一个很好用的侧滑框架ICSDrawerController实现的 QQ 侧滑及换肤功能

- (void)hiddenHeadView:(hiddenHeadViewBlock)block;

@property(nonatomic,copy) hiddenHeadViewBlock hiddenBlock;

- (void)hiddenHeadView:(hiddenHeadViewBlock)block
{
    self.hiddenBlock = block;
}

- (void)panGestureRecognized:(UIPanGestureRecognizer *)panGestureRecognizer
{
    NSParameterAssert(self.leftView);
    NSParameterAssert(self.centerView);
    
    UIGestureRecognizerState state = panGestureRecognizer.state;
    CGPoint location = [panGestureRecognizer locationInView:self.view];
    CGPoint velocity = [panGestureRecognizer velocityInView:self.view];
    
    switch (state) {

        case UIGestureRecognizerStateBegan:
            self.panGestureStartLocation = location;//记录当前的位置
            if (self.drawerState == ICSDrawerControllerStateClosed) {
                [self willOpen];
            }
            else {
                [self willClose];
            }
            break;
            
        case UIGestureRecognizerStateChanged: { //每次拖拽滑动
            CGFloat delta = 0.0f;
            if (self.drawerState == ICSDrawerControllerStateOpening) {
                delta = location.x - self.panGestureStartLocation.x;
            }
            else if (self.drawerState == ICSDrawerControllerStateClosing) {
                delta = kICSDrawerControllerDrawerDepth - (self.panGestureStartLocation.x - location.x);
            }
            
            CGRect l = self.leftView.frame;
            CGRect c = self.centerView.frame;
            if (delta > kICSDrawerControllerDrawerDepth) {
                l.origin.x = 0.0f;
                c.origin.x = kICSDrawerControllerDrawerDepth;
            }
            else if (delta < 0.0f) {
                l.origin.x = kICSDrawerControllerLeftViewInitialOffset;
                c.origin.x = 0.0f;
            }
            else {
                // While the centerView can move up to kICSDrawerControllerDrawerDepth points, to achieve a parallax effect
                // the leftView has move no more than kICSDrawerControllerLeftViewInitialOffset points
                l.origin.x = kICSDrawerControllerLeftViewInitialOffset
                           - (delta * kICSDrawerControllerLeftViewInitialOffset) / kICSDrawerControllerDrawerDepth;

                c.origin.x = delta;
                CGFloat alpha = 1 - delta/100/2.6;
                if (alpha > 1.0) {
                    alpha = 1.0;
                }else if(alpha < 0){
                    alpha = 0;
                }
                //头像是否显示隐藏
                self.hiddenBlock(alpha);
            }
            
            self.leftView.frame = l;
            self.centerView.frame = c;
            
            break;
        }
            
        case UIGestureRecognizerStateEnded: { //拖拽结束

            if (self.drawerState == ICSDrawerControllerStateOpening) {
                CGFloat centerViewLocation = self.centerView.frame.origin.x;
                if (centerViewLocation == kICSDrawerControllerDrawerDepth) {
                    // Open the drawer without animation, as it has already being dragged in its final position
                    [self setNeedsStatusBarAppearanceUpdate];
                    [self didOpen];
                }
                else if (centerViewLocation > self.view.bounds.size.width / 3
                         && velocity.x > 0.0f) {
                    // Animate the drawer opening
                    [self animateOpening];
                }
                else {
                    // Animate the drawer closing, as the opening gesture hasn‘t been completed or it has
                    // been reverted by the user
                    [self didOpen];
                    [self willClose];
                    [self animateClosing];
                }

            } else if (self.drawerState == ICSDrawerControllerStateClosing) {
                CGFloat centerViewLocation = self.centerView.frame.origin.x;
                if (centerViewLocation == 0.0f) {
                    // Close the drawer without animation, as it has already being dragged in its final position
                    [self setNeedsStatusBarAppearanceUpdate];
                    [self didClose];
                }
                else if (centerViewLocation < (2 * self.view.bounds.size.width) / 3
                         && velocity.x < 0.0f) {
                    // Animate the drawer closing
                    [self animateClosing];
                }
                else {
                    // Animate the drawer opening, as the opening gesture hasn‘t been completed or it has
                    // been reverted by the user
                    [self didClose];

                    // Here we save the current position for the leftView since
                    // we want the opening animation to start from the current position
                    // and not the one that is set in ‘willOpen‘
                    CGRect l = self.leftView.frame;
                    [self willOpen];
                    self.leftView.frame = l;
                    
                    [self animateOpening];
                }
            }
        }
            break;
            
        default:
            break;
    }
}

#pragma mark - Animations
#pragma mark Opening animation
- (void)animateOpening
{
    NSParameterAssert(self.drawerState == ICSDrawerControllerStateOpening);
    NSParameterAssert(self.leftView);
    NSParameterAssert(self.centerView);
    
    // Calculate the final frames for the container views
    CGRect leftViewFinalFrame = self.view.bounds;
    CGRect centerViewFinalFrame = self.view.bounds;
    centerViewFinalFrame.origin.x = kICSDrawerControllerDrawerDepth;
    
    [UIView animateWithDuration:kICSDrawerControllerAnimationDuration
                          delay:0
         usingSpringWithDamping:kICSDrawerControllerOpeningAnimationSpringDamping
          initialSpringVelocity:kICSDrawerControllerOpeningAnimationSpringInitialVelocity
                        options:UIViewAnimationOptionCurveLinear
                     animations:^{
                         self.centerView.frame = centerViewFinalFrame;
                         self.leftView.frame = leftViewFinalFrame;
                         self.hiddenBlock(0);

                         [self setNeedsStatusBarAppearanceUpdate];
                     }
                     completion:^(BOOL finished) {
                         [self didOpen];
                     }];
}
#pragma mark Closing animation
- (void)animateClosing
{
    NSParameterAssert(self.drawerState == ICSDrawerControllerStateClosing);
    NSParameterAssert(self.leftView);
    NSParameterAssert(self.centerView);
    
    // Calculate final frames for the container views
    CGRect leftViewFinalFrame = self.leftView.frame;
    leftViewFinalFrame.origin.x = kICSDrawerControllerLeftViewInitialOffset;
    CGRect centerViewFinalFrame = self.view.bounds;
    
    [UIView animateWithDuration:kICSDrawerControllerAnimationDuration
                          delay:0
         usingSpringWithDamping:kICSDrawerControllerClosingAnimationSpringDamping
          initialSpringVelocity:kICSDrawerControllerClosingAnimationSpringInitialVelocity
                        options:UIViewAnimationOptionCurveLinear
                     animations:^{
                         self.centerView.frame = centerViewFinalFrame;
                         self.leftView.frame = leftViewFinalFrame;
                         self.hiddenBlock(1);

                         [self setNeedsStatusBarAppearanceUpdate];
                     }
                     completion:^(BOOL finished) {
                         [self didClose];
                     }];
}

@interface UIViewController (ICSDrawerController)

//拿到当前conroller的menuController
//如果不存在，返回nil
@property (nonatomic, readonly) ICSDrawerController* menuController;

@end

@implementation UIViewController (ICSDrawerController)

- (ICSDrawerController *)menuController {

    if (self.parentViewController == nil) {
        return nil;
    }else if ([self.parentViewController isKindOfClass:[ICSDrawerController class]]) {
        return (ICSDrawerController* )self.parentViewController;
    }else {
        return self.parentViewController.menuController;
    }
}

@end