components/AppBar/examples/AppBarPresentedExample.m

/*
 Copyright 2018-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 "MaterialAppBar.h"
#import "MaterialAppBar+ColorThemer.h"
#import "MaterialAppBar+TypographyThemer.h"
#import "MaterialButtons.h"
#import "MaterialButtons+ButtonThemer.h"

@interface PresentedDemoViewController : UICollectionViewController
@property(nonatomic, strong) MDCAppBar *appBar;
@property(nonatomic, strong) MDCSemanticColorScheme *colorScheme;
@property(nonatomic, strong) MDCTypographyScheme *typographyScheme;
@end

@implementation PresentedDemoViewController

- (id)init {
  UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
  layout.minimumInteritemSpacing = 10.0f;

  self = [super initWithCollectionViewLayout:layout];

  if (self) {
    self.title = @"Presented App Bar";

    _appBar = [[MDCAppBar alloc] init];
    [self addChildViewController:_appBar.headerViewController];

    self.colorScheme = [[MDCSemanticColorScheme alloc] init];
    self.typographyScheme = [[MDCTypographyScheme alloc] init];
  }
  return self;
}

- (void)viewDidLoad {
  [super viewDidLoad];

  _appBar.headerViewController.headerView.shiftBehavior = MDCFlexibleHeaderShiftBehaviorEnabled;
  [_appBar.headerViewController.headerView hideViewWhenShifted:_appBar.headerStackView];

  _appBar.navigationBar.useFlexibleTopBottomInsets = YES;

  [MDCAppBarColorThemer applySemanticColorScheme:self.colorScheme
                                        toAppBar:_appBar];
  [MDCAppBarTypographyThemer applyTypographyScheme:self.typographyScheme
                                          toAppBar:_appBar];

  // Need to update the status bar style after applying the theme.
  [self setNeedsStatusBarAppearanceUpdate];

  _appBar.headerViewController.headerView.trackingScrollView = self.collectionView;
  [_appBar addSubviewsToParent];

  [self.collectionView registerClass:[UICollectionViewCell class]
          forCellWithReuseIdentifier:@"Cell"];

  self.navigationItem.leftBarButtonItem =
      [[UIBarButtonItem alloc] initWithTitle:@"Dismiss" style:UIBarButtonItemStyleDone
                                      target:self
                                      action:@selector(dismiss)];
}

- (void)dismiss {
  [self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
}

- (NSInteger)collectionView:(UICollectionView *)collectionView
     numberOfItemsInSection:(NSInteger)section {
  return 100;
}

- (CGSize)preferredContentSize {
  return CGSizeMake(300, 300);
}

- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
                           cellForItemAtIndexPath:(NSIndexPath *)indexPath {
  UICollectionViewCell *cell =
  [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
  switch (indexPath.row%3) {
    case 0:
      cell.backgroundColor = [UIColor colorWithWhite:0.2f alpha:1.0f];
      break;
    case 1:
      cell.backgroundColor = [UIColor colorWithWhite:0.5f alpha:1.0f];
      break;
    case 2:
      cell.backgroundColor = [UIColor colorWithWhite:0.7f alpha:1.0f];
      break;
    default:
      break;
  }

  return cell;
}

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout*)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
  CGRect collectionViewFrame = collectionView.frame;
  return CGSizeMake(collectionViewFrame.size.width/2.f - 14.f, 40.f);
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
  MDCFlexibleHeaderView *headerView = self.appBar.headerViewController.headerView;
  if (scrollView == headerView.trackingScrollView) {
    [headerView trackingScrollViewDidScroll];
  }
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
  MDCFlexibleHeaderView *headerView = self.appBar.headerViewController.headerView;
  if (scrollView == headerView.trackingScrollView) {
    [headerView trackingScrollViewDidEndDraggingWillDecelerate:decelerate];
  }
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
  MDCFlexibleHeaderView *headerView = self.appBar.headerViewController.headerView;
  if (scrollView == headerView.trackingScrollView) {
    [headerView trackingScrollViewDidEndDecelerating];
  }
}

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView
                     withVelocity:(CGPoint)velocity
              targetContentOffset:(inout CGPoint *)targetContentOffset {
  MDCFlexibleHeaderView *headerView = self.appBar.headerViewController.headerView;
  if (scrollView == headerView.trackingScrollView) {
    [headerView trackingScrollViewWillEndDraggingWithVelocity:velocity
                                          targetContentOffset:targetContentOffset];
  }
}

@end

@interface AppBarPresentedExample : UIViewController

@property(nonatomic, strong) PresentedDemoViewController *demoViewController;
@property(nonatomic, strong) MDCSemanticColorScheme *colorScheme;
@property(nonatomic, strong) MDCTypographyScheme *typographyScheme;

@end

@implementation AppBarPresentedExample

- (void)viewDidLoad {
  [super viewDidLoad];

  self.view.backgroundColor = [UIColor colorWithWhite:0.95f alpha:1];

  self.demoViewController = [[PresentedDemoViewController alloc] init];
  self.demoViewController.colorScheme = self.colorScheme;
  self.demoViewController.typographyScheme = self.typographyScheme;

  // Need to update the status bar style after applying the theme.
  [self setNeedsStatusBarAppearanceUpdate];

  MDCButtonScheme *buttonScheme = [[MDCButtonScheme alloc] init];
  buttonScheme.colorScheme = self.colorScheme;
  buttonScheme.typographyScheme = self.typographyScheme;

  CGFloat buttonMargin = 10;
  MDCButton *button = [[MDCButton alloc] init];
  [button setTitle:@"Present Modal App Bar Demo" forState:UIControlStateNormal];
  [button sizeToFit];
  button.center = self.view.center;
  button.frame =
      CGRectMake(button.frame.origin.x,
                 button.center.y - 48 * 2 - buttonMargin,
                 button.bounds.size.width,
                 MAX(button.bounds.size.height, 48));
  [button addTarget:self
             action:@selector(presentDemo)
   forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:button];
  [MDCContainedButtonThemer applyScheme:buttonScheme toButton:button];

  if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
    MDCButton *popoverButton = [[MDCButton alloc] init];
    [popoverButton setTitle:@"Present Popover App Bar Demo" forState:UIControlStateNormal];
    [popoverButton sizeToFit];
    popoverButton.center = self.view.center;
    popoverButton.frame =
    CGRectMake(popoverButton.frame.origin.x,
               popoverButton.center.y - 48,
               popoverButton.bounds.size.width,
               MAX(popoverButton.bounds.size.height, 48));
    [popoverButton addTarget:self
                      action:@selector(presentDemoPopover)
            forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:popoverButton];

    [MDCContainedButtonThemer applyScheme:buttonScheme toButton:popoverButton];
  }
}

- (void)presentDemo {
  self.demoViewController.modalPresentationStyle = UIModalPresentationPageSheet;
  [self presentViewController:self.demoViewController animated:YES completion:nil];
}

- (void)presentDemoPopover {
  CGRect rect = CGRectMake(self.view.bounds.size.width / 2, self.topLayoutGuide.length, 1, 1);
#if defined(__IPHONE_11_0) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_11_0)
  if (@available(iOS 11.0, *)) {
    rect = CGRectMake(self.view.bounds.size.width / 2, self.view.safeAreaInsets.top, 1, 1);
  }
#endif
  
  self.demoViewController.modalPresentationStyle = UIModalPresentationPopover;
  self.demoViewController.popoverPresentationController.sourceView = self.view;
  self.demoViewController.popoverPresentationController.sourceRect = rect;
  UIPopoverController *popoverController =
      [[UIPopoverController alloc] initWithContentViewController:self.demoViewController];
  [popoverController presentPopoverFromRect:rect
                                     inView:self.view
                   permittedArrowDirections:UIPopoverArrowDirectionAny
                                   animated:YES];
}

@end

@implementation AppBarPresentedExample (CatalogByConvention)

+ (NSArray *)catalogBreadcrumbs {
  return @[ @"App Bar", @"Presented" ];
}

+ (BOOL)catalogIsPrimaryDemo {
  return NO;
}

+ (BOOL)catalogIsPresentable {
  return YES;
}

@end