ProgressHUD源码详解

ProgressHUD是iOS开发中常用的等待控件(菊花控件)，用户网络请求等

主要结构

ProgressHUD只包含两个代码文件ProgressHUD.h和ProgressHUD.m，以及一个资源文件ProgressHUD.bundle

ProgressHUD本质上为UIView的子类

@interface ProgressHUD : UIView

其主要结构包含5部分：

@interface ProgressHUD()
{
    UIWindow *window;
    UIView *viewBackground;
    UIToolbar *toolbarHUD;
    UIActivityIndicatorView *spinner;
    UIImageView *imageView;
    UILabel *labelStatus;
}

以上控件之间的结构关系如下：

image

初始化控件

• 在show方法中调用

+ (void)show
{
    dispatch_async(dispatch_get_main_queue(), ^{
        [[self shared] hudCreate:nil image:nil spin:YES hide:NO interaction:YES];
    });
}

• 初始化

- (void)hudCreate:(NSString *)status image:(UIImage *)image spin:(BOOL)spin hide:(BOOL)hide interaction:(BOOL)interaction
{
    //初始化toolbarHUD
    if (toolbarHUD == nil)
    {
        toolbarHUD = [[UIToolbar alloc] initWithFrame:CGRectZero];
        toolbarHUD.translucent = YES;
        toolbarHUD.backgroundColor = self.hudColor;
        toolbarHUD.layer.cornerRadius = 10;
        toolbarHUD.layer.masksToBounds = YES;
        [self registerNotifications];
    }
    
    if (toolbarHUD.superview == nil)
    {
        //如果与背景视图不可交互，初始化背景视图，背景视图为toolbarHUD的父视图
        if (interaction == NO)
        {
            viewBackground = [[UIView alloc] initWithFrame:window.frame];
            viewBackground.backgroundColor = self.backgroundColor;
            [window addSubview:viewBackground];
            [viewBackground addSubview:toolbarHUD];
        }//如果与背景视图可交互，顶层window为toolbarHUD的父视图
        else [window addSubview:toolbarHUD];
    }
    //初始化spinner(菊花),并添加到toolbarHUD
    if (spinner == nil)
    {
        spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
        spinner.color = self.spinnerColor;
        spinner.hidesWhenStopped = YES;
    }
    if (spinner.superview == nil) [toolbarHUD addSubview:spinner];
    //初始化imageView并添加到toolbarHUD
    if (imageView == nil)
    {
        imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 28, 28)];
    }
    if (imageView.superview == nil) [toolbarHUD addSubview:imageView];
    //初始化labelStatus，添加到toolbarHUD
    if (labelStatus == nil)
    {
        labelStatus = [[UILabel alloc] initWithFrame:CGRectZero];
        labelStatus.font = self.statusFont;
        labelStatus.textColor = self.statusColor;
        labelStatus.backgroundColor = [UIColor clearColor];
        labelStatus.textAlignment = NSTextAlignmentCenter;
        labelStatus.baselineAdjustment = UIBaselineAdjustmentAlignCenters;
        labelStatus.numberOfLines = 0;
    }
    if (labelStatus.superview == nil) [toolbarHUD addSubview:labelStatus];

    //文本信息添加
    labelStatus.text = status;
    labelStatus.hidden = (status == nil) ? YES : NO;
    //图片信息添加
    imageView.image = image;
    imageView.hidden = (image == nil) ? YES : NO;
    //spinner(菊花)旋转(或停止)
    if (spin) [spinner startAnimating]; else [spinner stopAnimating];
    
    [self hudSize];//尺寸设置
    [self hudPosition:nil];//位置设置
    [self hudShow];//动画显示
    //定时关闭
    if (hide) [self timedHide];
}

设置Size

- (void)hudSize
{
    CGRect rectLabel = CGRectZero;
    CGFloat widthHUD = 100, heightHUD = 100;//toolbarHUD默认的尺寸
    if (labelStatus.text != nil)
    {
        NSDictionary *attributes = @{NSFontAttributeName:labelStatus.font};
        NSInteger options = NSStringDrawingUsesFontLeading | NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesLineFragmentOrigin;
        rectLabel = [labelStatus.text boundingRectWithSize:CGSizeMake(200, 300) options:options attributes:attributes context:NULL];//计算文字所需的Rect

        //toolbarHUD对应的Rect
        widthHUD = rectLabel.size.width + 50;
        heightHUD = rectLabel.size.height + 75;

        if (widthHUD < 100) widthHUD = 100;
        if (heightHUD < 100) heightHUD = 100;

        rectLabel.origin.x = (widthHUD - rectLabel.size.width) / 2;
        rectLabel.origin.y = (heightHUD - rectLabel.size.height) / 2 + 25;
    }
    
    toolbarHUD.bounds = CGRectMake(0, 0, widthHUD, heightHUD);
    //imageView对应的位置
    CGFloat imageX = widthHUD/2;
    CGFloat imageY = (labelStatus.text == nil) ? heightHUD/2 : 36;
    imageView.center = spinner.center = CGPointMake(imageX, imageY);
    
    labelStatus.frame = rectLabel;
}

设置postion

- (void)hudPosition:(NSNotification *)notification
{
    CGFloat heightKeyboard = 0;
    NSTimeInterval duration = 0;
    //计算键盘高度
    if (notification != nil)
    {
        NSDictionary *info = [notification userInfo];
        CGRect keyboard = [[info valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
        duration = [[info valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
        if ((notification.name == UIKeyboardWillShowNotification) || (notification.name == UIKeyboardDidShowNotification))
        {
            heightKeyboard = keyboard.size.height;
        }
    }
    else heightKeyboard = [self keyboardHeight];
    //toolbarHUD的水平中心在屏幕中间，垂直中心在除去键盘高度的中心。
    CGRect screen = [UIScreen mainScreen].bounds;
    CGPoint center = CGPointMake(screen.size.width/2, (screen.size.height-heightKeyboard)/2);
    //动态设置toolbarHUD的中心
    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionAllowUserInteraction animations:^{
        self->toolbarHUD.center = CGPointMake(center.x, center.y);
    } completion:nil];
    if (viewBackground != nil) viewBackground.frame = window.frame;
}

• 注意:

1. toolbarHUD的水平中心在屏幕中间，垂直中心在除去键盘高度的中心。

CGPoint center = CGPointMake(screen.size.width/2, (screen.size.height-heightKeyboard)/2);

2. toolbarHUD的垂直中心会根据键盘消息进行调整。

显示

- (void)hudShow
{
    if (self.alpha == 0)
    {
        self.alpha = 1;
        toolbarHUD.alpha = 0; //初始设置为完全透明，实现隐藏功能
        toolbarHUD.transform = CGAffineTransformScale(toolbarHUD.transform, 1.4, 1.4); //放大

        UIViewAnimationOptions options = UIViewAnimationOptionAllowUserInteraction | UIViewAnimationCurveEaseOut; //动画模式设置
        //动画显示
        [UIView animateWithDuration:0.15 delay:0 options:options animations:^{
            self->toolbarHUD.transform = CGAffineTransformScale(self->toolbarHUD.transform, 1/1.4, 1/1.4); //恢复正常
            self->toolbarHUD.alpha = 1; //设为不透明，显示出来
        } completion:nil];
    }
}

隐藏

- (void)hudHide
{
    if (self.alpha == 1)
    {
        UIViewAnimationOptions options = UIViewAnimationOptionAllowUserInteraction | UIViewAnimationCurveEaseIn; //动画模式设置
        [UIView animateWithDuration:0.15 delay:0 options:options animations:^{
            self->toolbarHUD.transform = CGAffineTransformScale(self->toolbarHUD.transform, 0.7, 0.7); //缩小为原来的0.7倍
            self->toolbarHUD.alpha = 0; //设置为透明，实现隐藏
        }
        completion:^(BOOL finished) {
            [self hudDestroy]; //删除各控件的依赖关系，再删除控件
            self.alpha = 0;
        }];
    }
}