components/TextControls/examples/supplemental/MDCTextControlContentViewController.m - external/github.com/material-components/material-components-ios - Git at Google

 // Copyright 2019-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 "MDCTextControlContentViewController.h"

 #import "MaterialButtons.h"

 #import "MDCBaseTextField.h"
 #import "MaterialButtons+Theming.h"
 #import "MaterialColorScheme.h"

 #import "MDCFilledTextField+MaterialTheming.h"
 #import "MDCFilledTextField.h"
 #import "MDCOutlinedTextField+MaterialTheming.h"
 #import "MDCOutlinedTextField.h"

 #import "MDCTraitEnvironmentChangeDelegate.h"

 @interface MDCTextControlContentViewController ()

 /**
 This scrollview contains all the subviews through which the user interacts with the screen.
 */
 @property(strong, nonatomic) UIScrollView *scrollView;

 /**
 This button allows the user to signal that they want the content size category to decrease.
 */
 @property(nonatomic, strong) MDCButton *decreaseContentSizeButton;

 /**
 This button allows the user to signal that they want the content size category to increase.
 */
 @property(nonatomic, strong) MDCButton *increaseContentSizeButton;

 /**
  This button allows the user to signal that they want the first responder to resign first responder.
  */
 @property(nonatomic, strong) MDCButton *resignFirstResponderButton;

 /**
 This button allows the user to signal that they want all text controls to become disabled.
 */
 @property(nonatomic, strong) MDCButton *toggleDisabledButton;

 /**
 This button allows the user to signal that they want the view controller to enter an error state.
 */
 @property(nonatomic, strong) MDCButton *toggleErrorButton;

 /**
 This button allows the user to signal that they want the view controller to toggle dark mode.
 */
 @property(nonatomic, strong) MDCButton *toggleDarkModeButton;

 /**
 This button allows the user to signal that they want to toggle the layout direction.
 */
 @property(nonatomic, strong) MDCButton *toggleLayoutDirectionButton;

 @end

 @implementation MDCTextControlContentViewController

 #pragma mark Object Lifecycle

 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 }

 #pragma mark View Controller Overrides

 - (void)viewDidLoad {
   [super viewDidLoad];

   [self addObservers];
   [self setUpSubviews];
 }

 - (void)viewWillLayoutSubviews {
   [super viewWillLayoutSubviews];

   self.view.backgroundColor = self.containerScheme.colorScheme.backgroundColor;
   [self applyThemesToScrollViewSubviews];
   [self enforcePreferredFonts];
 }

 - (void)viewDidLayoutSubviews {
   [super viewDidLayoutSubviews];

   [self layoutScrollView];
   [self resizeScrollViewSubviews];
   [self layoutScrollViewSubviews];
   [self updateScrollViewContentSize];
 }

 #pragma mark Setup

 - (void)addObservers {
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(keyboardWillShow:)
                                                name:UIKeyboardWillShowNotification
                                              object:nil];
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(keyboardWillHide:)
                                                name:UIKeyboardWillHideNotification
                                              object:nil];
 }

 - (void)setUpSubviews {
   [self createBaseSubviews];
   [self initializeScrollViewSubviewsArray];
   [self addSubviews];
 }

 - (void)createBaseSubviews {
   self.scrollView = [[UIScrollView alloc] init];
   self.increaseContentSizeButton = [self createIncreaseContentSizeButton];
   self.decreaseContentSizeButton = [self createDecreaseContentSizeButton];
   self.toggleDisabledButton = [self createToggleDisabledButton];
   self.toggleErrorButton = [self createToggleErrorButton];
   self.resignFirstResponderButton = [self createResignFirstResponderButton];
   self.toggleDarkModeButton = [self createToggleDarkModeButton];
   self.toggleLayoutDirectionButton = [self createToggleLayoutDirectionButton];
 }

 - (MDCButton *)createDecreaseContentSizeButton {
   return [self createContentSizeButtonWithTitle:@"Decrease size"
                                        selector:@selector(decreaseContentSizeButtonTapped:)];
 }

 - (MDCButton *)createIncreaseContentSizeButton {
   return [self createContentSizeButtonWithTitle:@"Increase size"
                                        selector:@selector(increaseContentSizeButtonTapped:)];
 }

 - (MDCButton *)createContentSizeButtonWithTitle:(NSString *)title selector:(SEL)selector {
   MDCButton *button = [[MDCButton alloc] init];
   [button setTitle:title forState:UIControlStateNormal];
   [button addTarget:self action:selector forControlEvents:UIControlEventTouchUpInside];
   [button applyContainedThemeWithScheme:self.containerScheme];
   [button sizeToFit];
   button.enabled = NO;
   if (@available(iOS 10.0, *)) {
     button.enabled = YES;
   }
   return button;
 }

 - (MDCButton *)createToggleDisabledButton {
   MDCButton *button = [[MDCButton alloc] init];
   [button setTitle:@"Toggle disabled" forState:UIControlStateNormal];
   [button addTarget:self
                 action:@selector(disableButtonTapped:)
       forControlEvents:UIControlEventTouchUpInside];
   [button applyContainedThemeWithScheme:self.containerScheme];
   [button sizeToFit];
   return button;
 }

 - (MDCButton *)createResignFirstResponderButton {
   MDCButton *button = [[MDCButton alloc] init];
   [button setTitle:@"Resign first responder" forState:UIControlStateNormal];
   [button addTarget:self
                 action:@selector(resignFirstResponderButtonTapped:)
       forControlEvents:UIControlEventTouchUpInside];
   [button applyContainedThemeWithScheme:self.containerScheme];
   [button sizeToFit];
   return button;
 }

 - (MDCButton *)createToggleErrorButton {
   MDCButton *button = [[MDCButton alloc] init];
   [button setTitle:@"Toggle error" forState:UIControlStateNormal];
   [button addTarget:self
                 action:@selector(toggleErrorButtonTapped:)
       forControlEvents:UIControlEventTouchUpInside];
   [button applyContainedThemeWithScheme:self.containerScheme];
   [button sizeToFit];
   return button;
 }

 - (MDCButton *)createToggleDarkModeButton {
   MDCButton *button = [[MDCButton alloc] init];
   [button setTitle:@"Toggle dark mode" forState:UIControlStateNormal];
   [button addTarget:self
                 action:@selector(toggleDarkModeButtonTapped:)
       forControlEvents:UIControlEventTouchUpInside];
   [button applyContainedThemeWithScheme:self.containerScheme];
   [button sizeToFit];
   return button;
 }

 - (MDCButton *)createToggleLayoutDirectionButton {
   MDCButton *button = [[MDCButton alloc] init];
   [button setTitle:@"Toggle layout direction" forState:UIControlStateNormal];
   [button addTarget:self
                 action:@selector(toggleLayoutDirectionButtonTapped:)
       forControlEvents:UIControlEventTouchUpInside];
   [button applyContainedThemeWithScheme:self.containerScheme];
   [button sizeToFit];
   return button;
 }

 - (UILabel *)createLabelWithText:(NSString *)text {
   UILabel *label = [[UILabel alloc] init];
   label.textColor = self.containerScheme.colorScheme.primaryColor;
   label.font = self.containerScheme.typographyScheme.subtitle2;
   label.text = text;
   return label;
 }

 - (void)initializeScrollViewSubviewsArray {
   self.scrollViewSubviews = @[
     self.toggleErrorButton,
     self.toggleDarkModeButton,
     self.toggleDisabledButton,
     self.toggleLayoutDirectionButton,
     self.decreaseContentSizeButton,
     self.increaseContentSizeButton,
     self.resignFirstResponderButton,
   ];
 }

 - (void)addSubviews {
   [self.view addSubview:self.scrollView];
   for (UIView *view in self.scrollViewSubviews) {
     [self.scrollView addSubview:view];
   }
 }

 #pragma mark Custom Layout Methods

 - (void)layoutScrollView {
   CGFloat originX = CGRectGetMinX(self.view.bounds);
   CGFloat originY = CGRectGetMinY(self.view.bounds);
   CGFloat width = CGRectGetWidth(self.view.bounds);
   CGFloat height = CGRectGetHeight(self.view.bounds);
   if (@available(iOS 11.0, *)) {
     originX += self.view.safeAreaInsets.left;
     originY += self.view.safeAreaInsets.top;
     width -= (self.view.safeAreaInsets.left + self.view.safeAreaInsets.right);
     height -= (self.view.safeAreaInsets.top + self.view.safeAreaInsets.bottom);
   }
   CGRect frame = CGRectMake(originX, originY, width, height);
   self.scrollView.frame = frame;
 }

 - (void)resizeScrollViewSubviews {
   [self resizeButtons];
   [self resizeLabels];
 }

 - (void)resizeButtons {
   [self.allButtons enumerateObjectsUsingBlock:^(MDCButton *button, NSUInteger idx, BOOL *stop) {
     [button sizeToFit];
   }];
 }

 - (void)resizeLabels {
   [self.allLabels enumerateObjectsUsingBlock:^(UILabel *label, NSUInteger idx, BOOL *stop) {
     [label sizeToFit];
   }];
 }

 - (void)layoutScrollViewSubviews {
   CGFloat viewMinX = self.defaultPadding;
   CGFloat viewMinY = self.defaultPadding;
   for (UIView *view in self.scrollViewSubviews) {
     CGSize viewSize = view.frame.size;
     CGRect viewFrame = CGRectMake(viewMinX, viewMinY, viewSize.width, viewSize.height);
     view.frame = viewFrame;
     viewMinY = viewMinY + CGRectGetHeight(view.frame) + self.defaultPadding;
   }
 }

 - (void)updateScrollViewContentSize {
   CGFloat maxX = CGRectGetWidth(self.scrollView.bounds);
   CGFloat maxY = CGRectGetHeight(self.scrollView.bounds);
   for (UIView *subview in self.scrollView.subviews) {
     CGFloat subViewMaxX = CGRectGetMaxX(subview.frame);
     if (subViewMaxX > maxX) {
       maxX = subViewMaxX;
     }
     CGFloat subViewMaxY = CGRectGetMaxY(subview.frame);
     if (subViewMaxY > maxY) {
       maxY = subViewMaxY;
     }
   }
   self.scrollView.contentSize = CGSizeMake(maxX, maxY + self.defaultPadding);
 }

 - (CGFloat)defaultPadding {
   return 20;
 }

 #pragma mark Subview configuration

 - (void)applyThemesToScrollViewSubviews {
   [self applyThemesToButtons];
   [self updateLabelColors];
 }

 - (void)applyThemesToButtons {
   [self.allButtons enumerateObjectsUsingBlock:^(MDCButton *button, NSUInteger idx, BOOL *stop) {
     if (self.isErrored) {
       MDCSemanticColorScheme *colorScheme = [[MDCSemanticColorScheme alloc] init];
       colorScheme.primaryColor = colorScheme.errorColor;
       MDCContainerScheme *containerScheme = [[MDCContainerScheme alloc] init];
       containerScheme.colorScheme = colorScheme;
       [button applyContainedThemeWithScheme:containerScheme];
     } else {
       [button applyOutlinedThemeWithScheme:self.containerScheme];
     }
   }];
 }

 - (void)updateLabelColors {
   [self.allLabels enumerateObjectsUsingBlock:^(UILabel *label, NSUInteger idx, BOOL *stop) {
     id<MDCColorScheming> colorScheme = self.containerScheme.colorScheme;
     UIColor *textColor = self.isErrored ? colorScheme.errorColor : colorScheme.primaryColor;
     label.textColor = textColor;
   }];
 }

 - (void)enforcePreferredFonts {
 }

 - (NSArray<MDCButton *> *)allButtons {
   return [self allScrollViewSubviewsOfClass:[MDCButton class]];
 }

 - (NSArray<UILabel *> *)allLabels {
   return [self allScrollViewSubviewsOfClass:[UILabel class]];
 }

 - (NSArray *)allScrollViewSubviewsOfClass:(Class)class {
   return [self.scrollViewSubviews
       objectsAtIndexes:[self.scrollViewSubviews indexesOfObjectsPassingTest:^BOOL(
                                                     UIView *view, NSUInteger idx, BOOL *stop) {
         return [view isKindOfClass:class];
       }]];
 }

 #pragma mark Notification Observing

 - (void)keyboardWillShow:(NSNotification *)notification {
   CGRect frame = [[notification.userInfo valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
   self.scrollView.contentInset = UIEdgeInsetsMake(0, 0, CGRectGetHeight(frame), 0);
 }

 - (void)keyboardWillHide:(NSNotification *)notification {
   self.scrollView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);
 }

 #pragma mark IBActions

 - (void)resignFirstResponderButtonTapped:(UIButton *)button {
   [self handleResignFirstResponderTapped];
 }

 - (void)disableButtonTapped:(UIButton *)button {
   [self handleDisableButtonTapped];
 }

 - (void)toggleErrorButtonTapped:(UIButton *)button {
   [self handleToggleErrorButtonTapped];
 }

 - (void)increaseContentSizeButtonTapped:(id)sender {
   [self.traitEnvironmentChangeDelegate
       childViewControllerDidRequestPreferredContentSizeCategoryIncrement:self
                                                           decreaseButton:
                                                               self.decreaseContentSizeButton
                                                           increaseButton:
                                                               self.increaseContentSizeButton];
 }

 - (void)decreaseContentSizeButtonTapped:(id)sender {
   [self.traitEnvironmentChangeDelegate
       childViewControllerDidRequestPreferredContentSizeCategoryDecrement:self
                                                           decreaseButton:
                                                               self.decreaseContentSizeButton
                                                           increaseButton:
                                                               self.increaseContentSizeButton];
 }

 - (void)toggleDarkModeButtonTapped:(id)sender {
   [self handleToggleDarkModeButtonTapped];
 }

 - (void)toggleLayoutDirectionButtonTapped:(id)sender {
   [self handleToggleLayoutDirectionButtonTapped];
 }

 #pragma mark IBAction handling

 - (void)handleToggleDarkModeButtonTapped {
   if (@available(iOS 12.0, *)) {
     UIUserInterfaceStyle currentUserInterfaceStyle = self.traitCollection.userInterfaceStyle;
     UIUserInterfaceStyle newUserInterfaceStyle = UIUserInterfaceStyleUnspecified;
     if (currentUserInterfaceStyle == UIUserInterfaceStyleLight) {
       newUserInterfaceStyle = UIUserInterfaceStyleDark;
     } else if (currentUserInterfaceStyle == UIUserInterfaceStyleDark) {
       newUserInterfaceStyle = UIUserInterfaceStyleLight;
     } else {
       return;
     }
     [self.traitEnvironmentChangeDelegate
         childViewControllerDidRequestUserInterfaceStyle:self
                                      userInterfaceStyle:newUserInterfaceStyle];
   }
   [self.view setNeedsLayout];
 }

 - (void)handleToggleErrorButtonTapped {
   self.isErrored = !self.isErrored;
   [self.view setNeedsLayout];
 }

 - (void)handleDisableButtonTapped {
   self.isDisabled = !self.isDisabled;
   [self.view setNeedsLayout];
 }

 - (void)handleResignFirstResponderTapped {
 }

 - (void)handleToggleLayoutDirectionButtonTapped {
   if (@available(iOS 12.0, *)) {
     UITraitEnvironmentLayoutDirection currentTraitEnvironmentLayoutDirection =
         self.traitCollection.layoutDirection;
     UITraitEnvironmentLayoutDirection newTraitEnvironmentLayoutDirection =
         UITraitEnvironmentLayoutDirectionUnspecified;
     if (currentTraitEnvironmentLayoutDirection == UITraitEnvironmentLayoutDirectionRightToLeft) {
       newTraitEnvironmentLayoutDirection = UITraitEnvironmentLayoutDirectionLeftToRight;
     } else if (currentTraitEnvironmentLayoutDirection ==
                UITraitEnvironmentLayoutDirectionLeftToRight) {
       newTraitEnvironmentLayoutDirection = UITraitEnvironmentLayoutDirectionRightToLeft;
     } else {
       return;
     }
     [self.traitEnvironmentChangeDelegate
         childViewControllerDidRequestLayoutDirection:self
                                      layoutDirection:newTraitEnvironmentLayoutDirection];
   }
   [self.view setNeedsLayout];
 }

 @end
	// Copyright 2019-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 "MDCTextControlContentViewController.h"

	#import "MaterialButtons.h"

	#import "MDCBaseTextField.h"
	#import "MaterialButtons+Theming.h"
	#import "MaterialColorScheme.h"

	#import "MDCFilledTextField+MaterialTheming.h"
	#import "MDCFilledTextField.h"
	#import "MDCOutlinedTextField+MaterialTheming.h"
	#import "MDCOutlinedTextField.h"

	#import "MDCTraitEnvironmentChangeDelegate.h"

	@interface MDCTextControlContentViewController ()

	/**
	This scrollview contains all the subviews through which the user interacts with the screen.
	*/
	@property(strong, nonatomic) UIScrollView *scrollView;

	/**
	This button allows the user to signal that they want the content size category to decrease.
	*/
	@property(nonatomic, strong) MDCButton *decreaseContentSizeButton;

	/**
	This button allows the user to signal that they want the content size category to increase.
	*/
	@property(nonatomic, strong) MDCButton *increaseContentSizeButton;

	/**
	This button allows the user to signal that they want the first responder to resign first responder.
	*/
	@property(nonatomic, strong) MDCButton *resignFirstResponderButton;

	/**
	This button allows the user to signal that they want all text controls to become disabled.
	*/
	@property(nonatomic, strong) MDCButton *toggleDisabledButton;

	/**
	This button allows the user to signal that they want the view controller to enter an error state.
	*/
	@property(nonatomic, strong) MDCButton *toggleErrorButton;

	/**
	This button allows the user to signal that they want the view controller to toggle dark mode.
	*/
	@property(nonatomic, strong) MDCButton *toggleDarkModeButton;

	/**
	This button allows the user to signal that they want to toggle the layout direction.
	*/
	@property(nonatomic, strong) MDCButton *toggleLayoutDirectionButton;

	@end

	@implementation MDCTextControlContentViewController

	#pragma mark Object Lifecycle

	- (void)dealloc {
	[[NSNotificationCenter defaultCenter] removeObserver:self];
	}

	#pragma mark View Controller Overrides

	- (void)viewDidLoad {
	[super viewDidLoad];

	[self addObservers];
	[self setUpSubviews];
	}

	- (void)viewWillLayoutSubviews {
	[super viewWillLayoutSubviews];

	self.view.backgroundColor = self.containerScheme.colorScheme.backgroundColor;
	[self applyThemesToScrollViewSubviews];
	[self enforcePreferredFonts];
	}

	- (void)viewDidLayoutSubviews {
	[super viewDidLayoutSubviews];

	[self layoutScrollView];
	[self resizeScrollViewSubviews];
	[self layoutScrollViewSubviews];
	[self updateScrollViewContentSize];
	}

	#pragma mark Setup

	- (void)addObservers {
	[[NSNotificationCenter defaultCenter] addObserver:self
	selector:@selector(keyboardWillShow:)
	name:UIKeyboardWillShowNotification
	object:nil];
	[[NSNotificationCenter defaultCenter] addObserver:self
	selector:@selector(keyboardWillHide:)
	name:UIKeyboardWillHideNotification
	object:nil];
	}

	- (void)setUpSubviews {
	[self createBaseSubviews];
	[self initializeScrollViewSubviewsArray];
	[self addSubviews];
	}

	- (void)createBaseSubviews {
	self.scrollView = [[UIScrollView alloc] init];
	self.increaseContentSizeButton = [self createIncreaseContentSizeButton];
	self.decreaseContentSizeButton = [self createDecreaseContentSizeButton];
	self.toggleDisabledButton = [self createToggleDisabledButton];
	self.toggleErrorButton = [self createToggleErrorButton];
	self.resignFirstResponderButton = [self createResignFirstResponderButton];
	self.toggleDarkModeButton = [self createToggleDarkModeButton];
	self.toggleLayoutDirectionButton = [self createToggleLayoutDirectionButton];
	}

	- (MDCButton *)createDecreaseContentSizeButton {
	return [self createContentSizeButtonWithTitle:@"Decrease size"
	selector:@selector(decreaseContentSizeButtonTapped:)];
	}

	- (MDCButton *)createIncreaseContentSizeButton {
	return [self createContentSizeButtonWithTitle:@"Increase size"
	selector:@selector(increaseContentSizeButtonTapped:)];
	}

	- (MDCButton )createContentSizeButtonWithTitle:(NSString )title selector:(SEL)selector {
	MDCButton *button = [[MDCButton alloc] init];
	[button setTitle:title forState:UIControlStateNormal];
	[button addTarget:self action:selector forControlEvents:UIControlEventTouchUpInside];
	[button applyContainedThemeWithScheme:self.containerScheme];
	[button sizeToFit];
	button.enabled = NO;
	if (@available(iOS 10.0, *)) {
	button.enabled = YES;
	}
	return button;
	}

	- (MDCButton *)createToggleDisabledButton {
	MDCButton *button = [[MDCButton alloc] init];
	[button setTitle:@"Toggle disabled" forState:UIControlStateNormal];
	[button addTarget:self
	action:@selector(disableButtonTapped:)
	forControlEvents:UIControlEventTouchUpInside];
	[button applyContainedThemeWithScheme:self.containerScheme];
	[button sizeToFit];
	return button;
	}

	- (MDCButton *)createResignFirstResponderButton {
	MDCButton *button = [[MDCButton alloc] init];
	[button setTitle:@"Resign first responder" forState:UIControlStateNormal];
	[button addTarget:self
	action:@selector(resignFirstResponderButtonTapped:)
	forControlEvents:UIControlEventTouchUpInside];
	[button applyContainedThemeWithScheme:self.containerScheme];
	[button sizeToFit];
	return button;
	}

	- (MDCButton *)createToggleErrorButton {
	MDCButton *button = [[MDCButton alloc] init];
	[button setTitle:@"Toggle error" forState:UIControlStateNormal];
	[button addTarget:self
	action:@selector(toggleErrorButtonTapped:)
	forControlEvents:UIControlEventTouchUpInside];
	[button applyContainedThemeWithScheme:self.containerScheme];
	[button sizeToFit];
	return button;
	}

	- (MDCButton *)createToggleDarkModeButton {
	MDCButton *button = [[MDCButton alloc] init];
	[button setTitle:@"Toggle dark mode" forState:UIControlStateNormal];
	[button addTarget:self
	action:@selector(toggleDarkModeButtonTapped:)
	forControlEvents:UIControlEventTouchUpInside];
	[button applyContainedThemeWithScheme:self.containerScheme];
	[button sizeToFit];
	return button;
	}

	- (MDCButton *)createToggleLayoutDirectionButton {
	MDCButton *button = [[MDCButton alloc] init];
	[button setTitle:@"Toggle layout direction" forState:UIControlStateNormal];
	[button addTarget:self
	action:@selector(toggleLayoutDirectionButtonTapped:)
	forControlEvents:UIControlEventTouchUpInside];
	[button applyContainedThemeWithScheme:self.containerScheme];
	[button sizeToFit];
	return button;
	}

	- (UILabel )createLabelWithText:(NSString )text {
	UILabel *label = [[UILabel alloc] init];
	label.textColor = self.containerScheme.colorScheme.primaryColor;
	label.font = self.containerScheme.typographyScheme.subtitle2;
	label.text = text;
	return label;
	}

	- (void)initializeScrollViewSubviewsArray {
	self.scrollViewSubviews = @[
	self.toggleErrorButton,
	self.toggleDarkModeButton,
	self.toggleDisabledButton,
	self.toggleLayoutDirectionButton,
	self.decreaseContentSizeButton,
	self.increaseContentSizeButton,
	self.resignFirstResponderButton,
	];
	}

	- (void)addSubviews {
	[self.view addSubview:self.scrollView];
	for (UIView *view in self.scrollViewSubviews) {
	[self.scrollView addSubview:view];
	}
	}

	#pragma mark Custom Layout Methods

	- (void)layoutScrollView {
	CGFloat originX = CGRectGetMinX(self.view.bounds);
	CGFloat originY = CGRectGetMinY(self.view.bounds);
	CGFloat width = CGRectGetWidth(self.view.bounds);
	CGFloat height = CGRectGetHeight(self.view.bounds);
	if (@available(iOS 11.0, *)) {
	originX += self.view.safeAreaInsets.left;
	originY += self.view.safeAreaInsets.top;
	width -= (self.view.safeAreaInsets.left + self.view.safeAreaInsets.right);
	height -= (self.view.safeAreaInsets.top + self.view.safeAreaInsets.bottom);
	}
	CGRect frame = CGRectMake(originX, originY, width, height);
	self.scrollView.frame = frame;
	}

	- (void)resizeScrollViewSubviews {
	[self resizeButtons];
	[self resizeLabels];
	}

	- (void)resizeButtons {
	[self.allButtons enumerateObjectsUsingBlock:^(MDCButton button, NSUInteger idx, BOOL stop) {
	[button sizeToFit];
	}];
	}

	- (void)resizeLabels {
	[self.allLabels enumerateObjectsUsingBlock:^(UILabel label, NSUInteger idx, BOOL stop) {
	[label sizeToFit];
	}];
	}

	- (void)layoutScrollViewSubviews {
	CGFloat viewMinX = self.defaultPadding;
	CGFloat viewMinY = self.defaultPadding;
	for (UIView *view in self.scrollViewSubviews) {
	CGSize viewSize = view.frame.size;
	CGRect viewFrame = CGRectMake(viewMinX, viewMinY, viewSize.width, viewSize.height);
	view.frame = viewFrame;
	viewMinY = viewMinY + CGRectGetHeight(view.frame) + self.defaultPadding;
	}
	}

	- (void)updateScrollViewContentSize {
	CGFloat maxX = CGRectGetWidth(self.scrollView.bounds);
	CGFloat maxY = CGRectGetHeight(self.scrollView.bounds);
	for (UIView *subview in self.scrollView.subviews) {
	CGFloat subViewMaxX = CGRectGetMaxX(subview.frame);
	if (subViewMaxX > maxX) {
	maxX = subViewMaxX;
	}
	CGFloat subViewMaxY = CGRectGetMaxY(subview.frame);
	if (subViewMaxY > maxY) {
	maxY = subViewMaxY;
	}
	}
	self.scrollView.contentSize = CGSizeMake(maxX, maxY + self.defaultPadding);
	}

	- (CGFloat)defaultPadding {
	return 20;
	}

	#pragma mark Subview configuration

	- (void)applyThemesToScrollViewSubviews {
	[self applyThemesToButtons];
	[self updateLabelColors];
	}

	- (void)applyThemesToButtons {
	[self.allButtons enumerateObjectsUsingBlock:^(MDCButton button, NSUInteger idx, BOOL stop) {
	if (self.isErrored) {
	MDCSemanticColorScheme *colorScheme = [[MDCSemanticColorScheme alloc] init];
	colorScheme.primaryColor = colorScheme.errorColor;
	MDCContainerScheme *containerScheme = [[MDCContainerScheme alloc] init];
	containerScheme.colorScheme = colorScheme;
	[button applyContainedThemeWithScheme:containerScheme];
	} else {
	[button applyOutlinedThemeWithScheme:self.containerScheme];
	}
	}];
	}

	- (void)updateLabelColors {
	[self.allLabels enumerateObjectsUsingBlock:^(UILabel label, NSUInteger idx, BOOL stop) {
	id<MDCColorScheming> colorScheme = self.containerScheme.colorScheme;
	UIColor *textColor = self.isErrored ? colorScheme.errorColor : colorScheme.primaryColor;
	label.textColor = textColor;
	}];
	}

	- (void)enforcePreferredFonts {
	}

	- (NSArray<MDCButton > )allButtons {
	return [self allScrollViewSubviewsOfClass:[MDCButton class]];
	}

	- (NSArray<UILabel > )allLabels {
	return [self allScrollViewSubviewsOfClass:[UILabel class]];
	}

	- (NSArray *)allScrollViewSubviewsOfClass:(Class)class {
	return [self.scrollViewSubviews
	objectsAtIndexes:[self.scrollViewSubviews indexesOfObjectsPassingTest:^BOOL(
	UIView view, NSUInteger idx, BOOL stop) {
	return [view isKindOfClass:class];
	}]];
	}

	#pragma mark Notification Observing

	- (void)keyboardWillShow:(NSNotification *)notification {
	CGRect frame = [[notification.userInfo valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
	self.scrollView.contentInset = UIEdgeInsetsMake(0, 0, CGRectGetHeight(frame), 0);
	}

	- (void)keyboardWillHide:(NSNotification *)notification {
	self.scrollView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);
	}

	#pragma mark IBActions

	- (void)resignFirstResponderButtonTapped:(UIButton *)button {
	[self handleResignFirstResponderTapped];
	}

	- (void)disableButtonTapped:(UIButton *)button {
	[self handleDisableButtonTapped];
	}

	- (void)toggleErrorButtonTapped:(UIButton *)button {
	[self handleToggleErrorButtonTapped];
	}

	- (void)increaseContentSizeButtonTapped:(id)sender {
	[self.traitEnvironmentChangeDelegate
	childViewControllerDidRequestPreferredContentSizeCategoryIncrement:self
	decreaseButton:
	self.decreaseContentSizeButton
	increaseButton:
	self.increaseContentSizeButton];
	}

	- (void)decreaseContentSizeButtonTapped:(id)sender {
	[self.traitEnvironmentChangeDelegate
	childViewControllerDidRequestPreferredContentSizeCategoryDecrement:self
	decreaseButton:
	self.decreaseContentSizeButton
	increaseButton:
	self.increaseContentSizeButton];
	}

	- (void)toggleDarkModeButtonTapped:(id)sender {
	[self handleToggleDarkModeButtonTapped];
	}

	- (void)toggleLayoutDirectionButtonTapped:(id)sender {
	[self handleToggleLayoutDirectionButtonTapped];
	}

	#pragma mark IBAction handling

	- (void)handleToggleDarkModeButtonTapped {
	if (@available(iOS 12.0, *)) {
	UIUserInterfaceStyle currentUserInterfaceStyle = self.traitCollection.userInterfaceStyle;
	UIUserInterfaceStyle newUserInterfaceStyle = UIUserInterfaceStyleUnspecified;
	if (currentUserInterfaceStyle == UIUserInterfaceStyleLight) {
	newUserInterfaceStyle = UIUserInterfaceStyleDark;
	} else if (currentUserInterfaceStyle == UIUserInterfaceStyleDark) {
	newUserInterfaceStyle = UIUserInterfaceStyleLight;
	} else {
	return;
	}
	[self.traitEnvironmentChangeDelegate
	childViewControllerDidRequestUserInterfaceStyle:self
	userInterfaceStyle:newUserInterfaceStyle];
	}
	[self.view setNeedsLayout];
	}

	- (void)handleToggleErrorButtonTapped {
	self.isErrored = !self.isErrored;
	[self.view setNeedsLayout];
	}

	- (void)handleDisableButtonTapped {
	self.isDisabled = !self.isDisabled;
	[self.view setNeedsLayout];
	}

	- (void)handleResignFirstResponderTapped {
	}

	- (void)handleToggleLayoutDirectionButtonTapped {
	if (@available(iOS 12.0, *)) {
	UITraitEnvironmentLayoutDirection currentTraitEnvironmentLayoutDirection =
	self.traitCollection.layoutDirection;
	UITraitEnvironmentLayoutDirection newTraitEnvironmentLayoutDirection =
	UITraitEnvironmentLayoutDirectionUnspecified;
	if (currentTraitEnvironmentLayoutDirection == UITraitEnvironmentLayoutDirectionRightToLeft) {
	newTraitEnvironmentLayoutDirection = UITraitEnvironmentLayoutDirectionLeftToRight;
	} else if (currentTraitEnvironmentLayoutDirection ==
	UITraitEnvironmentLayoutDirectionLeftToRight) {
	newTraitEnvironmentLayoutDirection = UITraitEnvironmentLayoutDirectionRightToLeft;
	} else {
	return;
	}
	[self.traitEnvironmentChangeDelegate
	childViewControllerDidRequestLayoutDirection:self
	layoutDirection:newTraitEnvironmentLayoutDirection];
	}
	[self.view setNeedsLayout];
	}

	@end