#import <UIKit/UIKit.h>
@class FSTextView;
typedef void(^FSTextViewHandler)(FSTextView *textView);
IB_DESIGNABLE
@interface FSTextView : UITextView
/**
便利构造器.
*/
+ (instancetype)textView;
/**
设定文本改变Block回调. (切记弱化引用, 以免造成内存泄露.)
*/
- (void)addTextDidChangeHandler:(FSTextViewHandler)eventHandler;
/**
设定达到最大长度Block回调. (切记弱化引用, 以免造成内存泄露.)
*/
- (void)addTextLengthDidMaxHandler:(FSTextViewHandler)maxHandler;
/**
最大限制文本长度, 默认为无穷大, 即不限制, 如果被设为 0 也同样表示不限制字符数.
*/
@property (nonatomic, assign) IBInspectable NSUInteger maxLength;
/**
圆角半径.
*/
@property (nonatomic, assign) IBInspectable CGFloat cornerRadius;
/**
边框宽度.
*/
@property (nonatomic, assign) IBInspectable CGFloat borderWidth;
/**
边框颜色.
*/
@property (nonatomic, strong) IBInspectable UIColor *borderColor;
/**
placeholder, 会自适应TextView宽高以及横竖屏切换, 字体默认和TextView一致.
*/
@property (nonatomic, copy) IBInspectable NSString *placeholder;
/**
placeholder文本颜色, 默认为#C7C7CD.
*/
@property (nonatomic, strong) IBInspectable UIColor *placeholderColor;
/**
placeholder文本字体, 默认为UITextView的默认字体.
*/
@property (nonatomic, strong) UIFont *placeholderFont;
/**
是否允许长按弹出UIMenuController, 默认为YES.
*/
@property (nonatomic, assign, getter=isCanPerformAction) BOOL canPerformAction;
/**
该属性返回一个经过处理的 `self.text` 的值, 去除了首位的空格和换行.
*/
@property (nonatomic, readonly) NSString *formatText;
@end
#import "FSTextView.h"
CGFloat const kFSTextViewPlaceholderVerticalMargin = 8.0; ///< placeholder垂直方向边距
CGFloat const kFSTextViewPlaceholderHorizontalMargin = 6.0; ///< placeholder水平方向边距
@interface FSTextView ()
@property (nonatomic, copy) FSTextViewHandler changeHandler; ///< 文本改变Block
@property (nonatomic, copy) FSTextViewHandler maxHandler; ///< 达到最大限制字符数Block
@property (nonatomic, strong) UILabel *placeholderLabel; ///< placeholderLabel
@end
@implementation FSTextView
#pragma mark - Override
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
_changeHandler = NULL;
_maxHandler = NULL;
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
if (!(self = [super initWithCoder:aDecoder])) return nil;
if ([[[UIDevice currentDevice] systemVersion] compare:@"10.0" options:NSNumericSearch] != NSOrderedAscending) {
[self layoutIfNeeded];
}
[self initialize];
return self;
}
- (instancetype)initWithFrame:(CGRect)frame
{
if (!(self = [super initWithFrame:frame])) return nil;
[self initialize];
return self;
}
- (BOOL)becomeFirstResponder
{
BOOL become = [super becomeFirstResponder];
// 成为第一响应者时注册通知监听文本变化
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange:) name:UITextViewTextDidChangeNotification object:nil];
return become;
}
- (BOOL)resignFirstResponder
{
BOOL resign = [super resignFirstResponder];
// 注销第一响应者时移除文本变化的通知, 以免影响其它的`UITextView`对象.
[[NSNotificationCenter defaultCenter] removeObserver:self name:UITextViewTextDidChangeNotification object:nil];
return resign;
}
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
BOOL result = [super canPerformAction:action withSender:sender];
if (result) {
if (![self respondsToSelector:action]) {
result = NO;
} else {
result = _canPerformAction;
}
}
return result;
}
#pragma mark - Private
- (void)initialize
{
// 基本配置 (需判断是否在Storyboard中设置了值)
_canPerformAction = YES;
if (_maxLength == 0 || _maxLength == NSNotFound) {
_maxLength = NSUIntegerMax;
}
if (!_placeholderColor) {
_placeholderColor = [UIColor colorWithRed:0.780 green:0.780 blue:0.804 alpha:1.000];
}
// 基本设定 (需判断是否在Storyboard中设置了值)
if (!self.backgroundColor) {
self.backgroundColor = [UIColor whiteColor];
}
if (!self.font) {
self.font = [UIFont systemFontOfSize:15.f];
}
// placeholderLabel
self.placeholderLabel.font = self.font;
self.placeholderLabel.text = _placeholder; // 可能在Storyboard中设置了Placeholder
self.placeholderLabel.textColor = _placeholderColor;
[self addSubview:self.placeholderLabel];
// constraint
[self addConstraint:[NSLayoutConstraint constraintWithItem:self.placeholderLabel
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self
attribute:NSLayoutAttributeTop
multiplier:1.0
constant:kFSTextViewPlaceholderVerticalMargin]];
[self addConstraint:[NSLayoutConstraint constraintWithItem:self.placeholderLabel
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:self
attribute:NSLayoutAttributeLeft
multiplier:1.0
constant:kFSTextViewPlaceholderHorizontalMargin]];
[self addConstraint:[NSLayoutConstraint constraintWithItem:self.placeholderLabel
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationLessThanOrEqual
toItem:self
attribute:NSLayoutAttributeWidth
multiplier:1.0
constant:-kFSTextViewPlaceholderHorizontalMargin*2]];
[self addConstraint:[NSLayoutConstraint constraintWithItem:self.placeholderLabel
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationLessThanOrEqual
toItem:self
attribute:NSLayoutAttributeHeight
multiplier:1.0
constant:-kFSTextViewPlaceholderVerticalMargin*2]];
}
#pragma mark - Getter
/// 返回一个经过处理的 `self.text` 的值, 去除了首位的空格和换行.
- (NSString *)formatText
{
return [[super text] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; // 去除首尾的空格和换行.
}
- (UILabel *)placeholderLabel
{
if (!_placeholderLabel) {
_placeholderLabel = [[UILabel alloc] init];
_placeholderLabel.numberOfLines = 0;
_placeholderLabel.translatesAutoresizingMaskIntoConstraints = NO;
}
return _placeholderLabel;
}
#pragma mark - Setter
- (void)setText:(NSString *)text
{
[super setText:text];
self.placeholderLabel.hidden = [@(text.length) boolValue];
// 手动模拟触发通知
NSNotification *notification = [NSNotification notificationWithName:UITextViewTextDidChangeNotification object:self];
[self textDidChange:notification];
}
- (void)setFont:(UIFont *)font
{
[super setFont:font];
self.placeholderLabel.font = font;
}
- (void)setMaxLength:(NSUInteger)maxLength
{
_maxLength = fmax(0, maxLength);
self.text = self.text;
}
- (void)setCornerRadius:(CGFloat)cornerRadius
{
_cornerRadius = cornerRadius;
self.layer.cornerRadius = _cornerRadius;
}
- (void)setBorderColor:(UIColor *)borderColor
{
if (!borderColor) return;
_borderColor = borderColor;
self.layer.borderColor = _borderColor.CGColor;
}
- (void)setBorderWidth:(CGFloat)borderWidth
{
_borderWidth = borderWidth;
self.layer.borderWidth = _borderWidth;
}
- (void)setPlaceholder:(NSString *)placeholder
{
if (!placeholder) return;
_placeholder = [placeholder copy];
if (_placeholder.length > 0) {
self.placeholderLabel.text = _placeholder;
}
}
- (void)setPlaceholderColor:(UIColor *)placeholderColor
{
if (!placeholderColor) return;
_placeholderColor = placeholderColor;
self.placeholderLabel.textColor = _placeholderColor;
}
- (void)setPlaceholderFont:(UIFont *)placeholderFont
{
if (!placeholderFont) return;
_placeholderFont = placeholderFont;
self.placeholderLabel.font = _placeholderFont;
}
#pragma mark - NSNotification
- (void)textDidChange:(NSNotification *)notification
{
// 通知回调的实例的不是当前实例的话直接返回
if (notification.object != self) return;
// 根据字符数量显示或者隐藏 `placeholderLabel`
self.placeholderLabel.hidden = [@(self.text.length) boolValue];
// 禁止第一个字符输入空格或者换行
if (self.text.length == 1) {
if ([self.text isEqualToString:@" "] || [self.text isEqualToString:@"\n"]) {
self.text = @"";
}
}
// 只有当maxLength字段的值不为无穷大整型也不为0时才计算限制字符数.
if (_maxLength != NSUIntegerMax && _maxLength != 0 && self.text.length > 0) {
if (!self.markedTextRange && self.text.length > _maxLength) {
!_maxHandler ?: _maxHandler(self); // 回调达到最大限制的Block.
self.text = [self.text substringToIndex:_maxLength]; // 截取最大限制字符数.
[self.undoManager removeAllActions]; // 达到最大字符数后清空所有 undoaction, 以免 undo 操作造成crash.
}
}
// 回调文本改变的Block.
!_changeHandler ?: _changeHandler(self);
}
#pragma mark - Public
+ (instancetype)textView
{
return [[self alloc] init];
}
- (void)addTextDidChangeHandler:(FSTextViewHandler)changeHandler
{
_changeHandler = [changeHandler copy];
}
- (void)addTextLengthDidMaxHandler:(FSTextViewHandler)maxHandler
{
_maxHandler = [maxHandler copy];
}
@end
