WHToolView自定义工具栏

在开始之前我们先分析一下UITabBarController的UITabBar的基本层次。UITabBar继承自UIView，负责UITabBarController.viewControllers中每个 UIViewController.UITabBarItem的管理和显示。而UITabBarItem<-UIBarItem<-NSObject，组装了UITabBar显示的每个对象的title,imang,selectedImage以及badgeValue等数据。UITabBar的代理UITabBarDelegate在tabbar显示流程中和点击了UITabBarItem对象的时候回调给委托者。

在理解清楚了内部机制的时候我们可以整理我们自己的思路了。首先需要一个类似UITabBarItem的对象进行数据的组装，再者需要一个UIView绘制组装的数据。
为了便于区分：我们暂定义WHToolItem<-NSObject,WHToolView<-UIView两个类。

@interface WHToolItem : NSObject
@property (nonatomic, retain) UIImage *image;
@property (nonatomic, retain) UIImage *selectedImage;
@property (nonatomic, retain) NSString *title;
- (instancetype)initWithImage:(NSString *)image selectedImage:(NSString *)selectedImage title:(NSString *)title;
@end

@implementation WHToolItem
- (void)dealloc{
    self.image = nil;
    self.selectedImage = nil;
    self.title = nil;
    [super dealloc];
}
- (instancetype)initWithImage:(NSString *)image selectedImage:(NSString *)selectedImage title:(NSString *)title{
    if(self = [super init]){
        self.image = [UIImage imageNamed:image];
        self.selectedImage = [UIImage imageNamed:selectedImage];
        self.title = title;
    }
    return self;
}
@end

ypedef void(^WHToolViewActionHandler)(WHToolView *toolView, NSInteger indexPath, BOOL animated);
@interface WHToolView : UIView
@property (nonatomic, copy) WHToolViewActionHandler actionHandler;
- (instancetype)initWithToolItem:(NSMutableArray *)arrToolItem indexPath:(NSInteger)indexPath;
- (void)reloadBadge:(NSString *)badge atIndexPath:(NSInteger)indexPath;
@end

@implementation WHToolView
- (void)dealloc{
    self.arrToolItem = nil;
    self.actionHandler = nil;
    self.dicToolView = nil;
    [super dealloc];
}

- (id)initWithToolItem:(NSMutableArray *)arrToolItem indexPath:(NSInteger)indexPath{
    if(self = [super initWithFrame:frame]){
        self.arrToolItem = arrToolItem;
        self.indexPath = indexPath;
        
        self.tapGesture = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureAction:)] autorelease];
        [self addGestureRecognizer:_tapGesture];
    }
    return self;
}

- (void)tapGestureAction:(UITapGestureRecognizer *)tapGesture{
    CGPoint point = [tapGesture locationInView:self];
    if(CGRectContainsPoint(self.bounds, point)){
        NSInteger indexPath = point.x*_arrToolItem.count/CGRectGetWidth(self.bounds);
        if(indexPath != _indexPath){
            self.indexPath = indexPath;
            [self reloadBadge:@"" atIndexPath:_indexPath];
            
            [self setNeedsDisplay];
            if(_actionHandler){
                self.actionHandler(self, _indexPath, NO);
            }
        }
    }
}

- (void)reloadBadge:(NSString *)badge atIndexPath:(NSInteger)indexPath{
    if((_arrToolItem != nil) && (_arrToolItem.count > 0) && (indexPath >= 0) && (indexPath < _arrToolItem.count)){
        self.dicToolView =  [NSMutableDictionary dictionaryWithDictionary:[[NSUserDefaults standardUserDefaults] objectForKey:@"toolView"]];
        if(badge.length > 0){
            [_dicToolView setObject:badge forKey:[NSString stringWithFormat:@"indexPath%@",@(indexPath)]];
        }
        else{
            [_dicToolView removeObjectForKey:[NSString stringWithFormat:@"indexPath%@",@(indexPath)]];
        }
        [[NSUserDefaults standardUserDefaults] setObject:_dicToolView forKey:@"toolView"];
        [[NSUserDefaults standardUserDefaults] synchronize];
        [self setNeedsDisplay];
    }
}

- (void)drawRect:(CGRect)rect{
    CGContextRef content = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(content, 0.5);
    CGContextSetStrokeColorWithColor(content, [UIColor lightGrayColor].CGColor);
    CGContextMoveToPoint(content, 0, 0+0.5/2);
    CGContextAddLineToPoint(content, CGRectGetWidth(self.bounds), 0+0.5/2);
    CGContextDrawPath(content, kCGPathStroke);
    
    if(_arrToolItem != nil && _arrToolItem.count > 0){
        CGFloat widthItem = CGRectGetWidth(self.bounds)/_arrToolItem.count;
        CGFloat topItem = 4;
        NSDictionary *dicToolView = [[NSUserDefaults standardUserDefaults] objectForKey:@"toolView"];
        
        for(NSInteger loop = 0; loop < _arrToolItem.count; loop++){
            WHToolItem *toolItem = [_arrToolItem objectAtIndex:loop];
            UIImage *image = nil;
            NSString *title = toolItem.title;
            if(_indexPath == loop){
                image = toolItem.selectedImage;
                [KMainViewColor set];
            }
            else{
                image = toolItem.image;
                [KTitleColorBlack set];
            }
            if(image){
                [image drawInRect:CGRectMake(widthItem*loop+(widthItem-26)/2,topItem,26,26) blendMode:kCGBlendModeNormal alpha:0.70];
            }
            
            if(title.length > 0){
                [title drawInCenter:CGRectMake(0+widthItem*loop, 28, widthItem, 22) withFont:[UIFont systemFontOfSize:11] alignment:NSTextAlignmentCenter];
            }
            
            NSString *aKey = [NSString stringWithFormat:@"indexPath%@",@(loop).stringValue];
            NSString *badge = [dicToolView objectForKey: aKey];
            if(badge.length){
                CGContextSetFillColorWithColor(content, [UIColor redColor].CGColor);
                CGContextAddPath(content, [UIBezierPath bezierPathWithRoundedRect:CGRectMake(widthItem*(loop+0.5)+12, topItem, 8, 8) cornerRadius:4].CGPath);
                CGContextDrawPath(content, kCGPathFill);
            }
        }
    }
}
@end