#import "SimpleCoreTextView.h"

#import <QuartzCore/CALayer.h>

#pragma mark SimpleCoreTextView class extension

@interface SimpleCoreTextView ()

@property (nonatomic, retain) NSDictionary *attributes;

- (void)clearPreviousLayoutInformation;

- (void)textChanged;

+ (UIColor *)selectionColor;

+ (UIColor *)caretColor;

#pragma mark SimpleCaretView definition

@interface SimpleCaretView : UIView {

NSTimer *_blinkTimer;

}

- (void)delayBlink;

#pragma mark SimpleCoreTextView implementation

@implementation SimpleCoreTextView

@synthesize text = _text;

@synthesize font = _font;

@synthesize editing = _editing;

@synthesize markedTextRange = _markedTextRange;

@synthesize selectedTextRange = _selectedTextRange;

@synthesize attributes = _attributes;

- (id)initWithFrame:(CGRect)frame {

if ((self = [super initWithFrame:frame])) {

self.layer.geometryFlipped = YES; // For ease of interaction with the CoreText coordinate system.

self.text = @"";

self.font = [UIFont systemFontOfSize:18];

self.backgroundColor = [UIColor clearColor];

_caretView = [[SimpleCaretView alloc] initWithFrame:CGRectZero];

}

return self;

}

- (void)dealloc

{

self.text = nil;

self.font = nil;

self.attributes = nil;

[_caretView release];

[super dealloc];

}

- (void)clearPreviousLayoutInformation

{

if (_framesetter != NULL) {

CFRelease(_framesetter);

_framesetter = NULL;

}

if (_frame != NULL) {

CFRelease(_frame);

_frame = NULL;

}

}

- (void)setFont:(UIFont *)font

{

UIFont *oldFont = _font;

_font = [font retain];

// Find matching CTFont via name and size

CTFontRef ctFont = CTFontCreateWithName((CFStringRef) self.font.fontName, self.font.pointSize, NULL);

// Set CTFont instance in our attributes dictionary, to be set on our attributed string

self.attributes = [[NSDictionary dictionaryWithObject:(id)ctFont forKey:(NSString *)kCTFontAttributeName] retain];

CFRelease(ctFont);

[self textChanged];

[oldFont release];

}

- (void)textChanged

{

[self setNeedsDisplay];

[self clearPreviousLayoutInformation];

// Build the attributed string from our text data and string attribute data

NSAttributedString *attributedString = [[NSAttributedString alloc] initWithString:self.text attributes:self.attributes];

// Create the Core Text framesetter using the attributed string

_framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attributedString);

// Create the Core Text frame using our current view rect bounds

UIBezierPath *path = [UIBezierPath bezierPathWithRect:self.bounds];

_frame = CTFramesetterCreateFrame(_framesetter, CFRangeMake(0, 0), [path CGPath], NULL);

[attributedString release];

}

- (NSString *)text {

return _text;

}

- (void)setText:(NSString *)text

{

NSString *oldText = _text;

_text = [text copy];

[oldText release];

// We need to call textChanged after setting the new property text to update layout

[self textChanged];

}

- (NSRange)RangeIntersection:(NSRange)first withSecond:(NSRange)second

{

NSRange result = NSMakeRange(NSNotFound, 0);

// Ensure first range does not start after second range

if (first.location > second.location) {

NSRange tmp = first;

first = second;

second = tmp;

}

// Find the overlap intersection range between first and second

if (second.location < first.location + first.length) {

result.location = second.location;

NSUInteger end = MIN(first.location + first.length, second.location + second.length);

result.length = end - result.location;

}

return result;

}

- (void)drawRangeAsSelection:(NSRange)selectionRange

{

// If not in editing mode, we do not draw selection rects

if (!self.editing)

return;

// If selection range empty, do not draw

if (selectionRange.length == 0 || selectionRange.location == NSNotFound)

return;

// set the fill color to the selection color

[[SimpleCoreTextView selectionColor] setFill];

// Iterate over the lines in our CTFrame, looking for lines that intersect

// with the given selection range, and draw a selection rect for each intersection

NSArray *lines = (NSArray *) CTFrameGetLines(_frame);

for (int i = 0; i < [lines count]; i++) {

CTLineRef line = (CTLineRef) [lines objectAtIndex:i];

CFRange lineRange = CTLineGetStringRange(line);

NSRange range = NSMakeRange(lineRange.location, lineRange.length);

NSRange intersection = [self RangeIntersection:range withSecond:selectionRange];

if (intersection.location != NSNotFound && intersection.length > 0) {

// The text range for this line intersects our selection range

CGFloat xStart = CTLineGetOffsetForStringIndex(line, intersection.location, NULL);

CGFloat xEnd = CTLineGetOffsetForStringIndex(line, intersection.location + intersection.length, NULL);

CGPoint origin;

// Get coordinate and bounds information for the intersection text range

CTFrameGetLineOrigins(_frame, CFRangeMake(i, 0), &origin);

CGFloat ascent, descent;

CTLineGetTypographicBounds(line, &ascent, &descent, NULL);

// Create a rect for the intersection and draw it with selection color

CGRect selectionRect = CGRectMake(xStart, origin.y - descent, xEnd - xStart, ascent + descent);

UIRectFill(selectionRect);

}

}

}

- (void)drawRect:(CGRect)rect

{

// First draw selection / marked text, then draw text

[self drawRangeAsSelection:_selectedTextRange];

[self drawRangeAsSelection:_markedTextRange];

CTFrameDraw(_frame, UIGraphicsGetCurrentContext());

}

- (NSInteger)closestIndexToPoint:(CGPoint)point

{

// Use Core Text to find the text index for a given CGPoint by

// iterating over the y-origin points for each line, finding the closest

// line, and finding the closest index within that line.

NSArray *lines = (NSArray *) CTFrameGetLines(_frame);

CGPoint origins[lines.count];

CTFrameGetLineOrigins(_frame, CFRangeMake(0, lines.count), origins);

for (int i = 0; i < lines.count; i++) {

if (point.y > origins[i].y) {

// This line origin is closest to the y-coordinate of our point,

// now look for the closest string index in this line.

CTLineRef line = (CTLineRef) [lines objectAtIndex:i];

return CTLineGetStringIndexForPosition(line, point);

}

}

return _text.length;

}

- (CGRect)caretRectForIndex:(int)index

{

NSArray *lines = (NSArray *) CTFrameGetLines(_frame);

// Special case, no text

if (_text.length == 0) {

CGPoint origin = CGPointMake(CGRectGetMinX(self.bounds), CGRectGetMaxY(self.bounds) - self.font.leading);

// Note: using fabs() for typically negative descender from fonts

return CGRectMake(origin.x, origin.y - fabs(self.font.descender), 3, self.font.ascender + fabs(self.font.descender));

}

// Special case, insertion point at final position in text after newline

if (index == _text.length && [_text characterAtIndex:(index - 1)] == '\n') {

CTLineRef line = (CTLineRef) [lines lastObject];

CFRange range = CTLineGetStringRange(line);

CGFloat xPos = CTLineGetOffsetForStringIndex(line, range.location, NULL);

CGPoint origin;

CGFloat ascent, descent;

CTLineGetTypographicBounds(line, &ascent, &descent, NULL);

CTFrameGetLineOrigins(_frame, CFRangeMake(lines.count - 1, 0), &origin);

// Place point after last line, including any font leading spacing if applicable

origin.y -= self.font.leading;

return CGRectMake(xPos, origin.y - descent, 3, ascent + descent);

}

// Regular case, caret somewhere within our text content range

for (int i = 0; i < [lines count]; i++) {

CTLineRef line = (CTLineRef) [lines objectAtIndex:i];

CFRange range = CTLineGetStringRange(line);

NSInteger localIndex = index - range.location;

if (localIndex >= 0 && localIndex <= range.length) {

// index is in the range for this line

CGFloat xPos = CTLineGetOffsetForStringIndex(line, index, NULL);

CGPoint origin;

CGFloat ascent, descent;

CTLineGetTypographicBounds(line, &ascent, &descent, NULL);

CTFrameGetLineOrigins(_frame, CFRangeMake(i, 0), &origin);

// Make a small "caret" rect at the index position

return CGRectMake(xPos, origin.y - descent, 3, ascent + descent);

}

}

return CGRectNull;

}

- (CGRect)firstRectForNSRange:(NSRange)range;

{

NSInteger index = range.location;

// Iterate over our CTLines, looking for the line that encompasses the given range

NSArray *lines = (NSArray *) CTFrameGetLines(_frame);

for (int i = 0; i < [lines count]; i++) {

CTLineRef line = (CTLineRef) [lines objectAtIndex:i];

CFRange lineRange = CTLineGetStringRange(line);

NSInteger localIndex = index - lineRange.location;

if (localIndex >= 0 && localIndex < lineRange.length) {

// For this sample, we use just the first line that intersects range

NSInteger finalIndex = MIN(lineRange.location + lineRange.length, range.location + range.length);

// Create a rect for the given range within this line

CGFloat xStart = CTLineGetOffsetForStringIndex(line, index, NULL);

CGFloat xEnd = CTLineGetOffsetForStringIndex(line, finalIndex, NULL);

CGPoint origin;

CTFrameGetLineOrigins(_frame, CFRangeMake(i, 0), &origin);

CGFloat ascent, descent;

CTLineGetTypographicBounds(line, &ascent, &descent, NULL);

return CGRectMake(xStart, origin.y - descent, xEnd - xStart, ascent + descent);

}

}

return CGRectNull;

}

- (void)selectionChanged

{

// If not in editing mode, we don't show the caret

if (!self.editing) {

[_caretView removeFromSuperview];

return;

}

// If there is no selection range (always true for this sample), find the

// insert point rect and create a caretView to draw the caret at this position

if (self.selectedTextRange.length == 0) {

_caretView.frame = [self caretRectForIndex:self.selectedTextRange.location];

if (!_caretView.superview) {

[self addSubview:_caretView];

[self setNeedsDisplay];

}

// Set up a timer to "blink" the caret

[_caretView delayBlink];

} else {

// If there is an actual selection, don't draw the insertion caret too

[_caretView removeFromSuperview];

[self setNeedsDisplay];

}

if (self.markedTextRange.location != NSNotFound) {

[self setNeedsDisplay];

}

}

- (NSRange)markedTextRange

{

return _markedTextRange;

}

- (void)setMarkedTextRange:(NSRange)range

{

_markedTextRange = range;

// Call selectionChanged to update view if necessary

[self selectionChanged];

}

- (NSRange)selectedTextRange

{

return _selectedTextRange;

}

- (void)setSelectedTextRange:(NSRange)range

{

_selectedTextRange = range;

// Call selectionChanged to update view if necessary

[self selectionChanged];

}

- (BOOL)isEditing

{

return _editing;

}

- (void)setEditing:(BOOL)editing

{

_editing = editing;

// Call selectionChanged to update view if necessary

[self selectionChanged];

}

+ (UIColor *)selectionColor

{

static UIColor *color = nil;

if (color == nil) {

color = [[UIColor alloc] initWithRed:0.25 green:0.50 blue:1.0 alpha:0.50];

}

return color;

}

+ (UIColor *)caretColor

{

static UIColor *color = nil;

if (color == nil) {

color = [[UIColor alloc] initWithRed:0.25 green:0.50 blue:1.0 alpha:1.0];

}

return color;

}

#pragma mark SimpleCaretView implementation

@implementation SimpleCaretView

static const NSTimeInterval InitialBlinkDelay = 0.7;

static const NSTimeInterval BlinkRate = 0.5;

- (id)initWithFrame:(CGRect)frame {

if ((self = [super initWithFrame:frame])) {

self.backgroundColor = [SimpleCoreTextView caretColor];

}

return self;

}

- (void)blink

{

self.hidden = !self.hidden;

}

- (void)didMoveToSuperview

{

self.hidden = NO;

if (self.superview) {

_blinkTimer = [[NSTimer scheduledTimerWithTimeInterval:BlinkRate target:self selector:@selector(blink) userInfo:nil repeats:YES] retain];

[self delayBlink];

} else {

[_blinkTimer invalidate];

[_blinkTimer release];

_blinkTimer = nil;

}

}

- (void)dealloc

{

[_blinkTimer invalidate];

[_blinkTimer release];

[super dealloc];

}

- (void)delayBlink

{

self.hidden = NO;

[_blinkTimer setFireDate:[NSDate dateWithTimeIntervalSinceNow:InitialBlinkDelay]];

}