components/FlexibleHeader/examples/FlexibleHeaderWrappedExample.m

/*
 Copyright 2016-present the Material Components for iOS authors. All Rights Reserved.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

#import <UIKit/UIKit.h>

#import "FlexibleHeaderWrappedSupplemental.h"

#import "MaterialFlexibleHeader.h"

@interface FlexibleHeaderWrappedExample () <UIScrollViewDelegate>

@property(nonatomic) MDCFlexibleHeaderViewController *fhvc;
@property(nonatomic) UILabel *label;
@property(nonatomic) UIViewController *wrappedViewController;

@end

@implementation FlexibleHeaderWrappedExample

- (instancetype)init {
  self = [super init];
  if (self) {
    [self commonMDCFlexibleHeaderViewControllerInit];
  }
  return self;
}

- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
  if (self) {
    [self commonMDCFlexibleHeaderViewControllerInit];
  }
  return self;
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
  self = [super initWithCoder:aDecoder];
  if (self) {
    [self commonMDCFlexibleHeaderViewControllerInit];
  }
  return self;
}

- (void)commonMDCFlexibleHeaderViewControllerInit {
  _fhvc = [[MDCFlexibleHeaderViewController alloc] initWithNibName:nil bundle:nil];
  [self addChildViewController:_fhvc];

  _label = [[UILabel alloc] init];
  _label.text = @"Wrapped View Controller";
  [_label sizeToFit];
  _wrappedViewController = [[UIViewController alloc] init];
  [_wrappedViewController.view addSubview:_label];
}

- (void)viewDidLoad {
  [super viewDidLoad];

  self.scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
  self.scrollView.backgroundColor = [UIColor whiteColor];
  self.scrollView.autoresizingMask =
      UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
  [self.view addSubview:self.scrollView];

  self.scrollView.delegate = self;
  self.fhvc.headerView.trackingScrollView = self.scrollView;

  self.fhvc.view.frame = self.view.bounds;
  [self.view addSubview:self.fhvc.view];
  [self.fhvc didMoveToParentViewController:self];

  self.fhvc.headerView.backgroundColor = [UIColor colorWithWhite:0.1 alpha:1];

  [self.scrollView setScrollEnabled:YES];
  [self.scrollView addSubview:self.wrappedViewController.view];
}

- (void)viewWillAppear:(BOOL)animated {
  [super viewWillAppear:animated];

  // If the MDCFlexibleHeaderViewController's view is not going to replace a navigation bar,
  // comment this line:
  [self.navigationController setNavigationBarHidden:YES animated:animated];

  self.label.center = CGPointMake(self.wrappedViewController.view.frame.size.width / 2.f, 120.f);
}

// This method must be implemented for MDCFlexibleHeaderViewController's
// MDCFlexibleHeaderView to properly support MDCFlexibleHeaderShiftBehavior should you choose
// to customize it.
- (UIViewController *)childViewControllerForStatusBarHidden {
  return self.fhvc;
}

- (void)viewWillTransitionToSize:(CGSize)size
       withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
  self.label.center = CGPointMake(size.width / 2.f, 120.f);
}

- (void)viewDidLayoutSubviews {
  [super viewDidLayoutSubviews];

  self.scrollView.contentSize = self.wrappedViewController.view.bounds.size;
}

#pragma mark - <UIScrollViewDelegate>

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
  [self.fhvc scrollViewDidScroll:scrollView];
}

@end