objective-c : Textkit and TableView with note (ios 7)

snippet.m

//Textkit and TableView with note (ios 7)

//1. start with basic dummy data 

//AppDelegate.h

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property NSMutableArray* notes;

@end


//AppDelegate.m

#import "Note.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    // create some notes!
    self.notes = [NSMutableArray arrayWithArray: @[
        [Note noteWithText:@"Shopping List\r\r1. Cheese\r2. Biscuits\r3. Sausages\r4. IMPORTANT Cash for going out!\r5. -potatoes-\r6. A copy of iOS6 by tutorials\r7. A new iPhone\r8. A present for mum"],
        [Note noteWithText:@"Meeting notes\rA long and drawn out meeting, it lasted hours and hours and hours!"],
        [Note noteWithText:@"Perfection ... \n\nPerfection is achieved not when there is nothing left to add, but when there is nothing left to take away - Antoine de Saint-Exupery"],
        [Note noteWithText:@"Notes on iOS7\nThis is a big change in the UI design, it's going to take a *lot* of getting used to!"],
        [Note noteWithText:@"Meeting notes\rA dfferent meeting, just as long and boring"],
        [Note noteWithText:@"A collection of thoughts\rWhy do birds sing? Why is the sky blue? Why is it so hard to create good test data?"]]];
    
    return YES;
}


//Note.h

@interface Note : NSObject

@property NSString* contents;
@property NSDate* timestamp;

// an automatically generated not title, based on the first few words
@property (readonly) NSString* title;

+ (Note*) noteWithText:(NSString*)text;

@end


//Note.m

#import "Note.h"

@implementation Note

+ (Note *)noteWithText:(NSString *)text {
    Note* note = [Note new];
    note.contents = text;
    note.timestamp = [NSDate date];
    return note;
}

- (NSString *)title {
    // split into lines
    NSArray* lines = [self.contents componentsSeparatedByCharactersInSet: [NSCharacterSet newlineCharacterSet]];
    
    // return the first
    return lines[0];
}

@end


//NotesListViewController.h

#import <UIKit/UIKit.h>

@interface NotesListViewController : UITableViewController

@end


//NotesListViewController.m

#import "NotesListViewController.h"
#import "AppDelegate.h"
#import "Note.h"

@implementation NotesListViewController

- (NSMutableArray*) notes
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}

    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    return appDelegate.notes;
}

- (void)viewDidAppear:(BOOL)animated {
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    // Whenever this view controller appears, reload the table. This allows it to reflect any changes
    // made whilst editing notes.
    [self.tableView reloadData];
    
    [super viewDidAppear:animated];
}

- (void)viewDidLoad
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    [super viewDidLoad];
}


#pragma mark - Table view data source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self notes].count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    
    Note* note = [self notes][indexPath.row];
    cell.textLabel.text = note.title;
    return cell;
}

@end



//2. transfering data between views

//NoteEditorViewController.h

@class Note;

@interface NoteEditorViewController : UIViewController

@property Note* note;

@end


//NoteEditorViewController.m

#import "NoteEditorViewController.h"
#import "Note.h"

@interface NoteEditorViewController () <UITextViewDelegate>

@property (weak, nonatomic) IBOutlet UITextView *textView;

@end

@implementation NoteEditorViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.textView.text = self.note.contents;
    self.textView.delegate = self;
}

#pragma mark - UITextView 델리게이트 메소드

- (void)textViewDidEndEditing:(UITextView *)textView //tells the delegate that editing of the specified text view has ended
{
    // copy the updated note text to the underlying model.
    self.note.contents = textView.text;
}


@end


//transfering data from tableview to detailview

//before implementing prepareForSegue 메소드
//hook up with TextView, in NotesListViewController add bar button to segue identifier "AddNewNote" and prototype cell to segue identifier "CellSelected"

//NotesListViewController.m

#import "NoteEditorViewController.h"

#pragma mark - Navigation

// In a story board-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    NoteEditorViewController* editorVC = (NoteEditorViewController*)segue.destinationViewController;
    
    if ([segue.identifier isEqualToString:@"CellSelected"]) { //CellSelected : for edit
        // if the cell selected segue was fired, edit the selected note
        NSIndexPath *path = [self.tableView indexPathForSelectedRow];
        editorVC.note = [self notes][path.row];
    }
    
    if ([segue.identifier isEqualToString:@"AddNewNote"]) { //AddNewNote : for new note
        // if the add new note segue was fired, create a new note, and edit it
        editorVC.note = [Note noteWithText:@" "];
        // also, add this note to the collection
        [[self notes] addObject:editorVC.note];
    }
}



//3. Dynamic type
//for starter implementing Basic support

//NoteEditorViewController.m

//add the following code to the end of method

- (void)viewDidLoad
{
    self.textView.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
    
    // handle content size change notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(preferredContentSizeChanged:)
                                                 name:UIContentSizeCategoryDidChangeNotification
                                               object:nil];
}

- (void)preferredContentSizeChanged:(NSNotification *)n {
    self.textView.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
}

//NotesListViewController.m

//add the following code to the end of method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    cell.textLabel.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
}

- (void)viewDidLoad
{
    // handle content size change notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(preferredContentSizeChanged:)
                                                 name:UIContentSizeCategoryDidChangeNotification
                                               object:nil];
}

- (void)preferredContentSizeChanged:(NSNotification *)n {
    [self.tableView reloadData];
}


//change cell's height follow dynamic type font size

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    
    // size the row based on the size required to render a label.
    static UILabel* label;
    if (!label) {
        label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, FLT_MAX, FLT_MAX)];
        label.text = @"test";
    }
    
    label.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
    [label sizeToFit];
    return label.frame.size.height * 1.7;
}


//4. Letterpress effects

//NotesListViewController.m

//add folling code

#pragma mark - Table view data source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self notes].count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    //...
    
    //creates an attributed string for the title of a table cell using the letterpress style
    UIColor* textColor = [UIColor colorWithRed:0.175f green:0.458f blue:0.831f alpha:1.0f];
    NSDictionary *attrs = @{NSForegroundColorAttributeName : textColor,
                            NSFontAttributeName : font,
                            NSTextEffectAttributeName : NSTextEffectLetterpressStyle};
    
    NSAttributedString* attrString = [[NSAttributedString alloc] initWithString:note.title
                                                                     attributes:attrs];
    
    cell.textLabel.attributedText = attrString;
    
    return cell;
}



//5. Apply exclusion paths (flowing text around images or other objects)


//Adding the view

//NoteEditorViewController.m
#import "TimeIndicatorView.h"


//TimeIndicatorView.h
// a view that renders the time of a note within a circle
@interface TimeIndicatorView : UIView

- (id)init:(NSDate*)date;

// updates the size of this view to comfortably hold the current text. After this
// method is invoked the view will be located at the origin.
- (void)updateSize;

- (UIBezierPath *)curvePathWithOrigin:(CGPoint)origin;

@end


//TimeIndicatorView.m

#import "TimeIndicatorView.h"

@implementation TimeIndicatorView
{
    UILabel* _label;
}

-(id)init:(NSDate *)date {
    if (self = [super init]) {
        // Initialization code
        self.backgroundColor = [UIColor clearColor];
        self.clipsToBounds = NO;
        
        _label = [[UILabel alloc] init];
        _label.textAlignment = NSTextAlignmentRight;
        
        // format and style the date
        NSDateFormatter* format = [NSDateFormatter new];
        [format setDateFormat:@"dd\rMMMM\ryyyy"];
        NSString* formattedDate = [format stringFromDate:date];
        _label.text = [formattedDate uppercaseString];
        _label.textAlignment = NSTextAlignmentCenter;
        _label.textColor = [UIColor whiteColor];
        _label.numberOfLines = 0;
        
        [self addSubview:_label];
    }
    return self;
}


- (void)updateSize {
    
    // size the label based on the font
    _label.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
    _label.frame = CGRectMake(0, 0, FLT_MAX, FLT_MAX);
    [_label sizeToFit];
    
    // set the frame to be large enough to accomodate circle that surrounds the text
    float radius = [self radiusToSurroundFrame:_label.frame];
    self.frame = CGRectMake(0, 0, radius*2, radius*2);
    
    // center the label within this circle
    _label.center = self.center;
    
    // offset the center of this view to ... erm ... can I just draw you a picture?
    // You know the story - the designer provides a mock-up with some static data, leaving
    // you to work out the complex calculatins required to accomodate the variability of real-world
    // data. C'est la vie!
    float padding = 5.0f;
    self.center = CGPointMake(self.center.x + _label.frame.origin.x - padding,
                              self.center.y - _label.frame.origin.y + padding);
    
}

// calculates the radius of the circle that surrounds the label
- (float) radiusToSurroundFrame:(CGRect)frame {
    return MAX(frame.size.width, frame.size.height) * 0.5 + 20.0f;
}

- (UIBezierPath *)curvePathWithOrigin:(CGPoint)origin {
    return [UIBezierPath bezierPathWithArcCenter:origin
                                          radius:[self radiusToSurroundFrame:_label.frame]
                                      startAngle:-180.0f
                                        endAngle:180.0f
                                       clockwise:YES];
    
}

- (void)drawRect:(CGRect)rect
{
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextSetShouldAntialias(ctx, YES);
    UIBezierPath* path = [self curvePathWithOrigin:_label.center];
    
    [[UIColor colorWithRed:0.329f green:0.584f blue:0.898f alpha:1.0f] setFill];
    [path fill];
}


@end


//NoteEditorViewController.m

//add the following instance variable

@implementation NoteEditorViewController
{
    TimeIndicatorView* _timeView;
}

- (void)viewDidLoad
{
	//...
    _timeView = [[TimeIndicatorView alloc] init:self.note.timestamp];
    [self.view addSubview:_timeView];

}


- (void)viewDidLayoutSubviews { //viewDidLayoutSubviews: called to notify the view controller that its view has just laid out its subviews.
    [self updateTimeIndicatorFrame];
}


//call updateSize to make TimeIndicatorView calculates its own size automatically
- (void) updateTimeIndicatorFrame {
    [_timeView updateSize];
    _timeView.frame = CGRectOffset(_timeView.frame,
          self.view.frame.size.width - _timeView.frame.size.width, 0.0); //frame, x, y
}


//add following code
//when view controller receives notification that the size of the content has changed
- (void)preferredContentSizeChanged:(NSNotification *)n {
    //... 
    [self updateTimeIndicatorFrame];
}


//TimeIndicatorView.h
//add the following method declaration:

- (UIBezierPath *)curvePathWithOrigin:(CGPoint)origin; 

//NoteEditorViewController.m
//add the following code to the end of updateTimeIndicatorFrame:

/*below method creates an exclusion path based on the Bezier path created in your time indicator view, but with an origin and coordinates that are relative to the text view*/

- (void) updateTimeIndicatorFrame {
    //...
    
    //add an exclusion path for the time display
    UIBezierPath* exclusionPath = [_timeView curvePathWithOrigin:_timeView.center];
    _textView.textContainer.exclusionPaths = @[exclusionPath];
}



//6. Dynamic text formatting and storage

//make subclass of NSTextStorage

//SyntaxHighlightTextStorage.h

// a text storage subclass that performs syntax highlighting
@interface SyntaxHighlightTextStorage : NSTextStorage

@end

//SyntaxHighlightTextStorage.m

@implementation SyntaxHighlightTextStorage
{
	//NSMutableAttributedString cause text storage subclass must provide its own ‘persistence’
    NSMutableAttributedString *_backingStore;
}

- (id)init
{
    if (self = [super init]) {
        _backingStore = [NSMutableAttributedString new];
    }
    return self;
}


#pragma mark - NSTextStorage mandatory overrides

- (NSString *)string
{
    return [_backingStore string];
}


- (NSDictionary *)attributesAtIndex:(NSUInteger)location
                     effectiveRange:(NSRangePointer)range
{
    return [_backingStore attributesAtIndex:location
                             effectiveRange:range];
}


- (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)str
{
    NSLog(@"replaceCharactersInRange:%@ withString:%@",
          NSStringFromRange(range), str);

    [self beginEditing];
    [_backingStore replaceCharactersInRange:range withString:str];
    [self edited:NSTextStorageEditedCharacters | NSTextStorageEditedAttributes
           range:range changeInLength:str.length - range.length];
    [self endEditing];
}


- (void)setAttributes:(NSDictionary *)attrs range:(NSRange)range
{
    NSLog(@"setAttributes:%@ range:%@",
          attrs, NSStringFromRange(range));
    
    [self beginEditing];
    [_backingStore setAttributes:attrs range:range];
    [self edited:NSTextStorageEditedAttributes
           range:range changeInLength:0];
    [self endEditing];
}




//7. UITextView with a custom Text Kit stack

//create the UITextView and Text Kit stack programatically

//delete UITextView instance in storyboard, delete UITextView outlet in NoteEditorViewController.m

//NoteEditorControllerViewController.m

@implementation NoteEditorViewController
{
    //...
    SyntaxHighlightTextStorage* _textStorage;
    UITextView* _textView;
}


//remove following lines from viewDidLoad in NoteEditorViewController.m

- (void)viewDidLoad
{
    //...
    //remove following code
    self.textView.text = self.note.contents; 
    self.textView.delegate = self; 
    self.textView.font = [UIFont
    preferredFontForTextStyle:UIFontTextStyleBody];

}


//create TextView programatically

//NoteEditorViewController.m

- (void)createTextView
{
	// 1. Create the text storage that backs the editor
    NSDictionary* attrs = @{NSFontAttributeName:
                                [UIFont preferredFontForTextStyle:UIFontTextStyleBody]};
    
    NSAttributedString* attrString = [[NSAttributedString alloc] initWithString:_note.contents
                                                                     attributes:attrs];
    _textStorage = [SyntaxHighlightTextStorage new];
    [_textStorage appendAttributedString:attrString];
    
    CGRect newTextViewRect = self.view.bounds;
    
    // 2. Create the layout manager
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    
    // 3. Create a text container
    CGSize containerSize = CGSizeMake(newTextViewRect.size.width, CGFLOAT_MAX);
    NSTextContainer *container = [[NSTextContainer alloc] initWithSize:containerSize];
    container.widthTracksTextView = YES;
    [layoutManager addTextContainer:container];
    [_textStorage addLayoutManager:layoutManager];
    
    // 4. Create a UITextView
    _textView = [[UITextView alloc] initWithFrame:newTextViewRect
                                    textContainer:container];
    _textView.delegate = self;
    [self.view addSubview:_textView];
    
    // ensure that the text view is not editable initially
    _textView.editable = NO;
    _textView.dataDetectorTypes = UIDataDetectorTypeLink; //clickable URLs in the text view
}


//call createTextView method 
- (void)viewDidLoad
{
    //...
    [self createTextView];

}


//replace the old outlet property with the new instance variable

- (void)preferredContentSizeChanged:(NSNotification *)n {
    _textView.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
}


- (void)viewDidLayoutSubviews { //called to notify the view controller that view has just laid out subviews
    //...
    _textView.frame = _textViewFrame;
    //custom view created in code doesn’t automatically inherit the layout constraints set in the storyboard
    //therefore, the frame of your new view won’t resize when the device orientation changes
    //need to explicitly set the frame yourself
}



//8. Dynamic formatting

//SyntaxHighlightTextStorage.m

-(void)processEditing { //Triggers post-editing operations
	[self performReplacementsForRange:[self editedRange]];
	[super processEditing]; 
}


- (void)performReplacementsForRange:(NSRange)changedRange {

	//expands the range because changedRange typically indicates a single character
	//lineRangeForRange extends that range to the entire line of text

	NSRange extendedRange = NSUnionRange(changedRange, [[_backingStore string] lineRangeForRange:NSMakeRange(changedRange.location, 0)]); 
	extendedRange = NSUnionRange(extendedRange, [[_backingStore string] lineRangeForRange:NSMakeRange(NSMaxRange(changedRange), 0)]);

	[self applyStylesToRange:extendedRange]; 

}



- (void)applyStylesToRange:(NSRange)searchRange {
    
    // 1. create some fonts
    UIFontDescriptor* fontDescriptor = [UIFontDescriptor
                                        preferredFontDescriptorWithTextStyle:UIFontTextStyleBody];
    UIFontDescriptor* boldFontDescriptor = [fontDescriptor
                                            fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitBold];
    
    UIFont* boldFont = [UIFont fontWithDescriptor:boldFontDescriptor size: 0.0];
    UIFont* normalFont = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
    
    // 2. match items surrounded by asterisks
    NSString* regexStr = @"(\\*\\w+(\\s\\w+)*\\*)\\s";
    
    NSRegularExpression* regex = [NSRegularExpression
                                  regularExpressionWithPattern:regexStr
                                  options:0
                                  error:nil];
    
    NSDictionary* boldAttributes = @{ NSFontAttributeName : boldFont };
    NSDictionary* normalAttributes = @{ NSFontAttributeName : normalFont };
    
    // 3. iterate over each match, making the text bold
    [regex enumerateMatchesInString:[_backingStore string] options:0 range:searchRange usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop){
        NSRange matchRange = [match range];
        [self addAttributes:boldAttributes range:matchRange];
        
        // 4. reset the style to the original
        if (NSMaxRange(matchRange)+1 < self.length) {
            [self addAttributes:normalAttributes range:NSMakeRange(NSMaxRange(matchRange)+1, 1)];
        }
    }];
}



//9. Adding further styles

//basic principle of applying styles:
//*** use a regex to find and replace the string using applyStylesToRange

//Add an instance variable to 
//SyntaxHighlightTextStorage.m

@implementation SyntaxHighlightTextStorage
{
    //...
    NSDictionary* _replacements;
}


- (void) createHighlightPatterns {
    UIFontDescriptor *scriptFontDescriptor = [UIFontDescriptor
                                              fontDescriptorWithFontAttributes: 
                                              @{UIFontDescriptorFamilyAttribute: @"Zapfino"}];
    
    // 1. base our script font on the preferred body font size
    UIFontDescriptor* bodyFontDescriptor = [UIFontDescriptor
                                            preferredFontDescriptorWithTextStyle:UIFontTextStyleBody];
    NSNumber* bodyFontSize = bodyFontDescriptor.fontAttributes[UIFontDescriptorSizeAttribute];
    UIFont* scriptFont = [UIFont fontWithDescriptor:scriptFontDescriptor
                                               size:[bodyFontSize floatValue]];
    
    // 2. create the attributes
    NSDictionary* boldAttributes = [self
                                    createAttributesForFontStyle:UIFontTextStyleBody
                                    withTrait:UIFontDescriptorTraitBold];
    NSDictionary* italicAttributes = [self
                                      createAttributesForFontStyle:UIFontTextStyleBody
                                      withTrait:UIFontDescriptorTraitItalic];
    NSDictionary* strikeThroughAttributes = @{ NSStrikethroughStyleAttributeName : @1};
    NSDictionary* scriptAttributes = @{ NSFontAttributeName : scriptFont};
    NSDictionary* redTextAttributes = @{ NSForegroundColorAttributeName : [UIColor redColor]};
    
    // construct a dictionary of replacements based on regexes
    _replacements = @{
                      @"(\\*\\w+(\\s\\w+)*\\*)\\s" : boldAttributes,
                      @"(_\\w+(\\s\\w+)*_)\\s" : italicAttributes,
                      @"([0-9]+\\.)\\s" : boldAttributes,
                      @"(-\\w+(\\s\\w+)*-)\\s" : strikeThroughAttributes,
                      @"(~\\w+(\\s\\w+)*~)\\s" : scriptAttributes,
                      @"\\s([A-Z]{2,})\\s" : redTextAttributes};
}



/*

deconstruct the regular expression
1. (\* - match an asterisk
2. \w+ - followed by one or more “word” characters
3. (\s\w+)* - followed by zero or more groups of spaces followed by “word”
characters
4. \*) - followed by an asterisk
5. \s - terminated by a space

http://www.raywenderlich.com/30288/nsregularexpression-tutorial-and-cheat-sheet

 */


//actually call createHighlightPatterns. Update init

- (id)init {
	if (self = [super init]) {
		//...
		[self createHighlightPatterns];
	}
	return self; 
}


//Add the following method

//below method applies the supplied font style to the body font. 
//provides a zero size to return a size that matches the user’s current font size preferences
- (NSDictionary*)createAttributesForFontStyle:(NSString*)style
                                    withTrait:(uint32_t)trait {
    UIFontDescriptor *fontDescriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleBody];
    UIFontDescriptor *descriptorWithTrait = [fontDescriptor fontDescriptorWithSymbolicTraits:trait];
    UIFont* font =  [UIFont fontWithDescriptor: descriptorWithTrait
                                          size: 0.0];
    return @{ NSFontAttributeName : font };
}


//replace the existing applyStylesToRange method

//below method code does pretty much exactly what it did before
//but this time it iterates over the dictionary of regex matches and attributes
//and applies the specified style to the matched patterns
- (void)applyStylesToRange:(NSRange)searchRange
{
    NSDictionary* normalAttrs = @{NSFontAttributeName:
                                      [UIFont preferredFontForTextStyle:UIFontTextStyleBody]};
    
    // iterate over each replacement
    for (NSString* key in _replacements) {
        NSRegularExpression *regex = [NSRegularExpression
                                      regularExpressionWithPattern:key
                                      options:0
                                      error:nil];
        
        NSDictionary* attributes = _replacements[key];
        
        [regex enumerateMatchesInString:[_backingStore string]
                                options:0
                                  range:searchRange
                             usingBlock:^(NSTextCheckingResult *match,
                                          NSMatchingFlags flags,
                                          BOOL *stop){
                                 // apply the style
                                 NSRange matchRange = [match range];
                                 [self addAttributes:attributes range:matchRange];
                                 
                                 // reset the style to the original
                                 if (NSMaxRange(matchRange)+1 < self.length) {
                                     [self addAttributes:normalAttrs
                                                   range:NSMakeRange(NSMaxRange(matchRange)+1, 1)];
                                 }
                             }];
    }
}


//10. Reviving dynamic type

//Problem : 
//1. changed the orientation of your screen, app no longer responds to changing content size 
//2. add a lot of text to a note, bottom of the text view is partially obscured by the keyboard

//SyntaxHighlightTextStorage.h
//add the following method declaration to the interface

@interface SyntaxHighlightTextStorage : NSTextStorage

- (void)update; 

@end

//SyntaxHighlightTextStorage.m

-(void)update {
    // update the highlight patterns
    [self createHighlightPatterns];
    
    // change the 'global' font
    NSDictionary* bodyFont = @{NSFontAttributeName :
                                   [UIFont preferredFontForTextStyle:UIFontTextStyleBody]};
    [self addAttributes : bodyFont
                  range : NSMakeRange(0, self.length)];
    
    // re-apply the regex matches
    [self applyStylesToRange:NSMakeRange(0, self.length)];
}


//NoteEditorViewController.m

//update preferredContentSizeChanged: to invoke update:

- (void)preferredContentSizeChanged:(NSNotification *)n {
    //...
    [_textStorage update];
}


//11. Resizing text views

//Add the following instance variable to NoteEditorViewController.m


@implementation NoteEditorViewController
{
  	//...
    CGRect _textViewFrame; //used to store the current text view frame
}


//update viewDidLayoutSubviews to make use of this newly added instance variable

- (void)viewDidLayoutSubviews 
{ 
	//called to notify the view controller that view has just laid out subviews
    //...
    _textView.frame = _textViewFrame;
}


//add the following to the bottom of viewDidLoad to set the initial frame value

- (void)viewDidLoad
{
    //...
    _textViewFrame = self.view.bounds;
    //...
}


//update _textViewFrame variable when the keyboard is shown

#pragma mark - UITextView 델리게이트 메소드

- (void)textViewDidBeginEditing:(UITextView *)textView 
{
    //텍스트 뷰 사이즈 조정
    [UIView animateWithDuration:0.3 animations:^{
        _textViewFrame = self.view.bounds;
        _textViewFrame.size.height -= 216.0f; //reduces the height of the on-screen keyboard
        _textView.frame = _textViewFrame;
    }];
}


//return the text view frame to its original size when editing finishes

- (void)textViewDidEndEditing:(UITextView *)textView
{
    //copy the updated note text to the underlying model
    self.note.contents = textView.text;
    
    _textViewFrame = self.view.bounds;
    _textView.frame = _textViewFrame;
}