permutation image and title postion for button

UIButton+ZDUtility

typedef NS_ENUM(NSUInteger, ZDImagePosition) {
    ZDImagePosition_Left = 0,
    ZDImagePosition_Right,
    ZDImagePosition_Top,
    ZDImagePosition_Bottom
};

@implementation UIButton (ZDUtility)

- (void)zd_imagePosition:(ZDImagePosition)postion spacing:(CGFloat)spacing {
    [self setTitle:self.currentTitle forState:UIControlStateNormal];
    [self setImage:self.currentImage forState:UIControlStateNormal];
    
    CGFloat imageWidth = self.imageView.image.size.width;
    CGFloat imageHeight = self.imageView.image.size.height;
    
    CGSize labelSize = [self.titleLabel.text sizeWithAttributes:@{NSFontAttributeName : self.titleLabel.font}];
    CGFloat labelWidth = labelSize.width;
    CGFloat labelHeight = labelSize.height;
    
    CGFloat imageOffsetX = (imageWidth + labelWidth) / 2.0f - imageWidth / 2.0f;//image中心移动的x距离
    CGFloat imageOffsetY = imageHeight / 2.0f + spacing / 2.0f;//image中心移动的y距离
    CGFloat labelOffsetX = (imageWidth + labelWidth / 2.0f) - (imageWidth + labelWidth) / 2.0f;//label中心移动的x距离
    CGFloat labelOffsetY = labelHeight / 2.0f + spacing / 2.0f;//label中心移动的y距离
    
    CGFloat tempWidth = MAX(labelWidth, imageWidth);
    CGFloat changedWidth = labelWidth + imageWidth - tempWidth;
    CGFloat tempHeight = MAX(labelHeight, imageHeight);
    CGFloat changedHeight = labelHeight + imageHeight + spacing - tempHeight;
    
    switch (postion) {
        case ZDImagePosition_Left:
            self.imageEdgeInsets = UIEdgeInsetsMake(0, -spacing/2.0f, 0, spacing/2.0f);
            self.titleEdgeInsets = UIEdgeInsetsMake(0, spacing/2.0f, 0, -spacing/2.0f);
            self.contentEdgeInsets = UIEdgeInsetsMake(0, spacing/2.0f, 0, spacing/2.0f);
            break;
            
        case ZDImagePosition_Right:
            self.imageEdgeInsets = UIEdgeInsetsMake(0, labelWidth + spacing/2.0f, 0, -(labelWidth + spacing/2.0f));
            self.titleEdgeInsets = UIEdgeInsetsMake(0, -(imageWidth + spacing/2.0f), 0, imageWidth + spacing/2.0f);
            self.contentEdgeInsets = UIEdgeInsetsMake(0, spacing/2.0f, 0, spacing/2.0f);
            break;
            
        case ZDImagePosition_Top:
            self.imageEdgeInsets = UIEdgeInsetsMake(-imageOffsetY, imageOffsetX, imageOffsetY, -imageOffsetX);
            self.titleEdgeInsets = UIEdgeInsetsMake(labelOffsetY, -labelOffsetX, -labelOffsetY, labelOffsetX);
            self.contentEdgeInsets = UIEdgeInsetsMake(imageOffsetY, -changedWidth/2.0f, changedHeight-imageOffsetY, -changedWidth/2.0f);
            break;
            
        case ZDImagePosition_Bottom:
            self.imageEdgeInsets = UIEdgeInsetsMake(imageOffsetY, imageOffsetX, -imageOffsetY, -imageOffsetX);
            self.titleEdgeInsets = UIEdgeInsetsMake(-labelOffsetY, -labelOffsetX, labelOffsetY, labelOffsetX);
            self.contentEdgeInsets = UIEdgeInsetsMake(changedHeight-imageOffsetY, -changedWidth/2.0f, imageOffsetY, -changedWidth/2.0f);
            break;
            
        default:
            break;
    }
}

@end