yunjingIOS/ybvideoios/YBVideo/功能/极光消息/单聊/View/JCHATMessageTextView.m

//
//  JCHATMessageTextView.m
//  JPush IM
//
//  Created by Apple on 15/1/14.
//  Copyright (c) 2015年 Apple. All rights reserved.
//

#import "JCHATMessageTextView.h"
#import "JChatConstants.h"
#import "JCHATAlertToSendImage.h"

@implementation JCHATMessageTextView
#pragma mark - Setters

- (void)setPlaceHolder:(NSString *)placeHolder {
    if([placeHolder isEqualToString:_placeHolder]) {
        return;
    }

    NSUInteger maxChars = [JCHATMessageTextView maxCharactersPerLine];
    if([placeHolder length] > maxChars) {
        placeHolder = [placeHolder substringToIndex:maxChars - 8];
        placeHolder = [[placeHolder stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] stringByAppendingFormat:@"..."];
    }

    _placeHolder = placeHolder;
    [self setNeedsDisplay];
}
- (UIResponder *)nextResponder {
    if(_overrideNextResponder == nil){
        return [super nextResponder];
    } else {
        return _overrideNextResponder;
    }
}
-(BOOL)canPerformAction:(SEL)action withSender:(id)sender{
    if (_overrideNextResponder != nil) {
        return NO;
    }
    if(action ==@selector(copy:) ||
       action ==@selector(selectAll:)||
       action ==@selector(cut:)||
       action ==@selector(select:)||
       action ==@selector(paste:)) {
        return[super canPerformAction:action withSender:sender];
    }
    return NO;
}
/*
//"反馈"关心的功能
-(BOOL)canPerformAction:(SEL)action withSender:(id)sender{
    return (action == @selector(paste:));
}

- (void)paste:(id)sender {
    UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
    NSTextAttachment *textAttachment = [NSTextAttachment new];
    if (pasteboard.string != nil) {
        [super paste:sender];
        return;
    }
    if (pasteboard.image != nil) {
        textAttachment.image = pasteboard.image;
        NSAttributedString *attString = [NSAttributedString attributedStringWithAttachment:textAttachment];
        [[JCHATAlertToSendImage shareInstance] showInViewWith:pasteboard.image];
    }
}
*/
- (void)setPlaceHolderTextColor:(UIColor *)placeHolderTextColor {
    if([placeHolderTextColor isEqual:_placeHolderTextColor]) {
        return;
    }
    
    _placeHolderTextColor = placeHolderTextColor;
    [self setNeedsDisplay];
}

#pragma mark - Message text view

- (NSUInteger)numberOfLinesOfText {
    return [JCHATMessageTextView numberOfLinesForMessage:self.text];
}

+ (NSUInteger)maxCharactersPerLine {
    return ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPhone) ? 33 : 109;
}

+ (NSUInteger)numberOfLinesForMessage:(NSString *)text {
    return (text.length / [JCHATMessageTextView maxCharactersPerLine]) + 1;
}

#pragma mark - Text view overrides

- (void)setText:(NSString *)text {
    [super setText:text];
    [self setNeedsDisplay];
}

- (void)setAttributedText:(NSAttributedString *)attributedText {
    [super setAttributedText:attributedText];
    [self setNeedsDisplay];
}

- (void)setContentInset:(UIEdgeInsets)contentInset {
    [super setContentInset:contentInset];
    [self setNeedsDisplay];
}

- (void)setFont:(UIFont *)font {
    JCHATMAINTHREAD(^{
        [super setFont:font];
        [self setNeedsDisplay];
    });
    
}

- (void)setTextAlignment:(NSTextAlignment)textAlignment {
    [super setTextAlignment:textAlignment];
    [self setNeedsDisplay];
}

#pragma mark - Notifications

- (void)didReceiveTextDidChangeNotification:(NSNotification *)notification {
    [self setNeedsDisplay];
}

#pragma mark - Life cycle

- (void)setup {
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(didReceiveTextDidChangeNotification:)
                                                 name:UITextViewTextDidChangeNotification
                                               object:self];
    
    _placeHolderTextColor = [UIColor lightGrayColor];
    
    self.autoresizingMask = UIViewAutoresizingFlexibleWidth;
    self.scrollIndicatorInsets = UIEdgeInsetsMake(4.0f, 0.0f, 4.0f, 8.0f);
    self.contentInset = UIEdgeInsetsZero;
    self.scrollEnabled = YES;
    self.scrollsToTop = NO;
    self.userInteractionEnabled = YES;
    self.font = [UIFont systemFontOfSize:16.0f];
    self.textColor = [UIColor blackColor];
    self.backgroundColor = [UIColor whiteColor];
    self.keyboardAppearance = UIKeyboardAppearanceDefault;
    self.keyboardType = UIKeyboardTypeDefault;
    self.returnKeyType = UIReturnKeyDefault;
    self.textAlignment = NSTextAlignmentLeft;
    self.layer.cornerRadius = 6;
    [self.layer setMasksToBounds:YES];
}
-(void)awakeFromNib {
    [super awakeFromNib];
    [self setup];
}
- (id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        [self setup];
    }
    return self;
}

- (void)dealloc {
    _placeHolder = nil;
    _placeHolderTextColor = nil;
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UITextViewTextDidChangeNotification object:self];
}

#pragma mark - Drawing

- (void)drawRect:(CGRect)rect {
    [super drawRect:rect];
    
    if([self.text isEqual:@""]) {
        CGRect placeHolderRect = CGRectMake(8.0f,
                                            7.0f,
                                            rect.size.width,
                                            rect.size.height);
        
        [self.placeHolderTextColor set];
        
        if (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_6_0) {
            NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
            paragraphStyle.lineBreakMode = NSLineBreakByTruncatingTail;
            paragraphStyle.alignment = self.textAlignment;
            [self.placeHolder drawInRect:placeHolderRect
                          withAttributes:@{ NSFontAttributeName : self.font,
                                            NSForegroundColorAttributeName : self.placeHolderTextColor,
                                            NSParagraphStyleAttributeName : paragraphStyle }];
        }
        else {
            NSMutableParagraphStyle *paragraphStyle= [[NSMutableParagraphStyle alloc] init];
            paragraphStyle.lineBreakMode = NSLineBreakByTruncatingTail;
            paragraphStyle.alignment = self.textAlignment;
            [self.placeHolder drawInRect:placeHolderRect withAttributes:@{NSFontAttributeName:self.font,NSParagraphStyleAttributeName:paragraphStyle}];
        }
    }
}

/*
 // Only override drawRect: if you perform custom drawing.
 // An empty implementation adversely affects performance during animation.
 - (void)drawRect:(CGRect)rect {
 // Drawing code
 }
 */

@end