NSTextContainer、NSLayoutManager、NSTextStorage is new to iOS7:
1) NSTextContainer:
The NSTextContainer class defines a region in which text is laid out.
An NSTextContainer object defines rectangular regions, and you can define exclusion paths inside the textcontainer'sboundingrectanglesothattextflowsaroundtheexclusionpathasitislaidout.
2) NSLayoutManager:
An NSLayoutManager object coordinates the layout and display of characters held in an NSTextStorage object. It maps Unicode character codes to glyphs, sets the glyphs in a series of NSTextContainer objects, and displays them in a series of text view objects.
3) NSTextStorage:
NSTextStorage is a semiconcrete subclass of NSMutableAttributedString that manages a set of client NSLayoutManagerobjects,notifyingthemofanychangestoitscharactersorattributessothattheycanrelay and redisplay the text as needed.
We could know NSTextStorage can store and manage UITextView's text,and it is NSMutableAttributedString's subclass.We can add or modify the attributes, so it is a good choice to store and manage UITextView's text.
NSLayoutManager use for manage the content of NSTextStorage's layout.
NSTextContainer provide a rectangle to stash the layouted text.
We can simply use them:
CGRect textViewRect = CGRectInset(self.view.bounds, 10.0, 20.0);
// NSTextContainer
NSTextContainer *container = [[NSTextContainer alloc] initWithSize:CGSizeMake(textViewRect.size.width, CGFLOAT_MAX)]; // new in iOS 7.0
container.widthTracksTextView = YES; // Controls whether the receiveradjusts the width of its bounding rectangle when its text view is resized
// NSLayoutManager
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init]; // new in iOS 7.0
[layoutManager addTextContainer:container];
// NSTextStorage subclass
self.textStorage = [[TextStorage alloc] init]; // new in iOS 7.0
[self.textStorage addLayoutManager:layoutManager];
Firstly is make instance of them, and create thier relationship.You must add NSTextContainer in UITextView by initWithFrame:textContainer: method.
// UITextView
UITextView *newTextView = [[UITextView alloc] initWithFrame:textViewRect textContainer:container];
newTextView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
newTextView.scrollEnabled = YES;
newTextView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag;
// newTextView.editable = NO;
newTextView.font = [UIFont fontWithName:self.textStorage.fontName size:18.0];
newTextView.dataDetectorTypes = UIDataDetectorTypeAll;
self.textView = newTextView;
[self.view addSubview:self.textView];
If want to use UITextStorage to change text's attributes, you can use:
[_textStorage beginEditing]; // begin edit
[_textStorage endEditing]; // end edit
Between them you can edit text, such as:
[_textStorage beginEditing];
NSDictionary *attrsDic = @{NSTextEffectAttributeName: NSTextEffectLetterpressStyle};
UIKIT_EXTERN NSString *const NSTextEffectAttributeName NS_AVAILABLE_IOS(7_0); // NSString, default nil: no text effect
NSMutableAttributedString *mutableAttrString = [[NSMutableAttributedString alloc] initWithString:@"Letterpress" attributes:attrsDic];
NSAttributedString *appendAttrString = [[NSAttributedString alloc] initWithString:@" Append:Letterpress"];
[mutableAttrString appendAttributedString:appendAttrString];
[_textStorage setAttributedString:mutableAttrString];
[_textStorage endEditing];
Or change color:
[_textStorage beginEditing];
/* Dynamic Coloring Text */
self.textStorage.bookItem = [[BookItem alloc] initWithBookName:@"Dynamic Coloring.rtf"];
self.textStorage.tokens = @{@"Alice": @{NSForegroundColorAttributeName: [UIColor redColor]},
@"Rabbit": @{NSForegroundColorAttributeName: [UIColor greenColor]},
DefaultTokenName: @{NSForegroundColorAttributeName: [UIColor blackColor]}
};
[_textStorage setAttributedString:_textStorage.bookItem.content];
[_textStorage endEditing];
