Following the idea from SouthernYankee65 (many thanks again) (see: Drawing Text to a CGContext for Quartz PDF not working) I'd like to know, if there's a way to get the range of text, that fits into the calculated frame
let frameSize = CTFramesetterSuggestFrameSizeWithConstraints(frameSetter, CFRangeMake(0, attributedString.string.count), nil, rect.size, nil)
might be the answer, because the docs say for the last option:
fitRange: On return, contains the range of the string that actually fit in the constrained size.
How do I use this? When I know the range of text, that fits into my frame, I can calc the number of frames needed to display the whole string and therefor I can create a paginated pdf.
Related
When I call setFixedHeight() on a PdfPCell, and add more text than fits in the given height, iText seems to print the prefix of the string which fits.
Can I control this clipping algorithm? For example:
Print a suffix of the string rather than a prefix.
Mark a substring of the string as not to be removed. This is with footnote references. If I add text saying "Hello World [1]", the [1] is a reference to a footnote and should not be removed. It's okay to remove the other characters of the string, like "World".
When there are multiple words in the string, iText seems to eliminate a word that doesn't fit, while I would like it partially printed. That is, if the string is "Hello World", and the cell has room only for "Hello Wo...", I would like that to be printed, rather than just "Hello", as iText prints.
Rather than printing characters in their entirety, print only part of them. Imagine printing the text to a PNG and chopping off the top and/or bottom part of the PNG to fit it in the space available. For example, notice that the top line and the bottom line are partially clipped here:
Are any of these possible? Does iText give me any control over how text is clipped? Thanks.
This is with reference to iText 2.1.6.
I have written a proof of concept, ClipCenterCellContent, where we try to fit the text "D2 is a cell with more content than we can fit into the cell." in a cell that is too small.
Just like in your other question ( iText -- How do I get the rendered dimensions of text? ), we add the content using a cell event, but we now add it twice: once in simulation mode (to find out how much space is needed vertically) and once for real (using an offset).
This adds the content in simulation mode (we use the width of the cell and an arbitrary height):
PdfContentByte canvas = canvases[PdfPTable.TEXTCANVAS];
ColumnText ct = new ColumnText(canvas);
ct.setSimpleColumn(new Rectangle(0, 0, position.getWidth(), -1000));
ct.addElement(content);
ct.go(true);
float spaceneeded = 0 - ct.getYLine();
System.out.println(String.format("The content requires %s pt whereas the height is %s pt.", spaceneeded, position.getHeight()));
We now know the needed height and we can add the content for real using an offset:
float offset = (position.getHeight() - spaceneeded) / 2;
System.out.println(String.format("The difference is %s pt; we'll need an offset of %s pt.", -2f * offset, offset));
PdfTemplate tmp = canvas.createTemplate(position.getWidth(), position.getHeight());
ct = new ColumnText(tmp);
ct.setSimpleColumn(0, offset, position.getWidth(), offset + spaceneeded);
ct.addElement(content);
ct.go();
canvas.addTemplate(tmp, position.getLeft(), position.getBottom());
In this case, I used a PdfTemplate to clip the content.
I also have answers to your other questions, but I don't have the time to answer them right now.
For straight Text box clipping, I adapted the C# code given here
http://itextsharp.10939.n7.nabble.com/Limiting-Text-Width-using-PdfContentByte-td2481.html
to the Java code below. The clipping area ends up outside this rectangle, so you can still draw a rectangle on the same exact coordinates.
cb.saveState();
cb.rectangle(left,top,width,height);
cb.clip();
cb.newPath();
// perform clipped output here
cb.restoreState();
I used a try/finally to ensure restoreState() was called.
Here's a screenshot of the twitter app for reference: http://screencast.com/t/YmFmYmI4M
What I want to do is place a floating pop-over on top of a substring in an NSAttributedString that could span multiple lines. NSAttributedString is a requirement for the project.
In the screenshot supplied, you can see that links are background-highlighted, so it leads me to believe that they're using CoreText and NSAttributedStrings. I also found something called CTRunRef ( http://developer.apple.com/library/ios/#documentation/Carbon/Reference/CTRunRef/Reference/reference.html ) which looks promising, but I'm having trouble fitting it all together conceptually.
In short, if I have a paragraph in core text and when I tap on a word, how do I find the bounding box for that word?
Set some attribute in the attributed string that won't effect display, but will cause it to be laid out as a seperate glyph run, then use CoreText to layout the string
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrString);
CTFrameRef ctframe = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), path, NULL);
Now you will have to hunt through the frame to find the relevant chunk of text. Get the array of CTLineRefs with CTFrameGetLines().
Iterate through the array, testing if the touch was on that line, by checking it is within the rect returned by CTLineGetImageBounds(). If it is, now look through the glyph runs in the line.
Again, you can get an array of CTRunRefs with CTLineGetGlyphRuns(). Check whether the tap was within the glyph run with CTRunGetImageBounds(), and if it was you can find the the range of indices in the original attributed string that the glyph run corresponds to with CTRunGetStringIndices().
you need to find Y by CTLine and X by CTRun width and height you can get by word and font itself. ill attache my project link, its really simple code but you can reedit in order to meet your needs. hope it helps cheers if you improve general logic please let me know thx.
textViewProject
The link given by George was very helpful and got me what I wanted. But strange thing happened. It was working in iOS SDK 4.0 but in the iOS SDK 5 the position of the link appeared in wrong position on the view.
So I had to tweak the code a little bit. For the x coordinates of the touchable button, I had to use CTRunGetTypographicBounds instead of the CTRunGetImageBounds function.
So over all, in the tweaked code:
The y Coordinate , width and height was calculated using CTRunGetImageBounds.
And x coordinate was calculated using CTRunGetTypographicBounds.
I've been working on a small library that does exactly that. You can find it here: https://github.com/pothibo/CMFramework
However, this library is in its alpha stage, there's optimization needed and some feature are lacking (line height is one of the urgent feature I want to add)
If you decide to use it and find issue, don't hesitate to post issues on github!
How does one use the CGRectIntegral function? I understand it's purpose.
The documentation isn't clear on it's exact use.
CGRectIntegral to convert any decimal values to their integer equivalents
see image may be you can understand
How do I fix it?
frame = CGRectIntegral(frame);
-OR-
myTextView.frame = CGRectIntegral(myTextView.frame);
see this for more information of CGRectIntegral
CGRectIntegral Method is used to create integer rect . I mean to say suppose if you calculate frame in app you may get frames value in float.
Setting float value as frame to some UIElement like UILabel would make the text looks blur. To avoid that, we use CGRectIntegral.Please look at the example below,
NSLog(#"%#",NSStringFromCGRect( CGRectIntegral(CGRectMake(0, 15.6, 16.1, 20.2))));
This will print, {0,15},{17,21}.
This explanation is found in the header file.
/* Expand `rect' to the smallest rect containing it with integral origin and
size. */
One particular usage is to fix frames that do not align perfectly with on-screen pixels.
See this question: UITextField blurred text
If a label or textfield has a frame that isn't pixel-aligned when rendered to the screen, the text will appear blurred. This can happen if you calculate the frame using division (for example to center it in a parent view).
CGRectIntegral will remove the fractional part of the frame, fixing this problem. Note however that with retina displays a .5 frame value is pixel aligned, but CGRectIntgral will still remove the fractional part.
Is this possible? Basically, I have a bunch of NSAttributedString objects and corresponding CTLine objects. I want to get the image bounds before the drawRect stage. So at this point, there is nothing to draw into. I will then use these image bounds to decide exactly what I need to create for drawing.
EDIT: Another measurement of the size would probably work just fine. But calling the deceptively named CTLineGetTypographicBounds function only returns the width. If I pass in addresses of ascent and descent floats, they come back as zero.
EDIT: The given answer works great in MacOS. Can anyone do it in iOS?
If you are developing for iOS6+. You can use the following method:
CTLineRef line;
// Create the line...
CGRect bounds = CTLineGetBoundsWithOptions(line, kCTLineBoundsUseGlyphPathBounds);
// use bounds...
This is gives the same bounds as CTLineGetImageBounds() assuming you have no transforms applied in your context, but does not require the context. For iOS 5 and below, you would need to use the method described by Иван.
CTLineGetTypographicBounds() gives me a different width than this function or image bounds. I am not sure why. And the ascent and descent returned are those of the font and not the characters displayed in the CTLineRef.
Yes, you can, but not so easy.
You should, generally use CTLineGetTypographicBounds() which, for me, does return ascent, descent and leading, but a bit messed up - 'ascent' equals the total height (i.e. what should be ascent + descent) and 'descent' is always the maximum descent of the font - no matter if you have descending characters or not.
Other way is to retrieve the CTRun(s) from the line (CTLineGetGlyphRuns), then get the glyphs array (CTRunGetGlyphs or CTRunGetGlyphsPtr) and then using CTFontGetBoundingRectsForGlyphs and CTFontGetAdvancesForGlyphs build up the information you need.
EDIT:
I've just found this method: "- (NSRect) boundingRectWithSize:(NSSize)size options:(NSStringDrawingOptions)options" of NSAttributedString which seems to do exactly what is needed.
Hope, this is helpful...
Bounds returned by CTLineGetTypographicBounds() are not the same as image bounds. As the name, (and Иван's answer) suggests, ascent etc. are defined for the font and won't change based on the string. For example, you would use it if you want to find the correct line height if you have a multiline text, as line height normally should not depend on the exact characters you use.
CTLineGetImageBounds() on the other hand, returns the bounds that exactly fit the image. For example, if you want to draw a box around a single line, this is what you need.
CTLineGetImageBounds() needs a context because there may be text transforms and things like that. If you don't want to worry about that, just use a dummy context. For example:
CTLineRef line;
// create the line...
UIGraphicsBeginImageContext(CGSizeMake(1, 1));
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetTextPosition(context, 0, 0);
CGRect bounds = CTLineGetImageBounds(line, context);
UIGraphicsEndImageContext();
// use bounds...
Another method is to convert the string to glyphs usingCTFontGetGlyphsForCharacters() and then calling CTFontGetBoundingRectsForGlyphs() with the glyph array you get from the first function. The latter function returns "the overall bounding rectangle for the glyph run" so don't worry about having to do processing on the individual bounding rects. If used both these functions successfully in iOS.
If you do this remember the mapping between glyphs and characters is not always one to one, especially when the string has non-English characters.
How would I get a CGRect from an NSRange for text rendered with Core Text?
I am using Core Text with an NSAttributedString.
It is an absolute pain but can be done.
You need to get all of the lines in the frame using CTFrameGetLines(), check if their character range is in the range you're looking for using CTLineGetStringRange(), use CTLineGetTypographicBounds() to find how big the line itself would render as, and use CTLineGetOffsetForStringIndex() to determine the actual position of the start/end character of the range (if the line is just a subrange of the desired range).
Combining all of this and adding up offsets and heights and such can get you what you want. Note that CTLineGetImageBounds() doesn't work without a graphics context (and, from what I gather, it is pretty expensive anyway) and is not necessary to solve this problem.
FIrst determine the line(s) in which the range you are interested in lies is. Then call CTLineGetOffsetForStringIndex() to get an offset of a specific string position from the start of the line. Together with CTLineGetImageBounds(), it should be possible to calculate a CGPoint position of the first and last characters in your range.