#import <UIKit/UIKit.h>

// 定义一个枚举（包含了四种类型的button）
typedef NS_ENUM(NSUInteger, MKButtonEdgeInsetsStyle) {
    MKButtonEdgeInsetsStyleTop, // image在上，label在下
    MKButtonEdgeInsetsStyleLeft, // image在左，label在右
    MKButtonEdgeInsetsStyleBottom, // image在下，label在上
    MKButtonEdgeInsetsStyleRight // image在右，label在左
};

@interface UIButton (ImageTitleSpace)

/**
 * 设置button的titleLabel和imageView的布局样式，及间距
 *
 * @param style titleLabel和imageView的布局样式
 * @param space titleLabel和imageView的间距
 */
- (void)layoutButtonWithEdgeInsetsStyle:(MKButtonEdgeInsetsStyle)style
                        imageTitleSpace:(CGFloat)space;

@end

#import "UIButton+ImageTitleSpace.h"

@implementation UIButton (ImageTitleSpace)

- (void)layoutButtonWithEdgeInsetsStyle:(MKButtonEdgeInsetsStyle)style
                        imageTitleSpace:(CGFloat)space {
    /**
     * 知识点：titleEdgeInsets是title相对于其上下左右的inset，跟tableView的contentInset是类似的，
     * 如果只有title，那它上下左右都是相对于button的，image也是一样；
     * 如果同时有image和label，那这时候image的上左下是相对于button，右边是相对于label的；title的上右下是相对于button，左边是相对于image的。
     */
    
    // 1. 得到imageView和titleLabel的宽、高
    CGFloat imageWith = self.imageView.frame.size.width;
    CGFloat imageHeight = self.imageView.frame.size.height;
    
    CGFloat labelWidth = 0.0;
    CGFloat labelHeight = 0.0;
    if ([UIDevice currentDevice].systemVersion.floatValue >= 8.0) {
        // 由于iOS8中titleLabel的size为0，用下面的这种设置
        labelWidth = self.titleLabel.intrinsicContentSize.width;
        labelHeight = self.titleLabel.intrinsicContentSize.height;
    } else {
        labelWidth = self.titleLabel.frame.size.width;
        labelHeight = self.titleLabel.frame.size.height;
    }
    
    // 2. 声明全局的imageEdgeInsets和labelEdgeInsets
    UIEdgeInsets imageEdgeInsets = UIEdgeInsetsZero;
    UIEdgeInsets labelEdgeInsets = UIEdgeInsetsZero;
    
    // 3. 根据style和space得到imageEdgeInsets和labelEdgeInsets的值
    /**
     MKButtonEdgeInsetsStyleTop, // image在上，label在下
     MKButtonEdgeInsetsStyleLeft, // image在左，label在右
     MKButtonEdgeInsetsStyleBottom, // image在下，label在上
     MKButtonEdgeInsetsStyleRight // image在右，label在左
     */
    switch (style) {
        case MKButtonEdgeInsetsStyleTop:
        {
            imageEdgeInsets = UIEdgeInsetsMake(-labelHeight-space/2.0, 0, 0, -labelWidth);
            labelEdgeInsets = UIEdgeInsetsMake(0, -imageWith, -imageHeight-space/2.0, 0);
        }
            break;
        case MKButtonEdgeInsetsStyleLeft:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, -space/2.0, 0, space/2.0);
            labelEdgeInsets = UIEdgeInsetsMake(0, space/2.0, 0, -space/2.0);
        }
            break;
        case MKButtonEdgeInsetsStyleBottom:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, 0, -labelHeight-space/2.0, -labelWidth);
            labelEdgeInsets = UIEdgeInsetsMake(-imageHeight-space/2.0, -imageWith, 0, 0);
        }
            break;
        case MKButtonEdgeInsetsStyleRight:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, labelWidth+space/2.0, 0, -labelWidth-space/2.0);
            labelEdgeInsets = UIEdgeInsetsMake(0, -imageWith-space/2.0, 0, imageWith+space/2.0);
        }
            break;
        default:
            break;
    }
    
    // 4. 赋值
    self.titleEdgeInsets = labelEdgeInsets;
    self.imageEdgeInsets = imageEdgeInsets;
}

@end

#import "UIButton+ImageTitleSpace.h"

// 图片标题
- (UIButton *)imageTitleButton
{
    if (!_imageTitleButton) {
        _imageTitleButton = [[UIButton alloc]initWithFrame:CGRectZero];
        _imageTitleButton.backgroundColor = [UIColor blackColor];
        [_imageTitleButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        [_imageTitleButton setImage:[UIImage imageNamed:@"nv"] forState:UIControlStateNormal];
        _imageTitleButton.titleLabel.font = [UIFont systemFontOfSize:ImageTitleButtonFontSize];
        //懒加载按钮中 调用即可
        [_imageTitleButton layoutButtonWithEdgeInsetsStyle:MKButtonEdgeInsetsStyleLeft imageTitleSpace:5];
        
        [_imageTitleButton setContentEdgeInsets:UIEdgeInsetsMake(5, 5, 5, 5)];
        _imageTitleButton.clipsToBounds = YES;
        _imageTitleButton.layer.cornerRadius = 5;
        _imageTitleButton.alpha = 0.5;
        
    }
    return _imageTitleButton;
}