[iOS] Add account picker sheet, configuration, layout delegate

This CL is the first step to add the account picker UI for the Save to
Photos feature. This code is essentially copy-pasted from
`i/c/b/ui/**/consistency_promo_signin/consistency_sheet/`.

Fixed: 1474414
Change-Id: I0418d964c647e300506688d9048a9129beec339b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4798155
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Quentin Pubert <qpubert@google.com>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1187854}

ios/chrome/browser/ui/account_picker/BUILD.gn

@@ -0,0 +1,15 @@
+# Copyright 2023 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("account_picker_configuration") {
+  sources = [
+    "account_picker_configuration.h",
+    "account_picker_configuration.mm",
+  ]
+}
+
+source_set("account_picker_layout") {
+  sources = [ "account_picker_layout_delegate.h" ]
+  deps = [ "//ui/base" ]
+}

ios/chrome/browser/ui/account_picker/OWNERS

@@ -0,0 +1 @@
+jlebel@chromium.org

ios/chrome/browser/ui/account_picker/account_picker_configuration.h

@@ -0,0 +1,29 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_CONFIGURATION_H_
+#define IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_CONFIGURATION_H_
+
+#import <Foundation/Foundation.h>
+
+// Configuration for the AccountPickerCoordinator.
+@interface AccountPickerConfiguration : NSObject
+
+// Title of the account picker confirmation screen.
+@property(nonatomic, copy) NSString* titleText;
+
+// Body of the account picker confirmation screen which explains what the
+// account will be used for.
+@property(nonatomic, copy) NSString* bodyText;
+
+// Title of the account picker confirmation screen submit button.
+@property(nonatomic, copy) NSString* submitButtonTitle;
+
+// The label of the "Ask every time" switch. If left nil, the switch will not be
+// shown.
+@property(nonatomic, copy) NSString* askEveryTimeSwitchLabelText;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_CONFIGURATION_H_

ios/chrome/browser/ui/account_picker/account_picker_configuration.mm

@@ -0,0 +1,9 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/ui/account_picker/account_picker_configuration.h"
+
+@implementation AccountPickerConfiguration
+
+@end

ios/chrome/browser/ui/account_picker/account_picker_layout_delegate.h

@@ -0,0 +1,26 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_LAYOUT_DELEGATE_H_
+#define IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_LAYOUT_DELEGATE_H_
+
+#import <UIKit/UIKit.h>
+
+// Style to display the account picker sheet.
+enum AccountPickerSheetDisplayStyle {
+  // Bottom sheet at the bottom of the screen (for compact size).
+  kAccountPickerSheetDisplayStyleBottom,
+  // Bottom sheet centered in the middle of the screen (for regular size).
+  kAccountPickerSheetDisplayStyleCentered,
+};
+
+@protocol AccountPickerLayoutDelegate <NSObject>
+
+// Display style according to the trait collection.
+@property(nonatomic, assign, readonly)
+    AccountPickerSheetDisplayStyle displayStyle;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_LAYOUT_DELEGATE_H_

ios/chrome/browser/ui/account_picker/account_picker_screen/BUILD.gn

@@ -0,0 +1,24 @@
+# Copyright 2023 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("account_picker_screen") {
+  sources = [
+    "account_picker_screen_constants.h",
+    "account_picker_screen_constants.mm",
+    "account_picker_screen_navigation_controller.h",
+    "account_picker_screen_navigation_controller.mm",
+    "account_picker_screen_presentation_controller.h",
+    "account_picker_screen_presentation_controller.mm",
+    "account_picker_screen_slide_transition_animator.h",
+    "account_picker_screen_slide_transition_animator.mm",
+    "account_picker_screen_view_controller.h",
+  ]
+  deps = [
+    "//base",
+    "//ios/chrome/browser/shared/ui/util",
+    "//ios/chrome/browser/shared/ui/util/image",
+    "//ios/chrome/browser/ui/account_picker:account_picker_layout",
+    "//ios/chrome/common/ui/util",
+  ]
+}

ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_constants.h

@@ -0,0 +1,17 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_SCREEN_ACCOUNT_PICKER_SCREEN_CONSTANTS_H_
+#define IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_SCREEN_ACCOUNT_PICKER_SCREEN_CONSTANTS_H_
+
+#import <UIKit/UIKit.h>
+
+// Maximum height ratio for the bottom sheet container view.
+extern const CGFloat kMaxPickAccountHeightRatioWithWindow;
+
+// AccountPickerScreenNavigationController accessibility identifier.
+extern NSString* const
+    kAccountPickerScreenNavigationControllerAccessibilityIdentifier;
+
+#endif  // IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_SCREEN_ACCOUNT_PICKER_SCREEN_CONSTANTS_H_

ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_constants.mm

@@ -0,0 +1,11 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_constants.h"
+
+const CGFloat kMaxPickAccountHeightRatioWithWindow = 0.75;
+
+NSString* const
+    kAccountPickerScreenNavigationControllerAccessibilityIdentifier =
+        @"AccountPickerScreenNavigationControllerAccessibilityIdentifier";

ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_navigation_controller.h

@@ -0,0 +1,48 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_SCREEN_ACCOUNT_PICKER_SCREEN_NAVIGATION_CONTROLLER_H_
+#define IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_SCREEN_ACCOUNT_PICKER_SCREEN_NAVIGATION_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+#import "ios/chrome/browser/ui/account_picker/account_picker_layout_delegate.h"
+
+// Delegate for updating navigation controller content.
+@protocol AccountPickerScreenNavigationControllerLayoutDelegate <NSObject>
+
+// Performs updates due to changes in preferred content size.
+- (void)preferredContentSizeDidChangeForAccountPickerScreenViewController;
+
+@end
+
+// Navigation controller presented from the bottom. The pushed view controllers
+// view have to be UIScrollView. This is required to support high font size
+// (related to accessibility) with small devices (like iPhone SE).
+// The view is automatically sized according to the last child view controller.
+// This class works with AccountPickerScreenPresentationController and
+// AccountPickerScreenSlideTransitionAnimator.
+// Child view controller are required to implement
+// AccountPickerScreenViewController protocol.
+@interface AccountPickerScreenNavigationController
+    : UINavigationController <AccountPickerLayoutDelegate>
+
+// Returns the desired size related to the current view controller shown by
+// `AccountPickerScreenNavigationController`, based on `width`.
+- (CGSize)layoutFittingSizeForWidth:(CGFloat)width;
+
+// Updates internal views according to the consistency sheet view position.
+- (void)didUpdateControllerViewFrame;
+
+// Delegate for layout.
+@property(nonatomic, weak)
+    id<AccountPickerScreenNavigationControllerLayoutDelegate>
+        layoutDelegate;
+// Interaction transition to swipe from left to right to pop a view controller.
+@property(nonatomic, strong, readonly)
+    UIPercentDrivenInteractiveTransition* interactionTransition;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_ACCOUNT_PICKER_ACCOUNT_PICKER_SCREEN_ACCOUNT_PICKER_SCREEN_NAVIGATION_CONTROLLER_H_

ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_navigation_controller.mm

@@ -0,0 +1,185 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_navigation_controller.h"
+
+#import <algorithm>
+
+#import "base/check.h"
+#import "base/notreached.h"
+#import "ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_constants.h"
+#import "ios/chrome/browser/ui/account_picker/account_picker_screen/account_picker_screen_view_controller.h"
+#import "ios/chrome/common/ui/util/background_util.h"
+
+namespace {
+
+// Corner radius for centered style dialog.
+constexpr CGFloat kCornerRadius = 12.;
+
+}  // namespace
+
+@interface AccountPickerScreenNavigationController ()
+
+// View to get transparent blurred background.
+@property(nonatomic, strong, readwrite) UIView* backgroundView;
+@property(nonatomic, strong, readwrite)
+    UIPercentDrivenInteractiveTransition* interactionTransition;
+
+@end
+
+@implementation AccountPickerScreenNavigationController
+
+- (CGSize)layoutFittingSizeForWidth:(CGFloat)width {
+  UINavigationController* navigationController =
+      self.childViewControllers.lastObject;
+  DCHECK([navigationController
+      conformsToProtocol:@protocol(AccountPickerScreenViewController)]);
+  UIViewController<AccountPickerScreenViewController>*
+      childNavigationController =
+          static_cast<UIViewController<AccountPickerScreenViewController>*>(
+              navigationController);
+
+  // If the child controller updates its view due to an external action such
+  // as adding or removing an identity then force a layout to ensure the child
+  // height is up-to-date.
+  [childNavigationController.view setNeedsLayout];
+  [childNavigationController.view layoutIfNeeded];
+
+  CGFloat height =
+      [childNavigationController layoutFittingHeightForWidth:width];
+  CGFloat maxViewHeight =
+      self.view.window.frame.size.height * kMaxPickAccountHeightRatioWithWindow;
+  return CGSizeMake(width, std::min(height, maxViewHeight));
+}
+
+- (void)didUpdateControllerViewFrame {
+  self.backgroundView.frame = self.view.bounds;
+}
+
+- (void)preferredContentSizeDidChangeForChildContentContainer:
+    (id<UIContentContainer>)container {
+  [super preferredContentSizeDidChangeForChildContentContainer:container];
+  [self.layoutDelegate
+          preferredContentSizeDidChangeForAccountPickerScreenViewController];
+}
+
+#pragma mark - AccountPickerLayoutDelegate
+
+- (AccountPickerSheetDisplayStyle)displayStyle {
+  return [self displayStyleWithTraitCollection:self.traitCollection];
+}
+
+#pragma mark - UIViewController
+
+- (void)viewDidLoad {
+  [super viewDidLoad];
+  self.backgroundView = PrimaryBackgroundBlurView();
+  [self.view insertSubview:self.backgroundView atIndex:0];
+  self.backgroundView.frame = self.view.bounds;
+  self.view.layer.masksToBounds = YES;
+  self.view.clipsToBounds = YES;
+  self.view.accessibilityIdentifier =
+      kAccountPickerScreenNavigationControllerAccessibilityIdentifier;
+  UIScreenEdgePanGestureRecognizer* edgeSwipeGesture =
+      [[UIScreenEdgePanGestureRecognizer alloc]
+          initWithTarget:self
+                  action:@selector(swipeAction:)];
+  edgeSwipeGesture.edges = UIRectEdgeLeft;
+  [self.view addGestureRecognizer:edgeSwipeGesture];
+}
+
+- (void)viewWillAppear:(BOOL)animated {
+  [super viewWillAppear:animated];
+  [self.navigationBar setBackgroundImage:[[UIImage alloc] init]
+                           forBarMetrics:UIBarMetricsDefault];
+  [self updateViewWithTraitCollection:self.traitCollection];
+}
+
+- (void)viewDidLayoutSubviews {
+  [super viewDidLayoutSubviews];
+  [self didUpdateControllerViewFrame];
+}
+
+#pragma mark - UINavigationController
+
+- (void)pushViewController:(UIViewController*)viewController
+                  animated:(BOOL)animated {
+  DCHECK([viewController
+      conformsToProtocol:@protocol(AccountPickerScreenViewController)]);
+  [super pushViewController:viewController animated:animated];
+}
+
+#pragma mark - UIContentContainer
+
+- (void)willTransitionToTraitCollection:(UITraitCollection*)newCollection
+              withTransitionCoordinator:
+                  (id<UIViewControllerTransitionCoordinator>)coordinator {
+  [self updateViewWithTraitCollection:newCollection];
+}
+
+#pragma mark - SwipeGesture
+
+// Called when the swipe gesture is active. This method controls the sliding
+// between two view controls in `self`.
+- (void)swipeAction:(UIScreenEdgePanGestureRecognizer*)gestureRecognizer {
+  if (!gestureRecognizer.view) {
+    self.interactionTransition = nil;
+    return;
+  }
+  UIView* view = gestureRecognizer.view;
+  CGFloat percentage =
+      [gestureRecognizer translationInView:view].x / view.bounds.size.width;
+  switch (gestureRecognizer.state) {
+    case UIGestureRecognizerStateBegan:
+      self.interactionTransition =
+          [[UIPercentDrivenInteractiveTransition alloc] init];
+      [self popViewControllerAnimated:YES];
+      [self.interactionTransition updateInteractiveTransition:percentage];
+      break;
+    case UIGestureRecognizerStateChanged:
+      [self.interactionTransition updateInteractiveTransition:percentage];
+      break;
+    case UIGestureRecognizerStateEnded:
+      if (percentage > .5 &&
+          gestureRecognizer.state != UIGestureRecognizerStateCancelled) {
+        [self.interactionTransition finishInteractiveTransition];
+      } else {
+        [self.interactionTransition cancelInteractiveTransition];
+      }
+      self.interactionTransition = nil;
+      break;
+    case UIGestureRecognizerStatePossible:
+    case UIGestureRecognizerStateCancelled:
+    case UIGestureRecognizerStateFailed:
+      break;
+  }
+}
+
+#pragma mark - Private
+
+// Updates the view according to the trait collection.
+- (void)updateViewWithTraitCollection:(UITraitCollection*)collection {
+  switch ([self displayStyleWithTraitCollection:collection]) {
+    case kAccountPickerSheetDisplayStyleBottom:
+      self.view.layer.cornerRadius = 0;
+      break;
+    case kAccountPickerSheetDisplayStyleCentered:
+      self.view.layer.cornerRadius = kCornerRadius;
+      break;
+  }
+}
+
+// Returns the display style based on the trait collection.
+- (AccountPickerSheetDisplayStyle)displayStyleWithTraitCollection:
+    (UITraitCollection*)collection {
+  // If one trait dimension is compact, the returned style is bottom.
+  // Otherwise, the returned style is centered.
+  BOOL hasAtLeastOneCompactSize =
+      (collection.horizontalSizeClass == UIUserInterfaceSizeClassCompact) ||
+      (collection.verticalSizeClass == UIUserInterfaceSizeClassCompact);
+  return hasAtLeastOneCompactSize ? kAccountPickerSheetDisplayStyleBottom
+                                  : kAccountPickerSheetDisplayStyleCentered;
+}
+
+@end