I'm working on an iPad app and I need to be able to format some output on the screen in a columnar format. This was similar to my question:
How can I use the \t [tab] operator to format a NSString in columns?
and I used that solution, unfortunately I'm not seeing the same results. My code is as follows:
NSString* titleColumn = [[NSString stringWithFormat:#"%#", displayName] stringByPaddingToLength:25 withString:#" " startingAtIndex:0];
NSString* serializedValue = [[NSMutableString alloc] init];
NSString* valueAsString = [NSString stringWithFormat:#"%.03f", value];
serializedValue = [serializedValue stringByAppendingFormat:#"%#%#", titleColumn, valueAsString];
When logging the items in the console, they are properly aligned, however, when plugging them into a UITextView, they are misaligned. This is how I'm sticking them in the text view:
NSMutableString* displayString = [[NSMutableString alloc] initWithString:#""];
for (NSString* entry in textToDisplay)
{
NSLog(#"%#", entry);
[displayString appendString:entry];
[displayString appendString:#"\n"];
}
[self.fTextPanel setText:displayString];
Any ideas on what I'm doing wrong?
EDIT:
In the log, it looks like this:
Inclination 0.000
Version 0.000
Inferior/Superior 0.000
Anterior/Posterior 0.500
And the UITextView version looks like this: http://imgur.com/vrUzybP,OYxGVd8
The reason for misaligned is the different width for each character. The best way for displaying this type of information is by using UITableView, You can use title and subTitle field for displaying or you can design a custom UITableView.
the reason is because when drawing charachters (glymphs), each character will have different widths,i.e character small c and big C will take different widths for drawing , so it wont work. Even though there are two strings with equal lengths but different characters, the drawing text will have different widths.
What i would suggest you for this is to have two textViews side by side, render titles in one textVIew and values in the next TextView.
If the number of titles is large and if you enable scrolling in textVIews, use delegate Methods of UIScrollView, and when scrollHappens in either of them, set the contentOffset of the other to make it look like single TextView.
Hope this helps.
Related
I'm trying to add a left hand margin to an NSAttributedString so that when I concatenate it with another NSAS, there is a bit of space between the two box frames.
All I have so far is this:
NSMutableAttributedString *issn = [[NSMutableAttributedString alloc] initWithString:jm.issn attributes:nil];
NSRange range = NSMakeRange(0, [issn length]);
[issn addAttribute:NSFontAttributeName
value:[UIFont fontWithName:#"AvenirNext-Medium" size:8]
range:range];
NSMutableAttributedString *textLabel = [[NSMutableAttributedString alloc] initWithAttributedString:title];
[textLabel appendAttributedString:issn];
I want the margin on the left side of the second string.
Thanks!
Edit: image upload
Why not just use a tab character between the two strings?
You could do this by changing your first line to this:
NSMutableAttributedString *issn = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:#"\t%#", jm.issn] attributes:nil];
This should output something like like what you want. You may, however, want to add 2 \t characters instead of one because depending on the string length, it may not need a tab character to align it (for example, in that exact string you posted, it didn't add anything to my output).
1 tab with your string:
2 tabs with your string:
You can't. If you're concatenating attributed strings then there is no "margin" around a specific range in the final string. How would that work with multiple lines or text wrapping?
If you want clear space within an attributed string, use white space characters - spaces or tabs. You can define the position of tab stops using paragraph styles.
All you can do is, add the required spaces(or whitespace characters) before the source string and then add it to your NSMutableAttributedString.
NSString *newString = [NSString stringWithFormat:#" %#", jm.issn] <- Have given two spaces here.
Thanks
I am needing to replace a line of text in code on my iOS app, however the lines that need to be replaced in the particular NSString will be different for different entries on the XML that is being parsed.
For example, I need to replace 129727-the-cave.mp3 with 129727.jpg.
However, I can't just tell it to replace -the-cave.mp3, because some instances of the string will have a different number and title of mp3. I think the next line is:
129838-my-song.mp3.
So, basically, I need a way to find everything from the first hyphen through mp3 and replace it, no matter what the text is?
Try this:
NSString *original = #"129727-the-cave.mp3";
NSString *sub = [original substringToIndex:[original rangeOfString:#"-"].location];
NSString *finalString = [sub stringByAppendingString:#".jpg"];
NSLog(#"finalString: %#", finalString);
I am trying to load a UITextView with content from instances of a NSManagedObject subclass (verses in a Bible reader app).
My UITextView is loaded by iterating through the verses in a selected chapter and appending each consecutive verse.
NSArray *selectedVerses = [[Store sharedStore] versesForBookName:selectedBook
ChapterNumber:selectedChapterNum];
displayString = #"";
for (Verse *v in selectedVerses) {
NSMutableString *addedString =
[NSMutableString stringWithFormat:#"%d %#", [v versenum], [v verse]];
displayString = [NSMutableString stringWithFormat:#"%# %#", addedString, displayString];
}
NSString *title = [NSString stringWithFormat:#"%# %#", selectedBook, selectedChapter];
[self setTitle:title];
[[self readerTextView] setNeedsDisplay];
[[self readerTextView] setText:displayString];
The above code generates the correct view, but only allows for one size of text for the entire UITextView.
I would like to have the verse number that precedes each verse to be a smaller size font than its verse, but have not found a way to make it work. I've been reading through the documentation, and it seems that this should be possible with TextKit and CoreText through the use of attributed strings, but I can't seem to get this to compile.
I do not want to load the view as a UIWebView.
Any suggestions for this are greatly appreciated.
You're looking for NSAttributedString and NSMutableAttributedString. You should read Introduction to Attributed String Programming Guide. They're generally like normal strings, but additionally contain attributes with ranges to which they apply. One more method that would be helpful to you is:
[self readerTextView].attributedText = yourAttributedString;
If you have some specific problems with attributed strings, please post your code.
I am trying to determine the precise position of a character in a UILabel, say:
(UILabel *)label.text = #"Hello!";
I'd like to determine the position of the 'o'. I thought that I could just sum the widths of all the preceding characters (or the whole preceding string) using sizeWithFont. The width value I get though is bigger by about 10% than what it should be. Summing the widths of individual letters (i.e. [#"H" sizeWithFont...] + [#"e" sizeWithFont...] + l... + l...) accumulates more error than [#"Hell" sizeWithFont...].
Is there a way of accurately determining the position of a single glyph in a string?
Many thanks.
Yes, but not in a UILabel and not using sizeWithFont:.
I recently worked with Apple Developer Support, and apparently sizeWithFont: is actually an approximation. It becomes less accurate when your text (1) wraps across multiple lines and (2) contains non-latin characters (i.e. Chinese, Arabic), both of which cause line spacing changes not captured by sizeWithFont:. So, don't rely on this method if you want 100% accuracy.
Here are two things you can do:
(1) Instead of UILabel, use a non-editable UITextView. This will support the UITextInput protocol method firstRectForRange:, which you can use to get the rect of the character you need. You could use a method like this one:
- (CGRect)rectOfCharacterAtIndex:(NSUInteger)characterIndex inTextView:(UITextView *)textView
{
// set the beginning position to the index of the character
UITextPosition *beginningPosition = [textView positionFromPosition:textView.beginningOfDocument offset:characterIndex];
// set the end position to the index of the character plus 1
UITextPosition *endPosition = [textView positionFromPosition:beginningPosition offset:1];
// get the text range between these two positions
UITextRange *characterTextRange = [textView textRangeFromPosition:beginningPosition toPosition:endPosition]];
// get the rect of the character
CGRect rectOfCharacter = [textView firstRectForRange:characterTextRange];
// return the rect, converted from the text input view (unless you want it to be relative the text input view)
return [textView convertRect:rectOfCharacter fromView:textView.textInputView];
}
To use it, (assuming you have a UITextView called myTextView already on the screen), you would do this:
myTextView.text = #"Hello!";
CGRect rectOfOCharacter = [self rectOfCharacterAtIndex:4 inTextView:myTextView];
// do whatever you need with rectOfOCharacter
Only use this method for determining the rect for ONE character. The reason for this is that in the event of a line break, firstRectForRange: only returns the rect on the first line, before the break.
Also, consider adding the method above as a UITextView category if you're gong to be using it a lot. Don't forget to add error handling!
You can learn more about how firstRectForRange: works "under the hood" by reading the Text, Web, and Editing Programming Guide for iOS.
(2) Create your own UILabel by subclassing UIView and using Core Text to render the strings. Since you're doing the rendering, you'll be able to get the positions of characters. This approach is a lot of work, and only worthwhile if you really need it (I, of course, don't know the other needs of your app). If you aren't sure how this would work, I suggest using the first approach.
Well fonts are smart now a day and take in respect the position of a character to its pervious character.
Here is an example on how the starting position of the letter o:
NSRange posRange = [hello rangeOfString:#"o"];
NSString *substring = [hello substringToIndex:posRange.location];
CGSize size = [substring sizeWithFont:[UIFont systemFontOfSize:14.0f]];
No you can do the same for the string including the letter o and substract the size found in the string without the letter o.
THis should give the an nice start position of the letter and the size.
in ios6 you can do using attributed string
NSMutableAttributedString *titleText2 = [[NSMutableAttributedString alloc] initWithString:strHello];
NSRange posRange = [hello rangeOfString:#"o"];
[titleText2 addAttributes:[NSDictionary dictionaryWithObject:[UIFont systemFontOfSize:14.0f] forKey:NSFontAttributeName] range:NameRange];
and set your textView with this attributed string
In UILabel there's functionality to truncate labels using different truncation techniques (UILineBreakMode). In NSString UIKit Additions there is a similar functionality for drawing strings.
However, I found no way to access the actual truncated string. Is there any other way to get a truncated string based on the (graphical) width for a given font?
I'd like to have a category on NSString with this method:
-(NSString*)stringByTruncatingStringWithFont:(UIFont *)font forWidth:(CGFloat)width lineBreakMode:(UILineBreakMode)lineBreakMode
- (NSString*)stringByTruncatingStringWithFont:(UIFont *)font forWidth:(CGFloat)width lineBreakMode:(UILineBreakMode)lineBreakMode {
NSMutableString *resultString = [[self mutableCopy] autorelease];
NSRange range = {resultString.length-1, 1};
while ([resultString boundingRectWithSize:CGSizeMake(FLT_MAX, FLT_MAX) options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:attributes context:nil].size.width > width) {
// delete the last character
[resultString deleteCharactersInRange:range];
range.location--;
// replace the last but one character with an ellipsis
[resultString replaceCharactersInRange:range withString:truncateReplacementString];
}
return resultString;
}
Note that since iOS 6 this method is not safe to run on background threads anymore.
One option is trying different sizes by looping until you get the right width. I.e. start with the full string, if that's wider than what you need, replace the last two characters with an ellipsis character. Loop until it's narrow enough.
If you think you'll be working with long strings, you can binary search your way towards the truncation point to make it a bit faster.