:attributes] autorelease];
CFRelease(font);
//Create a TypeSetter object with the attributed text created earlier on
CTTypesetterRef typeSetter = CTTypesetterCreateWithAttributedString((CFAttributedStringRef)attributedString);
//Start drawing from the upper side of view (the context is flipped, so we need to grab the height to do so)
CGFloat y = self.bounds.origin.y + self.bounds.size.height - rect.origin.y - aFont.ascender;
BOOL shouldDrawAlong = YES;
int count = 0;
CFIndex currentIndex = 0;
float _textHeight = 0;
CGContextSaveGState(context);
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextTranslateCTM(context, 0, self.bounds.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
//Start drawing lines until we run out of text
while (shouldDrawAlong) {
//Get CoreText to suggest a proper place to place the line break
CFIndex lineLength = CTTypesetterSuggestLineBreak(typeSetter,
currentIndex,
rect.size.width);
//Create a new line with from current index to line-break index
CFRange lineRange = CFRangeMake(currentIndex, lineLength);
CTLineRef line = CTTypesetterCreateLine(typeSetter, lineRange);
//Check to see if our index didn't exceed the text, and if should limit to number of lines
if (currentIndex + lineLength >= [text length])
{
shouldDrawAlong = NO;
}
else
{
if (!(_limitToNumberOfLines && count < _numberOfLines-1))
{
int i = 0;
if ([[[text substringWithRange:NSMakeRange(currentIndex, lineLength)] stringByAppendingString:#"…"] sizeWithFont:aFont].width > rect.size.width)
{
i--;
while ([[[text substringWithRange:NSMakeRange(currentIndex, lineLength + i)] stringByAppendingString:#"…"] sizeWithFont:aFont].width > rect.size.width)
{
i--;
}
}
else
{
i++;
while ([[[text substringWithRange:NSMakeRange(currentIndex, lineLength + i)] stringByAppendingString:#"…"] sizeWithFont:aFont].width < rect.size.width)
{
i++;
}
i--;
}
attributedString = [[[NSAttributedString alloc] initWithString:[[text substringWithRange:NSMakeRange(currentIndex, lineLength + i)] stringByAppendingString:#"…"] attributes:attributes] autorelease];
CFRelease(typeSetter);
typeSetter = CTTypesetterCreateWithAttributedString((CFAttributedStringRef)attributedString);
CFRelease(line);
CFRange lineRange = CFRangeMake(0, 0);
line = CTTypesetterCreateLine(typeSetter, lineRange);
shouldDrawAlong = NO;
}
}
CGFloat x = rect.origin.x;
//Setup the line position
CGContextSetTextPosition(context, x, y);
CTLineDraw(line, context);
count++;
CFRelease(line);
y -= _lineHeight;
currentIndex += lineLength;
_textHeight += _lineHeight;
}
CFRelease(typeSetter);
CGContextRestoreGState(context);
}

How to use CTRunDelegate in iPad?

I am a developing an iPad application in which i have to use CTRunDelegate. I have defined all the the callbacks that are required viz CTRunDelegateGetAscentCallback , CTRunDelegateGetDescentCallback , CTRunDelegateGetWidthCallback. I dont know how to use CTRunDelegateRef object that I am creating. Right now what is happening is that my callbacks are not getting called.
Any pointers in this regard will be highly appreciated.
Thanx in advance.
You should add your run delegate as an attribute for a range of characters in your attributed string. See Core Text String Attributes. When drawing, Core Text will call your callbacks to get the sizing of that characters.
Update
This is a sample code for a view drawing a simple text (Note that there's no memory management code here).
#implementation View
/* Callbacks */
void MyDeallocationCallback( void* refCon ){
}
CGFloat MyGetAscentCallback( void *refCon ){
return 10.0;
}
CGFloat MyGetDescentCallback( void *refCon ){
return 4.0;
}
CGFloat MyGetWidthCallback( void* refCon ){
return 125;
}
- (void)drawRect:(CGRect)rect {
// create an attributed string
NSMutableAttributedString * attrString = [[NSMutableAttributedString alloc] initWithString:#"This is my delegate space"];
// create the delegate
CTRunDelegateCallbacks callbacks;
callbacks.version = kCTRunDelegateVersion1;
callbacks.dealloc = MyDeallocationCallback;
callbacks.getAscent = MyGetAscentCallback;
callbacks.getDescent = MyGetDescentCallback;
callbacks.getWidth = MyGetWidthCallback;
CTRunDelegateRef delegate = CTRunDelegateCreate(&callbacks, NULL);
// set the delegate as an attribute
CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attrString, CFRangeMake(19, 1), kCTRunDelegateAttributeName, delegate);
// create a frame and draw the text
CTFramesetterRef frameSetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attrString);
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddRect(path, NULL, rect);
CTFrameRef frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, attrString.length), path, NULL);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextSetTextPosition(context, 0.0, 0.0);
CTFrameDraw(frame, context);
}
#end
The size of the space character between "delegate" and "space" in the text are controlled by the run delegate.

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