components/ChipTextField/examples/MDCChipTextField.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 "MDCChipTextField.h"

 #import "MDCChipTextFieldScrollView.h"
 #import "MaterialChips.h"

 static CGFloat const kChipsSpacing = 0.0f;
 static CGFloat const kTextToEnterPlaceholderLength = 16.0f;

 @interface MDCChipTextField () <MDCChipTextFieldScrollViewDataSource,
                                 MDCChipTextFieldScrollViewDelegate>

 @property(nonatomic, strong) MDCChipTextFieldScrollView *chipsContainerView;

 @property(nonatomic, readwrite, weak) NSLayoutConstraint *chipContainerViewConstraintLeading;
 @property(nonatomic, readwrite, weak) NSLayoutConstraint *chipContainerViewConstraintTrailing;
 @property(nonatomic) CGFloat chipContainerViewConstraintTrailingConstant;
 // Chip view models
 @property(nonatomic, readwrite, copy) NSMutableArray<MDCChipView *> *mutableChipViews;

 @end

 @implementation MDCChipTextField

 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     _mutableChipViews = [[NSMutableArray alloc] init];
     _chipContainerViewConstraintTrailingConstant = 0.0f;
     [self setupChipsContainerView];

     [self addTarget:self
                   action:@selector(chipTextFieldTextDidChange)
         forControlEvents:UIControlEventEditingChanged];

     [self addTextFieldObservers];
   }
   return self;
 }

 #pragma mark - Property Getter

 - (NSArray<MDCChipView *> *)chipViews {
   return [self.mutableChipViews copy];
 }

 #pragma mark - Public API

 - (MDCChipView *)appendChipWithText:(NSString *)text {
   MDCChipView *chipView = [[MDCChipView alloc] init];
   chipView.titleLabel.text = text;
   chipView.translatesAutoresizingMaskIntoConstraints = NO;

   [self appendChipView:chipView];

   return chipView;
 }

 - (void)appendChipView:(MDCChipView *)chipView {
   if ([self.chipTextFieldDelegate respondsToSelector:@selector(chipField:shouldAddChip:)]) {
     NSInteger indexToAppend = self.mutableChipViews.count;
     BOOL shouldAppend = [self.chipTextFieldDelegate chipTextField:self
                                                 shouldAddChipView:chipView
                                                           atIndex:indexToAppend];
     if (!shouldAppend) {
       return;
     }
   }

   [self.chipsContainerView appendChipView:chipView];

   // recalculate the layout to get a correct chip frame values
   [self.chipsContainerView layoutIfNeeded];
   [self.mutableChipViews addObject:chipView];

   [self clearChipsContainerOffsetWithConstant:kTextToEnterPlaceholderLength];

   if ([self.chipTextFieldDelegate respondsToSelector:@selector(chipField:didAddChip:)]) {
     NSInteger index = self.mutableChipViews.count - 1;
     [self.chipTextFieldDelegate chipTextField:self didAddChipView:chipView atIndex:index];
   }
 }

 - (void)setChipViewSelected:(BOOL)selected atIndex:(NSInteger)index {
   MDCChipView *chipView = self.mutableChipViews[index];
   if (chipView.selected != selected) {
     chipView.selected = selected;
   }
 }

 - (void)addTextFieldObservers {
   [[NSNotificationCenter defaultCenter]
       addObserver:self
          selector:@selector(textFieldDidEndEditingWithNotification:)
              name:UITextFieldTextDidEndEditingNotification
            object:self];
   [[NSNotificationCenter defaultCenter]
       addObserver:self
          selector:@selector(textFieldDidBeginEditingWithNotification:)
              name:UITextFieldTextDidBeginEditingNotification
            object:self];
 }

 - (void)setupChipsContainerView {
   MDCChipTextFieldScrollView *chipsContainerView =
       [[MDCChipTextFieldScrollView alloc] initWithFrame:CGRectZero];
   chipsContainerView.translatesAutoresizingMaskIntoConstraints = NO;
   chipsContainerView.chipSpacing = kChipsSpacing;
   chipsContainerView.dataSource = self;
   chipsContainerView.touchDelegate = self;
   self.chipsContainerView = chipsContainerView;
   [self addSubview:chipsContainerView];

   NSLayoutConstraint *chipContainerViewConstraintTop =
       [NSLayoutConstraint constraintWithItem:self.chipsContainerView
                                    attribute:NSLayoutAttributeTop
                                    relatedBy:NSLayoutRelationEqual
                                       toItem:self
                                    attribute:NSLayoutAttributeTop
                                   multiplier:1
                                     constant:0];
   NSLayoutConstraint *chipContainerViewConstraintBottom =
       [NSLayoutConstraint constraintWithItem:self.chipsContainerView
                                    attribute:NSLayoutAttributeBottom
                                    relatedBy:NSLayoutRelationEqual
                                       toItem:self
                                    attribute:NSLayoutAttributeBottom
                                   multiplier:1
                                     constant:0];
   [NSLayoutConstraint
       activateConstraints:@[ chipContainerViewConstraintTop, chipContainerViewConstraintBottom ]];
   [self updateChipViewLeadingConstraints];
   [self updateChipViewTrailingConstraints];
 }

 // TODO: the constant here reflects the margin, places calling this method need to be refactored.
 // Ideally no constant needs to be passed into this method for the function to work.
 - (void)clearChipsContainerOffsetWithConstant:(CGFloat)constant {
   self.chipContainerViewConstraintTrailingConstant = -constant;
   [self invalidateIntrinsicContentSize];
   [self setNeedsLayout];
   [self layoutIfNeeded];
   [self.chipsContainerView setNeedsLayout];
   [self.chipsContainerView layoutIfNeeded];
   [self.chipsContainerView scrollToRight];
 }

 #pragma mark - Text Editing Handler

 - (void)chipTextFieldTextDidChange {
   [self deselectAllChips];
   [self setupEditingRect];
 }

 - (void)setupEditingRect {
   if (CGRectGetWidth(self.chipsContainerView.frame) <= 0) {
     return;
   }

   UITextRange *textRange = [self textRangeFromPosition:self.beginningOfDocument
                                             toPosition:self.endOfDocument];
   CGRect inputRect = [self firstRectForRange:textRange];
   CGFloat inputRectLength = inputRect.size.width;

   self.chipContainerViewConstraintTrailingConstant =
       -(inputRectLength + kTextToEnterPlaceholderLength);
   [self setNeedsUpdateConstraints];
   [self setNeedsLayout];
   [self layoutIfNeeded];
   [self.chipsContainerView setNeedsLayout];
   [self.chipsContainerView layoutIfNeeded];
   [self.chipsContainerView scrollToRight];
 }

 #pragma mark - Constraints

 - (void)updateConstraints {
   // TODO: This is not optimized for performance, but due to how MDCTextInputController works, we
   // need to update constraints here using the latest textInsets values.
   self.chipContainerViewConstraintLeading.constant = self.textInsets.left;
   self.chipContainerViewConstraintTrailing.constant =
       self.chipContainerViewConstraintTrailingConstant;

   [super updateConstraints];
 }

 - (void)updateChipViewLeadingConstraints {
   self.chipContainerViewConstraintLeading.active = NO;

   NSLayoutConstraint *chipContainerViewConstraintLeading = nil;
   if (self.leftView) {
     chipContainerViewConstraintLeading =
         [NSLayoutConstraint constraintWithItem:self.chipsContainerView
                                      attribute:NSLayoutAttributeLeading
                                      relatedBy:NSLayoutRelationEqual
                                         toItem:self.leftView
                                      attribute:NSLayoutAttributeTrailing
                                     multiplier:1
                                       constant:self.textInsets.left];
   } else {
     chipContainerViewConstraintLeading =
         [NSLayoutConstraint constraintWithItem:self.chipsContainerView
                                      attribute:NSLayoutAttributeLeading
                                      relatedBy:NSLayoutRelationEqual
                                         toItem:self
                                      attribute:NSLayoutAttributeLeading
                                     multiplier:1
                                       constant:self.textInsets.left];
   }
   chipContainerViewConstraintLeading.active = YES;

   self.chipContainerViewConstraintLeading = chipContainerViewConstraintLeading;
 }

 - (void)updateChipViewTrailingConstraints {
   self.chipContainerViewConstraintTrailing.active = NO;

   NSLayoutConstraint *chipContainerViewConstraintTrailing = nil;
   if (self.rightView) {
     chipContainerViewConstraintTrailing =
         [NSLayoutConstraint constraintWithItem:self.chipsContainerView
                                      attribute:NSLayoutAttributeTrailing
                                      relatedBy:NSLayoutRelationLessThanOrEqual
                                         toItem:self.rightView
                                      attribute:NSLayoutAttributeLeading
                                     multiplier:1
                                       constant:self.chipContainerViewConstraintTrailingConstant];
   } else {
     chipContainerViewConstraintTrailing =
         [NSLayoutConstraint constraintWithItem:self.chipsContainerView
                                      attribute:NSLayoutAttributeTrailing
                                      relatedBy:NSLayoutRelationLessThanOrEqual
                                         toItem:self.clearButton
                                      attribute:NSLayoutAttributeLeading
                                     multiplier:1
                                       constant:self.chipContainerViewConstraintTrailingConstant];
   }
   chipContainerViewConstraintTrailing.active = YES;

   self.chipContainerViewConstraintTrailing = chipContainerViewConstraintTrailing;
 }

 #pragma mark - overrides

 - (void)setLeftViewMode:(UITextFieldViewMode)leftViewMode {
   [super setLeftViewMode:leftViewMode];

   [self updateChipViewLeadingConstraints];
   [self setNeedsUpdateConstraints];
 }

 - (void)setLeftView:(UIView *)leftView {
   [super setLeftView:leftView];

   [self updateChipViewLeadingConstraints];
   [self setNeedsUpdateConstraints];
 }

 - (void)setRightViewMode:(UITextFieldViewMode)rightViewMode {
   [super setRightViewMode:rightViewMode];

   [self updateChipViewTrailingConstraints];
   [self setNeedsUpdateConstraints];
 }

 - (void)setRightView:(UIView *)rightView {
   [super setRightView:rightView];

   [self updateChipViewTrailingConstraints];
   [self setNeedsUpdateConstraints];
 }

 - (CGRect)textRectForBounds:(CGRect)bounds {
   CGRect textRect = [super textRectForBounds:bounds];
   textRect.origin.x = CGRectGetMaxX(self.chipsContainerView.frame);
   textRect.size.width = MAX(0, textRect.size.width - CGRectGetWidth(self.chipsContainerView.frame));
   return textRect;
 }

 - (CGRect)editingRectForBounds:(CGRect)bounds {
   CGRect editingRect = [super editingRectForBounds:bounds];
   return editingRect;
 }

 - (void)deleteBackward {
   NSInteger cursorPosition = [self offsetFromPosition:self.beginningOfDocument
                                            toPosition:self.selectedTextRange.start];
   if (cursorPosition == 0) {
     [self respondToDeleteBackward];
   }
   [super deleteBackward];
 }

 - (BOOL)hasTextContent {
   return self.text.length > 0 || self.mutableChipViews.count > 0;
 }

 - (void)clearText {
   self.text = @"";
   for (NSInteger index = self.mutableChipViews.count - 1; index >= 0; --index) {
     MDCChipView *chipView = self.mutableChipViews[index];
     [self removeChip:chipView];
   }
 }

 #pragma mark - Deletion

 - (void)deselectAllChipsExceptChip:(MDCChipView *)chip {
   for (MDCChipView *otherChip in self.mutableChipViews) {
     if (chip != otherChip) {
       otherChip.selected = NO;
     }
   }
 }

 - (void)selectLastChip {
   MDCChipView *lastChip = self.mutableChipViews.lastObject;
   [self deselectAllChipsExceptChip:lastChip];
   lastChip.selected = YES;
   UIAccessibilityPostNotification(UIAccessibilityAnnouncementNotification,
                                   [lastChip accessibilityLabel]);
 }

 - (void)deselectAllChips {
   [self deselectAllChipsExceptChip:nil];
 }

 - (void)removeChip:(MDCChipView *)chip {
   [self.mutableChipViews removeObject:chip];
   [self.chipsContainerView removeChipView:chip];
   [self clearChipsContainerOffsetWithConstant:kTextToEnterPlaceholderLength];

   [self invalidateIntrinsicContentSize];
   [self setNeedsLayout];
 }

 - (void)removeSelectedChips {
   NSMutableArray *chipsToRemove = [NSMutableArray array];
   for (MDCChipView *chip in self.mutableChipViews) {
     if (chip.isSelected) {
       [chipsToRemove addObject:chip];
     }
   }
   for (MDCChipView *chip in chipsToRemove) {
     [self removeChip:chip];
   }
 }

 - (BOOL)isAnyChipSelected {
   for (MDCChipView *chip in self.mutableChipViews) {
     if (chip.isSelected) {
       return YES;
     }
   }
   return NO;
 }

 - (void)respondToDeleteBackward {
   if ([self isAnyChipSelected]) {
     [self removeSelectedChips];
     [self deselectAllChips];
   } else {
     [self selectLastChip];
   }
 }
 #pragma mark Notification Listener Methods

 - (void)textFieldDidBeginEditingWithNotification:(NSNotification *)notification {
   [self setupEditingRect];
 }

 - (void)textFieldDidEndEditingWithNotification:(NSNotification *)notification {
   [self clearChipsContainerOffsetWithConstant:0.0f];
   [self.chipsContainerView scrollToLeft];
 }

 #pragma mark - MDCChipTextFieldScrollViewDataSource

 - (NSInteger)numberOfChipsInScrollView:(MDCChipTextFieldScrollView *)scrollView {
   return self.mutableChipViews.count;
 }

 - (MDCChipView *)scrollView:(MDCChipTextFieldScrollView *)scrollView chipForIndex:(NSInteger)index {
   return self.mutableChipViews[index];
 }

 #pragma mark - MDCChipTextFieldScrollViewDelegate

 - (void)chipTextFieldScrollView:(MDCChipTextFieldScrollView *)scrollView
                  didTapChipView:(MDCChipView *)chipView {
   if (self.chipsContainerView == scrollView && [self.chipViews containsObject:chipView]) {
     chipView.selected = !chipView.selected;
     NSInteger index = [self.mutableChipViews indexOfObject:chipView];
     if ([self.chipTextFieldDelegate respondsToSelector:@selector(chipTextField:
                                                                 didTapChipView:atIndex:)]) {
       [self.chipTextFieldDelegate chipTextField:self didTapChipView:chipView atIndex:index];
     }
   }
 }

 @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 "MDCChipTextField.h"

	#import "MDCChipTextFieldScrollView.h"
	#import "MaterialChips.h"

	static CGFloat const kChipsSpacing = 0.0f;
	static CGFloat const kTextToEnterPlaceholderLength = 16.0f;

	@interface MDCChipTextField () <MDCChipTextFieldScrollViewDataSource,
	MDCChipTextFieldScrollViewDelegate>

	@property(nonatomic, strong) MDCChipTextFieldScrollView *chipsContainerView;

	@property(nonatomic, readwrite, weak) NSLayoutConstraint *chipContainerViewConstraintLeading;
	@property(nonatomic, readwrite, weak) NSLayoutConstraint *chipContainerViewConstraintTrailing;
	@property(nonatomic) CGFloat chipContainerViewConstraintTrailingConstant;
	// Chip view models
	@property(nonatomic, readwrite, copy) NSMutableArray<MDCChipView > mutableChipViews;

	@end

	@implementation MDCChipTextField

	- (instancetype)initWithFrame:(CGRect)frame {
	self = [super initWithFrame:frame];
	if (self) {
	_mutableChipViews = [[NSMutableArray alloc] init];
	_chipContainerViewConstraintTrailingConstant = 0.0f;
	[self setupChipsContainerView];

	[self addTarget:self
	action:@selector(chipTextFieldTextDidChange)
	forControlEvents:UIControlEventEditingChanged];

	[self addTextFieldObservers];
	}
	return self;
	}

	#pragma mark - Property Getter

	- (NSArray<MDCChipView > )chipViews {
	return [self.mutableChipViews copy];
	}

	#pragma mark - Public API

	- (MDCChipView )appendChipWithText:(NSString )text {
	MDCChipView *chipView = [[MDCChipView alloc] init];
	chipView.titleLabel.text = text;
	chipView.translatesAutoresizingMaskIntoConstraints = NO;

	[self appendChipView:chipView];

	return chipView;
	}

	- (void)appendChipView:(MDCChipView *)chipView {
	if ([self.chipTextFieldDelegate respondsToSelector:@selector(chipField:shouldAddChip:)]) {
	NSInteger indexToAppend = self.mutableChipViews.count;
	BOOL shouldAppend = [self.chipTextFieldDelegate chipTextField:self
	shouldAddChipView:chipView
	atIndex:indexToAppend];
	if (!shouldAppend) {
	return;
	}
	}

	[self.chipsContainerView appendChipView:chipView];

	// recalculate the layout to get a correct chip frame values
	[self.chipsContainerView layoutIfNeeded];
	[self.mutableChipViews addObject:chipView];

	[self clearChipsContainerOffsetWithConstant:kTextToEnterPlaceholderLength];

	if ([self.chipTextFieldDelegate respondsToSelector:@selector(chipField:didAddChip:)]) {
	NSInteger index = self.mutableChipViews.count - 1;
	[self.chipTextFieldDelegate chipTextField:self didAddChipView:chipView atIndex:index];
	}
	}

	- (void)setChipViewSelected:(BOOL)selected atIndex:(NSInteger)index {
	MDCChipView *chipView = self.mutableChipViews[index];
	if (chipView.selected != selected) {
	chipView.selected = selected;
	}
	}

	- (void)addTextFieldObservers {
	[[NSNotificationCenter defaultCenter]
	addObserver:self
	selector:@selector(textFieldDidEndEditingWithNotification:)
	name:UITextFieldTextDidEndEditingNotification
	object:self];
	[[NSNotificationCenter defaultCenter]
	addObserver:self
	selector:@selector(textFieldDidBeginEditingWithNotification:)
	name:UITextFieldTextDidBeginEditingNotification
	object:self];
	}

	- (void)setupChipsContainerView {
	MDCChipTextFieldScrollView *chipsContainerView =
	[[MDCChipTextFieldScrollView alloc] initWithFrame:CGRectZero];
	chipsContainerView.translatesAutoresizingMaskIntoConstraints = NO;
	chipsContainerView.chipSpacing = kChipsSpacing;
	chipsContainerView.dataSource = self;
	chipsContainerView.touchDelegate = self;
	self.chipsContainerView = chipsContainerView;
	[self addSubview:chipsContainerView];

	NSLayoutConstraint *chipContainerViewConstraintTop =
	[NSLayoutConstraint constraintWithItem:self.chipsContainerView
	attribute:NSLayoutAttributeTop
	relatedBy:NSLayoutRelationEqual
	toItem:self
	attribute:NSLayoutAttributeTop
	multiplier:1
	constant:0];
	NSLayoutConstraint *chipContainerViewConstraintBottom =
	[NSLayoutConstraint constraintWithItem:self.chipsContainerView
	attribute:NSLayoutAttributeBottom
	relatedBy:NSLayoutRelationEqual
	toItem:self
	attribute:NSLayoutAttributeBottom
	multiplier:1
	constant:0];
	[NSLayoutConstraint
	activateConstraints:@[ chipContainerViewConstraintTop, chipContainerViewConstraintBottom ]];
	[self updateChipViewLeadingConstraints];
	[self updateChipViewTrailingConstraints];
	}

	// TODO: the constant here reflects the margin, places calling this method need to be refactored.
	// Ideally no constant needs to be passed into this method for the function to work.
	- (void)clearChipsContainerOffsetWithConstant:(CGFloat)constant {
	self.chipContainerViewConstraintTrailingConstant = -constant;
	[self invalidateIntrinsicContentSize];
	[self setNeedsLayout];
	[self layoutIfNeeded];
	[self.chipsContainerView setNeedsLayout];
	[self.chipsContainerView layoutIfNeeded];
	[self.chipsContainerView scrollToRight];
	}

	#pragma mark - Text Editing Handler

	- (void)chipTextFieldTextDidChange {
	[self deselectAllChips];
	[self setupEditingRect];
	}

	- (void)setupEditingRect {
	if (CGRectGetWidth(self.chipsContainerView.frame) <= 0) {
	return;
	}

	UITextRange *textRange = [self textRangeFromPosition:self.beginningOfDocument
	toPosition:self.endOfDocument];
	CGRect inputRect = [self firstRectForRange:textRange];
	CGFloat inputRectLength = inputRect.size.width;

	self.chipContainerViewConstraintTrailingConstant =
	-(inputRectLength + kTextToEnterPlaceholderLength);
	[self setNeedsUpdateConstraints];
	[self setNeedsLayout];
	[self layoutIfNeeded];
	[self.chipsContainerView setNeedsLayout];
	[self.chipsContainerView layoutIfNeeded];
	[self.chipsContainerView scrollToRight];
	}

	#pragma mark - Constraints

	- (void)updateConstraints {
	// TODO: This is not optimized for performance, but due to how MDCTextInputController works, we
	// need to update constraints here using the latest textInsets values.
	self.chipContainerViewConstraintLeading.constant = self.textInsets.left;
	self.chipContainerViewConstraintTrailing.constant =
	self.chipContainerViewConstraintTrailingConstant;

	[super updateConstraints];
	}

	- (void)updateChipViewLeadingConstraints {
	self.chipContainerViewConstraintLeading.active = NO;

	NSLayoutConstraint *chipContainerViewConstraintLeading = nil;
	if (self.leftView) {
	chipContainerViewConstraintLeading =
	[NSLayoutConstraint constraintWithItem:self.chipsContainerView
	attribute:NSLayoutAttributeLeading
	relatedBy:NSLayoutRelationEqual
	toItem:self.leftView
	attribute:NSLayoutAttributeTrailing
	multiplier:1
	constant:self.textInsets.left];
	} else {
	chipContainerViewConstraintLeading =
	[NSLayoutConstraint constraintWithItem:self.chipsContainerView
	attribute:NSLayoutAttributeLeading
	relatedBy:NSLayoutRelationEqual
	toItem:self
	attribute:NSLayoutAttributeLeading
	multiplier:1
	constant:self.textInsets.left];
	}
	chipContainerViewConstraintLeading.active = YES;

	self.chipContainerViewConstraintLeading = chipContainerViewConstraintLeading;
	}

	- (void)updateChipViewTrailingConstraints {
	self.chipContainerViewConstraintTrailing.active = NO;

	NSLayoutConstraint *chipContainerViewConstraintTrailing = nil;
	if (self.rightView) {
	chipContainerViewConstraintTrailing =
	[NSLayoutConstraint constraintWithItem:self.chipsContainerView
	attribute:NSLayoutAttributeTrailing
	relatedBy:NSLayoutRelationLessThanOrEqual
	toItem:self.rightView
	attribute:NSLayoutAttributeLeading
	multiplier:1
	constant:self.chipContainerViewConstraintTrailingConstant];
	} else {
	chipContainerViewConstraintTrailing =
	[NSLayoutConstraint constraintWithItem:self.chipsContainerView
	attribute:NSLayoutAttributeTrailing
	relatedBy:NSLayoutRelationLessThanOrEqual
	toItem:self.clearButton
	attribute:NSLayoutAttributeLeading
	multiplier:1
	constant:self.chipContainerViewConstraintTrailingConstant];
	}
	chipContainerViewConstraintTrailing.active = YES;

	self.chipContainerViewConstraintTrailing = chipContainerViewConstraintTrailing;
	}

	#pragma mark - overrides

	- (void)setLeftViewMode:(UITextFieldViewMode)leftViewMode {
	[super setLeftViewMode:leftViewMode];

	[self updateChipViewLeadingConstraints];
	[self setNeedsUpdateConstraints];
	}

	- (void)setLeftView:(UIView *)leftView {
	[super setLeftView:leftView];

	[self updateChipViewLeadingConstraints];
	[self setNeedsUpdateConstraints];
	}

	- (void)setRightViewMode:(UITextFieldViewMode)rightViewMode {
	[super setRightViewMode:rightViewMode];

	[self updateChipViewTrailingConstraints];
	[self setNeedsUpdateConstraints];
	}

	- (void)setRightView:(UIView *)rightView {
	[super setRightView:rightView];

	[self updateChipViewTrailingConstraints];
	[self setNeedsUpdateConstraints];
	}

	- (CGRect)textRectForBounds:(CGRect)bounds {
	CGRect textRect = [super textRectForBounds:bounds];
	textRect.origin.x = CGRectGetMaxX(self.chipsContainerView.frame);
	textRect.size.width = MAX(0, textRect.size.width - CGRectGetWidth(self.chipsContainerView.frame));
	return textRect;
	}

	- (CGRect)editingRectForBounds:(CGRect)bounds {
	CGRect editingRect = [super editingRectForBounds:bounds];
	return editingRect;
	}

	- (void)deleteBackward {
	NSInteger cursorPosition = [self offsetFromPosition:self.beginningOfDocument
	toPosition:self.selectedTextRange.start];
	if (cursorPosition == 0) {
	[self respondToDeleteBackward];
	}
	[super deleteBackward];
	}

	- (BOOL)hasTextContent {
	return self.text.length > 0 \|\| self.mutableChipViews.count > 0;
	}

	- (void)clearText {
	self.text = @"";
	for (NSInteger index = self.mutableChipViews.count - 1; index >= 0; --index) {
	MDCChipView *chipView = self.mutableChipViews[index];
	[self removeChip:chipView];
	}
	}

	#pragma mark - Deletion

	- (void)deselectAllChipsExceptChip:(MDCChipView *)chip {
	for (MDCChipView *otherChip in self.mutableChipViews) {
	if (chip != otherChip) {
	otherChip.selected = NO;
	}
	}
	}

	- (void)selectLastChip {
	MDCChipView *lastChip = self.mutableChipViews.lastObject;
	[self deselectAllChipsExceptChip:lastChip];
	lastChip.selected = YES;
	UIAccessibilityPostNotification(UIAccessibilityAnnouncementNotification,
	[lastChip accessibilityLabel]);
	}

	- (void)deselectAllChips {
	[self deselectAllChipsExceptChip:nil];
	}

	- (void)removeChip:(MDCChipView *)chip {
	[self.mutableChipViews removeObject:chip];
	[self.chipsContainerView removeChipView:chip];
	[self clearChipsContainerOffsetWithConstant:kTextToEnterPlaceholderLength];

	[self invalidateIntrinsicContentSize];
	[self setNeedsLayout];
	}

	- (void)removeSelectedChips {
	NSMutableArray *chipsToRemove = [NSMutableArray array];
	for (MDCChipView *chip in self.mutableChipViews) {
	if (chip.isSelected) {
	[chipsToRemove addObject:chip];
	}
	}
	for (MDCChipView *chip in chipsToRemove) {
	[self removeChip:chip];
	}
	}

	- (BOOL)isAnyChipSelected {
	for (MDCChipView *chip in self.mutableChipViews) {
	if (chip.isSelected) {
	return YES;
	}
	}
	return NO;
	}

	- (void)respondToDeleteBackward {
	if ([self isAnyChipSelected]) {
	[self removeSelectedChips];
	[self deselectAllChips];
	} else {
	[self selectLastChip];
	}
	}
	#pragma mark Notification Listener Methods

	- (void)textFieldDidBeginEditingWithNotification:(NSNotification *)notification {
	[self setupEditingRect];
	}

	- (void)textFieldDidEndEditingWithNotification:(NSNotification *)notification {
	[self clearChipsContainerOffsetWithConstant:0.0f];
	[self.chipsContainerView scrollToLeft];
	}

	#pragma mark - MDCChipTextFieldScrollViewDataSource

	- (NSInteger)numberOfChipsInScrollView:(MDCChipTextFieldScrollView *)scrollView {
	return self.mutableChipViews.count;
	}

	- (MDCChipView )scrollView:(MDCChipTextFieldScrollView )scrollView chipForIndex:(NSInteger)index {
	return self.mutableChipViews[index];
	}

	#pragma mark - MDCChipTextFieldScrollViewDelegate

	- (void)chipTextFieldScrollView:(MDCChipTextFieldScrollView *)scrollView
	didTapChipView:(MDCChipView *)chipView {
	if (self.chipsContainerView == scrollView && [self.chipViews containsObject:chipView]) {
	chipView.selected = !chipView.selected;
	NSInteger index = [self.mutableChipViews indexOfObject:chipView];
	if ([self.chipTextFieldDelegate respondsToSelector:@selector(chipTextField:
	didTapChipView:atIndex:)]) {
	[self.chipTextFieldDelegate chipTextField:self didTapChipView:chipView atIndex:index];
	}
	}
	}

	@end