From a9b6ca12b5cba778176b7cb129e866b8669ac8bc Mon Sep 17 00:00:00 2001
From: Nobody <no-reply@google.com>
Date: Wed, 20 Jan 2021 12:17:24 -0800
Subject: [PATCH 01/11] [Dialogs] Adding customized interface orientations and
 transition style support to the alert dialog.

Adding APIs to customize interface orientations and transition style.

PiperOrigin-RevId: 352847879
---
 components/Dialogs/src/MDCAlertController.h | 34 +++++++++++++++++--
 components/Dialogs/src/MDCAlertController.m | 36 ++++++++++++++-------
 2 files changed, 56 insertions(+), 14 deletions(-)

diff --git a/components/Dialogs/src/MDCAlertController.h b/components/Dialogs/src/MDCAlertController.h
index 7898f20d230..fef88628c1f 100644
--- a/components/Dialogs/src/MDCAlertController.h
+++ b/components/Dialogs/src/MDCAlertController.h
@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#import <CoreGraphics/CoreGraphics.h>
+#import <UIKit/UIKit.h>
+
 #import "MaterialButtons.h"
 // TODO(b/151929968): Delete import of delegate headers when client code has been migrated to no
 // longer import delegates as transitive dependencies.
@@ -19,9 +22,6 @@
 #import "MaterialElevation.h"
 #import "MaterialShadowElevations.h"
 
-#import <CoreGraphics/CoreGraphics.h>
-#import <UIKit/UIKit.h>
-
 @class MDCAlertAction;
 @class MDCAlertController;
 @protocol MDCAlertControllerDelegate;
@@ -388,6 +388,34 @@ typedef NS_ENUM(NSInteger, MDCContentHorizontalAlignment) {
 */
 @property(nonatomic, assign) BOOL orderVerticalActionsByEmphasis;
 
+/**
+ A Boolean value that indicates whether the alert's contents autorotates.
+
+ Defaults to UIKit's shouldAutorotate.
+*/
+@property(nonatomic) BOOL shouldAutorotateOverride;
+
+/**
+ A bit mask that specifies which orientations the view controller supports.
+
+ Defaults to UIKit's supportedInterfaceOrientations.
+*/
+@property(nonatomic) UIInterfaceOrientationMask supportedInterfaceOrientationsOverride;
+
+/**
+ The interface orientation to use when presenting the alert.
+
+ Defaults to UIKit's preferredInterfaceOrientationForPresentation.
+*/
+@property(nonatomic) UIInterfaceOrientation preferredInterfaceOrientationForPresentationOverride;
+
+/**
+ The transition style to use when presenting the view controller override.
+
+ Defaults to UIKit's modalTransitionStyle.
+*/
+@property(nonatomic) UIModalTransitionStyle modalTransitionStyleOverride;
+
 @end
 
 #pragma mark - MDCAlertAction
diff --git a/components/Dialogs/src/MDCAlertController.m b/components/Dialogs/src/MDCAlertController.m
index a3ad893b94b..04edbbc1e86 100644
--- a/components/Dialogs/src/MDCAlertController.m
+++ b/components/Dialogs/src/MDCAlertController.m
@@ -12,23 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#import "MDCAlertController.h"
-
-#import "MaterialButtons.h"
 #import "MDCAlertController+Customize.h"
-#import "MDCAlertControllerDelegate.h"
-#import "MDCAlertControllerView.h"
-#import "MDCDialogPresentationController.h"
-#import "MDCDialogTransitionController.h"
-#import "UIViewController+MaterialDialogs.h"
-#import "MaterialTypography.h"
-#import "MaterialMath.h"
-#import <MDFInternationalization/MDFInternationalization.h>
 
 #import "private/MDCAlertActionManager.h"
 #import "private/MDCAlertControllerView+Private.h"
 #import "private/MaterialDialogsStrings.h"
 #import "private/MaterialDialogsStrings_table.h"
+#import "MaterialDialogs.h"
+#import "MaterialElevation.h"
+#import "MaterialShadowElevations.h"
+#import "MaterialMath.h"
 
 // The Bundle for string resources.
 static NSString *const kMaterialDialogsBundle = @"MaterialDialogs.bundle";
@@ -180,6 +173,11 @@ - (nonnull instancetype)initWithTitle:(nullable NSString *)title {
     _adjustsFontForContentSizeCategoryWhenScaledFontIsUnavailable = YES;
     _shadowColor = UIColor.blackColor;
     _mdc_overrideBaseElevation = -1;
+    _shouldAutorotateOverride = super.shouldAutorotate;
+    _supportedInterfaceOrientationsOverride = super.supportedInterfaceOrientations;
+    _preferredInterfaceOrientationForPresentationOverride =
+        super.preferredInterfaceOrientationForPresentation;
+    _modalTransitionStyleOverride = super.modalTransitionStyle;
 
     super.transitioningDelegate = _transitionController;
     super.modalPresentationStyle = UIModalPresentationCustom;
@@ -740,6 +738,22 @@ - (void)viewWillTransitionToSize:(CGSize)size
                       completion:nil];
 }
 
+- (BOOL)shouldAutorotate {
+  return _shouldAutorotateOverride;
+}
+
+- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
+  return _supportedInterfaceOrientationsOverride;
+}
+
+- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
+  return _preferredInterfaceOrientationForPresentationOverride;
+}
+
+- (UIModalTransitionStyle)modalTransitionStyle {
+  return _modalTransitionStyleOverride;
+}
+
 #pragma mark - Resource bundle
 
 + (NSBundle *)bundle {

From 3f7cc9f51cf9ea9287b3e817bc730eaac31bd87e Mon Sep 17 00:00:00 2001
From: Andrew Overton <andrewoverton@google.com>
Date: Thu, 21 Jan 2021 13:10:42 -0800
Subject: [PATCH 02/11] [Chips] Add docs for MDCChipField

PiperOrigin-RevId: 353086025
---
 components/Chips/src/MDCChipField.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/components/Chips/src/MDCChipField.h b/components/Chips/src/MDCChipField.h
index 7c417cd88c4..b293434ad17 100644
--- a/components/Chips/src/MDCChipField.h
+++ b/components/Chips/src/MDCChipField.h
@@ -58,6 +58,18 @@ typedef NS_OPTIONS(NSUInteger, MDCChipFieldDelimiter) {
   MDCChipFieldDelimiterAll = 0xFFFFFFFF
 };
 
+/**
+  This class provides an "input chips" experience on iOS, where chip creation is
+ coordinated with a user's text input. It manages an @c MDCTextField and a series of @c
+ MDCChipViews. When the user hits the return key, new chips are added. When the client hits the
+ delete button and the text field has no text, the last chip is deleted.
+
+ @note The input chip experience this class provides is incomplete. For example, it only supports
+ chips laid out in multiple rows, as opposed to the single-row input chips you'd fine in an email
+ "to" field. Additionally, it does not theme the chips with the Material chip styles. It is
+ currently not considered high priority to provide these features, but if you are interested in
+ them, or any others, please consider filing a bug or reaching out to the Material iOS team.
+ */
 @interface MDCChipField : UIView
 
 /**

From d5bba14e9a51405ee2ed868fd630d852c49d0c6e Mon Sep 17 00:00:00 2001
From: Yarden Eitan <yar@google.com>
Date: Fri, 22 Jan 2021 12:09:09 -0800
Subject: [PATCH 03/11] [List] Use isKindOfClass to ensure there is support for
 all MDCShadowLayer's subclasses.

PiperOrigin-RevId: 353292179
---
 components/List/src/MDCBaseCell.m | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/components/List/src/MDCBaseCell.m b/components/List/src/MDCBaseCell.m
index 7efcbfca0e8..fa8bc431efc 100644
--- a/components/List/src/MDCBaseCell.m
+++ b/components/List/src/MDCBaseCell.m
@@ -15,8 +15,10 @@
 #import "MDCBaseCell.h"
 #import "MDCSelfSizingLayoutAttributes.h"
 
+#import "MaterialElevation.h"
 #import "MaterialInk.h"
 #import "MaterialRipple.h"
+#import "MaterialShadowElevations.h"
 #import "MaterialShadowLayer.h"
 
 @interface MDCBaseCell ()
@@ -208,7 +210,7 @@ - (UIColor *)rippleColor {
 }
 
 - (MDCShadowLayer *)shadowLayer {
-  if ([self.layer isMemberOfClass:[MDCShadowLayer class]]) {
+  if ([self.layer isKindOfClass:[MDCShadowLayer class]]) {
     return (MDCShadowLayer *)self.layer;
   }
   return nil;

From c727b890df3c0766706ad8000649f7733cdef997 Mon Sep 17 00:00:00 2001
From: Cody Weaver <codyleeweaver@google.com>
Date: Fri, 22 Jan 2021 12:11:43 -0800
Subject: [PATCH 04/11] [Buttons] Add documentation for Enums.

PiperOrigin-RevId: 353292772
---
 components/Buttons/src/MDCFloatingButton+Animation.h |  4 ++++
 components/Buttons/src/MDCFloatingButton.h           | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/components/Buttons/src/MDCFloatingButton+Animation.h b/components/Buttons/src/MDCFloatingButton+Animation.h
index 5b9c53d1689..8b7a360e312 100644
--- a/components/Buttons/src/MDCFloatingButton+Animation.h
+++ b/components/Buttons/src/MDCFloatingButton+Animation.h
@@ -14,6 +14,10 @@
 
 #import "MDCFloatingButton.h"
 
+/**
+ This category is used to animate @c MDCFloatingButton instances, to expand or
+ collapse.
+ */
 @interface MDCFloatingButton (Animation)
 
 /**
diff --git a/components/Buttons/src/MDCFloatingButton.h b/components/Buttons/src/MDCFloatingButton.h
index e23e9e69035..a76414c4f02 100644
--- a/components/Buttons/src/MDCFloatingButton.h
+++ b/components/Buttons/src/MDCFloatingButton.h
@@ -34,6 +34,11 @@ typedef NS_ENUM(NSInteger, MDCFloatingButtonShape) {
   MDCFloatingButtonShapeMini = 1
 };
 
+/**
+ Size of Material Floating button.
+
+ The expanded mode should only be used when text and an icon are used.
+ */
 typedef NS_ENUM(NSInteger, MDCFloatingButtonMode) {
   /**
    The floating button is a circle with its contents centered.
@@ -46,6 +51,12 @@ typedef NS_ENUM(NSInteger, MDCFloatingButtonMode) {
   MDCFloatingButtonModeExpanded = 1,
 };
 
+/**
+  Image location of Material Floating button.
+
+  If the button is @c MDCFloatingButtonModeExpanded this determines where the
+  text is rendered in relation to the icon.
+ */
 typedef NS_ENUM(NSInteger, MDCFloatingButtonImageLocation) {
   /**
    The image of the floating button is on the leading side of the title.

From 1fefeaf03268b9126dfaea00907a9bb5362560e5 Mon Sep 17 00:00:00 2001
From: Alyssa Weiss <afweiss@google.com>
Date: Fri, 22 Jan 2021 13:38:23 -0800
Subject: [PATCH 05/11] Add BOOL property for whether or not the height of the
 bottom sheet should adjust for safe area insets.

PiperOrigin-RevId: 353309637
---
 .../src/MDCBottomSheetController.h            | 10 +++
 .../src/MDCBottomSheetController.m            | 13 ++++
 .../MDCBottomSheetPresentationController.h    | 10 +++
 .../MDCBottomSheetPresentationController.m    | 18 +++++
 .../src/MDCBottomSheetTransitionController.h  | 10 +++
 .../src/MDCBottomSheetTransitionController.m  |  7 ++
 .../src/private/MDCSheetContainerView.h       |  8 ++-
 .../src/private/MDCSheetContainerView.m       | 29 +++++---
 .../unit/MDCBottomSheetCustomizationTests.m   | 63 +++++++++++++++-
 ...DCBottomSheetPresentationControllerTests.m | 72 +++++++++++++++++++
 10 files changed, 229 insertions(+), 11 deletions(-)

diff --git a/components/BottomSheet/src/MDCBottomSheetController.h b/components/BottomSheet/src/MDCBottomSheetController.h
index fa4d065f702..e6b806cc282 100644
--- a/components/BottomSheet/src/MDCBottomSheetController.h
+++ b/components/BottomSheet/src/MDCBottomSheetController.h
@@ -121,6 +121,16 @@
  */
 @property(nonatomic, assign) MDCShadowElevation elevation;
 
+/**
+ Whether or not the height of the bottom sheet should adjust to include extra height for any bottom
+ safe area insets. If, for example, this is set to @c YES, and the preferred content size height is
+ 100 and the screen has a bottom safe area inset of 10, the total height of the displayed bottom
+ sheet height would be 110. If set to @c NO, the height would be 100.
+
+ Defaults to @c YES.
+ */
+@property(nonatomic, assign) BOOL adjustHeightForSafeAreaInsets;
+
 /**
  Bottom sheet controllers must be created with @c initWithContentViewController:.
  */
diff --git a/components/BottomSheet/src/MDCBottomSheetController.m b/components/BottomSheet/src/MDCBottomSheetController.m
index 9fa68e9f3b2..eb1e1c000eb 100644
--- a/components/BottomSheet/src/MDCBottomSheetController.m
+++ b/components/BottomSheet/src/MDCBottomSheetController.m
@@ -18,7 +18,11 @@
 #import "MDCBottomSheetPresentationController.h"
 #import "MDCBottomSheetPresentationControllerDelegate.h"
 #import "MDCBottomSheetTransitionController.h"
+#import "MDCSheetState.h"
 #import "UIViewController+MaterialBottomSheet.h"
+#import "MaterialElevation.h"
+#import "MaterialShadowElevations.h"
+#import "MaterialShapes.h"
 #import "MaterialMath.h"
 
 static const CGFloat kElevationSpreadMaskAffordance = 50.0f;
@@ -48,6 +52,7 @@ - (nonnull instancetype)initWithContentViewController:
     _transitionController = [[MDCBottomSheetTransitionController alloc] init];
     _transitionController.dismissOnBackgroundTap = YES;
     _transitionController.dismissOnDraggingDownSheet = YES;
+    _transitionController.adjustHeightForSafeAreaInsets = YES;
     super.transitioningDelegate = _transitionController;
     super.modalPresentationStyle = UIModalPresentationCustom;
     _shapeGenerators = [NSMutableDictionary dictionary];
@@ -269,6 +274,14 @@ - (UIColor *)scrimColor {
   return _transitionController.scrimColor;
 }
 
+- (void)setAdjustHeightForSafeAreaInsets:(BOOL)adjustHeightForSafeAreaInsets {
+  _transitionController.adjustHeightForSafeAreaInsets = adjustHeightForSafeAreaInsets;
+}
+
+- (BOOL)adjustHeightForSafeAreaInsets {
+  return _transitionController.adjustHeightForSafeAreaInsets;
+}
+
 - (void)setIsScrimAccessibilityElement:(BOOL)isScrimAccessibilityElement {
   _transitionController.isScrimAccessibilityElement = isScrimAccessibilityElement;
 }
diff --git a/components/BottomSheet/src/MDCBottomSheetPresentationController.h b/components/BottomSheet/src/MDCBottomSheetPresentationController.h
index eded9683b38..0bf90bd9039 100644
--- a/components/BottomSheet/src/MDCBottomSheetPresentationController.h
+++ b/components/BottomSheet/src/MDCBottomSheetPresentationController.h
@@ -68,6 +68,16 @@
  */
 @property(nonatomic, assign) CGFloat preferredSheetHeight;
 
+/**
+Whether or not the height of the bottom sheet should adjust to include extra height for any bottom
+safe area insets. If, for example, this is set to @c YES, and the preferredSheetHeight is
+100 and the screen has a bottom safe area inset of 10, the total height of the displayed bottom
+sheet height would be 110. If set to @c NO, the height would be 100.
+
+Defaults to @c YES.
+*/
+@property(nonatomic, assign) BOOL adjustHeightForSafeAreaInsets;
+
 /**
  Customize the color of the background scrim.
 
diff --git a/components/BottomSheet/src/MDCBottomSheetPresentationController.m b/components/BottomSheet/src/MDCBottomSheetPresentationController.m
index 297c4446f40..d6ae0dbf26e 100644
--- a/components/BottomSheet/src/MDCBottomSheetPresentationController.m
+++ b/components/BottomSheet/src/MDCBottomSheetPresentationController.m
@@ -68,6 +68,16 @@ @implementation MDCBottomSheetPresentationController {
 
 @synthesize delegate;
 
+- (instancetype)initWithPresentedViewController:(UIViewController *)presentedViewController
+                       presentingViewController:(UIViewController *)presentingViewController {
+  self = [super initWithPresentedViewController:presentedViewController
+                       presentingViewController:presentingViewController];
+  if (self) {
+    _adjustHeightForSafeAreaInsets = YES;
+  }
+  return self;
+}
+
 - (UIView *)presentedView {
   return self.sheetView;
 }
@@ -126,6 +136,7 @@ - (void)presentationTransitionWillBegin {
   self.sheetView.delegate = self;
   self.sheetView.autoresizingMask = UIViewAutoresizingFlexibleHeight;
   self.sheetView.dismissOnDraggingDownSheet = self.dismissOnDraggingDownSheet;
+  self.sheetView.adjustHeightForSafeAreaInsets = self.adjustHeightForSafeAreaInsets;
 
   [containerView addSubview:_dimmingView];
   [containerView addSubview:self.sheetView];
@@ -301,6 +312,13 @@ - (void)setPreferredSheetHeight:(CGFloat)preferredSheetHeight {
   [self updatePreferredSheetHeight];
 }
 
+- (void)setAdjustHeightForSafeAreaInsets:(BOOL)adjustHeightForSafeAreaInsets {
+  _adjustHeightForSafeAreaInsets = adjustHeightForSafeAreaInsets;
+  if (_sheetView) {
+    _sheetView.adjustHeightForSafeAreaInsets = adjustHeightForSafeAreaInsets;
+  }
+}
+
 - (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection {
   [super traitCollectionDidChange:previousTraitCollection];
 
diff --git a/components/BottomSheet/src/MDCBottomSheetTransitionController.h b/components/BottomSheet/src/MDCBottomSheetTransitionController.h
index 4322750fcde..c2d72108812 100644
--- a/components/BottomSheet/src/MDCBottomSheetTransitionController.h
+++ b/components/BottomSheet/src/MDCBottomSheetTransitionController.h
@@ -63,6 +63,16 @@
  */
 @property(nonatomic, assign) CGFloat preferredSheetHeight;
 
+/**
+Whether or not the height of the bottom sheet should adjust to include extra height for any bottom
+safe area insets. If, for example, this is set to @c YES, and the preferred content size height is
+100 and the screen has a bottom safe area inset of 10, the total height of the displayed bottom
+sheet height would be 110. If set to @c NO, the height would be 100.
+
+Defaults to @c YES.
+*/
+@property(nonatomic, assign) BOOL adjustHeightForSafeAreaInsets;
+
 @end
 
 @interface MDCBottomSheetTransitionController (ScrimAccessibility)
diff --git a/components/BottomSheet/src/MDCBottomSheetTransitionController.m b/components/BottomSheet/src/MDCBottomSheetTransitionController.m
index 55a6d5f00ca..5e1eef3ae50 100644
--- a/components/BottomSheet/src/MDCBottomSheetTransitionController.m
+++ b/components/BottomSheet/src/MDCBottomSheetTransitionController.m
@@ -42,6 +42,7 @@ - (instancetype)init {
   self = [super init];
   if (self) {
     _scrimAccessibilityTraits = UIAccessibilityTraitButton;
+    _adjustHeightForSafeAreaInsets = YES;
   }
   return self;
 }
@@ -62,6 +63,7 @@ - (instancetype)init {
   presentationController.scrimAccessibilityHint = _scrimAccessibilityHint;
   presentationController.scrimAccessibilityLabel = _scrimAccessibilityLabel;
   presentationController.preferredSheetHeight = _preferredSheetHeight;
+  presentationController.adjustHeightForSafeAreaInsets = _adjustHeightForSafeAreaInsets;
   _currentPresentationController = presentationController;
   return presentationController;
 }
@@ -170,6 +172,11 @@ - (UIColor *)scrimColor {
   return _scrimColor;
 }
 
+- (void)setAdjustHeightForSafeAreaInsets:(BOOL)adjustHeightForSafeAreaInsets {
+  _adjustHeightForSafeAreaInsets = adjustHeightForSafeAreaInsets;
+  _currentPresentationController.adjustHeightForSafeAreaInsets = adjustHeightForSafeAreaInsets;
+}
+
 - (void)setIsScrimAccessibilityElement:(BOOL)isScrimAccessibilityElement {
   _isScrimAccessibilityElement = isScrimAccessibilityElement;
   _currentPresentationController.isScrimAccessibilityElement = isScrimAccessibilityElement;
diff --git a/components/BottomSheet/src/private/MDCSheetContainerView.h b/components/BottomSheet/src/private/MDCSheetContainerView.h
index 31f2d084d18..662eec2823f 100644
--- a/components/BottomSheet/src/private/MDCSheetContainerView.h
+++ b/components/BottomSheet/src/private/MDCSheetContainerView.h
@@ -22,6 +22,13 @@
 @property(nonatomic, weak, nullable) id<MDCSheetContainerViewDelegate> delegate;
 @property(nonatomic, readonly) MDCSheetState sheetState;
 @property(nonatomic) CGFloat preferredSheetHeight;
+/**
+Whether or not the height of the view should adjust to include extra height for any bottom
+ safe area insets. If, for example, this is set to @c YES, and the preferredSheetHeight is
+ 100 and the screen has a bottom safe area inset of 10, the total height of the displayed bottom
+ sheet height would be 110. If set to @c NO, the height would be 100.
+ */
+@property(nonatomic, assign) BOOL adjustHeightForSafeAreaInsets;
 @property(nonatomic) BOOL willBeDismissed;
 
 /**
@@ -37,4 +44,3 @@
 - (nullable instancetype)initWithCoder:(nullable NSCoder *)aDecoder NS_UNAVAILABLE;
 
 @end
-
diff --git a/components/BottomSheet/src/private/MDCSheetContainerView.m b/components/BottomSheet/src/private/MDCSheetContainerView.m
index 5193092fb95..8a808be9093 100644
--- a/components/BottomSheet/src/private/MDCSheetContainerView.m
+++ b/components/BottomSheet/src/private/MDCSheetContainerView.m
@@ -172,12 +172,13 @@ - (void)safeAreaInsetsDidChange {
   if (@available(iOS 11.0, *)) {
     [super safeAreaInsetsDidChange];
 
-    _preferredSheetHeight = self.originalPreferredSheetHeight + self.safeAreaInsets.bottom;
-
-    UIEdgeInsets contentInset = self.sheet.scrollView.contentInset;
-    contentInset.bottom = MAX(contentInset.bottom, self.safeAreaInsets.bottom);
-    self.sheet.scrollView.contentInset = contentInset;
+    if (self.adjustHeightForSafeAreaInsets) {
+      _preferredSheetHeight = self.originalPreferredSheetHeight + self.safeAreaInsets.bottom;
 
+      UIEdgeInsets contentInset = self.sheet.scrollView.contentInset;
+      contentInset.bottom = MAX(contentInset.bottom, self.safeAreaInsets.bottom);
+      self.sheet.scrollView.contentInset = contentInset;
+    }
     CGRect scrollViewFrame = CGRectStandardize(self.sheet.scrollView.frame);
     scrollViewFrame.size = CGSizeMake(scrollViewFrame.size.width, CGRectGetHeight(self.frame));
     self.sheet.scrollView.frame = scrollViewFrame;
@@ -219,12 +220,12 @@ - (void)layoutSubviews {
   }
 }
 
-- (void)setPreferredSheetHeight:(CGFloat)preferredSheetHeight {
-  self.originalPreferredSheetHeight = preferredSheetHeight;
-
+- (void)updateSheetHeight {
   CGFloat adjustedPreferredSheetHeight = self.originalPreferredSheetHeight;
   if (@available(iOS 11.0, *)) {
-    adjustedPreferredSheetHeight += self.safeAreaInsets.bottom;
+    if (self.adjustHeightForSafeAreaInsets) {
+      adjustedPreferredSheetHeight += self.safeAreaInsets.bottom;
+    }
   }
 
   if (_preferredSheetHeight == adjustedPreferredSheetHeight) {
@@ -240,6 +241,16 @@ - (void)setPreferredSheetHeight:(CGFloat)preferredSheetHeight {
   }
 }
 
+- (void)setPreferredSheetHeight:(CGFloat)preferredSheetHeight {
+  self.originalPreferredSheetHeight = preferredSheetHeight;
+  [self updateSheetHeight];
+}
+
+- (void)setAdjustHeightForSafeAreaInsets:(BOOL)adjustHeightForSafeAreaInsets {
+  _adjustHeightForSafeAreaInsets = adjustHeightForSafeAreaInsets;
+  [self updateSheetHeight];
+}
+
 // Slides the sheet position downwards, so the right amount peeks above the bottom of the superview.
 - (void)updateSheetFrame {
   [self.animator removeAllBehaviors];
diff --git a/components/BottomSheet/tests/unit/MDCBottomSheetCustomizationTests.m b/components/BottomSheet/tests/unit/MDCBottomSheetCustomizationTests.m
index 8313a680702..787bd07bbfe 100644
--- a/components/BottomSheet/tests/unit/MDCBottomSheetCustomizationTests.m
+++ b/components/BottomSheet/tests/unit/MDCBottomSheetCustomizationTests.m
@@ -17,7 +17,6 @@
 #import <XCTest/XCTest.h>
 
 #import "../../src/private/MDCSheetContainerView.h"
-#import "MaterialShadowElevations.h"
 
 /** Used to test the elevation @c MDCBottomSheetPresentationController and it's @c sheetView. */
 @interface MDCBottomSheetPresentationController (MDCElevationTesting)
@@ -93,4 +92,66 @@ - (void)testApplyingScrimColorToSheet {
   XCTAssertEqualObjects(self.presentationController.scrimColor, scrimColor);
 }
 
+// Test that the presentation controller's and sheet view's adjustHeightForSafeAreaInsets is set to
+// YES as the default.
+- (void)testDefaultadjustHeightForSafeAreaInsetsSheet {
+  // When
+  // Ensure that the presentation controller is allocated after the bottom sheet because the
+  // property is set on the presentation controller via the transition controller which keeps
+  // references to the properties it sets on the presentaiton controller but not the presentation
+  // conrollter itself.
+  self.presentationController = self.bottomSheet.mdc_bottomSheetPresentationController;
+
+  // Ensure that the bottom sheet has created all of the necessary internal storage for
+  // presentation by pretending to start the presentation.
+  [self.presentationController presentationTransitionWillBegin];
+
+  // Then
+  XCTAssertTrue(self.bottomSheet.adjustHeightForSafeAreaInsets);
+  XCTAssertTrue(self.presentationController.adjustHeightForSafeAreaInsets);
+  XCTAssertTrue(self.presentationController.sheetView.adjustHeightForSafeAreaInsets);
+}
+
+// Test that the presentation controller's and sheet view's adjustHeightForSafeAreaInsets is set to
+// NO when it is set on the sheet.
+- (void)testSettingadjustHeightForSafeAreaInsetsSheetNo {
+  // When
+  self.bottomSheet.adjustHeightForSafeAreaInsets = NO;
+
+  // Ensure that the presentation controller is allocated after the bottom sheet because the
+  // property is set on the presentation controller via the transition controller which keeps
+  // references to the properties it sets on the presentaiton controller but not the presentation
+  // conrollter itself.
+  self.presentationController = self.bottomSheet.mdc_bottomSheetPresentationController;
+
+  // Ensure that the bottom sheet has created all of the necessary internal storage for
+  // presentation by pretending to start the presentation.
+  [self.presentationController presentationTransitionWillBegin];
+
+  // Then
+  XCTAssertFalse(self.presentationController.adjustHeightForSafeAreaInsets);
+  XCTAssertFalse(self.presentationController.sheetView.adjustHeightForSafeAreaInsets);
+}
+
+// Test that the presentation controller's and sheet view's adjustHeightForSafeAreaInsets is set to
+// YES when it is set on the sheet.
+- (void)testSettingadjustHeightForSafeAreaInsetsSheetYes {
+  // When
+  self.bottomSheet.adjustHeightForSafeAreaInsets = YES;
+
+  // Ensure that the presentation controller is allocated after the bottom sheet because the
+  // property is set on the presentation controller via the transition controller which keeps
+  // references to the properties it sets on the presentaiton controller but not the presentation
+  // conrollter itself.
+  self.presentationController = self.bottomSheet.mdc_bottomSheetPresentationController;
+
+  // Ensure that the bottom sheet has created all of the necessary internal storage for
+  // presentation by pretending to start the presentation.
+  [self.presentationController presentationTransitionWillBegin];
+
+  // Then
+  XCTAssertTrue(self.presentationController.adjustHeightForSafeAreaInsets);
+  XCTAssertTrue(self.presentationController.sheetView.adjustHeightForSafeAreaInsets);
+}
+
 @end
diff --git a/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m b/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m
index 1720274eb1a..4fea4a447aa 100644
--- a/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m
+++ b/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m
@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#import "MDCSheetState.h"
 #import "MaterialBottomSheet.h"
 
 #import <UIKit/UIKit.h>
@@ -72,6 +73,7 @@ - (void)draggableView:(MDCDraggableView *)view draggingEndedWithVelocity:(CGPoin
        @c setFrame: in case there are side-effects in UIView.
  */
 @interface FakeSheetView : MDCSheetContainerView
+@property(nonatomic, assign) UIEdgeInsets customSafeAreaInsets;
 @end
 
 @implementation FakeSheetView {
@@ -87,6 +89,10 @@ - (void)setFrame:(CGRect)frame {
 
   _frame = frame;
 }
+
+- (UIEdgeInsets)safeAreaInsets {
+  return _customSafeAreaInsets;
+}
 @end
 
 @interface MDCBottomSheetPresentationControllerTests : XCTestCase
@@ -273,6 +279,72 @@ - (void)testVeryLargePreferredSheetHeightAndSmallContent {
   XCTAssertEqualWithAccuracy(CGRectGetHeight(sheetView.frame), CGRectGetHeight(smallFrame), 0.001);
 }
 
+- (void)testDefaultAdjustHeightForSafeAreaInsets {
+  XCTAssertTrue(self.presentationController.adjustHeightForSafeAreaInsets);
+}
+
+- (void)testAdjustHeightForSafeAreaInsetsIsNo {
+  // Given
+  CGFloat preferredSheetHeight = 200;
+  CGFloat inset = 20;
+  self.sheetView.customSafeAreaInsets = UIEdgeInsetsMake(inset, inset, inset, inset);
+  self.presentationController.preferredSheetHeight = preferredSheetHeight;
+  self.presentationController.adjustHeightForSafeAreaInsets = NO;
+
+  // When
+  [self.presentationController updatePreferredSheetHeight];
+
+  // Then
+  XCTAssertEqualWithAccuracy(self.sheetView.preferredSheetHeight, preferredSheetHeight, 0.001);
+}
+
+- (void)testAdjustHeightForSafeAreaInsetsSetBeforeHeightIsSet {
+  // Given
+  CGFloat preferredSheetHeight = 200;
+  CGFloat inset = 20;
+  self.sheetView.customSafeAreaInsets = UIEdgeInsetsMake(inset, inset, inset, inset);
+  self.presentationController.adjustHeightForSafeAreaInsets = NO;
+  self.presentationController.preferredSheetHeight = preferredSheetHeight;
+
+  // When
+  [self.presentationController updatePreferredSheetHeight];
+
+  // Then
+  XCTAssertEqualWithAccuracy(self.sheetView.preferredSheetHeight, preferredSheetHeight, 0.001);
+}
+
+- (void)testAdjustHeightForSafeAreaInsetsIsYes {
+  // Given
+  CGFloat preferredSheetHeight = 200;
+  CGFloat inset = 20;
+  self.sheetView.customSafeAreaInsets = UIEdgeInsetsMake(inset, inset, inset, inset);
+  self.presentationController.preferredSheetHeight = preferredSheetHeight;
+  self.presentationController.adjustHeightForSafeAreaInsets = YES;
+
+  // When
+  [self.presentationController updatePreferredSheetHeight];
+
+  // Then
+  XCTAssertEqualWithAccuracy(self.sheetView.preferredSheetHeight, preferredSheetHeight + inset,
+                             0.001);
+}
+
+- (void)testadjustHeightForSafeAreaInsetsChangesToNo {
+  // Given
+  CGFloat preferredSheetHeight = 200;
+  CGFloat inset = 20;
+  self.sheetView.customSafeAreaInsets = UIEdgeInsetsMake(inset, inset, inset, inset);
+  self.presentationController.adjustHeightForSafeAreaInsets = YES;
+  self.presentationController.preferredSheetHeight = preferredSheetHeight;
+  self.presentationController.adjustHeightForSafeAreaInsets = NO;
+
+  // When
+  [self.presentationController updatePreferredSheetHeight];
+
+  // Then
+  XCTAssertEqualWithAccuracy(self.sheetView.preferredSheetHeight, preferredSheetHeight, 0.001);
+}
+
 - (void)testSheetViewFrameMatchesScrollViewFrame {
   // Given
   CGFloat scrollViewHeight = 100;

From 1b70fd6ad949c143d7225e3719c912fce8181719 Mon Sep 17 00:00:00 2001
From: Andrew Overton <andrewoverton@google.com>
Date: Fri, 22 Jan 2021 13:50:57 -0800
Subject: [PATCH 06/11] [ProgressView] Add Objective-C generics to
 MDCProgressView

PiperOrigin-RevId: 353312272
---
 components/ProgressView/src/MDCProgressView.h | 2 +-
 components/ProgressView/src/MDCProgressView.m | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/components/ProgressView/src/MDCProgressView.h b/components/ProgressView/src/MDCProgressView.h
index ea943c246ac..ef54877c7a3 100644
--- a/components/ProgressView/src/MDCProgressView.h
+++ b/components/ProgressView/src/MDCProgressView.h
@@ -56,7 +56,7 @@ IB_DESIGNABLE
 
  The default is nil.
 */
-@property(nonatomic, copy, nullable) NSArray *progressTintColors;
+@property(nonatomic, copy, nullable) NSArray<UIColor *> *progressTintColors;
 
 /**
  The color shown for the portion of the progress view that is not filled.
diff --git a/components/ProgressView/src/MDCProgressView.m b/components/ProgressView/src/MDCProgressView.m
index 0beb13b1171..1da69dd46e7 100644
--- a/components/ProgressView/src/MDCProgressView.m
+++ b/components/ProgressView/src/MDCProgressView.m
@@ -140,7 +140,7 @@ - (void)setProgressTintColor:(UIColor *)progressTintColor {
   }
 }
 
-- (void)setProgressTintColors:(NSArray *)progressTintColors {
+- (void)setProgressTintColors:(NSArray<UIColor *> *)progressTintColors {
   _progressTintColors = [progressTintColors copy];
   _progressTintColor = nil;
   self.progressView.colors = _progressTintColors;

From 1b985100ec89ed142981bd8f3d51b247f88e6f0c Mon Sep 17 00:00:00 2001
From: Andrew Overton <andrewoverton@google.com>
Date: Mon, 25 Jan 2021 07:12:16 -0800
Subject: [PATCH 07/11] [BottomSheet] Add flag that turns off simulated
 bouncing when there isn't a tracking scroll view

PiperOrigin-RevId: 353639927
---
 .../MDCBottomSheetPresentationController.h    | 10 +++++
 .../MDCBottomSheetPresentationController.m    |  4 +-
 .../src/private/MDCDraggableView.h            |  7 +++
 .../src/private/MDCDraggableView.m            | 43 ++++++++++++-------
 .../src/private/MDCSheetBehavior.h            |  6 ++-
 .../src/private/MDCSheetBehavior.m            | 21 +++++++--
 .../src/private/MDCSheetContainerView.h       |  3 +-
 .../src/private/MDCSheetContainerView.m       | 21 +++++----
 ...DCBottomSheetPresentationControllerTests.m |  9 ++--
 9 files changed, 91 insertions(+), 33 deletions(-)

diff --git a/components/BottomSheet/src/MDCBottomSheetPresentationController.h b/components/BottomSheet/src/MDCBottomSheetPresentationController.h
index 0bf90bd9039..90a2fecc10e 100644
--- a/components/BottomSheet/src/MDCBottomSheetPresentationController.h
+++ b/components/BottomSheet/src/MDCBottomSheetPresentationController.h
@@ -35,6 +35,16 @@
  */
 @property(nonatomic, weak, nullable) UIScrollView *trackingScrollView;
 
+/**
+ When @c trackingScrollView is @c nil and this property is @ YES, the bottom sheet simulates the @c
+ UIScrollView bouncing effect. When @c trackingScrollView is @c nil and this property is set to @c
+ NO, the simulated bouncing effect is turned off. When  @c trackingScrollView is NOT @c nil, this
+ property doesn't do anything.
+
+ Defaults to @c YES.
+ */
+@property(nonatomic, assign) BOOL simulateScrollViewBounce;
+
 /**
  When set to false, the bottom sheet controller can't be dismissed by tapping outside of sheet area.
  */
diff --git a/components/BottomSheet/src/MDCBottomSheetPresentationController.m b/components/BottomSheet/src/MDCBottomSheetPresentationController.m
index d6ae0dbf26e..c30e3a4cc52 100644
--- a/components/BottomSheet/src/MDCBottomSheetPresentationController.m
+++ b/components/BottomSheet/src/MDCBottomSheetPresentationController.m
@@ -74,6 +74,7 @@ - (instancetype)initWithPresentedViewController:(UIViewController *)presentedVie
                        presentingViewController:presentingViewController];
   if (self) {
     _adjustHeightForSafeAreaInsets = YES;
+    _simulateScrollViewBounce = YES;
   }
   return self;
 }
@@ -132,7 +133,8 @@ - (void)presentationTransitionWillBegin {
   }
   self.sheetView = [[MDCSheetContainerView alloc] initWithFrame:sheetFrame
                                                     contentView:self.presentedViewController.view
-                                                     scrollView:scrollView];
+                                                     scrollView:scrollView
+                                       simulateScrollViewBounce:self.simulateScrollViewBounce];
   self.sheetView.delegate = self;
   self.sheetView.autoresizingMask = UIViewAutoresizingFlexibleHeight;
   self.sheetView.dismissOnDraggingDownSheet = self.dismissOnDraggingDownSheet;
diff --git a/components/BottomSheet/src/private/MDCDraggableView.h b/components/BottomSheet/src/private/MDCDraggableView.h
index db8905b91c8..4dc008e7e0e 100644
--- a/components/BottomSheet/src/private/MDCDraggableView.h
+++ b/components/BottomSheet/src/private/MDCDraggableView.h
@@ -23,6 +23,13 @@
  */
 @property(nonatomic, strong, readonly, nullable) UIScrollView *scrollView;
 
+/**
+ When @c scrollView is @c nil , the draggable view simulates the @c UIScrollView bouncing effect.
+ When this property is set to @c NO, the simulated bouncing effect is turned off.  When  @c
+ scrollView is not @c nil, this property doesn't do anything.
+ */
+@property(nonatomic, assign) BOOL simulateScrollViewBounce;
+
 /**
  * Delegate for handling drag events.
  */
diff --git a/components/BottomSheet/src/private/MDCDraggableView.m b/components/BottomSheet/src/private/MDCDraggableView.m
index 6a679cb8e9c..534615d0112 100644
--- a/components/BottomSheet/src/private/MDCDraggableView.m
+++ b/components/BottomSheet/src/private/MDCDraggableView.m
@@ -15,6 +15,7 @@
 #import "MDCDraggableView.h"
 
 #import "MDCDraggableViewDelegate.h"
+#import "MDCKeyboardWatcher.h"
 
 static void CancelGestureRecognizer(UIGestureRecognizer *gesture) {
   if (gesture.enabled) {
@@ -28,6 +29,7 @@ static void CancelGestureRecognizer(UIGestureRecognizer *gesture) {
 @interface MDCDraggableView () <UIGestureRecognizerDelegate>
 @property(nonatomic) UIPanGestureRecognizer *dragRecognizer;
 @property(nonatomic, strong) UIScrollView *scrollView;
+@property(nonatomic, assign) CGFloat mostRecentMinY;
 @end
 
 @implementation MDCDraggableView
@@ -50,30 +52,39 @@ - (instancetype)initWithFrame:(CGRect)frame scrollView:(UIScrollView *)scrollVie
 #pragma mark - Gesture handling
 
 - (void)didPan:(UIPanGestureRecognizer *)recognizer {
-  CGPoint point = [recognizer translationInView:self.superview];
-
-  // Ensure that dragging the sheet past the maximum height results in an exponential decay on the
-  // translation. This gives the same effect as when you overscroll a scrollview.
-  CGFloat newHeight = CGRectGetMaxY(self.superview.bounds) - CGRectGetMinY(self.frame);
-  if (newHeight > [self.delegate maximumHeightForDraggableView:self]) {
-    point.y -= point.y / (CGFloat)1.2;
+  if (recognizer.state == UIGestureRecognizerStateBegan) {
+    self.mostRecentMinY = CGRectGetMinY(self.frame);
+    [self.delegate draggableViewBeganDragging:self];
+    return;
   }
 
-  self.center = CGPointMake(self.center.x, self.center.y + point.y);
-  [recognizer setTranslation:CGPointZero inView:self.superview];
-
   CGPoint velocity = [recognizer velocityInView:self.superview];
   velocity.x = 0;
+  CGPoint translation = [recognizer translationInView:self.superview];
+  CGFloat maxHeight = [self.delegate maximumHeightForDraggableView:self];
+  CGFloat minimumStableMinY = CGRectGetHeight(self.superview.bounds) - maxHeight -
+                              [MDCKeyboardWatcher sharedKeyboardWatcher].visibleKeyboardHeight;
+  CGFloat newMinY = self.mostRecentMinY + translation.y;
+
+  if (newMinY < minimumStableMinY) {
+    if ((self.scrollView == nil) && !self.simulateScrollViewBounce) {
+      velocity = CGPointZero;
+      newMinY = minimumStableMinY;
+    } else {
+      // Ensure that dragging the sheet past the maximum height results in an exponential decay on
+      // the translation. This gives the same effect as when you overscroll a scrollview.
+      newMinY = minimumStableMinY + (translation.y - (translation.y / 1.2f));
+    }
+  }
+  CGRect newFrame = CGRectMake(CGRectGetMinX(self.frame), newMinY, CGRectGetWidth(self.frame),
+                               CGRectGetHeight(self.frame));
 
-  if (recognizer.state == UIGestureRecognizerStateBegan) {
-    [self.delegate draggableViewBeganDragging:self];
+  if (recognizer.state == UIGestureRecognizerStateChanged) {
+    self.frame = newFrame;
+    [self.delegate draggableView:self didPanToOffset:CGRectGetMinY(self.frame)];
   } else if (recognizer.state == UIGestureRecognizerStateEnded) {
     [self.delegate draggableView:self draggingEndedWithVelocity:velocity];
   }
-  if (recognizer.state == UIGestureRecognizerStateBegan ||
-      recognizer.state == UIGestureRecognizerStateChanged) {
-    [self.delegate draggableView:self didPanToOffset:CGRectGetMinY(self.frame)];
-  }
 }
 
 #pragma mark - UIGestureRecognizerDelegate
diff --git a/components/BottomSheet/src/private/MDCSheetBehavior.h b/components/BottomSheet/src/private/MDCSheetBehavior.h
index ceaa4b721bc..a6cb731ec5b 100644
--- a/components/BottomSheet/src/private/MDCSheetBehavior.h
+++ b/components/BottomSheet/src/private/MDCSheetBehavior.h
@@ -29,8 +29,12 @@
 /**
  * Initializes a @c MDCSheetBehavior.
  * @param item The dynamic item (a view) to apply the sheet behavior to.
+ * @param simulateScrollViewBounce If the user has specified that they do not want to simulate the
+ * scrollview bouncing in the absence of a bottom sheet's trackingScrollView we should also tone
+ * down the bounce effect the UIKit dynamics provide.
  */
-- (nonnull instancetype)initWithItem:(nonnull id<UIDynamicItem>)item NS_DESIGNATED_INITIALIZER;
+- (nonnull instancetype)initWithItem:(nonnull id<UIDynamicItem>)item
+            simulateScrollViewBounce:(BOOL)simulateScrollViewBounce NS_DESIGNATED_INITIALIZER;
 
 - (nonnull instancetype)init NS_UNAVAILABLE;
 
diff --git a/components/BottomSheet/src/private/MDCSheetBehavior.m b/components/BottomSheet/src/private/MDCSheetBehavior.m
index aa5fb28d087..d11274c0929 100644
--- a/components/BottomSheet/src/private/MDCSheetBehavior.m
+++ b/components/BottomSheet/src/private/MDCSheetBehavior.m
@@ -14,6 +14,15 @@
 
 #import "MDCSheetBehavior.h"
 
+/**
+ These values were arrived at empirically (through trial and error) to either emphasize or diminish
+ the bounce effect that UIKit dynamics provides.
+ */
+static const CGFloat kSimulateScrollViewBounceFrequency = 3.5f;
+static const CGFloat kSimulateScrollViewBounceDamping = 0.4f;
+static const CGFloat kDisableScrollViewBounceFrequency = 5.5f;
+static const CGFloat kDisableScrollViewBounceDamping = 1.0f;
+
 @interface MDCSheetBehavior ()
 @property(nonatomic) UIAttachmentBehavior *attachmentBehavior;
 @property(nonatomic) UIDynamicItemBehavior *itemBehavior;
@@ -22,14 +31,20 @@ @interface MDCSheetBehavior ()
 
 @implementation MDCSheetBehavior
 
-- (instancetype)initWithItem:(id<UIDynamicItem>)item {
+- (instancetype)initWithItem:(id<UIDynamicItem>)item
+    simulateScrollViewBounce:(BOOL)simulateScrollViewBounce {
   self = [super init];
   if (self) {
     _item = item;
     _attachmentBehavior = [[UIAttachmentBehavior alloc] initWithItem:self.item
                                                     attachedToAnchor:CGPointZero];
-    _attachmentBehavior.frequency = (CGFloat)3.5;
-    _attachmentBehavior.damping = (CGFloat)0.4;
+    if (simulateScrollViewBounce) {
+      _attachmentBehavior.frequency = kSimulateScrollViewBounceFrequency;
+      _attachmentBehavior.damping = kSimulateScrollViewBounceDamping;
+    } else {
+      _attachmentBehavior.frequency = kDisableScrollViewBounceFrequency;
+      _attachmentBehavior.damping = kDisableScrollViewBounceDamping;
+    }
     _attachmentBehavior.length = 0;
 
     // Anchor movement along the y-axis.
diff --git a/components/BottomSheet/src/private/MDCSheetContainerView.h b/components/BottomSheet/src/private/MDCSheetContainerView.h
index 662eec2823f..220466be13e 100644
--- a/components/BottomSheet/src/private/MDCSheetContainerView.h
+++ b/components/BottomSheet/src/private/MDCSheetContainerView.h
@@ -38,7 +38,8 @@ Whether or not the height of the view should adjust to include extra height for
 
 - (nonnull instancetype)initWithFrame:(CGRect)frame
                           contentView:(nonnull UIView *)contentView
-                           scrollView:(nullable UIScrollView *)scrollView NS_DESIGNATED_INITIALIZER;
+                           scrollView:(nullable UIScrollView *)scrollView
+             simulateScrollViewBounce:(BOOL)simulateScrollViewBounce NS_DESIGNATED_INITIALIZER;
 
 - (nonnull instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
 - (nullable instancetype)initWithCoder:(nullable NSCoder *)aDecoder NS_UNAVAILABLE;
diff --git a/components/BottomSheet/src/private/MDCSheetContainerView.m b/components/BottomSheet/src/private/MDCSheetContainerView.m
index 8a808be9093..21188b043a3 100644
--- a/components/BottomSheet/src/private/MDCSheetContainerView.m
+++ b/components/BottomSheet/src/private/MDCSheetContainerView.m
@@ -43,6 +43,7 @@ @interface MDCSheetContainerView () <MDCDraggableViewDelegate>
 @property(nonatomic) BOOL isDragging;
 @property(nonatomic) CGFloat originalPreferredSheetHeight;
 @property(nonatomic) CGRect previousAnimatedBounds;
+@property(nonatomic) BOOL simulateScrollViewBounce;
 
 @end
 
@@ -58,10 +59,12 @@ + (void)initialize {
 
 - (instancetype)initWithFrame:(CGRect)frame
                   contentView:(UIView *)contentView
-                   scrollView:(UIScrollView *)scrollView {
+                   scrollView:(UIScrollView *)scrollView
+     simulateScrollViewBounce:(BOOL)simulateScrollViewBounce {
   self = [super initWithFrame:frame];
   if (self) {
-    self.willBeDismissed = NO;
+    _willBeDismissed = NO;
+    _simulateScrollViewBounce = simulateScrollViewBounce;
     if (UIAccessibilityIsVoiceOverRunning()) {
       _sheetState = MDCSheetStateExtended;
     } else {
@@ -70,6 +73,7 @@ - (instancetype)initWithFrame:(CGRect)frame
 
     // Don't set the frame yet because we're going to change the anchor point.
     _sheet = [[MDCDraggableView alloc] initWithFrame:CGRectZero scrollView:scrollView];
+    _sheet.simulateScrollViewBounce = _simulateScrollViewBounce;
     _sheet.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin;
     _sheet.delegate = self;
     _sheet.backgroundColor = contentView.backgroundColor;
@@ -145,7 +149,8 @@ - (void)didMoveToWindow {
   [super didMoveToWindow];
   if (self.window) {
     if (!self.sheetBehavior) {
-      self.sheetBehavior = [[MDCSheetBehavior alloc] initWithItem:self.sheet];
+      self.sheetBehavior = [[MDCSheetBehavior alloc] initWithItem:self.sheet
+                                         simulateScrollViewBounce:self.simulateScrollViewBounce];
     }
     [self animatePaneWithInitialVelocity:CGPointZero];
   } else {
@@ -419,15 +424,15 @@ - (void)draggableView:(__unused MDCDraggableView *)view
   MDCSheetState targetState;
   if (self.preferredSheetHeight == [self maximumSheetHeight]) {
     // Cannot be extended, only closed.
-    targetState = ((velocity.y >= 0 && self.dismissOnDraggingDownSheet) ? MDCSheetStateClosed
-                                                                        : MDCSheetStatePreferred);
+    targetState = ((velocity.y > 0 && self.dismissOnDraggingDownSheet) ? MDCSheetStateClosed
+                                                                       : MDCSheetStatePreferred);
   } else {
     CGFloat currentSheetHeight = CGRectGetMaxY(self.bounds) - CGRectGetMinY(self.sheet.frame);
     if (currentSheetHeight >= self.preferredSheetHeight) {
-      targetState = (velocity.y >= 0 ? MDCSheetStatePreferred : MDCSheetStateExtended);
+      targetState = (velocity.y > 0 ? MDCSheetStatePreferred : MDCSheetStateExtended);
     } else {
-      targetState = ((velocity.y >= 0 && self.dismissOnDraggingDownSheet) ? MDCSheetStateClosed
-                                                                          : MDCSheetStatePreferred);
+      targetState = ((velocity.y > 0 && self.dismissOnDraggingDownSheet) ? MDCSheetStateClosed
+                                                                         : MDCSheetStatePreferred);
     }
   }
   self.isDragging = NO;
diff --git a/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m b/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m
index 4fea4a447aa..f8f8ac16922 100644
--- a/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m
+++ b/components/BottomSheet/tests/unit/MDCBottomSheetPresentationControllerTests.m
@@ -111,7 +111,8 @@ - (void)setUp {
   // receives an updated value for `preferredSheetHeight`.
   self.sheetView = [[FakeSheetView alloc] initWithFrame:CGRectZero
                                             contentView:[[UIView alloc] init]
-                                             scrollView:[[UIScrollView alloc] init]];
+                                             scrollView:[[UIScrollView alloc] init]
+                               simulateScrollViewBounce:YES];
 
   // Only used as a required `-init` parameters for MDCBottomSheetPresentationController
   UIViewController *stubPresentingViewController = [[UIViewController alloc] init];
@@ -267,7 +268,8 @@ - (void)testVeryLargePreferredSheetHeightAndSmallContent {
   FakeSheetView *sheetView =
       [[FakeSheetView alloc] initWithFrame:smallFrame
                                contentView:[[UIView alloc] initWithFrame:smallFrame]
-                                scrollView:scrollView];
+                                scrollView:scrollView
+                  simulateScrollViewBounce:YES];
 
   self.presentationController.sheetView = sheetView;
   self.presentationController.preferredSheetHeight = 5000;
@@ -353,7 +355,8 @@ - (void)testSheetViewFrameMatchesScrollViewFrame {
   MDCSheetContainerView *fakeSheet =
       [[MDCSheetContainerView alloc] initWithFrame:fakeFrame
                                        contentView:[[UIView alloc] initWithFrame:fakeFrame]
-                                        scrollView:scrollView];
+                                        scrollView:scrollView
+                          simulateScrollViewBounce:YES];
 
   // When
   [fakeSheet setNeedsLayout];

From 7a4917f3d213a8c3a9ba3e7f200a4d201fd0b4fe Mon Sep 17 00:00:00 2001
From: Randall Li <randallli@google.com>
Date: Tue, 26 Jan 2021 11:20:51 -0500
Subject: [PATCH 08/11] Automatic changelog preparation for release.

---
 .gitattributes | 28 +++++++++++++++++++++++++---
 CHANGELOG.md   | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/.gitattributes b/.gitattributes
index c13f46c3bdc..f56e2dfb895 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,3 +1,25 @@
-# Do not merge this version into `stable`.	# DO NOT CHANGE THIS FILE
-snapshot_test_goldens/**/*.png filter=lfs diff=lfs merge=lfs -text	# DO NOT EDIT THE LINE BELOW.
-.gitattributes merge=gitattributes
+# DO NOT CHANGE THIS FILE
+# DO NOT EDIT THE LINE BELOW.
+/.gitattributes merge=gitattributes
+# DO NOT EDIT THE LINE ABOVE.
+#
+# You can of course edit this file, but make sure you understand what you are
+# doing. This file defines a custom filter driver that prevents snapshot test
+# images from being merged into `stable`. Snapshot test images are only
+# valuable in `develop` because they are only intended to help developers
+# identify changes in the appearance of the library.
+#
+# Before you change this file, please carefully consider whether such a change
+# is actually necessary. When you do change this file, it should almost always
+# be done in a dedicated commit directly on the `stable` branch and not part
+# of a release.  If you see this file being changed as part of a release,
+# block the release and work with the releaser to ensure that the change needs
+# to be propagated from the `develop` branch to the `stable` branch. In nearly
+# all cases, it should not be propagated from `develop` to `stable`.
+#
+# If you are a releaser and see this file change and you're not sure why, you
+# might have accidentally skipped [setting the correct
+# driver in your cloned
+# repository](https://github.com/material-components/material-components-ios/blob/develop/contributing/releasing.md#configure-the-merge-strategy-for-gitattributes).
+# If that's the case, please either revert the accidental change manually or
+# restart the release with a fresh clone and the correct driver.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 15ae95885ac..ba94bdadf62 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,46 @@
+# #develop#
+
+Replace this text with a summarized description of this release's contents.
+## Breaking changes
+
+Replace this explanations for how to resolve the breaking changes.
+## New deprecations
+
+Replace this text with links to deprecation guides.
+## New features
+
+Replace this text with example code for each new feature.
+## API changes
+
+## Component changes
+
+### BottomSheet
+
+* [Add BOOL property for whether or not the height of the bottom sheet should adjust for safe area insets.](https://github.com/material-components/material-components-ios/commit/1fefeaf03268b9126dfaea00907a9bb5362560e5) (Alyssa Weiss)
+* [Add flag that turns off simulated bouncing when there isn't a tracking scroll view](https://github.com/material-components/material-components-ios/commit/1b985100ec89ed142981bd8f3d51b247f88e6f0c) (Andrew Overton)
+
+### Buttons
+
+* [Add documentation for Enums.](https://github.com/material-components/material-components-ios/commit/c727b890df3c0766706ad8000649f7733cdef997) (Cody Weaver)
+
+### Chips
+
+* [Add docs for MDCChipField](https://github.com/material-components/material-components-ios/commit/3f7cc9f51cf9ea9287b3e817bc730eaac31bd87e) (Andrew Overton)
+
+### Dialogs
+
+* [Adding customized interface orientations and transition style support to the alert dialog.](https://github.com/material-components/material-components-ios/commit/a9b6ca12b5cba778176b7cb129e866b8669ac8bc) (Nobody)
+
+### List
+
+* [Use isKindOfClass to ensure there is support for all MDCShadowLayer's subclasses.](https://github.com/material-components/material-components-ios/commit/d5bba14e9a51405ee2ed868fd630d852c49d0c6e) (Yarden Eitan)
+
+### ProgressView
+
+* [Add Objective-C generics to MDCProgressView](https://github.com/material-components/material-components-ios/commit/1b70fd6ad949c143d7225e3719c912fce8181719) (Andrew Overton)
+
+---
+
 # 120.0.0
 
 In this major release, we deleted the `elevationOverlayColor` property from MDCSemanticColorScheme, added a `placeholderColor` property to MDCTextControls, added a `shapedBorderColor` property and a `shapedBorderWidth` property to MDCShapedView, and made multiple bug fixes.

From 132be3bdebcc4a0e8d5ea2b415281f5a4ef5407b Mon Sep 17 00:00:00 2001
From: Randall Li <randallli@google.com>
Date: Wed, 27 Jan 2021 01:56:43 -0500
Subject: [PATCH 09/11] Hand-modified CHANGELOG.md API diff.

---
 CHANGELOG.md | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba94bdadf62..b98ae3e15ba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,16 +1,26 @@
-# #develop#
+# 121.0.0
+
+In this major release, we added a `scrollViewBounce` property and a `adjustHeightForSafeAreaInsets` property to BottomSheets, added a `shouldAutorotateOverride` property, a `preferredInterfaceOrientationForPresentationOverride` property, a `supportedInterfaceOrientationsOverride` property, and a `modalTransitionStyleOverride` property to MDCAlertController, and converted `progressTintColors` property on MDCProgressView to use light weight generics.
 
-Replace this text with a summarized description of this release's contents.
 ## Breaking changes
 
-Replace this explanations for how to resolve the breaking changes.
-## New deprecations
+### ProgressView
+
+MDCProgressView's property `progressTintColors` started using light weight generics so values pass in need to be typed correctly.
 
-Replace this text with links to deprecation guides.
 ## New features
 
-Replace this text with example code for each new feature.
-## API changes
+### BottomSheet
+
+Bottom sheets have new propertie that turn off the overscroll and safe area insets.
+
+### Dialogs
+
+
+
+### ProgressView
+
+Converted `progressTintColors` property on MDCProgressView to use light weight generics.
 
 ## Component changes
 

From 548913f194d73332780afc9bacb81027da3e5d3e Mon Sep 17 00:00:00 2001
From: Randall Li <randallli@google.com>
Date: Wed, 27 Jan 2021 01:57:18 -0500
Subject: [PATCH 10/11] Bumped version number to 121.0.0.

---
 MaterialComponents.podspec                               | 2 +-
 MaterialComponentsEarlGreyTests.podspec                  | 2 +-
 MaterialComponentsExamples.podspec                       | 2 +-
 MaterialComponentsSnapshotTests.podspec                  | 2 +-
 VERSION                                                  | 2 +-
 catalog/MDCCatalog/Info.plist                            | 4 ++--
 catalog/MDCDragons/Info.plist                            | 4 ++--
 catalog/MaterialCatalog/MaterialCatalog.podspec          | 2 +-
 components/LibraryInfo/src/MDCLibraryInfo.m              | 2 +-
 components/LibraryInfo/tests/unit/LibraryInfoTests.m     | 2 +-
 demos/supplemental/RemoteImageServiceForMDCDemos.podspec | 2 +-
 11 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/MaterialComponents.podspec b/MaterialComponents.podspec
index f2a42397d9c..4c25cae0fbc 100644
--- a/MaterialComponents.podspec
+++ b/MaterialComponents.podspec
@@ -2,7 +2,7 @@ load 'scripts/generated/icons.rb'
 
 Pod::Spec.new do |mdc|
   mdc.name         = "MaterialComponents"
-  mdc.version      = "120.0.0"
+  mdc.version      = "121.0.0"
   mdc.authors      = "The Material Components authors."
   mdc.summary      = "A collection of stand-alone production-ready UI libraries focused on design details."
   mdc.homepage     = "https://github.com/material-components/material-components-ios"
diff --git a/MaterialComponentsEarlGreyTests.podspec b/MaterialComponentsEarlGreyTests.podspec
index a6378ce239a..228d209f678 100644
--- a/MaterialComponentsEarlGreyTests.podspec
+++ b/MaterialComponentsEarlGreyTests.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "MaterialComponentsEarlGreyTests"
-  s.version      = "120.0.0"
+  s.version      = "121.0.0"
   s.authors      = "The Material Components authors."
   s.summary      = "This spec is an aggregate of all the Material Components EarlGrey tests."
   s.description  = "This spec is made for use in the MDC Catalog."
diff --git a/MaterialComponentsExamples.podspec b/MaterialComponentsExamples.podspec
index 671c81eee67..1b4f4dcfe5d 100644
--- a/MaterialComponentsExamples.podspec
+++ b/MaterialComponentsExamples.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "MaterialComponentsExamples"
-  s.version      = "120.0.0"
+  s.version      = "121.0.0"
   s.authors      = "The Material Components authors."
   s.summary      = "This spec is an aggregate of all the Material Components examples."
   s.description  = "This spec is made for use in the MDC Catalog. Used in conjunction with CatalogByConvention we create our Material Catalog."
diff --git a/MaterialComponentsSnapshotTests.podspec b/MaterialComponentsSnapshotTests.podspec
index 36b50d9e130..298de0b76b1 100644
--- a/MaterialComponentsSnapshotTests.podspec
+++ b/MaterialComponentsSnapshotTests.podspec
@@ -53,7 +53,7 @@ end
 
 Pod::Spec.new do |s|
   s.name         = "MaterialComponentsSnapshotTests"
-  s.version      = "120.0.0"
+  s.version      = "121.0.0"
   s.authors      = "The Material Components authors."
   s.summary      = "This spec is an aggregate of all the Material Components snapshot tests."
   s.homepage     = "https://github.com/material-components/material-components-ios"
diff --git a/VERSION b/VERSION
index 57ee5f4db73..58326d9a847 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-120.0.0
+121.0.0
diff --git a/catalog/MDCCatalog/Info.plist b/catalog/MDCCatalog/Info.plist
index 54ec6ca455b..9b267e8fa46 100644
--- a/catalog/MDCCatalog/Info.plist
+++ b/catalog/MDCCatalog/Info.plist
@@ -15,11 +15,11 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>120.0.0</string>
+	<string>121.0.0</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
-	<string>120.0.0</string>
+	<string>121.0.0</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>UIAppFonts</key>
diff --git a/catalog/MDCDragons/Info.plist b/catalog/MDCDragons/Info.plist
index f925fa87ce7..602c55f4cf7 100644
--- a/catalog/MDCDragons/Info.plist
+++ b/catalog/MDCDragons/Info.plist
@@ -15,9 +15,9 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>120.0.0</string>
+	<string>121.0.0</string>
 	<key>CFBundleVersion</key>
-	<string>120.0.0</string>
+	<string>121.0.0</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>UILaunchStoryboardName</key>
diff --git a/catalog/MaterialCatalog/MaterialCatalog.podspec b/catalog/MaterialCatalog/MaterialCatalog.podspec
index dbb74aca153..44de03e3058 100644
--- a/catalog/MaterialCatalog/MaterialCatalog.podspec
+++ b/catalog/MaterialCatalog/MaterialCatalog.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "MaterialCatalog"
-  s.version      = "120.0.0"
+  s.version      = "121.0.0"
   s.summary      = "Helper Objective-C classes for the MDC catalog."
   s.description  = "This spec is made for use in the MDC Catalog."
   s.homepage     = "https://github.com/material-components/material-components-ios"
diff --git a/components/LibraryInfo/src/MDCLibraryInfo.m b/components/LibraryInfo/src/MDCLibraryInfo.m
index 36b171c7b42..a47df200e8c 100644
--- a/components/LibraryInfo/src/MDCLibraryInfo.m
+++ b/components/LibraryInfo/src/MDCLibraryInfo.m
@@ -19,7 +19,7 @@
 // This string is updated automatically as a part of the release process and should not be edited
 // manually. Do not rename this constant or change the formatting without updating the release
 // scripts.
-static NSString* const kMDCLibraryInfoVersionString = @"120.0.0";
+static NSString* const kMDCLibraryInfoVersionString = @"121.0.0";
 
 @implementation MDCLibraryInfo
 
diff --git a/components/LibraryInfo/tests/unit/LibraryInfoTests.m b/components/LibraryInfo/tests/unit/LibraryInfoTests.m
index bc78c0dd91e..fbddfa4e75b 100644
--- a/components/LibraryInfo/tests/unit/LibraryInfoTests.m
+++ b/components/LibraryInfo/tests/unit/LibraryInfoTests.m
@@ -26,7 +26,7 @@ - (void)testVersionFormat {
   // Given
 
   // This regex pattern does the following:
-  // Accept: "120.0.0", etc.
+  // Accept: "121.0.0", etc.
   // Reject: "0.0.0", "1.2", "1", "-1.2.3", "Hi, I'm a version 1.2.3", "1.2.3 is my version", etc.
   //
   // Note the major version must be >= 1 since "0.0.0" is used as the version when something goes
diff --git a/demos/supplemental/RemoteImageServiceForMDCDemos.podspec b/demos/supplemental/RemoteImageServiceForMDCDemos.podspec
index c9772dcac16..6269424ce18 100644
--- a/demos/supplemental/RemoteImageServiceForMDCDemos.podspec
+++ b/demos/supplemental/RemoteImageServiceForMDCDemos.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "RemoteImageServiceForMDCDemos"
-  s.version      = "120.0.0"
+  s.version      = "121.0.0"
   s.summary      = "A helper image class for the MDC demos."
   s.description  = "This spec is made for use in the MDC demos. It gets images via url."
   s.homepage     = "https://github.com/material-components/material-components-ios"

From d6d3cbe6b9b94823780438bad8d517bd4c61432e Mon Sep 17 00:00:00 2001
From: Randall Li <randallli@google.com>
Date: Wed, 27 Jan 2021 01:59:25 -0500
Subject: [PATCH 11/11] Hand-modified CHANGELOG.md API diff.

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b98ae3e15ba..e52ec76eefa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,7 +16,7 @@ Bottom sheets have new propertie that turn off the overscroll and safe area inse
 
 ### Dialogs
 
-
+Added a `shouldAutorotateOverride` property, a `preferredInterfaceOrientationForPresentationOverride` property, a `supportedInterfaceOrientationsOverride` property, and a `modalTransitionStyleOverride` property to MDCAlertController.
 
 ### ProgressView