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@nicpro85
Created October 27, 2014 11:25
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UIPlaceholderTextView
//
// UIPlaceholderTextView.h
//
// Created by Nicolas Manzini on 27.10.14.
// Free under MIT
//
#import <UIKit/UIKit.h>
@interface UIPlaceholderTextView : UITextView
@property (strong, nonatomic) NSAttributedString * attributedPlaceholder;
@property (assign, nonatomic) CGPoint placeholderOffset;
@end
//
// UIPlaceholderTextView.m
//
// Created by Nicolas Manzini on 27.10.14.
// Free under MIT
//
#import "UIPlaceholderTextView.h"
const CGPoint defaultPlaceholderOffset = {5.f,7.f};
@interface UIPlaceholderTextView ()
@property (strong, nonatomic) UILabel * labelPlaceholder;
- (void)textDidChange:(NSNotification *)note;
- (void)initLabelPlaceholder;
@end
@implementation UIPlaceholderTextView
- (id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
_placeholderOffset = defaultPlaceholderOffset;
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange:) name:UITextViewTextDidChangeNotification object:nil];
[self initLabelPlaceholder];
}
return self;
}
- (instancetype)init {
self = [super init];
if (self) {
_placeholderOffset = defaultPlaceholderOffset;
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange:) name:UITextViewTextDidChangeNotification object:nil];
[self initLabelPlaceholder];
}
return self;
}
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
_placeholderOffset = defaultPlaceholderOffset;
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange:) name:UITextViewTextDidChangeNotification object:nil];
[self initLabelPlaceholder];
}
return self;
}
- (instancetype)initWithFrame:(CGRect)frame textContainer:(NSTextContainer *)textContainer {
self = [super initWithFrame:frame textContainer:textContainer];
if (self) {
_placeholderOffset = defaultPlaceholderOffset;
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange:) name:UITextViewTextDidChangeNotification object:nil];
[self initLabelPlaceholder];
}
return self;
}
- (void)initLabelPlaceholder {
UIEdgeInsets insets = self.contentInset;
CGPoint offset = self.contentOffset;
CGPoint pOffset = self.placeholderOffset;
UILabel * label = [[UILabel alloc] initWithFrame:CGRectMake(insets.left+offset.x+pOffset.x, insets.top+ offset.y+pOffset.y, 0.f, 0.f)];
label.backgroundColor = [UIColor clearColor];
label.userInteractionEnabled = NO;
[self addSubview:label];
self.labelPlaceholder = label;
}
- (void)setPlaceholderOffset:(CGPoint)placeholderOffset {
CGPoint previousOffset = _placeholderOffset;
_placeholderOffset = placeholderOffset;
CGRect frame = self.labelPlaceholder.frame;
frame.origin.x -= previousOffset.x;
frame.origin.x += placeholderOffset.x;
frame.origin.y -= previousOffset.y;
frame.origin.x += placeholderOffset.y;
self.labelPlaceholder.frame = frame;
}
- (void)textDidChange:(NSNotification *)note {
if (note.object == self) {
self.labelPlaceholder.hidden = self.text.length;
}
}
- (void)setAttributedPlaceholder:(NSAttributedString *)attributedPlaceholder {
_attributedPlaceholder = attributedPlaceholder;
self.labelPlaceholder.attributedText = attributedPlaceholder;
if (attributedPlaceholder) {
[self resizeLabelPlaceholder];
}
}
- (void)resizeLabelPlaceholder {
NSStringDrawingContext * context = [NSStringDrawingContext new];
context.minimumScaleFactor = 0.f;
CGRect bounds =
[self.labelPlaceholder.attributedText boundingRectWithSize:self.bounds.size
options:NSStringDrawingUsesLineFragmentOrigin
context:context];
CGRect frame = self.labelPlaceholder.frame;
frame.size.height = bounds.size.height;
frame.size.width = bounds.size.width;
self.labelPlaceholder.frame = frame;
}
- (void)setFrame:(CGRect)frame {
[super setFrame:frame];
[self resizeLabelPlaceholder];
}
- (void)setBounds:(CGRect)bounds {
[super setBounds:bounds];
[self resizeLabelPlaceholder];
}
- (void)dealloc {
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
@end
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