components/CollectionCells/src/MDCCollectionViewCell.m - external/github.com/material-components/material-components-ios - Git at Google

 // 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 "MDCCollectionViewCell.h"

 #import <MDFInternationalization/MDFInternationalization.h>

 #import "MaterialCollectionLayoutAttributes.h"
 #import "MaterialIcons+ic_check.h"
 #import "MaterialIcons+ic_check_circle.h"
 #import "MaterialIcons+ic_chevron_right.h"
 #import "MaterialIcons+ic_info.h"
 #import "MaterialIcons+ic_radio_button_unchecked.h"
 #import "MaterialIcons+ic_reorder.h"
 #import "MaterialPalettes.h"

 static CGFloat kEditingControlAppearanceOffset = 16;

 // Default accessory insets.
 static const UIEdgeInsets kAccessoryInsetDefault = {0, 16, 0, 16};

 // Default editing icon colors.
 // Color is 0x626262
 static inline UIColor *MDCCollectionViewCellGreyColor(void) {
   return MDCPalette.greyPalette.tint700;
 }

 // Color is 0xF44336
 static inline UIColor *MDCCollectionViewCellRedColor(void) {
   return MDCPalette.redPalette.tint500;
 }

 // File name of the bundle (without the '.bundle' extension) containing resources.
 static NSString *const kResourceBundleName = @"MaterialCollectionCells";

 // String table name containing localized strings.
 static NSString *const kStringTableName = @"MaterialCollectionCells";

 NSString *const kSelectedCellAccessibilityHintKey =
     @"MaterialCollectionCellsAccessibilitySelectedHint";

 NSString *const kDeselectedCellAccessibilityHintKey =
     @"MaterialCollectionCellsAccessibilityDeselectedHint";

 // To be used as accessory view when an accessory type is set. It has no particular functionalities
 // other than being a private class defined here, to check if an accessory view was set via an
 // accessory type, or if the user of MDCCollectionViewCell set a custom accessory view.
 @interface MDCAccessoryTypeImageView : UIImageView
 @end
 @implementation MDCAccessoryTypeImageView
 @end

 @implementation MDCCollectionViewCell {
   MDCCollectionViewLayoutAttributes *_attr;
   BOOL _usesCellSeparatorHiddenOverride;
   BOOL _usesCellSeparatorInsetOverride;
   BOOL _shouldAnimateEditingViews;
   UIView *_separatorView;
   UIImageView *_backgroundImageView;
   UIImageView *_editingReorderImageView;
   UIImageView *_editingSelectorImageView;
 }

 @synthesize inkView = _inkView;

 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     [self commonMDCCollectionViewCellInit];
   }
   return self;
 }

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

 - (void)commonMDCCollectionViewCellInit {
   // Separator defaults.
   _separatorView = [[UIImageView alloc] initWithFrame:CGRectZero];
   [self addSubview:_separatorView];

   // Accessory defaults.
   _accessoryType = MDCCollectionViewCellAccessoryNone;
   _accessoryInset = kAccessoryInsetDefault;
   _editingSelectorColor = MDCCollectionViewCellRedColor();
 }

 #pragma mark - Layout

 - (void)prepareForReuse {
   [super prepareForReuse];

   // Accessory defaults.
   _accessoryType = MDCCollectionViewCellAccessoryNone;
   _accessoryInset = kAccessoryInsetDefault;
   [_accessoryView removeFromSuperview];
   _accessoryView = nil;

   // Reset properties.
   _shouldAnimateEditingViews = NO;
   _usesCellSeparatorHiddenOverride = NO;
   _usesCellSeparatorInsetOverride = NO;
   _separatorView.hidden = YES;

   [self drawSeparatorIfNeeded];
   [self updateInterfaceForEditing];

   // Reset cells hidden during swipe deletion.
   self.hidden = NO;

   [self.inkView cancelAllAnimationsAnimated:NO];
 }

 - (void)layoutSubviews {
   [super layoutSubviews];

   // Layout the accessory view and the content view.
   [self updateInterfaceForEditing];
   [self layoutForegroundSubviews];

   void (^editingViewLayout)(void) = ^() {
     CGFloat txReorderTransform;
     CGFloat txSelectorTransform;
     switch (self.mdf_effectiveUserInterfaceLayoutDirection) {
       case UIUserInterfaceLayoutDirectionLeftToRight:
         txReorderTransform = kEditingControlAppearanceOffset;
         txSelectorTransform = -kEditingControlAppearanceOffset;
         break;
       case UIUserInterfaceLayoutDirectionRightToLeft:
         txReorderTransform = -kEditingControlAppearanceOffset;
         txSelectorTransform = kEditingControlAppearanceOffset;
         break;
     }
     self->_editingReorderImageView.alpha = self->_attr.shouldShowReorderStateMask ? 1 : 0;
     self->_editingReorderImageView.transform = self->_attr.shouldShowReorderStateMask ?
         CGAffineTransformMakeTranslation(txReorderTransform, 0) : CGAffineTransformIdentity;

     self->_editingSelectorImageView.alpha = self->_attr.shouldShowSelectorStateMask ? 1 : 0;
     self->_editingSelectorImageView.transform = self->_attr.shouldShowSelectorStateMask ?
         CGAffineTransformMakeTranslation(txSelectorTransform, 0) : CGAffineTransformIdentity;

     self.accessoryView.alpha = self->_attr.shouldShowSelectorStateMask ? 0 : 1;
     self->_accessoryInset.right = self->_attr.shouldShowSelectorStateMask
                                   ? kAccessoryInsetDefault.right + kEditingControlAppearanceOffset
                                   : kAccessoryInsetDefault.right;
   };

   // Animate editing controls.
   if (_shouldAnimateEditingViews) {
     [UIView animateWithDuration:0.3 animations:editingViewLayout];
     _shouldAnimateEditingViews = NO;
   } else {
     [UIView performWithoutAnimation:editingViewLayout];
   }
 }

 - (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes {
   [super applyLayoutAttributes:layoutAttributes];
   if ([layoutAttributes isKindOfClass:[MDCCollectionViewLayoutAttributes class]]) {
     _attr = (MDCCollectionViewLayoutAttributes *)layoutAttributes;

     if (_attr.representedElementCategory == UICollectionElementCategoryCell) {
       // Cells are often set to editing via layout attributes so we default to animating.
       // This can be overridden by ensuring layoutSubviews is called inside a non-animation block.
       [self setEditing:_attr.editing animated:YES];
     }

     // Create image view to hold cell background image with shadowing.
     if (!_backgroundImageView) {
       _backgroundImageView = [[UIImageView alloc] initWithFrame:self.bounds];
       self.backgroundView = _backgroundImageView;
     }
     _backgroundImageView.image = _attr.backgroundImage;

     // Draw separator if needed.
     [self drawSeparatorIfNeeded];

     // Layout the accessory view and the content view.
     [self layoutForegroundSubviews];

     // Animate cell on appearance settings.
     [self updateAppearanceAnimation];
   }
 }

 - (void)layoutForegroundSubviews {
   // First lay out the accessory view.
   _accessoryView.frame = [self accessoryFrame];
   // Then lay out the content view, inset by the accessory view's width.
   self.contentView.frame = [self contentViewFrame];

   // If necessary flip subviews for RTL.
   if (self.mdf_effectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirectionRightToLeft) {
     _accessoryView.frame = MDFRectFlippedHorizontally(_accessoryView.frame,
                                                       CGRectGetWidth(self.bounds));
     self.contentView.frame = MDFRectFlippedHorizontally(self.contentView.frame,
                                                         CGRectGetWidth(self.bounds));
   }
 }

 #pragma mark - Accessory Views

 - (void)setAccessoryType:(MDCCollectionViewCellAccessoryType)accessoryType {
   _accessoryType = accessoryType;

   UIImageView *accessoryImageView =
       [_accessoryView isKindOfClass:[UIImageView class]] ? (UIImageView *)_accessoryView : nil;
   if (!_accessoryView && accessoryType != MDCCollectionViewCellAccessoryNone) {
     // Add accessory view.
     accessoryImageView = [[MDCAccessoryTypeImageView alloc] initWithFrame:CGRectZero];
     _accessoryView = accessoryImageView;
     _accessoryView.userInteractionEnabled = NO;
     [self addSubview:_accessoryView];
   }

   switch (_accessoryType) {
     case MDCCollectionViewCellAccessoryDisclosureIndicator: {
       UIImage *image = [MDCIcons imageFor_ic_chevron_right];
       if (self.mdf_effectiveUserInterfaceLayoutDirection ==
           UIUserInterfaceLayoutDirectionRightToLeft) {
         image = [image mdf_imageWithHorizontallyFlippedOrientation];
       }
       accessoryImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
       break;
     }
     case MDCCollectionViewCellAccessoryCheckmark: {
       UIImage *image = [MDCIcons imageFor_ic_check];
       accessoryImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
       break;
     }
     case MDCCollectionViewCellAccessoryDetailButton: {
       UIImage *image = [MDCIcons imageFor_ic_info];
       accessoryImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
       break;
     }
     case MDCCollectionViewCellAccessoryNone: {
       [_accessoryView removeFromSuperview];
       _accessoryView = nil;
       break;
     }
   }
   [_accessoryView sizeToFit];
 }

 - (void)setAccessoryView:(UIView *)accessoryView {
   if (_accessoryView) {
     [_accessoryView removeFromSuperview];
   }
   _accessoryView = accessoryView;
   if (_accessoryView) {
     [self addSubview:_accessoryView];
   }
 }

 - (CGRect)accessoryFrame {
   CGSize size = _accessoryView.frame.size;
   CGFloat originX = CGRectGetWidth(self.bounds) - size.width - _accessoryInset.right;
   CGFloat originY = (CGRectGetHeight(self.bounds) - size.height) / 2;
   return CGRectMake(originX, originY, size.width, size.height);
 }

 - (MDCInkView *)inkView {
   if (!_inkView) {
     _inkView = [[MDCInkView alloc] initWithFrame:self.bounds];
     _inkView.usesLegacyInkRipple = NO;
     [self addSubview:_inkView];
   }
   return _inkView;
 }

 - (void)setInkView:(MDCInkView *)inkView {
   if (inkView == _inkView) {
     return;
   }
   if (_inkView) {
     [_inkView removeFromSuperview];
   }
   if (inkView) {
     [self addSubview:inkView];
   }
   _inkView = inkView;
 }

 #pragma mark - Separator

 - (void)setShouldHideSeparator:(BOOL)shouldHideSeparator {
   _usesCellSeparatorHiddenOverride = YES;
   _shouldHideSeparator = shouldHideSeparator;
   [self drawSeparatorIfNeeded];
 }

 - (void)setSeparatorInset:(UIEdgeInsets)separatorInset {
   _usesCellSeparatorInsetOverride = YES;
   _separatorInset = separatorInset;
   [self drawSeparatorIfNeeded];
 }

 - (void)drawSeparatorIfNeeded {
   // Determine separator spec from attributes and cell overrides. Don't draw separator for bottom
   // cell or in grid layout cells. Separators are added here as cell subviews instead of decoration
   // views registered with the layout to overcome inability to animate decoration views in
   // coordination with cell animations.
   BOOL isHidden =
       _usesCellSeparatorHiddenOverride ? _shouldHideSeparator : _attr.shouldHideSeparators;
   UIEdgeInsets separatorInset =
       _usesCellSeparatorInsetOverride ? _separatorInset : _attr.separatorInset;
   BOOL isBottom = _attr.sectionOrdinalPosition & MDCCollectionViewOrdinalPositionVerticalBottom;
   BOOL isGrid = _attr.isGridLayout;

   BOOL hideSeparator = isBottom || isHidden || isGrid;
   if (hideSeparator != _separatorView.hidden) {
     _separatorView.hidden = hideSeparator;
   }

   if (!hideSeparator) {
     UIEdgeInsets insets = _attr.backgroundImageViewInsets;
     // Compute the frame in LTR.
     CGRect separatorFrame = CGRectMake(
         insets.left, CGRectGetHeight(self.bounds) - _attr.separatorLineHeight,
         CGRectGetWidth(self.bounds) - insets.left - insets.right, _attr.separatorLineHeight);
     separatorFrame = UIEdgeInsetsInsetRect(separatorFrame, separatorInset);
     if (self.mdf_effectiveUserInterfaceLayoutDirection ==
         UIUserInterfaceLayoutDirectionRightToLeft) {
       separatorFrame = MDFRectFlippedHorizontally(separatorFrame, CGRectGetWidth(self.bounds));
     }
     _separatorView.frame = separatorFrame;
     _separatorView.backgroundColor = _attr.separatorColor;
   }
 }

 #pragma mark - Editing

 - (void)setEditing:(BOOL)editing {
   [self setEditing:editing animated:NO];
 }

 - (void)setEditing:(BOOL)editing animated:(BOOL)animated {
   if (_editing == editing) {
     return;
   }
   _shouldAnimateEditingViews = animated;
   _editing = editing;
   [self setNeedsLayout];
   [self layoutIfNeeded];
 }

 - (void)updateInterfaceForEditing {
   self.contentView.userInteractionEnabled = [self shouldEnableCellInteractions];

   if (_editing) {
     // Disable implicit animations when setting initial positioning of these subviews.
     [CATransaction begin];
     [CATransaction setDisableActions:YES];

     // Create reorder editing controls.
     if (_attr.shouldShowReorderStateMask) {
       if (!_editingReorderImageView) {
         UIImage *reorderImage = [MDCIcons imageFor_ic_reorder];
         reorderImage = [reorderImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
         _editingReorderImageView = [[UIImageView alloc] initWithImage:reorderImage];
         _editingReorderImageView.tintColor = MDCCollectionViewCellGreyColor();
         _editingReorderImageView.autoresizingMask =
             MDFTrailingMarginAutoresizingMaskForLayoutDirection(
                 self.mdf_effectiveUserInterfaceLayoutDirection);
         [self addSubview:_editingReorderImageView];
       }
       CGAffineTransform transform = _editingReorderImageView.transform;
       _editingReorderImageView.transform = CGAffineTransformIdentity;
       CGSize size = _editingReorderImageView.image.size;
       CGRect frame =
           CGRectMake(0, (CGRectGetHeight(self.bounds) - size.height) / 2, size.width, size.height);
       if (self.mdf_effectiveUserInterfaceLayoutDirection ==
           UIUserInterfaceLayoutDirectionRightToLeft) {
         frame = MDFRectFlippedHorizontally(frame, CGRectGetWidth(self.bounds));
       }
       _editingReorderImageView.frame = frame;
       _editingReorderImageView.transform = transform;
       _editingReorderImageView.alpha = 1;
     } else {
       _editingReorderImageView.alpha = 0;
     }

     // Create selector editing controls.
     if (_attr.shouldShowSelectorStateMask) {
       if (!_editingSelectorImageView) {
         UIImage *selectorImage = [MDCIcons imageFor_ic_radio_button_unchecked];
         selectorImage = [selectorImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
         _editingSelectorImageView = [[UIImageView alloc] initWithImage:selectorImage];
         _editingSelectorImageView.tintColor = MDCCollectionViewCellGreyColor();
         _editingSelectorImageView.autoresizingMask =
             MDFLeadingMarginAutoresizingMaskForLayoutDirection(
                 self.mdf_effectiveUserInterfaceLayoutDirection);
         [self addSubview:_editingSelectorImageView];
       }
       CGAffineTransform transform = _editingSelectorImageView.transform;
       _editingSelectorImageView.transform = CGAffineTransformIdentity;
       CGSize size = _editingSelectorImageView.image.size;
       CGFloat originX = CGRectGetWidth(self.bounds) - size.width;
       CGFloat originY = (CGRectGetHeight(self.bounds) - size.height) / 2;
       CGRect frame = (CGRect){{originX, originY}, size};
       if (self.mdf_effectiveUserInterfaceLayoutDirection ==
           UIUserInterfaceLayoutDirectionRightToLeft) {
         frame = MDFRectFlippedHorizontally(frame, CGRectGetWidth(self.bounds));
       }
       _editingSelectorImageView.frame = frame;
       _editingSelectorImageView.transform = transform;
       _editingSelectorImageView.alpha = 1;
     } else {
       _editingSelectorImageView.alpha = 0;
     }
     [CATransaction commit];
   } else {
     _editingReorderImageView.alpha = 0;
     _editingSelectorImageView.alpha = 0;
   }

   // Update accessory view.
   _accessoryView.alpha = _attr.shouldShowSelectorStateMask ? 0 : 1;
   _accessoryInset.right = _attr.shouldShowSelectorStateMask
                               ? kAccessoryInsetDefault.right + kEditingControlAppearanceOffset
                               : kAccessoryInsetDefault.right;
 }

 #pragma mark - Selecting

 - (void)setSelected:(BOOL)selected {
   BOOL previousSelectedState = self.selected;
   [super setSelected:selected];
   if (selected) {
     if (_editingSelectorImageView && previousSelectedState != selected) {
       _editingSelectorImageView.image = [MDCIcons imageFor_ic_check_circle];
       _editingSelectorImageView.tintColor = self.editingSelectorColor;
       _editingSelectorImageView.image = [_editingSelectorImageView.image
           imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
     }
     self.accessibilityTraits |= UIAccessibilityTraitSelected;
   } else {
     if (_editingSelectorImageView && previousSelectedState != selected) {
       _editingSelectorImageView.image = [MDCIcons imageFor_ic_radio_button_unchecked];
       _editingSelectorImageView.tintColor = MDCCollectionViewCellGreyColor();
       _editingSelectorImageView.image = [_editingSelectorImageView.image
           imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
     }
     self.accessibilityTraits &= ~UIAccessibilityTraitSelected;
   }
 }

 - (void)setEditingSelectorColor:(UIColor *)editingSelectorColor {
   if (editingSelectorColor == nil) {
     editingSelectorColor = MDCCollectionViewCellRedColor();
   }
   _editingSelectorColor = editingSelectorColor;
 }

 #pragma mark - Cell Appearance Animation

 - (void)updateAppearanceAnimation {
   if (_attr.animateCellsOnAppearanceDelay > 0) {
     // Intially hide content view and separator.
     self.contentView.alpha = 0;
     _separatorView.alpha = 0;

     // Animate fade-in after delay.
     if (!_attr.willAnimateCellsOnAppearance) {
       [UIView animateWithDuration:_attr.animateCellsOnAppearanceDuration
                             delay:_attr.animateCellsOnAppearanceDelay
                           options:UIViewAnimationOptionCurveEaseOut
                        animations:^{
                          self.contentView.alpha = 1;
                          self->_separatorView.alpha = 1;
                        }
                        completion:nil];
     }
   }
 }

 #pragma mark - RTL

 // UISemanticContentAttribute was added in iOS SDK 9.0 but is available on devices running earlier
 // version of iOS. We ignore the partial-availability warning that gets thrown on our use of this
 // symbol.
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wpartial-availability"
 - (void)mdf_setSemanticContentAttribute:(UISemanticContentAttribute)mdf_semanticContentAttribute {
   [super mdf_setSemanticContentAttribute:mdf_semanticContentAttribute];
   // Reload the accessory type image if there is one.
   if ([_accessoryView isKindOfClass:[MDCAccessoryTypeImageView class]]) {
     self.accessoryType = self.accessoryType;
   }
 }
 #pragma clang diagnostic pop

 #pragma mark - Accessibility

 - (UIAccessibilityTraits)accessibilityTraits {
   UIAccessibilityTraits accessibilityTraits = [super accessibilityTraits];
   if (self.accessoryType == MDCCollectionViewCellAccessoryCheckmark) {
     accessibilityTraits |= UIAccessibilityTraitSelected;
   }
   return accessibilityTraits;
 }

 - (NSString *)accessibilityHint {
   if (_attr.shouldShowSelectorStateMask) {
     NSString *localizedHintKey =
         self.selected ? kSelectedCellAccessibilityHintKey : kDeselectedCellAccessibilityHintKey;
     return [[self class] localizedStringWithKey:localizedHintKey];
   }
   return nil;
 }

 #pragma mark - Private

 + (NSString *)localizedStringWithKey:(NSString *)key {
   NSBundle *containingBundle = [NSBundle bundleForClass:self];
   NSURL *resourceBundleURL =
       [containingBundle URLForResource:kResourceBundleName withExtension:@"bundle"];
   NSBundle *resourceBundle = [NSBundle bundleWithURL:resourceBundleURL];
   return [resourceBundle localizedStringForKey:key value:nil table:kStringTableName];
 }

 - (CGRect)contentViewFrame {
   CGFloat leadingPadding =
       _attr.shouldShowReorderStateMask
           ? CGRectGetWidth(_editingReorderImageView.bounds) + kEditingControlAppearanceOffset
           : 0;

   CGFloat accessoryViewPadding =
       _accessoryView ? CGRectGetWidth(self.bounds) - CGRectGetMinX(_accessoryView.frame) : 0;
   CGFloat trailingPadding =
       _attr.shouldShowSelectorStateMask
           ? CGRectGetWidth(_editingSelectorImageView.bounds) + kEditingControlAppearanceOffset
           : accessoryViewPadding;
   UIEdgeInsets insets = UIEdgeInsetsMake(0, leadingPadding, 0, trailingPadding);
   return UIEdgeInsetsInsetRect(self.bounds, insets);
 }

 - (BOOL)shouldEnableCellInteractions {
   return !_editing || _allowsCellInteractionsWhileEditing;
 }

 @end
	// 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 "MDCCollectionViewCell.h"

	#import <MDFInternationalization/MDFInternationalization.h>

	#import "MaterialCollectionLayoutAttributes.h"
	#import "MaterialIcons+ic_check.h"
	#import "MaterialIcons+ic_check_circle.h"
	#import "MaterialIcons+ic_chevron_right.h"
	#import "MaterialIcons+ic_info.h"
	#import "MaterialIcons+ic_radio_button_unchecked.h"
	#import "MaterialIcons+ic_reorder.h"
	#import "MaterialPalettes.h"

	static CGFloat kEditingControlAppearanceOffset = 16;

	// Default accessory insets.
	static const UIEdgeInsets kAccessoryInsetDefault = {0, 16, 0, 16};

	// Default editing icon colors.
	// Color is 0x626262
	static inline UIColor *MDCCollectionViewCellGreyColor(void) {
	return MDCPalette.greyPalette.tint700;
	}

	// Color is 0xF44336
	static inline UIColor *MDCCollectionViewCellRedColor(void) {
	return MDCPalette.redPalette.tint500;
	}

	// File name of the bundle (without the '.bundle' extension) containing resources.
	static NSString *const kResourceBundleName = @"MaterialCollectionCells";

	// String table name containing localized strings.
	static NSString *const kStringTableName = @"MaterialCollectionCells";

	NSString *const kSelectedCellAccessibilityHintKey =
	@"MaterialCollectionCellsAccessibilitySelectedHint";

	NSString *const kDeselectedCellAccessibilityHintKey =
	@"MaterialCollectionCellsAccessibilityDeselectedHint";

	// To be used as accessory view when an accessory type is set. It has no particular functionalities
	// other than being a private class defined here, to check if an accessory view was set via an
	// accessory type, or if the user of MDCCollectionViewCell set a custom accessory view.
	@interface MDCAccessoryTypeImageView : UIImageView
	@end
	@implementation MDCAccessoryTypeImageView
	@end

	@implementation MDCCollectionViewCell {
	MDCCollectionViewLayoutAttributes *_attr;
	BOOL _usesCellSeparatorHiddenOverride;
	BOOL _usesCellSeparatorInsetOverride;
	BOOL _shouldAnimateEditingViews;
	UIView *_separatorView;
	UIImageView *_backgroundImageView;
	UIImageView *_editingReorderImageView;
	UIImageView *_editingSelectorImageView;
	}

	@synthesize inkView = _inkView;

	- (instancetype)initWithFrame:(CGRect)frame {
	self = [super initWithFrame:frame];
	if (self) {
	[self commonMDCCollectionViewCellInit];
	}
	return self;
	}

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

	- (void)commonMDCCollectionViewCellInit {
	// Separator defaults.
	_separatorView = [[UIImageView alloc] initWithFrame:CGRectZero];
	[self addSubview:_separatorView];

	// Accessory defaults.
	_accessoryType = MDCCollectionViewCellAccessoryNone;
	_accessoryInset = kAccessoryInsetDefault;
	_editingSelectorColor = MDCCollectionViewCellRedColor();
	}

	#pragma mark - Layout

	- (void)prepareForReuse {
	[super prepareForReuse];

	// Accessory defaults.
	_accessoryType = MDCCollectionViewCellAccessoryNone;
	_accessoryInset = kAccessoryInsetDefault;
	[_accessoryView removeFromSuperview];
	_accessoryView = nil;

	// Reset properties.
	_shouldAnimateEditingViews = NO;
	_usesCellSeparatorHiddenOverride = NO;
	_usesCellSeparatorInsetOverride = NO;
	_separatorView.hidden = YES;

	[self drawSeparatorIfNeeded];
	[self updateInterfaceForEditing];

	// Reset cells hidden during swipe deletion.
	self.hidden = NO;

	[self.inkView cancelAllAnimationsAnimated:NO];
	}

	- (void)layoutSubviews {
	[super layoutSubviews];

	// Layout the accessory view and the content view.
	[self updateInterfaceForEditing];
	[self layoutForegroundSubviews];

	void (^editingViewLayout)(void) = ^() {
	CGFloat txReorderTransform;
	CGFloat txSelectorTransform;
	switch (self.mdf_effectiveUserInterfaceLayoutDirection) {
	case UIUserInterfaceLayoutDirectionLeftToRight:
	txReorderTransform = kEditingControlAppearanceOffset;
	txSelectorTransform = -kEditingControlAppearanceOffset;
	break;
	case UIUserInterfaceLayoutDirectionRightToLeft:
	txReorderTransform = -kEditingControlAppearanceOffset;
	txSelectorTransform = kEditingControlAppearanceOffset;
	break;
	}
	self->_editingReorderImageView.alpha = self->_attr.shouldShowReorderStateMask ? 1 : 0;
	self->_editingReorderImageView.transform = self->_attr.shouldShowReorderStateMask ?
	CGAffineTransformMakeTranslation(txReorderTransform, 0) : CGAffineTransformIdentity;

	self->_editingSelectorImageView.alpha = self->_attr.shouldShowSelectorStateMask ? 1 : 0;
	self->_editingSelectorImageView.transform = self->_attr.shouldShowSelectorStateMask ?
	CGAffineTransformMakeTranslation(txSelectorTransform, 0) : CGAffineTransformIdentity;

	self.accessoryView.alpha = self->_attr.shouldShowSelectorStateMask ? 0 : 1;
	self->_accessoryInset.right = self->_attr.shouldShowSelectorStateMask
	? kAccessoryInsetDefault.right + kEditingControlAppearanceOffset
	: kAccessoryInsetDefault.right;
	};

	// Animate editing controls.
	if (_shouldAnimateEditingViews) {
	[UIView animateWithDuration:0.3 animations:editingViewLayout];
	_shouldAnimateEditingViews = NO;
	} else {
	[UIView performWithoutAnimation:editingViewLayout];
	}
	}

	- (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes {
	[super applyLayoutAttributes:layoutAttributes];
	if ([layoutAttributes isKindOfClass:[MDCCollectionViewLayoutAttributes class]]) {
	_attr = (MDCCollectionViewLayoutAttributes *)layoutAttributes;

	if (_attr.representedElementCategory == UICollectionElementCategoryCell) {
	// Cells are often set to editing via layout attributes so we default to animating.
	// This can be overridden by ensuring layoutSubviews is called inside a non-animation block.
	[self setEditing:_attr.editing animated:YES];
	}

	// Create image view to hold cell background image with shadowing.
	if (!_backgroundImageView) {
	_backgroundImageView = [[UIImageView alloc] initWithFrame:self.bounds];
	self.backgroundView = _backgroundImageView;
	}
	_backgroundImageView.image = _attr.backgroundImage;

	// Draw separator if needed.
	[self drawSeparatorIfNeeded];

	// Layout the accessory view and the content view.
	[self layoutForegroundSubviews];

	// Animate cell on appearance settings.
	[self updateAppearanceAnimation];
	}
	}

	- (void)layoutForegroundSubviews {
	// First lay out the accessory view.
	_accessoryView.frame = [self accessoryFrame];
	// Then lay out the content view, inset by the accessory view's width.
	self.contentView.frame = [self contentViewFrame];

	// If necessary flip subviews for RTL.
	if (self.mdf_effectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirectionRightToLeft) {
	_accessoryView.frame = MDFRectFlippedHorizontally(_accessoryView.frame,
	CGRectGetWidth(self.bounds));
	self.contentView.frame = MDFRectFlippedHorizontally(self.contentView.frame,
	CGRectGetWidth(self.bounds));
	}
	}

	#pragma mark - Accessory Views

	- (void)setAccessoryType:(MDCCollectionViewCellAccessoryType)accessoryType {
	_accessoryType = accessoryType;

	UIImageView *accessoryImageView =
	[_accessoryView isKindOfClass:[UIImageView class]] ? (UIImageView *)_accessoryView : nil;
	if (!_accessoryView && accessoryType != MDCCollectionViewCellAccessoryNone) {
	// Add accessory view.
	accessoryImageView = [[MDCAccessoryTypeImageView alloc] initWithFrame:CGRectZero];
	_accessoryView = accessoryImageView;
	_accessoryView.userInteractionEnabled = NO;
	[self addSubview:_accessoryView];
	}

	switch (_accessoryType) {
	case MDCCollectionViewCellAccessoryDisclosureIndicator: {
	UIImage *image = [MDCIcons imageFor_ic_chevron_right];
	if (self.mdf_effectiveUserInterfaceLayoutDirection ==
	UIUserInterfaceLayoutDirectionRightToLeft) {
	image = [image mdf_imageWithHorizontallyFlippedOrientation];
	}
	accessoryImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	break;
	}
	case MDCCollectionViewCellAccessoryCheckmark: {
	UIImage *image = [MDCIcons imageFor_ic_check];
	accessoryImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	break;
	}
	case MDCCollectionViewCellAccessoryDetailButton: {
	UIImage *image = [MDCIcons imageFor_ic_info];
	accessoryImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	break;
	}
	case MDCCollectionViewCellAccessoryNone: {
	[_accessoryView removeFromSuperview];
	_accessoryView = nil;
	break;
	}
	}
	[_accessoryView sizeToFit];
	}

	- (void)setAccessoryView:(UIView *)accessoryView {
	if (_accessoryView) {
	[_accessoryView removeFromSuperview];
	}
	_accessoryView = accessoryView;
	if (_accessoryView) {
	[self addSubview:_accessoryView];
	}
	}

	- (CGRect)accessoryFrame {
	CGSize size = _accessoryView.frame.size;
	CGFloat originX = CGRectGetWidth(self.bounds) - size.width - _accessoryInset.right;
	CGFloat originY = (CGRectGetHeight(self.bounds) - size.height) / 2;
	return CGRectMake(originX, originY, size.width, size.height);
	}

	- (MDCInkView *)inkView {
	if (!_inkView) {
	_inkView = [[MDCInkView alloc] initWithFrame:self.bounds];
	_inkView.usesLegacyInkRipple = NO;
	[self addSubview:_inkView];
	}
	return _inkView;
	}

	- (void)setInkView:(MDCInkView *)inkView {
	if (inkView == _inkView) {
	return;
	}
	if (_inkView) {
	[_inkView removeFromSuperview];
	}
	if (inkView) {
	[self addSubview:inkView];
	}
	_inkView = inkView;
	}

	#pragma mark - Separator

	- (void)setShouldHideSeparator:(BOOL)shouldHideSeparator {
	_usesCellSeparatorHiddenOverride = YES;
	_shouldHideSeparator = shouldHideSeparator;
	[self drawSeparatorIfNeeded];
	}

	- (void)setSeparatorInset:(UIEdgeInsets)separatorInset {
	_usesCellSeparatorInsetOverride = YES;
	_separatorInset = separatorInset;
	[self drawSeparatorIfNeeded];
	}

	- (void)drawSeparatorIfNeeded {
	// Determine separator spec from attributes and cell overrides. Don't draw separator for bottom
	// cell or in grid layout cells. Separators are added here as cell subviews instead of decoration
	// views registered with the layout to overcome inability to animate decoration views in
	// coordination with cell animations.
	BOOL isHidden =
	_usesCellSeparatorHiddenOverride ? _shouldHideSeparator : _attr.shouldHideSeparators;
	UIEdgeInsets separatorInset =
	_usesCellSeparatorInsetOverride ? _separatorInset : _attr.separatorInset;
	BOOL isBottom = _attr.sectionOrdinalPosition & MDCCollectionViewOrdinalPositionVerticalBottom;
	BOOL isGrid = _attr.isGridLayout;

	BOOL hideSeparator = isBottom \|\| isHidden \|\| isGrid;
	if (hideSeparator != _separatorView.hidden) {
	_separatorView.hidden = hideSeparator;
	}

	if (!hideSeparator) {
	UIEdgeInsets insets = _attr.backgroundImageViewInsets;
	// Compute the frame in LTR.
	CGRect separatorFrame = CGRectMake(
	insets.left, CGRectGetHeight(self.bounds) - _attr.separatorLineHeight,
	CGRectGetWidth(self.bounds) - insets.left - insets.right, _attr.separatorLineHeight);
	separatorFrame = UIEdgeInsetsInsetRect(separatorFrame, separatorInset);
	if (self.mdf_effectiveUserInterfaceLayoutDirection ==
	UIUserInterfaceLayoutDirectionRightToLeft) {
	separatorFrame = MDFRectFlippedHorizontally(separatorFrame, CGRectGetWidth(self.bounds));
	}
	_separatorView.frame = separatorFrame;
	_separatorView.backgroundColor = _attr.separatorColor;
	}
	}

	#pragma mark - Editing

	- (void)setEditing:(BOOL)editing {
	[self setEditing:editing animated:NO];
	}

	- (void)setEditing:(BOOL)editing animated:(BOOL)animated {
	if (_editing == editing) {
	return;
	}
	_shouldAnimateEditingViews = animated;
	_editing = editing;
	[self setNeedsLayout];
	[self layoutIfNeeded];
	}

	- (void)updateInterfaceForEditing {
	self.contentView.userInteractionEnabled = [self shouldEnableCellInteractions];

	if (_editing) {
	// Disable implicit animations when setting initial positioning of these subviews.
	[CATransaction begin];
	[CATransaction setDisableActions:YES];

	// Create reorder editing controls.
	if (_attr.shouldShowReorderStateMask) {
	if (!_editingReorderImageView) {
	UIImage *reorderImage = [MDCIcons imageFor_ic_reorder];
	reorderImage = [reorderImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	_editingReorderImageView = [[UIImageView alloc] initWithImage:reorderImage];
	_editingReorderImageView.tintColor = MDCCollectionViewCellGreyColor();
	_editingReorderImageView.autoresizingMask =
	MDFTrailingMarginAutoresizingMaskForLayoutDirection(
	self.mdf_effectiveUserInterfaceLayoutDirection);
	[self addSubview:_editingReorderImageView];
	}
	CGAffineTransform transform = _editingReorderImageView.transform;
	_editingReorderImageView.transform = CGAffineTransformIdentity;
	CGSize size = _editingReorderImageView.image.size;
	CGRect frame =
	CGRectMake(0, (CGRectGetHeight(self.bounds) - size.height) / 2, size.width, size.height);
	if (self.mdf_effectiveUserInterfaceLayoutDirection ==
	UIUserInterfaceLayoutDirectionRightToLeft) {
	frame = MDFRectFlippedHorizontally(frame, CGRectGetWidth(self.bounds));
	}
	_editingReorderImageView.frame = frame;
	_editingReorderImageView.transform = transform;
	_editingReorderImageView.alpha = 1;
	} else {
	_editingReorderImageView.alpha = 0;
	}

	// Create selector editing controls.
	if (_attr.shouldShowSelectorStateMask) {
	if (!_editingSelectorImageView) {
	UIImage *selectorImage = [MDCIcons imageFor_ic_radio_button_unchecked];
	selectorImage = [selectorImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	_editingSelectorImageView = [[UIImageView alloc] initWithImage:selectorImage];
	_editingSelectorImageView.tintColor = MDCCollectionViewCellGreyColor();
	_editingSelectorImageView.autoresizingMask =
	MDFLeadingMarginAutoresizingMaskForLayoutDirection(
	self.mdf_effectiveUserInterfaceLayoutDirection);
	[self addSubview:_editingSelectorImageView];
	}
	CGAffineTransform transform = _editingSelectorImageView.transform;
	_editingSelectorImageView.transform = CGAffineTransformIdentity;
	CGSize size = _editingSelectorImageView.image.size;
	CGFloat originX = CGRectGetWidth(self.bounds) - size.width;
	CGFloat originY = (CGRectGetHeight(self.bounds) - size.height) / 2;
	CGRect frame = (CGRect){{originX, originY}, size};
	if (self.mdf_effectiveUserInterfaceLayoutDirection ==
	UIUserInterfaceLayoutDirectionRightToLeft) {
	frame = MDFRectFlippedHorizontally(frame, CGRectGetWidth(self.bounds));
	}
	_editingSelectorImageView.frame = frame;
	_editingSelectorImageView.transform = transform;
	_editingSelectorImageView.alpha = 1;
	} else {
	_editingSelectorImageView.alpha = 0;
	}
	[CATransaction commit];
	} else {
	_editingReorderImageView.alpha = 0;
	_editingSelectorImageView.alpha = 0;
	}

	// Update accessory view.
	_accessoryView.alpha = _attr.shouldShowSelectorStateMask ? 0 : 1;
	_accessoryInset.right = _attr.shouldShowSelectorStateMask
	? kAccessoryInsetDefault.right + kEditingControlAppearanceOffset
	: kAccessoryInsetDefault.right;
	}

	#pragma mark - Selecting

	- (void)setSelected:(BOOL)selected {
	BOOL previousSelectedState = self.selected;
	[super setSelected:selected];
	if (selected) {
	if (_editingSelectorImageView && previousSelectedState != selected) {
	_editingSelectorImageView.image = [MDCIcons imageFor_ic_check_circle];
	_editingSelectorImageView.tintColor = self.editingSelectorColor;
	_editingSelectorImageView.image = [_editingSelectorImageView.image
	imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	}
	self.accessibilityTraits \|= UIAccessibilityTraitSelected;
	} else {
	if (_editingSelectorImageView && previousSelectedState != selected) {
	_editingSelectorImageView.image = [MDCIcons imageFor_ic_radio_button_unchecked];
	_editingSelectorImageView.tintColor = MDCCollectionViewCellGreyColor();
	_editingSelectorImageView.image = [_editingSelectorImageView.image
	imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
	}
	self.accessibilityTraits &= ~UIAccessibilityTraitSelected;
	}
	}

	- (void)setEditingSelectorColor:(UIColor *)editingSelectorColor {
	if (editingSelectorColor == nil) {
	editingSelectorColor = MDCCollectionViewCellRedColor();
	}
	_editingSelectorColor = editingSelectorColor;
	}

	#pragma mark - Cell Appearance Animation

	- (void)updateAppearanceAnimation {
	if (_attr.animateCellsOnAppearanceDelay > 0) {
	// Intially hide content view and separator.
	self.contentView.alpha = 0;
	_separatorView.alpha = 0;

	// Animate fade-in after delay.
	if (!_attr.willAnimateCellsOnAppearance) {
	[UIView animateWithDuration:_attr.animateCellsOnAppearanceDuration
	delay:_attr.animateCellsOnAppearanceDelay
	options:UIViewAnimationOptionCurveEaseOut
	animations:^{
	self.contentView.alpha = 1;
	self->_separatorView.alpha = 1;
	}
	completion:nil];
	}
	}
	}

	#pragma mark - RTL

	// UISemanticContentAttribute was added in iOS SDK 9.0 but is available on devices running earlier
	// version of iOS. We ignore the partial-availability warning that gets thrown on our use of this
	// symbol.
	#pragma clang diagnostic push
	#pragma clang diagnostic ignored "-Wpartial-availability"
	- (void)mdf_setSemanticContentAttribute:(UISemanticContentAttribute)mdf_semanticContentAttribute {
	[super mdf_setSemanticContentAttribute:mdf_semanticContentAttribute];
	// Reload the accessory type image if there is one.
	if ([_accessoryView isKindOfClass:[MDCAccessoryTypeImageView class]]) {
	self.accessoryType = self.accessoryType;
	}
	}
	#pragma clang diagnostic pop

	#pragma mark - Accessibility

	- (UIAccessibilityTraits)accessibilityTraits {
	UIAccessibilityTraits accessibilityTraits = [super accessibilityTraits];
	if (self.accessoryType == MDCCollectionViewCellAccessoryCheckmark) {
	accessibilityTraits \|= UIAccessibilityTraitSelected;
	}
	return accessibilityTraits;
	}

	- (NSString *)accessibilityHint {
	if (_attr.shouldShowSelectorStateMask) {
	NSString *localizedHintKey =
	self.selected ? kSelectedCellAccessibilityHintKey : kDeselectedCellAccessibilityHintKey;
	return [[self class] localizedStringWithKey:localizedHintKey];
	}
	return nil;
	}

	#pragma mark - Private

	+ (NSString )localizedStringWithKey:(NSString )key {
	NSBundle *containingBundle = [NSBundle bundleForClass:self];
	NSURL *resourceBundleURL =
	[containingBundle URLForResource:kResourceBundleName withExtension:@"bundle"];
	NSBundle *resourceBundle = [NSBundle bundleWithURL:resourceBundleURL];
	return [resourceBundle localizedStringForKey:key value:nil table:kStringTableName];
	}

	- (CGRect)contentViewFrame {
	CGFloat leadingPadding =
	_attr.shouldShowReorderStateMask
	? CGRectGetWidth(_editingReorderImageView.bounds) + kEditingControlAppearanceOffset
	: 0;

	CGFloat accessoryViewPadding =
	_accessoryView ? CGRectGetWidth(self.bounds) - CGRectGetMinX(_accessoryView.frame) : 0;
	CGFloat trailingPadding =
	_attr.shouldShowSelectorStateMask
	? CGRectGetWidth(_editingSelectorImageView.bounds) + kEditingControlAppearanceOffset
	: accessoryViewPadding;
	UIEdgeInsets insets = UIEdgeInsetsMake(0, leadingPadding, 0, trailingPadding);
	return UIEdgeInsetsInsetRect(self.bounds, insets);
	}

	- (BOOL)shouldEnableCellInteractions {
	return !_editing \|\| _allowsCellInteractionsWhileEditing;
	}

	@end